Pharmaceutical formulations containing a serotonin reuptake inhibitor and a smooth muscle relaxant are provided for the treatment of premature ejaculation and the increase in intravaginal ejaculatory latency time. Specific formulations contain tadalafil (1-30 mg per dose) or tamsulosin (0.05-2 mg) and escitalopram (1-30 mg) in daily dose and on-demand formulations.