The practical nurse (PN) is reinforcing discharge instructions for a client with metastatic cancer who is prescribed morphine for bone pain. Which information from the client indicates to the PN an understanding of the medication?

Choice A reason: Using an Amsler grid monitors macular degeneration, not sildenafil-related visual changes, which include color tinting or blurred vision due to PDE5 inhibition affecting retinal blood flow. This is not a standard monitoring tool for sildenafil side effects, making it inappropriate for this context.

Choice B reason: Instilling eye drops is irrelevant, as sildenafil’s visual changes are systemic, caused by its effect on retinal phosphodiesterase, not a local eye condition treatable with drops. No evidence supports eye drops for this side effect, making this choice incorrect and ineffective.

Choice C reason: Wearing dark glasses may reduce light sensitivity but does not address sildenafil’s visual side effects, like blue-green color distortion, caused by altered retinal signaling. This is a temporary, drug-induced effect, and glasses do not mitigate the underlying issue, making this choice inadequate.

Choice D reason: Reporting visual changes immediately is critical, as sildenafil can cause rare but serious effects like non-arteritic anterior ischemic optic neuropathy, impairing retinal blood flow. Prompt reporting allows the provider to assess severity, adjust dosing, or discontinue the drug to prevent permanent vision loss.

Choice A reason: Appetite changes may occur with levothyroxine due to metabolic effects, but they are not the most critical side effect. Excessive thyroid hormone can overstimulate metabolism, but cardiovascular effects, like tachycardia, are more immediate and dangerous, making appetite monitoring less urgent.

Choice B reason: Sleep disturbances may result from levothyroxine’s stimulatory effects, but they are less severe than cardiovascular risks. Overdose can cause insomnia by increasing metabolism, but heart rate is a more direct indicator of hyperthyroidism, which poses greater health risks, making this choice secondary.

Choice C reason: Heart rate is critical to monitor, as levothyroxine increases metabolism, potentially causing tachycardia or arrhythmias if overdosed. Excess thyroid hormone mimics hyperthyroidism, stressing the cardiovascular system, which can lead to palpitations or heart failure, making this the most important parameter for side effect detection.

Choice D reason: Daily weights track fluid or metabolic changes but are less specific for levothyroxine side effects. Weight loss may occur with excess dosing, but cardiovascular effects, like increased heart rate, are more immediate and life-threatening, requiring closer monitoring than weight fluctuations.