chapter 9 (MED266)
common virus
A Nonretrovirus that uses either DNA or RNA as its genetic material and has a relatively low efficiency of cellular infection This means that most common viruses must invade the body in large numbers to cause disease. These viruses are responsible for common infections such as chickenpox, shingles, measles, mumps, herpes, warts, hepatitis, and the common cold. Most common viruses must enter the body in large numbers for infection to result in disease because these viruses have a low efficiency of infection.
DNA
A complex molecule containing the genetic information that makes up the chromosomes. is the genetic material of the human cell
acquired immune deficiency syndrome (AIDS)
A disorder in which the immune system is gradually weakened and eventually disabled by the human immunodeficiency virus (HIV). The most severe form of immune deficiency disease caused by HIV infection
cocktails
A patient with HIV infection receives drugs from several classes in regimens because HIV is not controlled by any one antiretroviral drug alone
Hepatitis C Virus (HCV)
A viral infection of the liver for which no vaccine is available Chronic hepatitis C Liver failure
HIV
A virus that attacks and destroys the human immune system HIV carries the enzyme reverse transcriptase to convert HIV RNA into DNA. Then the enzyme integrase inserts this DNA into the human DNA of the CD4+ T cell. particles are made in the infected CD4+ T cell using the machinery of the host cell
Respiratory Syncytial Virus (RSV)
A virus that causes an infection of the lungs and breathing passages; can lead to other serious illnesses that affect the lungs or heart, such as bronchiolitis and pneumonia. RSV is highly contagious and spread through droplets. Severe respiratory infection in infants, young children, and older adults
Life Span Considerations for Adefovir Dipivoxil Considerations for Older Adults.
Adefovir dipivoxil should be used cautiously, if at all, in patients over 65 years of age. This is especially true for older adults who are taking a variety of drugs for chronic disorders of the kidneys, liver, or heart.
adefovir dipivoxil (Hepsera)
Adults and Children over 12 years: 10 mg orally once daily Children under 12 years: Safety and efficacy have not been determined
raltegravir (Isentress)
Adults and children over 25 kg: 400 mg orally twice daily Children under 25 kg: Safety and efficacy have not been established
nelfinavir (Viracept)
Adults/Children older than 12 years:1250 mg orally every 12 hr or 750 mg orally every 8 hr
saquinavir (Invirase)
Adults/Children older than 16 years:1000 mg orally every 12 hr Children younger than 16 years:33 mg/kg orally every 8 hr
amantadine (Symmetrel, Endantadine )
Adults/Children over 10 years: 100 mg orally twice daily or 200 mg orally once dailyAdults over 65 years: 100 mg orally once daily Children under 10 years: 2.5-4 mg/kg orally every 12 hr
rimantadine (Flumadine)
Adults/Children over 10 years: 100 mg orally twice dailyAdults over 65 years: 100 mg orally once daily Children under 10 years: 3.3 mg/kg orally twice daily (maximum 150 mg)
zidovudine (Apo-Zidovudine , Azidothymidine, AZT, Novo-AZT , Retrovir)
Adults/Children over 30 kg:300 mg orally twice daily Children less than 30 kg:9 mg/kg orally twice daily
oseltamivir (Tamiflu)
Adults/Children over 40 g: 75 mg orally every 12 hr for 5 days (dosage adjusted downward by weight for children less than 40 kg)
efavirenz (Sustiva)
Adults/Children over 40 kg: 600 mg orally once daily Children 10 to 39 kg: 200-300 mg orally once daily at bedtime
didanosine (ddI, Videx)
Adults/Children over 60 kg:125-200 mg orally twice daily
didanosine (Videx EC)
Adults/Children over 60 kg:400 mg orally once daily
zanamivir (Relenza)
Adults/Children over 7 years: Two oral inhalations (one 5-mg blister per inhalation for a total dosage of 10 mg) every 12 hr for 5 days
ribavirin (Copegus, Moderiba, Rebetol, RibaPak, Ribasphere, RibaTab, Virazole)
Adults/Children over 75 kg: 600 mg orally every 12 hr Children 60-75 kg: 400-600 mg orally every 12 hr; other oral dosing is weight dependent Aerosol administration: 20 mg/mL for respiratory syncytial virus at 12-18 hr/day delivers an average of 190 mcg/L of air
valacyclovir (Valtrex)
Adults/Children: 1-2 g orally every 12 hr for initial treatment of herpes simplex virus 1 or 2; 500-1000 mg orally every 12 hr for management of recurrent infections
dolutegravir (TIVICAY)
Adults: 100 mg orally daily Children over 40 kg: 50 mg orally dailyChildren less than 40 kg: Safety and efficacy have not been established
simeprevir (Olysio)
Adults: 150 mg orally once daily with other antivirals to treat hepatitis C that is "genotype 1"
nevirapine (Viramune)
Adults: 200 mg orally daily for first 14 days, then 200 mg orally twice daily Children: Dosages for young children based on total body surface area
etravirine (INTELENCE)
Adults: 200 mg orally twice daily Children: Safety and efficacy have not been established
emtricitabine (Emtriva)
Adults: 200 mg tablet or 240 mg solution orally daily Children: 6 mg/kg, up to 240 mg (24 mL) orally daily
rilpivirine (EDURANT)
Adults: 25 mg orally once daily Children: Safety and efficacy have not been established
lamivudine (Epivir, Epivir-HPV, 3TC)
Adults: 300 mg orally daily Children: 4 mg/kg orally every 12 hr (maximum of 150 mg)
atazanavir (Reyataz)
Adults: 300 mg orally daily Children: 7 mg/kg orally daily
tenofovir (Viread)
Adults: 300 mg orally daily Children: Safe dosages have not been established
abacavir (Ziagen)
Adults: 300 mg orally twice daily or 600 mg orally once daily Children: 8 mg/kg orally twice daily
