Prep U, PN 125: Chapter 3:Toxic Effects of Drugs

A client taking a beta blocker for hypertension tells the nurse he will no longer take the medication because it is causing an inability for him to maintain an erection. What is the best explanation for this issue by the nurse?

"This is an expected adverse effect of the medication, but it is very important that you continue to take it. We can talk about other methods for sexual expression." Explanation: An adverse effect of drug therapy is a usually undesirable effect other than the intended therapeutic effect. It may occur even with normal drug dosing. Adverse effects may also occur independently of the dose and be unpredictable. The term adverse effect encompasses all nontherapeutic responses to drug therapy.

A client develops a cytotoxic reaction to a drug. What would the nurse expect to do?

Discontinue the drug immediately as ordered. Explanation: For a client experiencing a cytotoxic reaction, the prescriber is notified and the drug is discontinued. Subcutaneous epinephrine is used to treat an anaphylactic reaction. The client is also encouraged to wear some type of MedicAlert identification denoting the allergy. Antipyretics would be used to treat serum sickness reaction.

A client began a new medication four days ago and presents with a temperature of 38.2° C (100.8 °F), dependent edema, and swollen cervical lymph nodes. The nurse has informed the client's provider, who has discontinued the medication. What subsequent intervention should the nurse prioritize?

Provide supportive care to manage fever and inflammation. Explanation: This client's presentation and history are suggestive of a serum sickness reaction. Interventions include discontinuing the drug and providing supportive care. Resuscitation is not justified by this client's presentation. Epinephrine is prescribed to clients experiencing anaphylaxis. Naloxone is used to treat narcotic overdoses, not serum sickness reactions.

A client with a serious Escherichia coli infection is being treated with gentamicin. When monitoring for potential adverse effects, the nurse should prioritize:

blood urea nitrogen and creatinine levels. Explanation: Gentamicin is an example of a drug that holds the potential for renal toxicity. This drug is not associated with hepatic damage, electrolyte disturbances or disruptions of skin integrity.

The pharmacology instructor explains to the students that adverse effects can be extensions of:

primary action of a drug. Explanation: Adverse effects can be extensions of the primary action of a drug or secondary effects that are not necessarily desirable but are unavoidable.

Which client is experiencing a secondary action of a medication?

A client who is drowsy after taking antihistamine Explanation: A secondary action is the development of adverse effects in addition to the desired effects. Drowsiness from an antihistamine is an example of secondary action. A primary action is the development of adverse effects, an extension of the desired effect, from simple overdosage. Excessive relaxation after taking an antianxiety medication is an example of primary action. Drug allergies and hypersensitivities are not examples of secondary actions.

An older adult client has an elevated serum creatinine level. This client is at greatest risk for which medication-related effect?

Impaired excretion Explanation: The elevated creatinine level indicates impaired kidney function, which inhibits excretion. It does not affect absorption, and has no effect on gastric emptying. Idiosyncratic effects are reactions that occur rarely and unpredictably among the population.

A client receiving drug therapy develops numbness and tingling in the extremities and muscle cramps. What assessment should the nurse perform?

Review the client's most recent potassium level. Explanation: Hypokalemia is suggested by numbness and tingling in the extremities, muscle cramps, weakness, and irregular pulse. Fatigue, drowsiness, hunger, tremulousness, and cold clammy skin would suggest hypoglycemia. Renal injury would be manifested by elevated BUN and creatinine concentration, decreased hematocrit, and electrolyte imbalances, fatigue, malaise, decreased urine output and irritability. Neurologic dysfunction would most likely be manifested by confusion, delirium, insomnia, drowsiness, and changes in deep tendon reflexes.

The nurse is caring for a client receiving an aminoglycoside (antibiotic) that can be nephrotoxic. Which will alert the nurse that the client may be experiencing nephrotoxicity?

a decrease in urine output Explanation: Decreased urinary output, elevated blood urea nitrogen, increased serum creatinine, altered acid-base balance, and electrolyte imbalances can occur with nephrotoxicity. Ringing noise in the ears (tinnitus) is an indication of possible ototoxicity. Visual disturbances can suggest neurotoxicity, and yellowing of the skin (jaundice) is a sign of hepatotoxicity.

The nurse is called to a client's room 15 minutes after the client has received a new medication. The client reports pruritus as well as nausea. The nurse notes that the client appears pale, is sweating, and has begun to cough and wheeze. The nurse determines that the client is experiencing what type of reaction related to the new medication?

anaphylactic shock Explanation: Anaphylactic shock occurs shortly after administration of a drug to which the client is sensitive. It may be life-threatening and must be treated immediately. The client may experience respiratory, cardiovascular, integumentary, and gastrointestinal symptoms.

