What advice should be given to a patient taking acyclovir regarding hydration?

When a patient is taking acyclovir, it is crucial to advise them to drink plenty of fluids. This recommendation stems from the fact that acyclovir can be nephrotoxic, especially when given in high doses or in patients with dehydration. Adequate hydration helps to maintain renal function and reduces the risk of crystallization of the drug in the renal tubules, which can lead to kidney damage and acute renal failure.

Additionally, when the body is properly hydrated, the drug’s clearance from the body is more efficient, minimizing the risk of side effects associated with elevated drug levels. Therefore, a patient taking acyclovir should be encouraged to maintain sufficient fluid intake, typically around 2-3 liters of water daily, unless contraindicated for other reasons. This proactive approach ensures that the medication is processed effectively and helps to safeguard the patient's renal health.