Question

Desmethyl diazepam is an active metabolite, having an elimination half-life of more than 40 hours, of all the following drugs EXCEPT:

• A. Flurazepam
• B. Chlordiazepoxide
• C. Clorazepate
• D. Diazepam

Answer 1

The Correct Option is A

To determine which drug does not have Desmethyl diazepam as an active metabolite, we need to understand the metabolic pathways of each option provided.

• Desmethyl diazepam is a common active metabolite for many benzodiazepines including Chlordiazepoxide, Clorazepate, and Diazepam. This metabolite is known for its long elimination half-life of more than 40 hours.
• Flurazepam, however, is metabolized differently. Its primary active metabolite is N-desalkylflurazepam, which is not the same as Desmethyl diazepam. 

Let's go through each drug to understand their metabolite formation:

1. Diazepam: Metabolized into Desmethyl diazepam (also known as Nordiazepam), Oxazepam, and Temazepam. It is confirmed to have Desmethyl diazepam as a metabolite.
2. Chlordiazepoxide: Metabolized into Nordiazepam (Desmethyl diazepam) and other metabolites. It also forms Desmethyl diazepam.
3. Clorazepate: It is essentially an inactive prodrug that is rapidly decarboxylated to form Desmethyl diazepam. Thus, it directly contributes to Desmethyl diazepam formation.
4. Flurazepam: Primarily metabolized to N-desalkylflurazepam, rather than Desmethyl diazepam.

Thus, the drug that does not use Desmethyl diazepam as an active metabolite is Flurazepam.

Conclusion: The correct answer is

Flurazepam

, because it is metabolized differently compared to the other options.