MEDizzy - A 46-year-old woman complained to her physician that the

Feed Library Learning Discuss Leaderboard Journal

Pharmacodynamics

A 46-year-old woman complained to her physician that the sedative effect of the drug she was taking had increased substantially. The woman, who was suffering from generalised anxiety disorder, had been taking diazepam , one tablet daily. A few days earlier, she had started taking cimetidine to treat her heartburn. Cimetidine is an inhibitor of the cytochrome P-450 system in the liver. Which of the following terms best defines this cimetidine−diazepam interaction?

ExplanationAlthough benzodiazepines are no longer first-line agents for generalized anxiety disorder, they are still used when other drugs are poorly tolerated or ineffective, as most likely occurred in this case. Potentiation occurs when a drug enhances the effect of another drug but is devoid of that effect when given alone. Cimetidine is devoid of sedative effects but can increase the sedative effect of diazepam by inhibiting hepatic metabolism of diazepam metabolism .