Pharmacology: Chapter 03: Toxic Effects of Drugs

A client who regularly takes antihistamines for severe allergies is planning a tropical vacation. What health education related to drug therapy should the nurse provide?

"Avoid sightseeing during the hottest part of the day." Response Feedback: Antihistamines can cause anticholinergic effects, which would result in decreased sweating and place the client at high risk for heat stroke. Avoiding the hottest part of the day will help prevent dehydration and heat prostration. Extreme restlessness could indicate Parkinson-like syndrome not usually associated with antihistamines. Excessive thirst is characteristic of hyperglycemia. Nurses should never tell clients to decrease or discontinue a drug unless the prescriber has instructed them to do so. Sun protection is necessary for all clients, but this is unrelated to antihistamine use.

The home health nurse is caring for an older adult client with benign prostatic hypertrophy (BPH). An anticholinergic drug has been prescribed for an unrelated health problem. What health education should the nurse provide to this client?

"It's best if you can empty your bladder before taking the drug."

A client is taking chloroquine for rheumatoid arthritis. What report by the client should the nurse interpret as a possible adverse reaction to the medication?

"Sometimes I have blurred vision." Response Feedback: Chloroquine can cause ocular toxicity with blurring of vision, color vision changes, corneal damage, and blindness. Increased urination, tingling, and numbness are signs of hyperkalemia and hypokalemia. Loss of balance can be caused by auditory damage due to drug toxicity.

A client with diabetes is also taking ephedrine to treat asthma. On occasion, the client notes that the drug causes an increase in blood glucose. What should the nurse teach the client about this phenomenon?

"Stored glycogen is broken down by ephedrine, causing hyperglycemia." Response Feedback: Ephedrine breaks down stored glycogen, which then enters the bloodstream as glucose and causes an increase in serum blood glucose, or blood sugar, levels. Ephedrine is not mixed with sugar, and it does not cause glucose to stay in circulation longer. Ephedrine has no effect on insulin.

Before administering a macrolide antibiotic, the nurse should question the order for what client?

A 12-year-old boy with hearing loss Response Feedback: Macrolide antibiotics can cause severe auditory nerve damage, so the nurse would question administration of this drug to the child with hearing loss because another antibiotic may be indicated to preserve remaining hearing. This drug is not contraindicated in older adults, although a lower dosage may be indicated. It may safely be given in clients with irritable bowel syndrome and after myocardial infarction.

The nurse is assessing a client new to the clinic. The client says she is allergic to penicillin. What action should the nurse do next?

Assess the exact nature of the client's response to the drug Response Feedback: The nurse should ask additional questions of clients who state that they have a drug "allergy" to ascertain the exact nature of the response and whether it is a true drug allergy. Clients may confuse secondary actions of the drug with an allergy. The nurse is obliged to document the client's statement and should assess the client, but the nurse should first gather more data about the nature of the client's responses to penicillin.

A nurse is planning client teaching about a newly prescribed drug. What teaching point should the nurse provide to best improve adherence and safety?

Measures to alleviate any discomfort associated with adverse effects Response Feedback: If a client is aware of certain adverse effects and how to alleviate or decrease the discomfort, he or she is more likely to continue taking the medication. A list of pharmacies can be useful information but will not improve safety or compliance. Knowing the relative benefits of the drug over alternatives may enhance adherence but has no effect on safety. Most clients are not concerned with the statistics related to drug testing, and it would not improve adherence or safety even if the client was interested in the information.

The triage nurse in the emergency department admits a 16-year-old boy brought in by ambulance and accompanied by a friend. The client is in respiratory distress, is vomiting, and blood is noted in the vomitus. The client is somnolent, and the electrocardiogram demonstrates an arrhythmia. The friend admits that the client took "a bunch of little green pills" from the cupboard at the grandparents' house. The nurse should recognize the likelihood of what adverse reaction?

Poisoning Response Feedback: Poisoning occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions. The symptoms do not indicate an anaphylactic reaction, which would not normally include bloody vomitus. Serum sickness and delayed hypersensitivity do not cause this particular presentation.

The caregiver of an older adult client with ischemic heart disease tells the nurse that the client is only taking around half of the prescribed dosage of several medications. What possible effect should the nurse explain when providing health education?