stavudine (d4T, Zerit)
Adults: 40 mg orally twice daily Children less than 60 kg:0.5-1 mg/kg orally every 12 hr
delavirdine (Rescriptor)
Adults: 400 mg orally three times daily Children: Safety and efficacy have not been established
lopinavir/ritonavir (Kaletra)
Adults: 400 mg/100 mg orally twice daily Children: 300 mg/75 mg per m2 dose orally twice daily
acyclovir (Apo-Acyclovir , Avirax , Zovirax)
Adults: 5-10 mg/kg IV every 8 hr; 400 mg orally every 8 hr (genital herpes) Children: 10 mg/kg IV every 8 hr; 20 mg/kg orally 4 times daily (chickenpox)
tipranavir (Aptivus)
Adults: 500 mg (given with ritonavir) orally twice daily Children: 14 mg/kg (given with ritonavir) orally twice daily
fosamprenavir (Lexiva)
Adults: 700 mg orally twice daily Children: 18 mg/kg orally twice daily
indinavir (Crixivan)
Adults: 800 mg orally every 8 hr Children: 500 mg/m2 orally every 8 hr
darunavir (Prezista)
Adults: 800 mg orally twice dailyChildren over 40 kg: 600 mg orally every 12 hr Children under 40 kg: 450 mg orally every 12 hr
elvitegravir (EVG)
Adults: 85-150 mg orally once daily Children: Safety and efficacy have not been established
Amantadine and rimantadine Adverse Effects.
Amantadine affects the central nervous system (CNS) and may worsen glaucoma and urinary retention. It should not be taken by patients who have either of these problems. Patients who have psychiatric disorders may have an increased risk for suicidal thoughts while taking this drug. These adverse effects have been seen with rimantadine only at very high doses.
Life Span Considerations for Amantadine or Rimantadine Considerations for Pregnancy and Lactation.
Amantadine and rimantadine have a moderate likelihood of increasing the risk for birth defects or fetal damage and appear in breast milk. Therefore it is not recommended that either of these drugs be used during the first trimester of pregnancy or by women who are breastfeeding.
How Amantadine and Rimantadine work
Amantadine is an oral drug that prevents viral infection by blocking the opening of the external coating of the influenza A virus and stopping the release of viral particles into respiratory epithelial cells. These actions prevent infection and also inhibit viral replication in infected cells. Rimantadine is similar in chemical structure and action to amantadine; however, it tends to concentrate more in respiratory tissues and less in the brain than amantadine. Amantadine and rimantadine are most effective against the influenza A virus.
retrovirus
An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses. is a special type of virus that always uses RNA as its genetic material and carries with it the enzymes reverse transcriptase, integrase, and protease, which allow high efficiency of cellular infection
HIV protease
An enzyme that converts immature, noninfectious HIV to its infectious state within the cell These pieces are formed into a new finished viral particle, which then leaves the infected cell to infect other CD4+ T cells
host
An organism on which a parasite lives. is the person infected by a virus whose cells allow viral reproduction.
Antiviral drugs
Antiviral drugs do not kill viruses; they only suppress their reproduction and growth. are virustatic drugs that prevent viruses from either reproducing or from releasing their genetic material. ome antivirals suppress viral reproduction. Others prevent the virus from opening its coat and allowing the genetic material to be released. Allergic reactions are possible with any antiviral drug. The allergy may be mild and annoying or severe and life threatening (anaphylaxis). More serious reactions occur when antiviral drugs are given intravenously.
Life Span Considerations for Acyclovir or Valacyclovir Considerations for Pregnancy and Lactation.
Both acyclovir and valacyclovir have a low likelihood of increasing the risk for birth defects or fetal damage. These drugs appear in breast milk and can enter the infant during breastfeeding.
Herpes simplex virus type 1 (HSV1)
Cold sores Systemic infection in newborns and people with severe immunosuppression
NNRTIs side effects
Common side effects of NNRTIs are rash, nausea and vomiting, headache, and abdominal pain. Additional side effects with these drugs are difficulty sleeping and vivid dreams or nightmares. Be sure to consult a drug reference for side effects associated with each specific drug.
Side Effects for NRTI
Common side effects of NRTIs are nausea, headache, and increased digestive upsets when eating fatty or fried foods. Each NRTI may have more side effects. Be sure to consult a drug reference for side effects of each specific drug.
PI side effects
Common side effects of PIs are headache, diarrhea, depression, difficulty sleeping, and abdominal weight gain. Each drug may have more side effects. Be sure to consult a drug reference for side effects of each specific drug.
Life Span Considerations for Acyclovir or Valacyclovir Considerations for Older Adults.
Dizziness, agitation, and confusion may occur as side effects. Older adults are at greater risk for these effects as a result of age-related changes in kidney function and may require more frequent monitoring of kidney function tests Teach older patients to avoid driving or operating heavy equipment until they know how these drugs may affect them.
Entry inhibitors
Enfuvirtide Maraviroc are a class of antiretroviral drug that prevent HIV cellular infection by blocking the CCR5 receptor on CD4+ T cells. Because this drug is not effective against all HIV subtypes, the patient must first be tested to ensure that his or her HIV infection is likely to respond to this therapy.
NNRTIs Considerations for Pregnancy and Lactation.
Etravirine and nevirapine have a low likelihood of increasing the risk for birth defects or fetal damage and may be taken at any stage of pregnancy. Neither delavirdine nor efavirenz should be taken during pregnancy.
Herpes simplex virus type 2 (HSV2)
Genital herpes infections
What To Do After Giving Acyclovir or Valacyclovir
Give the patient a full glass of water to drink with oral doses and urge him or her to drink more fluids throughout the day to keep these drugs from precipitating in the kidneys. This is even more important if the patient also takes other drugs that can damage the kidney.
Hantavirus (HV)
Hantavirus pulmonary syndrome (HPS)
Integrase inhibitors adverse effects
Headache, dizziness, and an increased risk for the development of rhabdomyolysis and myopathy
Adefovir Dipivoxil adverse effects
Highly liver toxic and kidney toxic, interacts with antiretroviral drugs It should be used cautiously or not at all in patients who have impaired kidney function or non-hepatitis-related liver diseases.
What To Teach Patients About Amantadine or Rimantadine
In addition to teaching patients about the general care needs and precautions related to antiviral therapy, teach them not to stand or sit up quickly because this may lower blood pressure rapidly, causing dizziness and an increased risk for falls. Also instruct them to hold onto railings when going up or down steps. Tell the patient and family to report to the prescriber immediately any worsening of depression or thoughts of suicide.
How Integrase Inhibitors Work
Integrase inhibitors are a type of antiretroviral drug that prevents HIV infection by inhibiting the enzyme integrase, which is needed to allow insertion of viral DNA into the DNA of the human host cell. Without this action, viral proteins are not made, and viral replication is inhibited.
Raltegravir Pediatric Considerations.
Integrase inhibitors are not approved for use in small children.
Maraviroc Pediatric Considerations.
Maraviroc is not approved for use in children.
NRTIs Considerations for Pregnancy and Lactation.
NRTIs increase the risk for lactic acidosis in pregnant women. Signs and symptoms of lactic acidosis are muscle aches; tiredness and difficulty remaining awake; abdominal pain; hypotension; and a slow, irregular heartbeat.
Raltegravir Considerations for Older Adults.
Older adults are more likely to be taking a "statin" type of lipid-lowering drug, which increases the risk for muscle weakness. Older adults may have loss of muscle mass and strength as a result of the aging process. These conditions increase the risk for falls.
Protease Inhibitors Considerations for Older Adults
Older adults are more likely to be taking other drugs that could interact with PIs, especially cardiac drugs and lipid-lowering drugs. Remind the patient to tell all health care providers about all drugs that he or she takes. Teach older adults how to check their pulse for irregularities. Remind them to report new irregularities to the prescriber.
NNRTI Considerations for Older Adults.
Older adults are more likely to be taking other drugs that could interact with an NNRTI remind the patient to tell all health care providers about all drugs he or she takes. Also teach older adults how to take their pulse and assess it for irregularities. Remind the patient to report new irregularities to the prescriber.
Maraviroc Considerations for Older Adults.
Older adults are more likely to develop orthostatic hypotension with maraviroc and increase the risk for falls. Stress the need to change positions slowly and use handrails when going up or down steps. Also warn older adults to not drive or operate heavy equipment until they know how maraviroc affects them.
Life Span Considerations for Acyclovir or Valacyclovir Pediatric Considerations.
Oral dosages of these drugs for children older than 2 years of age are very similar to the dosages for adults.
How Oseltamivir and Zanamivir Work
Oseltamivir and zanamivir work by inhibiting the enzyme neuraminidase, which is needed to spread viral particles in the respiratory tract. For effective treatment oseltamivir must be taken within 12 to 48 hours, and zanamivir must be taken within 12 to 36 hours of the onset of the first influenza symptoms. These drugs shorten the duration and reduce the severity of influenza. They can also prevent influenza from developing after exposure to the virus.
Oseltamivir and Zanamivir side effects
Oseltamivir is an oral drug taken as a liquid (suspension) or capsule. The most common side effects are nausea and vomiting, diarrhea, dizziness, and headache. Zanamivir is an inhaled drug with side effects of nausea, cough, diarrhea, headache, and nasal congestion.
Acyclovir and Valacyclovir adverse effect
Pain and irritation at the injection site may occur with IV acyclovir, especially when the drug is given rapidly. Both drugs can reduce kidney function and lead to kidney damage and failure
NRTI Considerations for Older Adults.
Peripheral neuropathy develops more quickly in the older adult taking NRTIs. This greatly increases the risk for falls and other injuries.
How Ribavirin Works
Ribavirin is a "counterfeit" base that suppresses viral action and reproduction by unknown mechanisms. It is effective at suppressing many viruses; however, because of its severe side effects and adverse effects, it is most commonly used for viral infections that do not respond to other antiviral agents.
Ribavirin adervse effects
Ribavirin is a potent drug with many adverse effects, and its use is limited to patients who have severe viral infections for which no other drugs are effective. A major adverse effect is that ribavirin is a teratogen, an agent that can cause birth defects. It should not be given to pregnant or breastfeeding women. It should not be handled or inhaled by anyone who is pregnant. This drug can suppress the bone marrow production of red blood cells (RBCs) and white blood cells (WBCs), especially when it is used along with interferon therapy. As a result, the patient can be anemic and at risk for infection. With prolonged use, ribavirin can impair the function of the liver, kidneys, heart, and ears. In addition, it may lead to some forms of cancer.
