Nothing is simple when you’re HIV positive. Though many meds are now available for treating depression, HIVers must take special care when adding any drug to an already-complex regimen. And drug interactions aren’t the only concern: Lifestyle factors such as stress, drinking and recreational drug use, and intake of herbs and supplements can all influence the effectiveness and side effects of antidepressants.

Matt Harrison (name changed), an HIV positive ad exec in New York City, is a veteran of depression battles. Since he’d previously vanquished the blues with the help of Paxil (a drug in the SSRI class—see chart on page 59), his HIV doctor thought it was the obvious choice when Harrison recently began slipping back into the pits. At first, Harrison resisted—the drug had knocked down his sex drive and potency—but the doc said he could switch after a month to the less-libido-lowering Serzone. While Paxil worked as a stopgap, Harrison worried that the Serzone would mess with his four-drug HAART regimen. Indeed, the switch—and, Harrison believes, his stress-filled days of late nights and lots of coffee, booze and sugar—resulted in a manic episode that (among other disruptions) wreaked havoc with his HIV-med schedule.

Since drug interactions often hinge on uncontrollable factors ranging from genetic makeup to liver function, it’s often hard to guess which meds make a good match. There are no hard and fast rules. “Virtually all antidepressants can be used with antiretrovirals,” says Phil Bialer, MD, founder of the AIDS psychiatry program at Beth Israel Medical Center in New York City, “but you have to monitor closely for safety.” Harrison found that consulting with an HIV-savvy psychopharmacologist was well worth the cost. Suspecting that the interaction between Serzone and his HIV meds was one element of his problem, she substituted Wellbutrin, which, for Harrison, lived up to its name.

In the interaction stakes, ritonavir (Norvir) leads the antiretroviral pack, followed by Crixivan (indinavir), and some HIVers have problems with other HIV meds. So for everyone on HAART.

Dan Karasic, MD, associate clinical professor of psychiatry at the University of California at San Francisco, suggests reducing the normal starting dose of an antidepressant by one-half to two-thirds and then gradually raising it until reaching an effective level. “Ritonavir can increase blood levels of SSRIs by triple or more,” Karasic says, explaining that this may increase side effects but is not dangerous. However, with tricyclic antidepressants, an overdose can cause heart problems, so more caution is needed. Karasic discourages using Wellbutrin with ritonavir since the resulting elevated Wellbutrin can cause seizures.

During the first few weeks on any antidepressant, be alert for new symptoms. With SSRIs (such as Prozac, Zoloft and Paxil), mild diarrhea, nausea, light-headedness and even minor hallucinations are not out of the ordinary, especially in the first few days when the body is reacting to its new brain chemistry. But if during the first month you experience extreme anxiety, uncomfortable “speediness,” panic, severe diarrhea or worsening of side effects from other meds, contact your doctor. “It’s really important to learn how to identify possible side effects,” Harrison says of his own manic moment. Knowing that he had recently started Serzone, he was able to recognize that the elation, sped-up speech and inappropriate reactions were a drug effect, and to seek help.

Bialer says that although there are often adjustment problems, a review of his patients’ charts showed that 89 percent were able to successfully take antidepressants with their AIDS meds. For sexual side effects, Bialer sometimes adds Viagra, though the dose must be lowered for people taking protease inhibitors, particularly ritonavir and Crixivan, to avoid potentially dangerous effects on the heart.

Choosing a first antidepressant for someone on HAART is tricky. Bialer recommends either Effexor or Celexa, which cause fewer interaction problems and overall side effects than other selections. However, both drugs can also produce sexual dysfunction. Karasic stresses the importance of doctor-patient communication. For many HIVers, he says, potential interactions may be less important than whether a drug tends to depress libido, cause insomnia or spark weight loss. Ultimately, as with the decision about antiretrovirals, it’s up to you to do your own risk/benefit calculus.