Reduced therapeutic effect Response Feedback: Taking too little of the medication would mean that therapeutic levels are not being reached and the drugs will be less effective at lower dosages. Primary actions are the result of overdose, which is not the case in this client who is taking too little of the drug. Superinfection and eventual antibiotic resistance would only result if the client was taking an antibiotic, which is not indicated by the question.

The Kardex of a male client who is prescribed antihistamines for treating an allergy reads as follows:"Age: 32; Profession: Long-distance truck driver; Lifestyle & diet: Lives alone, chews tobacco, no alcohol use, no food preferences, practices martial arts; Medical history: Suffers from seasonal allergies, recent urinary tract infection that has been treated successfully."What information from the Kardex is likely to have the greatest implication in educating the client about antihistamine administration?

The client's profession

Why does the nurse need to be alert for any indication of an allergic reaction in clients?

To maintain the client's safety during drug therapy Response Feedback: Being alert to adverse effects—what to assess and how to intervene appropriately—can increase the effectiveness of a drug regimen, provide for client safety, and improve client compliance. Indications of allergic reactions would not indicate noncompliance or improve effectiveness of a specific medication. Indications of allergic reaction would indicate an adverse effect and would not reduce the risk.

A client with Parkinson's disease has been prescribed an anticholinergic medication. The client reports that he is having difficulty voiding. The nurse should recognize that this client is experiencing:

a secondary action of the drug. Response Feedback: Sometimes the drug dosage can be adjusted so that the desired effect is achieved without producing undesired secondary reactions. But sometimes this is not possible, and the adverse effects are almost inevitable. In such cases, the client needs to be informed that these effects may occur and counseled about ways to cope with the undesired effects. The situation described is not a hypersensitivity reaction that would indicate an allergic reaction, a primary reaction that would be excessive therapeutic response, or an allergic reaction to the drug.

The nurse is caring for a client who is exhibiting adverse medication effects. The nurse should recognize that adverse effects can be extensions of:

the primary action of a drug.

A nurse is providing teaching to a group of clients who are beginning drug therapy for human immunodeficiency syndrome (HIV). What should the nurse teach the group?

"Make sure not to take more than prescribed, because poisoning can cause damage to more than one body system." Response Feedback: Poisoning resulting from overdosage can lead to the potential for fatal reactions when more than one body system is affected. Liver, not kidney, injury can be caused by the first-pass effect and can cause the skin to have a yellow appearance. Most drugs are metabolized in the liver, but liver damage causes jaundice, manifested as a yellow tinge to the skin and sclera. Dark red papules appearing on limbs are characteristic of Stevens-Johnson syndrome, a potentially fatal erythema multiforme exudativum, which should be reported but is not due to liver damage.

The nurse should consider teratogenic effects when caring for what clients?

A 29-year-old client receiving prenatal care in her first trimester of pregnancy A 37-year-old female client who is taking fertility drugs Response Feedback: A teratogen is a drug that can harm the fetus or embryo, so the nurse would consider the teratogenic properties of medications when caring for woman of childbearing age including adolescents and young adult women. Teratogens have no impact on clients who are not pregnant and who may not become pregnant.

A client's most recent laboratory result indicates an elevated potassium level. What drug in this client's medication regimen should the care team consider discontinuing?

A diuretic Response Feedback: Elevated potassium levels can result from the use of certain diuretics. Narcotics, antipsychotics, and antianxiety drugs are not associated with this adverse effect.

The nurse is assessing a client who has developed shortness of breath, a rash, panic, and a blood pressure of 189/106 mm Hg after being administered a new medication. In addition to promptly informing the care team, the nurse should perform what action?

Administering epinephrine as prescribed Response Feedback: This client is likely experiencing anaphylaxis and requires epinephrine. There is no indication that CPR is needed. Supplementary oxygen is likely needed, but nasal cannula would likely be insufficient. Monoclonal antibodies are not used to treat anaphylaxis.

A client with seasonal allergies is taking an OTC antihistamine to relieve itchy, watery eyes, and a runny nose. When planning teaching for this client, the nurse would include what teaching point?

Avoid driving or operating machinery. Response Feedback: An adverse effect of antihistamines is drowsiness, so that injury to the client or others can occur if driving or operating machinery. An increase in fluids would be indicated to help keep nasal membranes moist. Drowsiness is more likely than insomnia. Grapefruit juice does not interfere with the metabolism of antihistamines.

The nurse is caring for a client receiving an antineoplastic medication who reports fever, chills, sore throat, weakness, and back pain. The nurse should recognize the possibility of what adverse effect?