Life Span Considerations with Ribavirin Considerations for Older Adults.
Ribavirin should be administered cautiously to older adults. These patients are more likely to have age-related changes in major organs and are at greater risk for organ toxicities. The older adult may be started at a lower drug dosage. Older patients taking ribavirin have a much greater risk for anemia than younger patients. Aerosolized ribavirin is not indicated for older adults.
Enfuvirtide Considerations for Older Adults.
Some older adults have vision or mobility problems that make self-administration of enfuvirtide more difficult. Assess the older patient's ability to prepare the drug, draw up the correct dosage, and reach an appropriate injection site. Include a family member or other responsible person when teaching about drug preparation and administration.
Oseltamivir and Zanamivir adverse effects
Specific adverse effects of oseltamivir are rare but include worsening hyperglycemia in people who have diabetes and also can elevate liver enzyme levels. Specific adverse effects of zanamivir are rare but include breathing problems, confusion, and seizures.
Life Span Considerations for Amantadine or Rimantadine Considerations for older adults
The dosage of either drug should be reduced for patients older than age 65 years. Both drugs can worsen heart failure and increase edema. Teach older adults taking either amantadine or rimantadine to weigh themselves daily and notify the prescriber if they have gained more than 3 lb in 2 days. Also teach older patients to measure their pulse at least once daily and notify the prescriber if it becomes more irregular or is hard to find.
PI adverse effects
The most common adverse effect of PIs is liver toxicity. They also increase lipid levels, leading to hyperlipidemia, atherosclerosis, and pancreatitis. PIs should be used cautiously in anyone who has hemophilia. They can induce uncontrolled bleeding in these patients. Atazanavir and ritonavir can impair electrical conduction in the heart and lead to heart block, especially in a person who has an abnormally slow heart rate. Darunavir and fosamprenavir both contain sulfa and should not be used for patients who have allergies to sulfa drugs.
Ribavirin side effects
The most common include nausea, vomiting, diarrhea, fever, and headache. Additional side effects include conjunctivitis, muscle pain, fatigue, dizziness, and injection site pain or irritation (parenteral form).
human immune deficiency virus (HIV)
The most common retrovirus known to cause disease among humans. It is the organism known to cause HIV disease and AIDS. is a retrovirus that attacks the immune system of an infected person, eventually causing him or her to have little or no immune protection.
Amantadine and rimantadine side effect
The most common side effects of amantadine (and to a lesser extent rimantadine) include the anticholinergic effects of blurred vision, dry mouth, and hallucinations, along with orthostatic (postural) hypotension and dizziness.
Integrase Inhibitors side effects
The most common side effects of integrase inhibitors are diarrhea, rash, and insomnia. Other side effects may include dizziness, headache, nausea and vomiting, and abdominal pain.
adverse effect for NRTI
The two most common adverse effects of NRTIs are liver toxicity and peripheral neuropathy with long-term use. Abacavir is more likely to cause hypersensitivity reactions within the first 4 weeks. This response starts with flulike symptoms and progresses to life-threatening hypersensitivity.
NNRTI adverse effects
The two most common adverse effects with NNRTIs are anemia and liver toxicity.
maraviroc (Selzentry)
The usual dosage range for an adult is 150 to 600 mg orally twice daily.
Life Span Considerations with Ribavirin Considerations for Pregnancy and Lactation.
This drug has a high likelihood of increasing the risk for birth defects and fetal damage. It should never be given to a woman who is pregnant. If a woman of childbearing age who is sexually active is prescribed ribavirin, she must use two forms of contraception Male patients taking this drug whose partners are pregnant should use condoms to prevent exposure of the pregnant women to the drug. Pregnant women living in the household of a person taking ribavirin should not touch the drug.
Antiretroviral drugs
Used to treat infections caused by HIV, the virus that causes AIDS are a broad category of antiviral drugs that suppress the replication (reproduction) of retroviruses, which use RNA as their primary genetic material instead of DNA. are virustatic and do not kill the virus can cause an allergic reaction. It may be minor, with a rash appearing days after starting the drug, or can result in anaphylaxis. interact with other drugs and food. These interactions can cause serious adverse effects and can change the activity of drugs.
Viruses
Viruses can only reproduce inside host cells, and they damage the cell when they do this VIRUSES GET INTO CELL are intracellular, submicroscopic parasites that must infect a living host cell to reproduce When viruses infect a living cell in just the right way, the resources, energy, and machinery of that living cell are used to make new viruses. Viruses are not capable of self-reproduction. A healthy person will not become ill from most viruses unless the number of invading viruses overwhelms the normal protections.
West Nile Virus (WNV)
a mosquito-borne virus Severe infection with symptoms similar to those of encephalitis or meningitis
highly active antiretroviral therapy (HAART)
a strategy for treating HIV-infected people with a combination of antiretroviral drugs Different types of HAART drugs are available as combination tablets containing two or three drugs to reduce the number of individual drugs that a patient may have to take. Do not delay, skip, or reduce HAART doses.
virulence
ability to produce disease The more virulent a virus is, the fewer viruses are needed to cause infection and disease. The efficiency of infection is higher.
Epstein-Barr virus (EBV)
acute infection which causes sore throat, fever, fatigue, and enlarged lymph nodes; also called mononucleosis Chronic fatigue syndrome Some types of lymphoma Systemic infection in newborns and people with severe immunosuppression
Raltegravir Considerations for Pregnancy and Lactation.
altegravir has a moderate likelihood of increasing the risk for birth defects or fetal damage. It should not be used during pregnancy if the patient's viral load indicates that her traditional HAART therapy is effective. Dolutegravir has a low likelihood of increasing the risk for birth defects or fetal damage and can be part of HAART therapy during pregnancy.
Zyvox
an antibacterial drug used to treat methicillin-resistant Staphylococcus aureus (MRSA).
Zovirax
antiviral drug
Non-nucleoside analog reverse transcriptase inhibitors (NNRTIs)
are a class of antiretroviral drugs that inhibit the action of the enzyme reverse transcriptase by binding directly to the enzyme, preventing it from converting viral RNA to DNA
Protease inhibitors (PIs)
are a class of antiretroviral drugs that prevent HIV replication and prevent the release of HIV particles from infected cells. When PIs are taken into an HIV-infected cell, they make the protease enzyme work on the drug rather than on the initial large protein.
Nucleoside analog reverse transcriptase inhibitors (NRTIs)
are drugs that are similar in structure to bases that form DNA. These drugs compete with real bases in HIV-infected cells and reduce viral replication
Two common adverse effects of the antiretrovirals
are liver toxicity and worsening hyperglycemia
Enfuvirtide adverse effect
are peripheral neuropathy with pain and numbness of the hands and feet (most common), increased respiratory infections (including pneumonia), and liver toxicity.
Integrase inhibitors
are usually prescribed for people who have HIV disease, are already taking HAART, and are beginning to have increased viral load. The safety and effectiveness of these drugs in small children have not yet been established.
Before giving an antiviral drug
ask whether the patient has any drug allergies. If so, notify the prescriber before giving the drug.
What To Do Before Giving Amantadine or Rimantadine
ask whether the patient has glaucoma or a problem with urinary retention, especially whether male patients have an enlarged prostate gland. Also check whether the patient has any known psychiatric problems, especially severe depression, or has attempted suicide in the past. If the patient has any of these problems, notify the prescriber before administering the drug.
What To Do Before Giving Ribavirin
before giving ribavirin check the patient's heart rate, rhythm, and pulse quality. Also check lung function by assessing the rate and depth of respiratory effort, breath sounds, pulse oximetry, color of skin and mucous membranes, and level of consciousness. Assess kidney function by checking the most recent 24-hour intake and output and comparing the amount of urine excreted with the amount of fluids consumed. Also check the patient's current kidney tests, especially the blood urea nitrogen (BUN) and serum creatinine levels. If the values are higher than normal before starting the drug, the risk for kidney damage is greater. Assess liver function by checking for yellowing (jaundice) of the skin, palate, or whites of the eyes and by checking liver function tests. Check the patient's hearing Use these data as a baseline to detect changes that may result from adverse drug effects. (ribavirin often suppresses the growth of bone marrow cells,) check the patient's most recent WBC and RBC counts before drug therapy begins. Use these data as a baseline in determining the presence of side effects and whether or not the drug is effective against the infection. Check the patient's vital signs (including temperature and mental status) before starting ribavirin. Use this information as a baseline to determine whether any side effect or adverse effect is present and whether the drug therapy is effective against the infection. When administering aerosolized ribavirin, use only the SPAG-2 aerosol generator. Read the instruction manual before using this instrument. Prepare the aerosolized form of the drug using sterile technique and following the manufacturer's directions for preparation and dilution.
Viral infections
cannot be treated by antibiotics are not cured but are self-limiting, meaning that in a person with a healthy immune system the illness only lasts for so long. If a person's immune system is working properly, the body fights off the infection by itself. If the immune system is weak or if the body has other health problems, the person may die from the effects of the disease.
After giving an antiretroviral drug
check the patient daily for yellowing of the skin or sclera (jaundice), which is a symptom of liver problems. The best places to check are the whites of the eyes closest to the iris, the roof of the mouth, and the skin of the chest. Avoid checking the soles of the feet or palms of the hands, especially in a patient with darker skin, because these areas often appear yellow even when the patient is not jaundiced. If the patient has diabetes, check blood glucose levels more often, and assess fasting blood glucose levels whenever they are ordered. Report higher-than-normal levels to the prescriber because adjustments may be needed in the dosages of antidiabetic drugs. Check the patient's skin every shift for rash, blisters, or other skin eruptions that may indicate a reaction to the drug. Ask the patient about any itching or skin changes.
After giving the first dose of an intravenous (IV) antiviral drug,
check the patient every 15 minutes for signs or symptoms of an allergic reaction (hives at the IV site; low blood pressure; rapid, irregular pulse; swelling of the lips or lower face; the patient feeling a lump in the throat). If the patient is having an anaphylactic reaction, your first action is to prevent any more drug from entering him or her. Stop the drug from infusing but maintain the IV access. If the drug is infusing high into the IV tubing, change the tubing after stopping the drug and do not let any drug left in the tubing infuse into the patient. Inspect the IV site at the beginning of the infusion, halfway through the infusion, and at the end of the infusion and document your findings. If redness is present or the patient reports discomfort at the site, slow the infusion and check for a blood return. Look for any redness or pain or the feeling of hard or cordlike veins above the site. If any of these problems occur, follow the policy of your facility for removing the IV line.
What To Do Before Giving Acyclovir or Valacyclovir
check whether the patient takes phenytoin (Dilantin) or another drug for seizure control. Acyclovir and valacyclovir reduce the effectiveness of phenytoin, and the prescriber may need to adjust the phenytoin dosage to prevent seizures while the patient is on antiviral therapy. Make sure that the IV infusion is running well and has a good blood return. Dilute parenteral acyclovir to the proper concentration with only sterile water for injection. Inspect the drug for discoloration or particles. Acyclovir can interact with other drugs in the tubing. Either flush the line before giving acyclovir or use fresh tubing for the infusion. Administer the drug slowly over 60 minutes to avoid kidney problems and reduce the risk for irritation at the injection site. Administer IV acyclovir as an infusion over 60 minutes.
