A nurse is teaching a client who has a new prescription for aluminum hydroxide to treat heartburn. The nurse should instruct the client to monitor for and report which of the following adverse reactions?

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: Peak level is the correct term to describe the highest concentration of a drug in the blood after it is administered. Peak level is also known as peak plasma concentration or Cmax, and it reflects the rate and extent of drug absorption. Peak level is influenced by factors such as the route of administration, the dose, the formulation, and the bioavailability of the drug. Peak level is important to monitor for drugs that have a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should measure the peak level at the appropriate time after the drug administration, and adjust the dose or the frequency as needed to achieve the desired therapeutic effect and avoid adverse effects .

Choice B reason: Halflife is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Halflife is the time it takes for the concentration of a drug in the blood to decrease by 50%. Halflife reflects the rate of drug elimination, which depends on factors such as the metabolism and excretion of the drug. Halflife is important to determine the dosing interval and the time to reach steady state. The nurse should consider the halflife of the drug when prescribing or administering the drug, and avoid drug accumulation or subtherapeutic levels .

Choice C reason: Trough level is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Trough level is the lowest concentration of a drug in the blood before the next dose is given. Trough level reflects the balance between drug absorption and elimination, and it indicates the minimum effective concentration of the drug. Trough level is important to monitor for drugs that have a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should measure the trough level just before the next dose of the drug, and adjust the dose or the frequency as needed to achieve the desired therapeutic effect and avoid adverse effects .

Choice D reason: Steady state is not the correct term to describe the highest concentration of a drug in the blood after it is administered. Steady state is the condition when the rate of drug administration is equal to the rate of drug elimination, and the concentration of the drug in the blood remains constant. Steady state is usually reached after four to five halflives of the drug, and it reflects the optimal therapeutic level of the drug. Steady state is important to maintain for drugs that have a long halflife or a narrow therapeutic range, meaning that there is a small difference between the effective and toxic doses. The nurse should ensure that the drug is administered at regular intervals and at the appropriate dose to achieve and maintain steady state.