Switching From an SSRI to Tiagabine(GABITRIL) in Order to Alleviate SSRI Induced Sexual Dysfunction

Overview

Anxious patients are now treated with Selective Serotonin Reuptake Inhibitor medications (common antidepressants) which elevate serotonin and thus alleviate anxiety. These medications have clearly proven efficacy upwards of 70% for many anxiety disorders. In regards to tolerability, they have a major problem in that they often produce sexual dysfunction in men and women (ie. decreased libido, anorgasmia, impotence) upwards of 30% of the time. Benzodiazepine anxiolytics are also FDA approved to treat anxiety with equal efficacy and greater tolerability (very little, if any sexual dysfunction). They do, however, carry a substantial risk for addiction. Tiagabine is a Selective GABA Reuptake Inhibitor (SGRI) that is FDA approved to treat certain types of epilepsy. Like benzodiazepines, Tiagabine also increases the neurotransmitter, GABA, in the brain and is thought to alleviate anxiety (see references below) this way too, but without any addiction risk common to Valium-type drugs. The safety profile of Tiagabine is thought to be much safer. Two double blind studies are ongoing which are looking at Tiagabine's effectiveness in PTSD and GAD. There are many open label studies showing anxiety reduction and many psychiatrists in clinical practice are utilizing this agent as an anxiety treatment in an off-label manner. This study is designed to evaluate anxious patients who are taking SSRI medication, have had a reasonable response, but are experiencing significant sexual side effects which are pushing them towards noncompliance and possible relapse into anxiety. 30 subjects (15 men and 15 women) will be asked to join the study and be placed on Tiagabine as well as their current SSRI. Once an acceptable dose of Tiagabine is reached in the first four weeks, the subjects' SSRIs will be slowly stopped. Two weeks after enrollment, all subjects will be called in order to check for any side effects to the study drug and to insure that each subject is titrating to the proper dose of study drug according to the study protocol. An open-label, non-placebo prospective 10 week follow up will occur, where the now Tiagabine monotherapy subjects will be followed to see primarily if their sexual dysfunction improves and if there anxiety remains controlled.

This is an open-label (no placebo) study to see if a change from SSRI to Tiagabine may alleviate sexual dysfunction while maintaining subject in a non-anxious state. 30 Subjects ( at least 50% female) will currently be taking a single SSRI for at least 4 weeks and report at least a 50% drop in their anxiety severity as a result. They must also report a chronological emergence of sexual dysfunction ( decreased sex drive, arousal, lubrication, or onset of impotence, anorgasmia or delayed ejaculation) following the SSRI initiation. Subjects will complete consenting process and attend a screening visit where they will be given a MINI psychiatric diagnostic evaluation to confirm anxiety disorder, be given a Hamilton Anxiety and a Hospital Anxiety \& Depression Scale evaluation to delineate current anxiety level (secondary measure). They will also complete self rated sexual health scales such as the ASEX to assess sexual functioning (primary measure). Subjects will undergo a brief physical exam and bloodwork will be ordered if the patient has an underlying medical condition that warrants this type of medical clearance. The same would hold true if an EKG is needed. Neither SSRIs, nor tiagabine warrants blood monitoring or EKGs per the FDA. Assuming subject meets eligibility, they will start titrating upwards as tolerated on tiagabine and downwards on their SSRI. Titration with Tiagabine is flexible but typically starts at the night of Day 1: 4 mg/day (2mg qAm with breakfast and 2mq qHS before bedtime with a snack for five days). On day 6: 8mg/day (2mg with breakfast and 6mg before bedtime with a snack). Day 13: 12mg/day in split doses: (4mg am with breakfast and 8mg before bedtime with a snack). Two weeks after enrollment, all subjects will be called in order to check for any side effects to the study drug and to insure that each subject is titrating to the proper dose of study drug according to the study protocol. At the discretion of the investigator, dosing may be lowered to alleviate side effects. Vist 2 will occur at the end of week 4 when all SSRI is off and optimal tiagabine is in place. All scales except MINI will be completed. Vist 3 will occur at the end of week 8 and scales will be completed. Visit 4 will be the final visit at end of week 14, scales, PE and blood/EKG collected as warranted. The efficacy and safety of Tiagabine will be evaluated throughout the treatment period (see flow chart). At the end of the study, subjects may opt to continue tiagabine or be titrated back to their SSRI. Our team will also liaison with the subject's prescriber to ensure follow up and continuity of care after study exit.