Varicella-Zoster Virus (VZV)
chickenpox and shingles
There are two basic types of viruses:
common viruses(nonretroviruses) and retroviruses.
Life Span Considerations for Adefovir Dipivoxil Considerations for Pregnancy and Lactation.
defovir has a moderate likelihood of increasing the risk for birth defects or fetal damage and appears in breast milk. Therefore it is not recommended that this drug be used during pregnancy unless the benefits clearly outweigh the risks. Breastfeeding is not recommended while taking this drug to avoid exposure to the infant.
Virustatic
drug actions that reduce the number of viruses present by preventing them from reproducing and growing They are not virucidal and cannot kill the virus.
Efficiency of infection
ease with which an organism causes disease through infection
Enfuvirtide (Fuzeon)
fusion inhibitor
Acyclovir and Valacyclovir Side Effects.
headache, dizziness, nausea, vomiting
CD4+ T cells
helper T-cells, recruit other immune cells are the "generals" of the immune system army. When they are infected and destroyed, the person is immune deficient and cannot successfully fight off other infections.
Cytomegalovirus (CMV)
herpes-type virus that usually causes disease when the immune system is compromised MononucleosisSerious eye infection (retinitis) in people who are immunosuppressed
adverse effects of maraviroc
hypotension, liver toxicity
Entrance sites for viruses
include mucous membranes in the nose, conjunctiva of the eye, respiratory tract, digestive tract, and genital or urinary tract. They can also enter through broken skin, and they can be injected into the body in blood or blood products.
side effects of maraviroc
include muscle aches and pains, cough, diarrhea, dizziness, and trouble sleeping. Other less common side effects include rhinitis, sinusitis, depression, and numbness or tingling of the hands and feet.
Pediatric considerations for antiretroviral therapy
include that most antiretroviral drugs and HAART therapy are used for control of the disease in HIV positive children. Two exceptions are maraviroc and raltegravir. The safety and efficacy of these drugs have not yet been established for children.
Opportunistic infections
infections seen in patients with compromised immune systems are caused by organisms that are present as part of the normal environment and kept in check by normal immune function
What To Teach Patients About NRTIs
instruct them to avoid fatty foods and fried foods. These foods can cause digestive upsets and lead to pancreatitis when combined with NRTIs. After long-term use patients often develop peripheral neuropathy with reduced sensation. Teach patients who have reduced sensation to prevent injury. Loss of sensation increases the patient's risk for injury because he or she may not be aware of excessive heat, cold, or pressure. Teach patients taking abacavir to stop the drug and notify the prescriber if flulike symptoms occur. Warn them that, if this response occurs, to never take the drug again.
What To Teach Patients About Acyclovir or Valacyclovir
instruct them to drink a full glass of water with each dose of the drug and to drink at least 3 L of fluid daily.
Valcyte
is a drug for cytomegalovirus retinitis for patients with AIDS.
Side effect of enfuvirtide
is an injection site reaction (itching, warmth, swelling, bump formation, skin hardening). Other common side effects are constipation, trouble sleeping, depression, and muscle aches.
How Adefovir Dipivoxil Works
is an oral drug that acts as a counterfeit base limiting the DNA replication and reproduction of the hepatitis B virus (HBV). These actions suppress viral replication in infected cells, especially liver cells. Adefovir dipivoxil is most effective against the hepatitis B virus
One of the cells that has receptors for the docking proteins
is the CD4+ cell, helper/inducer T cell, or T4 cell The main cell type infected and destroyed by HIV infection is the CD4+ cell (helper/inducer T cell)
What To Do After Giving Ribavirin
monitor the patient receiving ribavirin closely for any sign of side effects or organ toxicity. Check laboratory values daily for WBC and RBC counts, bilirubin level, liver enzyme levels, and BUN and creatinine levels. Compare urine output with fluid intake. Check hearing daily. Document all changes and notify the prescriber.
Viruses that enter the body and survive
must enter cells and insert their genetic material into the genetic material of the host cells.
Adefovir Dipivoxil side effects
nausea, abdominal pain
considerations for pregnancy and lactation for antiretroviral therapy
nclude that most antiretroviral drugs for HAART are recommended to be taken by HIV-positive pregnant women because the virus can cross the placenta and infect the fetus. When these drugs are taken as prescribed, they can reduce the chances of fetal infection. The woman who is HIV-positive should not breastfeed because the virus can be transferred from the mother to the infant in breast milk.
Before giving an antiretroviral drug
obtain a list of all other drugs that the patient takes because antiretrovirals interact with many other drugs Check with the pharmacist for possible interactions and the need to consult the prescriber about dosage or changing the patient's other drugs. Ask the patient about previous allergic reactions to drugs. If a drug allergy has occurred, determine which drug or drugs caused it, the specific reactions the patient had, and how the problem was treated. Notify the prescriber of previous allergic reactions to drugs and make sure that this information is documented in the patient's chart. antiretroviral therapy can lead to liver toxicity, make sure that the patient does not have a liver problem before starting these drugs. Check the patient's most recent laboratory values for liver problems If the patient has diabetes, check his or her blood glucose level before administering an antiretroviral drug. Use this value as a baseline to monitor whether the drug is affecting the patient's blood glucose level. Some antiretroviral drugs must be taken with food; others must be taken on an empty stomach. Check a drug reference to determine how an individual drug should be given with regard to meals.