Blood dyscrasia Response Feedback: Symptoms of blood dyscrasias include fever, chills, sore throat, weakness, back pain, dark urine, decreased hematocrit (anemia), low platelet count (thrombocytopenia), low white blood cell count (leukopenia), and a reduction of all cellular elements of the complete blood count (pancytopenia). Dermatologic reactions would be reflected in skin alterations, electrolyte imbalances would result in differing symptoms depending on the electrolyte involved but would not cause chills and fever, and a superinfection could cause a fever but would not cause a sore throat, weakness, or back pain unless the infection involved those body parts.

A client in distress is brought to the emergency department by ambulance. Emergency medical technicians state that an anaphylactic reaction from oral penicillin is suspected. Which of the nurse's assessment findings best supports this diagnosis?

Blood pressure: 186/100 mm Hg, shortness of breath Response Feedback: An anaphylactic reaction is an immune reaction that causes a massive release of histamine, which results in edema and swelling that can lead to respiratory distress and increased blood pressure. A decreased hematocrit and decreased urine output suggest a cytotoxic reaction. An increased temperature and swollen joints could suggest serum sickness. Oxygen saturation levels would be decreased due to respiratory distress.

The nurse administers a medication to the client that induces the secondary action of hypoglycemia. What organ will be most acutely impacted by inadequate circulating glucose?

Brain Response Feedback: While all cells require glucose to function, the brain uses the greatest amount. As a result, hypoglycemia has the greatest impact on the brain, which explains why hypoglycemia has so many neurological signs and symptoms including fatigue, drowsiness, anxiety, headache, shaking, lack of coordination, and numbness and tingling of the mouth, tongue, and/or lips; confusion and, in severe cases, seizures or coma may occur because the brain cannot function without adequate supplies of glucose.

A client is admitted to the intensive care unit with hyperkalemia due to the use of potassium-sparing diuretics. What assessment should the nurse prioritize?

Cardiac monitoring Response Feedback: Monitor for cardiac irregularities because potassium is an important electrolyte in the action potential, needed for cell membrane stability. When potassium levels are too high, the cells of the heart become very irritable and rhythm disturbances can occur. Be prepared for a possible cardiac emergency, cardiac monitoring is prioritized over cognition, urine output, and temperature, though all of these would be i

A client presents at the clinic reporting vaginal itching and a clear discharge. The client reports to the nurse that she has been taking an oral antibiotic for 10 days. What is the nurse's best action?

Educate the client about the likelihood of a superinfection caused by destruction of normal flora Response Feedback: Superinfections often occur with antibiotic use because the drug kills normal bacterial flora. This is not a result of toxic levels of the antibiotic, but rather an effect of the medication that has killed normal flora, which it is designed to do. Vaginal itching and a clear discharge are not considered adverse effects of an antibiotic. An overdose of a drug that damages more than one body systems is considered drug poisoning.

The nurse is caring for a client who has been taking potassium-sparing diuretic. What assessment finding would suggest an adverse reaction?

Heart rate of 47 beats/minute

The nurse administers typical antipsychotic medications to the client who has taken these same drugs for many years. What signs and symptoms should the nurse attribute to secondary actions of the drug? Select all that apply.

Muscular tremors Drooling Changes in gait Response Feedback: Drugs that affect the dopamine levels in the brain (e.g., typical antipsychotic drugs) cause a syndrome that resembles Parkinson's disease including lack of activity, akinesia, muscular tremors, drooling, changes in gait, rigidity, extreme restlessness or "jitters" (akathisia), or spasms (dyskinesia). Yellow discoloration of the skin and sclera indicate jaundice and would suggest liver damage. A fine red rash on the trunk would be a dermatologic reaction unrelated to an antipsychotic agent's secondary effects.

The postanesthesia care unit nurse is serving a client after a right knee arthroscopy. As the client begins to wake up from anesthesia, the nurse assesses rigidity, involuntary movements, and tachycardia. The nurse should recognize the possibility of what adverse effect?

Neuroleptic malignant syndrome Response Feedback: Neuroleptic malignant syndrome is a generalized syndrome that includes extrapyramidal symptoms such as slowed reflexes, rigidity, involuntary movements; hyperthermia; autonomic disturbances (e.g., hypertension, fast heart rate); fever may be noted as well. This is most often seen after administering general anesthesia or drugs with central nervous system (CNS) effects. This syndrome was once known as malignant hyperthermia. These symptoms are not consistent with Parkinson-like syndrome or anaphylactic shock. Malignant tachycardia is not an actual phenomenon.

