Question

A patient on phenytoin is found to have a low blood phenytoin level. Of the following drugs, which is LEAST likely to cause this?

1) Non-compliance
2) Carbemazepime
3) Hypoalbuminemia
4) Disulfiram

Answer 1

Disulfiram is the LEAST likely to cause a low blood phenytoin level because it inhibits the metabolism of phenytoin, which would tend to increase or maintain the levels of phenytoin, rather than decrease it.

Step-by-step explanation:

The question is inquiring which of the listed factors is LEAST likely to cause a low blood phenytoin level in a patient. Phenytoin levels can be affected by various factors, including drug interactions, disease states, and compliance with the treatment regimen.Non-compliance to medication is a common reason for low levels of phenytoin in the blood as the medication is not taken as prescribed. Carbamazepine can induce the enzymes that metabolize phenytoin, leading to lower levels of phenytoin. Hypoalbuminemia can also affect levels because phenytoin is a drug that binds extensively to albumin, and the quantity of available albumin can alter the levels of phenytoin.However, disulfiram is known to inhibit the metabolism of phenytoin and would more likely increase or have no effect on phenytoin levels rather than decrease them. Therefore, disulfiram is the LEAST likely of the options given to cause a low blood phenytoin level.