Valtrex
oral antiviral drug use to treat herpes simplex, varicella zoster, cytomegalovirus, and Epstein-Barr viruses
Fusion inhibitors
prevent viruses from successfully fusing with the host cell are a class of antiretroviral drug that prevents infection by blocking the viral docking protein (gp41) from fusing with the host cell. Without fusion, infection of new cells does not occur. the only drug in this category is enfuvirtide (Fuzeon). The usual dosage is 90 mg subcutaneously twice daily. It is used with other drugs as part of a HAART regimen.
Teach patients taking ribavirin to report any of the following symptoms immediately to the prescriber:
rash; itching or hives; swelling of the face, lips, or tongue; trouble breathing; chest pain; fever; bluish tinge to the lips or nail beds; tremors or seizures; persistent changes in heart rate or rhythm; decrease in urine output; and feeling unusually weak or tired.
Acyclovir and valacyclovir are
related drugs. At the cell level valacyclovir is converted to acyclovir when it is metabolized. slow viral reproduction by forming "counterfeit" DNA bases and inhibiting the enzymes needed to complete the formation of viral DNA chains most effective against Epstein-Barr virus, cytomegalovirus, herpes simplex virus types 1 and 2, and varicella zoster virus.
What To Teach Patients About Oseltamivir or Zanamivir
teach patients how to take these drugs properly. Teach patients prescribed oseltamivir suspension about the proper way to mix it and take it. This drug comes with its own mixing device and measuring device. Teach patients taking zanamivir how to use an inhaler. For this drug, remind the patient not to use a spacer. If the patient takes other drugs by inhalation for another breathing problem such as asthma or chronic obstructive pulmonary disease, teach him or her to use the bronchodilator before using the zanamivir inhaler and to wait at least 5 minutes before using the zanamivir inhaler. Teach patients and families that, if an adverse effect occurs, they should stop taking the drug and notify the prescriber as soon as possible.
What To Teach Patients About Integrase Inhibitors
teaching patients about the general care needs and precautions related to antiretroviral therapy tell them not to crush or chew raltegravir tablets and to take the drug with food to reduce GI side effects. Dolutegravir can be taken with or without food. Teach patients to report any persistent muscle pain or weakness to the prescriber as soon as possible. Tell patients to report increased fatigue, paleness, and increased heart rate or shortness of breath to the prescriber. These are symptoms of anemia. Teach patients with diabetes to monitor blood glucose levels more closely. Adjustments in diet and diabetes drug therapy may be needed.
What To Teach Patients About NNRTIs
teaching patients about the general care needs and precautions related to antiretroviral therapy tell them to notify their prescriber if they develop a sore throat, fever, different types of rashes, blisters, or multiple bruises. These problems are signs of serious adverse effects of drugs from this class. Teach patients to take the drug at least 1 hour before or 2 hours after taking an antacid. Antacids inhibit the absorption of drugs in the NNRTI class. Remind patients to keep all appointments for blood tests because NNRTIs can cause anemia.
What To Teach Patients About Enfuvirtide
teaching patients about the general care needs and precautions related to antiretroviral therapy, instruct them how to safely self-inject the drug. A 1-month supply of the drug is available in a kit that contains single-use vials, vials of sterile water for injection, preparation syringes, administration syringes, alcohol wipes, and instruction guides. Teach the patient how to prepare the drug correctly, draw it up, inject it, dispose of the needle, and store it following the instruction guide. Teach patients the manifestations of respiratory infection (cough, shortness of breath, fever, mucus production or a change in the color of mucus from clear to yellow, green, or brown). Instruct them to report these symptoms immediately to the prescriber. Teach patients to store unmixed vials of drug and water at room temperature, between 59° F and 86° F and to store the mixed drug and water vial in a refrigerator between 36° F and 46° F for up to 24 hours. Unused mixed drug should be discarded after 24 hours. Teach patients to assess injection sites daily for signs of infection or reactions. Remind them that if an injection site reaction occurs, they should not use that site again until it heals and the skin is normal. Instruct patients to report an injection site infection to the prescriber and to not reuse that site until the infection has completely cleared and the skin has healed.
What To Teach Patients About Maraviroc
teaching patients about the general care needs and precautions related to antiretroviral therapy, warn them not to crush or chew capsules because these actions may cause the drug to be absorbed too rapidly and increase the risk for side effects. Teach patients about safety and low blood pressure and to change positions slowly. When they are getting out of bed, teach them to sit on the side of the bed for a few minutes and then slowly move to a standing position. If they become dizzy, they should sit back down again for a few more minutes. Tell them to use handrails when going up or down steps and to avoid driving or operating heavy equipment while dizzy.
What To Teach Patients About Protease Inhibitors
teaching patients about the general care needs and precautions related to antiretroviral therapy, warn them not to crush or chew capsules because these actions may cause the drug to be absorbed too rapidly and increase the risk for side effects. Teach patients taking atazanavir or ritonavir to check their pulse for a full minute at least twice daily. They should report any changes in heart rate or regularity to the prescriber. An herbal supplement that greatly reduces the effectiveness of PIs is St. John's wort. Warn patients to not take St. John's wort while on HIV therapy that includes any of the PIs.
