Q. I have recently switched from 20 mg Prozac/day to 100 mg Serzone/day. I have been diagnosed as bipolar, rapid cycling for almost 20 years. My treatment has consisted of 1200 mg lithium and 20 mg Prozac for 16 years, and 20 mg Prozac for the last 4 years. I have been doing exceptionally well for the 4 years with Prozac only, but have changed to the Serzone due to reduced libido. I am very frightened that I am now at risk for a run of uncontrolled mania, or worse, a major depression. Am I insane to make this switch from Prozac to Serzone? What have your experiences been? FYI - I have been a self-mutilating, suicidal (4 hospitalizations), sex-crazed, ultra-depressed, supergirl, unmovable slug, and have triumphed over all through a combination of medications, exercise, positive self-help, and faith. I DO NOT want to sabotage my success for an increased sex drive. Let me know whether or not I am making a big mistake.

  A. If the libido means that much to you, I guess the change is appropriate if your doctor has okayed it. You need to know, that I have never had Serzone work in your type of illness below 500 mg at bedtime. If you have any obsessive-compulsive disorder symptoms, Serzone is a very poor choice statistically.

You may wish to consider Effexor XR. Once you get the dosage at or above 300 mg daily, it has a tendency to impact less on libido than Prozac or the SRIs. Our trial with Effexor showed an average dosage of about 375 mg per day.