A patient with renal impairment is prescribed a medication that is primarily excreted by the kidneys. What adjustment should the nurse anticipate?

Choice A reason: This is incorrect. Miosis is the constriction of the pupils, which can also be caused by morphine, but it is not a life-threatening side effect. Miosis occurs because morphine stimulates the parasympathetic nervous system, which controls the muscles that constrict the pupils¹.

Choice B reason: This is incorrect. Sedation is the state of being calm, relaxed, and sleepy, which can also be caused by morphine, but it is not a life-threatening side effect. Sedation occurs because morphine depresses the central nervous system, which reduces the activity of the brain and the body.

Choice C reason: This is correct. Respiratory depression is the slowing down of breathing, which can be a life-threatening side effect of morphine. Respiratory depression occurs because morphine depresses the respiratory center in the brainstem, which regulates the rate and depth of breathing. If the breathing becomes too slow or shallow, the patient may not get enough oxygen and may lose consciousness or die.

Choice D reason: This is incorrect. Euphoria is the feeling of intense happiness, pleasure, or wellbeing, which can also be caused by morphine, but it is not a life-threatening side effect. Euphoria occurs because morphine stimulates the reward system in the brain, which releases dopamine, a neurotransmitter that causes positive emotions.

Choice A reason: Administering the medication with meals only is not a valid adjustment for a medication that is primarily excreted by the kidneys. The food intake does not affect the renal clearance of the drug, unless it alters the pH of the urine or the blood flow to the kidneys. The nurse should follow the instructions on the medication label or the prescriber's order regarding the timing of the administration.

Choice B reason: No dose adjustment is required is an incorrect statement for a medication that is primarily excreted by the kidneys. The renal impairment can reduce the elimination of the drug and increase its concentration in the blood. This can cause adverse effects and toxicity. The nurse should consult with the prescriber or the pharmacist about the appropriate dose reduction or frequency change for the patient's level of renal function.

Choice C reason: Increasing the dose to ensure therapeutic effect is a dangerous and inappropriate adjustment for a medication that is primarily excreted by the kidneys. The renal impairment can reduce the elimination of the drug and increase its concentration in the blood. This can cause adverse effects and toxicity. The nurse should not increase the dose without the prescriber's order and should monitor the patient for signs of overdose or toxicity.

Choice D reason: Decreasing the dose to prevent toxicity is the correct and rational adjustment for a medication that is primarily excreted by the kidneys. The renal impairment can reduce the elimination of the drug and increase its concentration in the blood. This can cause adverse effects and toxicity. The nurse should consult with the prescriber or the pharmacist about the appropriate dose reduction or frequency change for the patient's level of renal function. The nurse should also monitor the patient for the therapeutic response and the adverse effects of the drug.