What To Teach Patients About Ribavirin
teaching patients about the general care needs and precautions related to antiviral therapy, instruct patients to take oral ribavirin for hepatitis C at least 1 hour before or 2 hours after taking an antacid because antacids interfere with ribavirin absorption. Instruct them to contact their prescriber as soon as possible if symptoms of allergy or other adverse effects develop
Teach patients receiving antiviral drugs
the importance of taking the drug long enough to ensure suppression of viral reproduction. If the patient stops taking the drug as soon as he or she feels better, symptoms of infection may recur, and resistant viruses may develop. Teach the patient to take antiviral drugs exactly as prescribed and for as long as prescribed. (For all antiviral therapy it is important to keep the blood level high enough to affect the viruses causing the infection.) So it is best for the patient to take the drug evenly throughout a 24-hour day. If the drug should be taken twice daily, teach the patient to take it every 12 hours. For three times a day, teach the patient to take it every 8 hours Help the patient plan an easy-to-remember schedule that keeps the drug at the best blood levels.
Teach patients receiving antiretroviral therapy
the importance of taking their drugs exactly as prescribed to maintain the effectiveness of HAART drugs. Even a few missed doses per month can promote drug resistance. Remind patients that antiretroviral drugs do not kill the virus or cure the disease. These drugs only help reduce the number of viruses in the body; the person will still have HIV disease. Teach patients to follow the manufacturer's directions for whether a specific drug should be taken with food or on an empty stomach. Warn patients taking antiretrovirals to tell all health care providers that they are taking these drugs because of the potential for drug interactions Teach patients not to take any over-the-counter drug or herbal supplement without consulting the antiretroviral prescriber. Tell patients to notify the prescriber if they develop yellowing of the skin or eyes, darkening of the urine, or lightening of the stools. These problems are signs of liver toxicity, a serious adverse effect of these drugs.
Hepatitis A virus (HAV)
the most prevalent type of hepatitis. caused by the highly contagious HAV virus and is transmitted mainly through contaminated food and water Hepatitis A
preexposure prophylaxis (PrEP)
the use of antiretroviral drugs to prevent infection in people who are HIV negative and are in a high-risk category The use of the combination drug Truvada (emtricitabine and tenofovir), which contains two NRTIs, by HIV-1 negative sexual partners of known HIV-1 positive individuals appears to reduce HIV transmission. Together these two drugs have a synergistic suppressive effect on HIV activity does not replace the standard safer sex practices recommended to prevent HIV transmission.
there are two basic categories of antiviral drugs:
those that work against some common viruses (antiviral drugs) and those that have some effect against retroviruses (antiretrovirals)
Hepatitis B virus (HBV)
virus that causes inflammation of the liver; transmitted through any body fluid, including vaginal secretions, semen, and blood Acute hepatitis B Chronic hepatitis B Liver failureLiver cancer
What To Do Teach Patients Taking Adefovir Dipivoxil
warn them that an acute exacerbation of hepatitis B symptoms can occur if the drug is stopped suddenly. Tell patients to notify the prescriber if they develop yellowing of the skin or eyes, darkening of the urine, or lightening of the stools. These problems are signs of liver toxicity, a serious adverse effect of adefovir dipivoxil. Warn patients not to take other drugs or supplements without checking with the prescriber because adefovir dipivoxil interacts with so many other drugs. Because of the potential for liver damage, urge patients to avoid drinking alcohol or using acetaminophen while taking this drug.
HIV has an outer layer
with special "docking proteins," known as gp41 and gp120, that help the virus enter cells with receptors for these protein
The six classes of antiretroviral drugs are:
• Nucleoside analog reverse transcriptase inhibitors (NRTIs) • Non-nucleoside analog reverse transcriptase inhibitors (NNRTIs) • Protease inhibitors (PIs) • Integrase inhibitors • Fusion inhibitors • Entry inhibitors
Intended responses for antiviral drugs include:
• The duration or intensity of an existing viral disease is shortened. • Reactivation of a dormant viral infection is prevented. • A viral infection is prevented from multiplying to the point that a disease results
Intended responses with antiretroviral therapy focus on the results of suppression of viral reproduction. These responses include:
• Viral load (the number of viral particles in a blood sample, which indicates the degree of viral infection) is reduced. • Immune function is improved, as evidenced by higher CD4+ cell count; higher CD4+ to CD8+ ratio. • The patient has fewer episodes of opportunistic infections.
Key Points
• Viruses are tiny intracellular parasites that are not capable of self-reproduction and must infect a living cell to reproduce. • Most common viruses have a relatively low efficiency of cellular infection and must invade the body in large numbers to cause disease. • A retrovirus, specifically HIV, is virulent with a high efficiency of infection. • Antiviral and antiretroviral drugs do not kill viruses; they only suppress viral reproduction and growth. They are virustatic rather than virucidal. • Teach patients taking antiviral or antiretroviral drugs to take them exactly as prescribed and for as long as prescribed and to not stop therapy just because they feel better. • Women should not breastfeed while taking an antiviral or antiretroviral drug. • Ribavirin is highly teratogenic, which means that it can cause birth defects. Do not allow a pregnant or breastfeeding woman to touch ribavirin or care for a patient taking it. • Antiretroviral therapy is most effective when given in multiple combinations of drugs known as highly active antiretroviral therapy (HAART). • Most antiretroviral drugs have interactions with other drugs and herbals. • HAART drugs can cause hyperglycemia and make diabetes worse. • Some PIs are to be taken with food, and others must be taken on an empty stomach. • Maraviroc and raltegravir are not approved for use in children. • Maraviroc can cause severe orthostatic hypotension and increase the risk for falls.