The nurse is reviewing the laboratory test results of a client receiving drug therapy. What would the nurse suspect if the results reveal an elevation in the blood urea nitrogen level and creatinine concentration?

renal injury Explanation: Renal injury is reflected by elevated blood urea nitrogen and creatinine concentration. Liver injury would be reflected by elevated liver enzymes such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Hypoglycemia would be indicated by decreased blood glucose levels. Hyperkalemia would be reflected by elevated potassium levels (greater than 5.0 mEq/L).

A client who is being treated for cancer developed a serum sickness reaction. The care team has been notified, and the client is being stabilized. What is the nurse's priority action?

Discontinue the drug immediately as ordered. Explanation: If serum sickness occurs, the prescriber is notified and the drug is discontinued. Epinephrine is given for an anaphylactic reaction and requires a prescriber's order. A MedicAlert identification may be indicated, but is not the nurse's first concern. Topical corticosteroids may be used to treat dermatological symptoms such as rash, but would not be the nurse's first concern.

An instructor is preparing a class that describes the toxic effects of drugs. Which effect would the instructor expect to include?

Drugs cause unexpected or unacceptable reactions despite screening and testing. Explanation: All drugs are potentially dangerous. Even though chemicals are carefully screened and tested in animals and in people before they are released as drugs, drug products often cause unexpected or unacceptable reactions when they are administered. Drugs are chemicals, and the human body operates by a vast series of chemical reactions. Consequently, many effects can be seen when just one chemical factor is altered. Today's potent drugs can cause a great variety of reactions, many of which are more severe than ever seen before.

A client develops bone marrow suppression related to a drug's effects. What would be most important for the nurse to do?

Monitor laboratory blood values. Explanation: Monitoring blood counts would be most important for the client with bone marrow suppression. Protective isolation would be appropriate if the client were immunocompromised. Bone marrow suppression does not pose an immediate threat to cardiovascular status. Frequent mouth care would be appropriate if the client develops stomatitis. Dialysis would be indicated if the client develops renal injury due to drug therapy.

A client is receiving an antineoplastic medication for treatment of breast cancer and begins having tonic-clonic seizure activity. What type of toxicity does the nurse recognize that this client is experiencing?

Neurotoxicity Explanation: Neurotoxicity, sometimes referred to as central nervous system toxicity, is a drug's ability to harm or poison a nerve cell or nerve tissue. Signs and symptoms of neurotoxicity include drowsiness, auditory and visual disturbances, restlessness, nystagmus, and tonic-clonic seizures. Neurotoxicity can occur after exposure to drugs and other chemicals and gases.

What changes due to aging in the geriatric client may affect excretion and promote accumulation of drugs in the body?

decreased glomerular filtration rate. Explanation: In older adults (65 years and older), physiologic changes may alter all pharmacokinetic processes. Changes in the gastrointestinal tract include decreased gastric acidity, decreased blood flow, and decreased motility. Despite these changes, however, there is little difference in drug absorption. Changes in the cardiovascular system include decreased cardiac output, and therefore slower distribution of drug molecules to their sites of action, metabolism, and excretion. In the liver, blood flow and metabolizing enzymes are decreased. Therefore, many drugs are metabolized more slowly, have a longer action, and are more likely to accumulate with chronic administration. In the kidneys, there is decreased blood flow, decreased glomerular filtration rate, and decreased tubular secretion of drugs; all of these changes tend to slow excretion and promote accumulation of drugs in the body. Impaired kidney and liver function greatly increases the risks of adverse drug effects. In addition, older adults are more likely to have acute and chronic illnesses that require the use of multiple drugs or long-term drug therapy. Therefore, possibilities for interactions among drugs and between drugs and diseased organs are greatly multiplie

A client comes to the clinic reporting of a ringing sound in the ears and dizziness. When the nurse takes the client's history, the nurse discovers that the client has been taking several ibuprofen every day for various discomforts. What does the nurse understand has occurred with this client?

ototoxicity from the ibuprofen Explanation: Ototoxicity is damage to the eighth cranial nerve. It may or may not be reversible. Signs and symptoms of ototoxicity include tinnitus, which is a buzzing or ringing sound in the ear, and sensorineural hearing loss. Other signs and symptoms, particularly of vestibular toxicity, include light-headedness, vertigo, a spinning sensation from a seated position, and nausea and vomiting.

The nurse is assessing a client whose debilitating headache did not respond to the recommended dose of an OTC analgesic. In response, the client took another dose 30 minutes later and then a double dose one hour after that. The nurse's assessment should focus on the possibility of:

poisoning. Explanation: Poisoning occurs when an overdose of a drug damages multiple body systems, leading to the potential for fatal reactions. Hypersensitivity, allergies, and anaphylaxis would not be indicated by an overdosage of the medication.