A patient reports a severe headache and dizziness after taking nitroglycerin.
What should the nurse do?

Choice A rationale

Serotonin agonists, such as triptans used for migraines, cause vasoconstriction by stimulating serotonin receptors on intracranial blood vessels. This vasoconstrictive effect is a contraindication in patients with a history of hypertension, especially uncontrolled hypertension, as it can dangerously increase blood pressure and lead to a hypertensive crisis or cardiovascular event.

Choice B rationale

There is no known cross-reactivity or contraindication between serotonin agonists and penicillin allergies. These drug classes have completely different chemical structures and mechanisms of action. Penicillin is an antibiotic that interferes with bacterial cell wall synthesis, while serotonin agonists act on specific neurotransmitter receptors.

Choice C rationale

Serotonin agonists do not directly affect the bronchial smooth muscle in a way that would be contraindicated in chronic bronchitis. The primary concern with these medications is their vascular effects, not their respiratory effects. Chronic bronchitis, while a respiratory condition, is not a known contraindication for serotonin agonists unless there is an underlying cardiovascular comorbidity.

Choice D rationale

Cataracts are a condition of the eye characterized by the clouding of the lens. This condition is not related to the mechanism of action or the side effect profile of serotonin agonists. There is no known pharmacological or physiological interaction between serotonin agonists and the development or progression of cataracts.

Choice A rationale

Benzodiazepines, such as diazepam, are central nervous system depressants. Their primary action is to enhance the effect of the neurotransmitter GABA, which results in sedative, anxiolytic, and muscle-relaxant properties. This mechanism of action often leads to a decrease, not an increase, in blood pressure. Therefore, hypertension is not an anticipated adverse effect.

Choice B rationale

Benzodiazepines enhance the inhibitory effects of GABA throughout the central nervous system, including the brainstem respiratory centers. This can lead to a significant dose-dependent depression of respiratory drive. This effect is particularly dangerous when these medications are combined with other CNS depressants like opioids or alcohol, leading to potentially fatal respiratory arrest.

Choice C rationale

Benzodiazepines are known to cause central nervous system depression, leading to sedation and decreased psychomotor activity. They are prescribed to treat anxiety and insomnia, and their intended effects are calming and sedating. Hyperactivity, which is an increase in activity and restlessness, is the opposite of the expected pharmacological effect and is not a typical adverse reaction.

Choice D rationale

Benzodiazepines are known to decrease alertness and cause drowsiness due to their central nervous system depressant effects. This is a common and expected side effect, especially at higher doses or with initial use. Advising a patient about decreased alertness is essential for safety, as it can impair their ability to perform tasks requiring focus.