The objective of this study was to assess the potential of phentolamine as a treatment of postmenopausal women with female arousal disorder (FSAD). Vaginal photoplethismography and a subjective questionnaire were used. Forty one women were enrolled and four treatments were tested: vaginal solutions 5 mg and 40 mg and an oral tablet each of 40 mg of phentolamine and placebo. Physiological readings were significantly different from placebo in the women using hormone replacement therapy (HRT) with 40 mg of phentolamine in vaginal solution (p = 0.0186). Subjective reports also were significantly different from placebo with the vaginal solution 40 mg and the oral tablet of 40 mg of phentolamine among hormone replacement users. No significant differences were found among women not receiving HRT. Results indicate that phentolamine may show promise as treatment for FSAD in estrogenized postmenopausal women.

Combination therapy for erectile dysfunction: a randomized, double blind, unblinded active-controlled, cross-over study of the pharmacodynamics and safety of combined oral formulations of apomorphine hydrochloride, phentolamine mesylate and papaverine hydrochloride in men with moderate to severe erectile dysfunction Oral therapy has become first line treatment for patients with mild to moderate erectile dysfunction (ED). Studies have shown that sildenafil may not be effective in all patients, and has been associated with a variety of adverse effects and an adverse interaction with nitrates and inhibitors of cytochrome P450 enzymes. The objective was to compare the efficacy and safety of three different oral combinations with the highest dose of sildenafil in men with moderate to severe ED. Randomized, double blind, unblinded active-controlled, Phase II study was carried out at three sites in Mexico. After a 4-week placebo run-in period, patients received all four of the following treatments using a 4-way cross-over design: 40 mg phentolamine (PM) þ 6 mg apomorphine (Apo); 40 mg PM þ 150 mg papaverine (Pap); 40 mg PM þ 6 mg Apo þ 150 mg Pap (Tricombo); 100 mg sildenafil (SC). With the exception of sildenafil tablets, all study medication was blinded. Moderate to severe ED was defined as a less than 50% vaginal penetration success rate during the placebo run-in period. A total of 44 patients were enrolled, of whom 36 completed all four treatment periods. All treatments produced a significant effect in primary efficacy variable (Sexual Encounter Profile) compared to baseline, however, no statistically significant differences were found between treatments. A significant period effect was observed. Also, the four treatments were found not to differ significantly in five out of six secondary efficacy variables. The lowest incidence of treatment-related adverse events (AE) occurred in the 40 mg PM þ 6 mg Apo group (9.8%), followed by 100 mg SC (15%), and the other two combinations (16.7 and 17.5%, respectively). Nasocongestion and headache were the most frequently reported AE. An oral combination of vasoactive agents may provide an alternative approach to sildenafil. Based on these results a combination of phentolamine and apomorphine warrants further clinical investigation.