Pharm Exam #2 ch.38

Mechanisms of action include the following:

-inhibition of bacterial cell wall synthesis -inhibition of protein synthesis - inhibition of nucleic acid synthesis -inhibition of cell metabolism and growth -disruption of microbial cell membranes -inhibition of viral enzymes.

You are working as a nurse educator in the hospital setting. Part of your responsibility includes developing a plan to prevent antibiotic resistance. What is the most important part of your plan?

An education campaign that focuses on handwashing between patients (Handwashing is one of the most effective ways to prevent antibiotic resistance, by preventing diseases from being spread from one person to another.)

As the nurse caring for Jane, a 24-year-old woman admitted with pneumonia, you are explaining how antibiotics work to help cure her pneumonia. Which statement would be correct about how antibiotic therapy works?

Antibiotics work by inhibiting cell wall synthesis. Antimicrobial drugs work in a variety of ways: - inhibition of bacterial cell wall synthesis, -inhibition of protein synthesis, -inhibition of nucleic acid synthesis, -inhibition of metabolic pathways (antimetabolites), -disruption of cell wall permeability -and inhibition of viral enzymes.

what would lead the nurse to suspect that a patient is experiencing a hypersensitivity reaction to an anti-infective?

Rash suggests a hypersensitivity reaction.

Microorganisms develop resistance in a number of ways, including the following:

Changing cellular permeability to prevent the drug from entering the cell or altering transport systems to exclude the drug from active transport into the cell; - Altering binding sites on the membranes or ribosomes, which then no longer accept the drug; - Producing a chemical that acts as an antagonist to the drug.

A patient is to be started on an antibiotic. what is most important to take into consideration before beginning the antibiotic regimen?

Culture and susceptibility The duration of symptoms and the patient's hydration status, age, and weight are important, but not imperative, in determining the antibiotic of choice.

Culture IDs what?

Culture identifies the causative organism,

______ suggests a GI toxic effect.

Diarrhea

________ suggests a neurotoxic adverse effect.

Drowsiness

what are some causes of nosocomial infections?

Drug-resistant strains of staphylococci, Pseudomonas, and Proteus

what is a mechanism of action found in some antimicrobial drugs?

Inhibition of bacterial cell wall synthesis

What term refers to an infection acquired in the hospital setting?

Nosocomial (often more difficult to treat then community acquired)

Which intervention is necessary to perform prior to initiating antibiotic therapy?

Obtain a specimen for culture and sensitivity Collect specimens (eg, sputum, urine) for culture and Gram's stain before giving the first dose of an antibiotic. For best results, specimens must be collected accurately and taken directly to the laboratory.

A 4-year-old girl has been admitted to Children's Hospital for an intractable infection. The patient is to receive large doses of an anti-infective agent. Which of the following would indicate the patient is developing a complication?

Poor skin turgor *Kidney damage occurs most frequently with drugs that are metabolized by the kidney and then eliminated in the urine. Such drugs, which have a direct toxic effect on the fragile cells in the kidney, can cause conditions ranging from renal dysfunction to full-blown renal failure. Poor skin turgor is a sign of dehydration. Children who take anti-infectives must be monitored for dehydration and weight loss. It would be normal for a 2-year-old to be restless especially being in the hospital, which limits their activities.

You are a home care nurse taking care of a patient on IV vancomycin for cellulitis of the left calf. How would you explain to your patient that microorganisms develop resistance to anti-infective?

Teach the patient that microorganisms can produce a chemical that acts as an antagonist to the drug.

Successful treatment with bacteriostatic antibiotics depends upon:

The ability of the host's immune system to eliminate the inhibited bacteria and an adequate duration of drug therapy.

Successful treatment with bacteriostatic antibiotics depends upon:

The ability of the host's immune system to eliminate the inhibited bacteria and an adequate duration of drug therapy. (Stopping an antibiotic prematurely can result in rapid resumption of bacterial growth.)

The critical concept in preventing the development of resistant strains of microbes is what?

The duration of drug use **Exposure of pathogens to an antimicrobial agent without cellular death leads to the development of resistance, so it is important to limit the use of these agents to treat pathogens with a known sensitivity to the drug being used. Drug dosages are also important in preventing the development of resistance. However, the duration of drug use is critical to ensure that microbes are completely eliminated and not given the chance to grow and develop resistant strains. It is hard to convince patients that they must always complete the entire course of antimicrobial agents when they begin to "feel better," but stopping early favors the emergence of resistant strains.

Antimicrobials are among the most frequently used drugs worldwide.

Their success in saving lives and decreasing severity and duration of infectious diseases has encouraged their extensive use. Authorities believe that much antibiotic use involves overuse, misuse, or abuse of the drugs. That is, an antibiotic is not indicated at all or the wrong drug, dose, route, or duration is prescribed.

What is the most common, potentially serious, adverse effect of antimicrobial drugs?

Toxic effects on the kidney, gastrointestinal (GI) tract, and nervous system.

_____ may suggest a neurotoxic adverse effect.

Vertigo

Inappropriate use of antibiotics increases:

adverse drug effects - infections with drug-resistant microorganisms - and health care costs.

Microorganisms do not:

alter the blood supply to the infection, stop a cell from reproducing or act as an agonist to the drug.

community-acquired infections

are less severe and easier to treat, although antibiotic-resistant strains are increasing (eg, methicillin-resistant Staphylococcus aureus [MRSA]).

Inappropriate use of antibiotics decreases:

decreases the number of effective drugs for serious or antibiotic-resistant infections.

An anti-infective with a narrow spectrum of activity

is selective in its action so that it is effective against only a few microorganisms with a very specific metabolic pathway or enzyme.

Nosocomial infections

may be more severe and difficult to manage because they often result from drug-resistant microorganisms and occur in people whose immunity is impaired.

Bacteriostatic

refers to a drug's effectiveness in interfering with a cell's ability to reproduce or divide.

Bactericidal=

refers to a highly aggressive drug that causes cell death.

Broad spectrum activity

refers to effectiveness against a wide variety of pathogens.

selective toxicity

the ability to suppress or kill an infecting microbe without injury to the host.

What is the typical duration of drug therapy for treatment of an acute infection?

the average duration is approximately 7 to 10 days.

Selective toxicity is achievable because

the drug accumulates in a microbe at a higher level than in human cells; -the drug has a specific action on cellular structures or biochemical processes that are unique to the microbe; - or an action of a drug on biochemical processes is more harmful to the microbe than to host cells.

You are caring for a child weighing 30 kg. The physician orders gentamicin (Garamycin) tid for your patient. The recommended dosage range is 6 to 7.5 mg/kg/day. Why is it important to give a dosage within this recommended range?

• To give a safe dose for this size child • So you don't overdose the child • To eradicate the bacteria Drug dosage is important in preventing the development of resistance. Doses should be high enough and the duration of drug therapy should be long enough to eradicate even slightly resistant microorganisms. The recommended dosage for a specific anti-infective agent takes this issue into account. The recommended dose is not set because a microorganism only affects a certain size child or to make sure the child gets to much medication.

susceptibility tests determine:

which drugs are likely to be effective against the organism.