American Board of Psychiatry and Neurology (ABPN) Practice Exam

Clozapine levels can be significantly influenced by other substances, particularly those that affect liver enzymes involved in its metabolism. Cimetidine, an H2 receptor antagonist, is known to inhibit certain cytochrome P450 enzymes. Specifically, it competes with clozapine's metabolism, leading to increased levels of clozapine in the body. This is particularly important for clinicians to consider, as elevated clozapine levels can result in enhanced therapeutic effects but also increase the risk of side effects, including agranulocytosis.

While red wine and cheese may have interactions with other medications or contribute to dietary considerations, they do not have documented evidence of increasing clozapine levels. Red wine contains compounds that can modulate various metabolic enzymes but not in the specific context of clozapine metabolism. Cheese contains tyramine, which is more significant in the context of monoamine oxidase inhibitors rather than clozapine. Acetaminophen, while it is a common analgesic, does not have a direct impact on clozapine levels in terms of metabolic enzymatic inhibition.

Thus, understanding the role of cimetidine as a potent inhibitor of clozapine metabolism helps in managing and adjusting dosing for individuals