Objective: To evaluate the efficacy, tolerability, and treatment satisfaction after initiating treatment with sildenafil 50 mg and later titrating to 100 mg, compared with continuing treatment with sildenafil 50 mg, in men with erectile dysfunction (ED).
Patients and methods: A multicentre, parallel-group trial was conducted in two 4-week periods. In period 1, patients received 50-mg doses of sildenafil single-blinded for 4 weeks. In period 2, patients were randomized to double-blind, placebo-controlled treatment with sildenafil 50 mg or sildenafil 100 mg for 4 weeks. All patients were aged >or=18 years with a documented clinical diagnosis of ED (score of <or=25 on the International Index of Erectile Function, IIEF, Erectile Function, EF, domain), and met the prescribing criteria for sildenafil 50 mg and 100 mg.
Results: Of 492 enrolled patients (mean age 53 years, SD 11), 476 (97%) completed period 1 and 473 (96%) completed period 2. Patients receiving sildenafil 50 mg in period 1 had an increase in the mean (SD) baseline EF domain score from 12.8 (5.2) to 22.5 (6.6) (P < 0.001), and improved scores on the Quality of Erection Questionnaire (QEQ) and Sexual Experience Questionnaire (SEX-Q). The IIEF EF domain scores were similar in the two groups at baseline and randomization. Patients titrated to the 100-mg dose (237 men) showed a significantly greater improvement than those who continued on the 50-mg dose (240; P < 0.001). There was a significant increase in QEQ and SEX-Q scores in patients titrated to sildenafil 100 mg compared with patients continuing at sildenafil 50 mg. At either sildenafil dose, headache, flushing and hot flushes were the most common adverse events. Neither the frequency nor the severity of adverse events increased with titration to sildenafil 100 mg.
Conclusions: After initial treatment with sildenafil 50 mg, patients titrated to 100 mg showed further increases in efficacy and satisfaction with no increase in the number or severity of adverse events than in those remaining on the starting dose.