After administration of a single iv dose of 300 mg acyclovir for the treatment of a viral infection, the resulting AUC was 26 mg-hr/L. What will be the expected AUC after iv administration of 500 mg acyclovir to the same patient and what will be the dose required to achieve an AUC of 100 mg-hr/L ?

Answer: The AUC is directly proportional to the administered dose when the total body clearance is constant