The nurse is caring for a client who experienced a severe headache. When the prescribed dose of analgesics did not cause relief, the client took double the dosage 1 hour later. The nurse should assess the client for what adverse effect?

Poisoning Response Feedback: This client has taken an overdosage of the medication. Poisoning occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions. Allergic and anaphylactic reactions can occur with any drug administration, but this is not the client's greatest risk. More information about the exact type of medication would be needed to determine whether sedative effects are likely.

The nurse administers a loop diuretic to the client. In addition to sodium and water, what other electrolyte would the nurse expect to be excreted in significant amounts?

Potassium Response Feedback: Loop diuretics increase excretion of sodium, water, and potassium most significantly. Although other electrolytes may be excreted, loss of magnesium, calcium, and zinc are usually not significant.

An older adult who has been taking a macrolide antibiotic has developed auditory nerve damage. What instructions should the nurse provide for the family regarding home care?

Provide protective measures to prevent falling or injury. Response Feedback: Macrolide antibiotics can cause severe auditory nerve damage, which can cause dizziness, ringing in the ears (tinnitus), and loss of balance and hearing. The client would be at high risk for injury due to falls. Usually a person who is dizzy is unable to lie flat and needs to recline with the head elevated. Sodium and sunlight limitations are not components of this client's health needs.

The nurse is writing a plan of care for a client who is exhibiting Parkinson-like syndrome. The nurse observes that the client is having occasional difficulty swallowing. In addition to close monitoring, what is the nurse's most appropriate action?

Provide small, frequent meals. Response Feedback: Provide small, frequent meals if swallowing becomes difficult. Keeping the client NPO would be inappropriate because these effects often result from medications that will be taken throughout the client's life. Soft or pureed foods are often more difficult to swallow than more rigid foods. Thickening liquids would only be necessary if the dysphagia, or difficulty swallowing, continued to progress. Tube feeding would be an action of last resort.

The nurse administers doxycycline, a drug known to cause gastritis. When the client reports abdominal discomfort after taking the medication, the nurse should classify this discomfort as what type of adverse effect?

Secondary action Response Feedback: Secondary actions are those actions that occur as a result of taking a medication but do not fall under the category of therapeutic action and are often negative. This client is experiencing a secondary action of erythromycin. Primary actions would be extensions of therapeutic action. Hypersensitivity reaction would be an excessive response to either the primary or secondary effects of a drug. An allergic reaction would be an immune response to the drug.

The nurse is assessing a client whose asthma is being treated with ephedrine. What assessment finding should the nurse attribute to a possible adverse reaction?

The client's blood glucose levels are 200 mg/dL (11.1 mmol/L) Response Feedback: Ephedrine (generic), a drug used as a bronchodilator to treat asthma and relieve nasal congestion, can break down stored glycogen and cause an elevation of blood glucose by its effects on the sympathetic nervous system. Ephedrine does not cause bronchoconstriction, cold intolerance, or constipation.

A student nurse asks the study group how to define a drug allergy. What would be the peer group's best response?

The formation of antibodies to a drug protein causing an immune response when the person is next exposed to that drug. Response Feedback: A drug allergy is the formation of antibodies to a drug or drug protein; causes an immune response when the person is next exposed to that drug. A drug allergy does not occur at the first exposure to a drug. A second action of a specific drug is an adverse response that the drug causes in addition to the therapeutic effect. Serum sickness is one type of allergic reaction but does not define allergic reaction. An immediate systemic reaction to a drug, usually not on first exposure, is an anaphylactic reaction.

The nurse administers an anticholinergic medication to the client. When assessing this client, what finding should the nurse interpret as a secondary effect of the drug?

Urinary hesitancy Response Feedback: Anticholinergic secondary effects include dry mouth, altered taste perception, dysphagia, heartburn, constipation, bloating, paralytic ileus, urinary hesitancy and retention, impotence, blurred vision, cycloplegia, photophobia, headache, mental confusion, nasal congestion, palpitations, decreased sweating, and dry skin. Tachycardia, hyperthermia, and profuse sweating would not be expected findings or consistent with anticholinergic effects and would require further assessment.

The nurse is providing care for a client whose type 2 diabetes is treated with glipizide. When monitoring the client for potential adverse effects, the nurse should assess for:

confusion and lack of coordination.