Transdermal nitroglycerine in the management of pain associated with primary dysmenorrhoea: a multinational pilot study. The Transdermal Nitroglycerine/Dysmenorrhoea Study Group.

Endogenous nitric oxide mediates smooth-muscle relaxation with subsequent vasodilatation in the vascular, pulmonary, gastrointestinal and genitourinary tissues. Transdermal nitroglycerine (a nitric oxide donor) has been found effective in inhibiting uterine contractility during premature labour. Sixty-five women with histories of moderate-to-severe pain associated with menses were treated with nitroglycerine patches that delivered 0.2 or 0.1 mg/h. Patches were applied as necessary during the first 3 days of the menstrual cycle for up to three consecutive cycles. Pain intensity was assessed at baseline and at 30 min and at 1, 2 and 4 h after patch application. Most patients obtained pain relief with the first dose of the first day. Pain relief was satisfactory to excellent in 90% of the patients. Headache was reported by 20% of the patients, most often in patients using two consecutive patches. A randomized, double-blind, placebo-controlled study is underway in an attempt to confirm the above findings.