Methadone interaction with Clairithromycin

Question

As I understand Methadone is broken down by an enzyme which is greatly retarded by Clairithromycin, this ay cause an overdose to occur in the user.
I have been taking Methadone for 5 years now (was at 180mg/day now at 10mg/day) can I safely take the Clairithromycin?

This discussion is related to Methadone and Biaxin.

caregiver222 · Answer

The specific enzyme is CYP 450 enzyme is 3A4. One must remember that naltraxane or naltraxone hydrochloride are specific drugs that can reverse opiate intoxication and restore respiratory function.

caregiver222 · Answer

What you are talking about are the so-called superenzymes CYP 450 series, heme proteins and catalysts, produced in the liver. If you have been taking the combination together for a long time there is no risk of overdose. The problem with certain drugs is that they reduce the ability of the body to metabolize the drug, usually by oxidation but in some cases by reduction. This, initially the drug does not completely metabolize and has an extended half-life. This why it is dangerous to take grapefruit juice with certain medications. Follow me on this. You take a substance that reduces the production of these enzymes (say grapefruit juice) and for the first four hours the drug does not fully metabolize. After six hours the grapefruit juice wears off, the liver again starts producing these enzymes, and you take a second dose of the medication. Now the blood levels rise above the therapeutic level because you are metabolizing the portion taken four hours ago added to the portion you are taking in the second dose. In the case of opiates this means that there will be an increased risk of respiratory depression. Codeine is one of these drugs because the CYP 450 enzymes are necessary to change it into morphine. Lone-term users of opiates have an increased tolerance for higher doses and the chances are that you would stop breathing are very slim.