TC-5214 as Augmentation Therapy in Patients With Refractory Hypertension

12 subjects with refractory hypertension will be randomized in a double-blind fashion to receive single escalating doses of study medication in-clinic: on Day 1 (1mg), Day 8 (2mg), Day 15 (4mg) and Day 22 (8mg). On each of these 4 days, 10 subjects will receive TC-5214, and 2 subjects will receive placebo. Placebo treatments will be pooled across the 4 days of single-dose to produce an equivalent reference cohort (n = 8) for each treatment dose (n=10). Following the single-dose administration of 8mg in the clinic on Day 22, subjects will continue with two weeks (Days 23 - 35) of outpatient self-administration of TC-5214 (4mg BID; n = 6), or matching placebo (BID; n = 6). On Day 36, subjects will return for a final in-clinic dose of either TC-5214 (4mg, n = 6) or placebo (n = 6). There will be a 1-week follow-up period at the end of the treatment period.