I've read that methadone is a fat-soluble medication, and I take 95mg/day.  Will alli decrease my absorption of methadone, and if so, what is the remedy?  Increasing my methadone dose?

Hi macarter1981,

There are no known interaction between Alli and methadone.  Methadone is water soluble so its absorption and effect will not be blocked when taken with orlistat.

Hope this helps.

Sophia De Monte RPh

I see that methadone is water soluble, but am reading that it's very lipophilic and is so long-acting because it is stored in fat around the body.  It is also excreted in the feces.  I take one daily dose of methadone in the morning, and it barely lasts all day as it is.  I really want to try alli because I've gained 40 lbs after having my baby last year, but was afraid that it will decrease the efficacy of my methadone.  Are you sure that alli will not have an effect on methadone? 

Hi macarter1981,

Alli should not interfere with the effect of methadone. The concern you raise is valid, but it is not an interaction with orlistat (the active ingredient in Alli) but the loss of body fat which comes with weight loss. Its excretion by the bowel is not a problem, 2 different mechanisms, Alli works and passing through the gut whereas methadone is metabolised by the liver and then it is eliminated. You need to check with your physician who will more closely  monitor your dosage or may suggest the immediate release product if you are not getting the control you require.

Hope this helps ans Best of Health.

Sophia De Monte RPh

Thanks for your reply... I spoke with my doctor and pharmacist as well, and they agree that alli shouldn't reduce my methadone efficacy.  I bought a starter pack this morning, and can't wait to get started.  :)