Information on Ecstasy and Ritonavir interaction

Some time ago New Scientist magazine published an interesting article, called Deadly combination, about the adverse interaction between Ecstasy and the HIV drug Ritonavir.

Author David Concar writes: "Ritonavir is designed to inhibit HIV's protease enzyme, but it also interferes with a liver enzyme called CYP2D6 that metabolises MDMA. Thus someone who took both drugs could have problems clearing MDMA from their bloodstream."

Concar goes on to discuss the fact that Abbott Laboratories, the Chicago-based drugs company that makes Ritonavir, had not, at the time that the article was written, issued a warning about the interaction between the two drugs despite being aware of the possible problems.

There are further interesting comments in the 'Reading and Reflections' for this article (a section on the New Scientist site where authors of articles can add further information to their pieces), especially regarding interaction between MDMA and Prozac, which is covered later in the article.
These additional comments are reprinted below as they can be hard to find on the New Scientist site:

Dangerous cocktails by David Concar

"Researching this article was a frustrating business because very little scientific work has been done on the interactions between prescribed and recreational drugs. For the most part, doctors are having to pick up what they can by monitoring their own patients. At the City Hospital in Edinburgh, for example, Ray Brettle and his colleagues have found that AIDS patients who take opiates such as methadone and heroin need only half the normal dose of Zidovudine (AZT). And yet using a half-dose is not standard practice, says Brettle - and the manufacturers have not issued a warning. Indeed, I could find only one pharmacologist who has systematically investigated a range of interactions between medically-prescribed drugs and recreational drugs - Katherine (Kit) Bonson.

Bonson's interest in these interactions developed a few years ago while she was working at the National Institute of Mental Health in Bethesda, Maryland. She now works at the National Institute on Drug Abuse.

So far, Kit Bonson has published two studies on the interactions between hallucinogens and antidepressants. Other studies (on psilocybin and MDMA) will be published soon.

Kit would like to hear from people who have experienced interactions between prescribed and recreational drugs and can be contacted by email: kbonson@codon.nih.gov

On reading the New Scientist article Kit raised some important points which arrived too late to include in the magazine. In particular, she questions the idea that mixing Prozac and MDMA could lead to an overdose:

"In the many people I have interviewed about their experience with MDMA and Prozac, none of them indicated that there was an *increase* in their response. Everyone either said it decreased their response to MDMA or it did not change it. Thus, people are not taking it to "modify or enhance" the experience per se. Also, the way people are mixing Prozac and MDMA is to take the Prozac acutely (one time), either before or after the MDMA experience, not typically as part of a daily regimen as if it was for antidepressant effects."

Kit also points out that is "more of a concern that people might mix MDMA with an MAO inhibitor (another antidepressant), because people have actually had hypertensive crises which could have led to death if they hadn't received immediate medical care. Manufacturers of MAOIs distinctly discourage the combination of their drug with any stimulant."