Posted by Sunnely on March 17, 2001, at 0:19:08
In reply to Re: Serzone, posted by isomac on March 16, 2001, at 17:14:25
Hi Isomac,
Indeed there is a potential drug-drug interaction between nefazodone (Serzone) and atorvastatin (Lipitor). This interaction is via drug metabolism (liver) of Lipitor. Lipitor is mainly metabolized (broken down) by the liver enzyme called CYP3A4. Serzone is a potent inhibitor of the action of this enzyme. Serzone slows it (CYP3A4) down, in turn slowing down the break down of Lipitor. In turn, this leads to Lipitor accumulating in the blood which in turn can lead to increase in side effects and toxicity including muscle aches, weakness, muscle damage and even kidney failure (due to massive muscle cells breaking down). If you must take the two drugs in combination for medical and psych reasons, your doctor may need to lower the dose of Lipitor to adjust for the expected rise in its blood level. (Not an exact method.)
Incidentally, like Serzone, there are other drugs that are considered potent inhibitors of this liver enzyme and therefore expected to raise the blood level of Lipitor. These drugs include (not complete list) erythromycin, ketoconazole (Nizoral), itraconazole (Sporanox), azithromycin (Zithromax), clarithromycin (Biaxin), cimetidine (Tagamet), diltiazem (Cardizem, Tiazac), nifedipine (Procardia), and the protease inhibitors (for HIV) such as indinavir (Crixivan), nelfinavir (Viracept), and ritonavir (Norvir). BTW, you should also avoid drinking grapefruit juice for the same reason.
On the opposite side, there are drugs (fortunately, not that many) that induce the action of this liver enzyme leading to a reduction in the blood level of Lipitor. They include carbamazepine (Tegretol), phenytoin (Dilantin), phenobarbital, and rifampin (Rifadin). BTW, might as well include St. John's Wort to this list, for the same reason.
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> I recently stopped taking Serzone because the drug interaction section of the DrKoop web site cautioned against a severe drug reaction to Lipitor, which I also take. I have been off Serzone for three weeks now (replaced with Wellbutrin), and my depression is back worse than ever.
>
> Anybody hear of this potential reaction (Serzone & Lipitor), or have experience with it? I'd like to get back on Serzone ASAP!
poster:Sunnely
thread:381
URL: http://www.dr-bob.org/babble/20010310/msgs/56724.html