Bristol-Myers Squibb Co., manufacturer of the antidepressant Serzone, is now being required by the U.S. Food and Drug Administration to include a black box warning label advising patients that a rare, but possibly life-threatening liver failure may occur to patients using the drug. The black box designation refers to the fact that it is set off from the text by a black outline. This designation is reserved for the most serious side-effects.
Just how rare is "rare"? The FDA reports one case of liver failure per every 250,000 to 300,000 patient-years. The total patient-years is a summation of each patient's duration of exposure expressed in years. For example, 1 patient-year is equal to 2 patients each treated for 6 months, 3 patients each treated for 4 months, etc. The warning further states: "This represents a rate of about 3-4 times the estimated background rate of liver failure. This rate is an underestimate because of underreporting, and the true risk could be considerably greater than this."
Liver effects range from asymptomatic reversible increases in serum transaminase to cases of liver failure resulting in transplant or death.
Patients who currently have liver disease or elevated baseline serum transaminase should not use Serzone. The existing abnormalities make it difficult to monitor for drug-induced changes in function.
Patients taking Serzone who develop any signs of liver dysfunction should report them to their doctor immediately. These signs include:
- Yellowing of the skin or the whites of the eyes (jaundice),
- Unusually dark urine,
- Loss of appetite that lasts several days or longer,
- Nausea,
- Or abdominal pain.
In addition to patient self-monitoring, physicians may order periodic liver function testing. Testing has not been shown to prevent serious injury, but it is believed that early detection of injury along with immediate withdrawal of the drug enhances the likelihood of recovery.
Serzone, generically known as nefazodone, is considered an important drug alternative in the treatment of depression because of the fact that it does not cause sexual side-effects as frequently as the popular class of drugs called SSRIs. One alternative for patients who are concerned about sexual side-effects is the antidepressant Wellbutrin (bupropion).
