Interaction Between Wellbutrin And Promethazine

Our pharmacist answers the latest question regarding an interaction between promethazine and Wellbutrin (buproprion).

Sep 28, 2017

Valerie asked

I am prescribed 150mg of Wellbutrin to take twice daily. I am also prescribed promethzine for insomnia. Is it dangerous to take even if I don't take the meds at the same time? Thank you!

Answer

There is some precaution when taking Wellbutrin (Buproprion) and promethazine together. Bupropion is well known to be associated with a dose-related risk of seizures, meaning that higher doses are more likely to cause seizures in people, especially people with a history of them or are at risk for them. Caution is recommended during concurrent use of other drugs that may lower the seizure threshold such as promethazine. In addition to this problem, both drugs are metabolized by the same metabolizing enzyme known as CYP2D6.

Co-administration of bupropion with medications that are metabolized by the CYP2D6 isoenzyme, such as promethazine, should be approached with caution since they may be cleared from the body at a slower rate. Dosage reductions of promethazine may be needed, particularly if chronic co-administration is anticipated. However, promethazine is typically only used for an acute period of time. During acute therapy with promethazine, it is advisable to initiate treatment with a low dose and slowly titrate if this combination must be used and the patient should be closely monitored.

Having said all this, I have seen many patients take both of these medications together will no ill effects.

A total daily dose of 300 mg of Wellbutrin is considered a mid-range dose and is not typically associated with causing seizures in healthy patients. The maximum daily dose of Wellbutrin is 450 mg. This interaction is purely precautionary based on the available data that we have. The fact that promethazine would be only for a short course, many practitioners would consider it OK to take both medications together in healthy patients with no history of seizure.

There are of course many other options to use if this interaction wants to be avoided all together. Some other possibilities for medications that could be used for nausea and vomiting are as follows:

  • ​Hydroxyzine
  • ​Meclizine
  • Ondansetron​​

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