A nurse understands that an anticholinergic drug will produce which of the following effects?

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.

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.