Posted by J.J. Starbuck on September 14, 2000, at 17:53:31
Would the combination of an MAOI (phenelzine) and gabapentin increase the likelihood of side effects related to the central nervous system from either the gabapentin or the MAOI? I'm most concerned about things like depression, mood lability, anger or irritability, thought disturbances, etc.
For the last 5 months, I have been on an MAOI (phenelzine) at 75mg per day, which is very close to the maximum recommended daily dose of 90mg per day. (In fact, I was on 90mg for over a year before that).
For that entire period, I have also been taking gabapentin (600mg at bedtime) to relieve insomnia caused by the phenelzine.
I can find no mention of an interaction between the two listed in the PDR, but I suspect that this may be due to the fact that MAOI's aren't widely used anymore, and I doubt whether the FDA would require the testing of anything but the most common drug combinations.
I couldn't find anything in MEDLINE either, but again, that could be due to the infrequent use of MAOI's (and that most people taking them are on lower dosages, so side effects from the combination wouldn't be as likely to show up).
I know both drugs are categorized as CNS depressants.
Also, (based on what I've read), it seems that gabapentin can indirectly affect the availability of dopamine by enhancing the production of GABA in the brain, and I believe that MAOI inhibitors can also affect the availability of dopamine as well as other neurotransmitters such as serotonin.
poster:J.J. Starbuck
thread:44824
URL: http://www.dr-bob.org/babble/20000905/msgs/44824.html