Efficacy of sildenafil citrate at 12 hours after dosing: re-exploring the therapeutic window.
OBJECTIVE
This open-label study investigated the efficacy of sildenafil citrate at 12 hours postdose among prior treatment responders.


METHODS
Eight 100-mg doses of sildenafil were provided to 40 eligible patients with erectile dysfunction (ED), who were to record the results of each sexual attempt in a patient diary. Each patient was instructed to make a sexual attempt at 1 and 12 hours postdose on 4 occasions (part 1) and only at 12 hours postdose on 4 subsequent occasions (part 2).


RESULTS
Of 40 enrolled patients, 34 (85%) completed the study. In these evaluable patients, 97% and 74% of patients achieved erections that resulted in successful intercourse at 1 hour and 12 hours postdose, respectively. There was a nonsignificant reduction in the percentage of responders at 12 hours during part 1 versus part 2 of this study (71% versus 78%).


CONCLUSIONS
This study demonstrates that, in the majority of these patients with ED, sildenafil remains clinically active 12 hours after administration. Larger studies may be necessary to confirm and clarify the therapeutic window of sildenafil.
Moncada
Ignacio
I
Urology Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain. imoncada@md.infonegocio.com
Jara
José
J
Subirá
David
D
Castaño
Irene
I
Hernández
Carlos
C
D000328:Adult; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D007172:Erectile Dysfunction / Q000188:drug therapy*; D006801:Humans; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D010879:Piperazines / Q000008:administration & dosage*; D011446:Prospective Studies; D011687:Purines; D000068677:Sildenafil Citrate; D013450:Sulfones; D013997:Time Factors; D016896:Treatment Outcome; D014665:Vasodilator Agents / Q000008:administration & dosage*
D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate