EFFECTIVENESS OF GLYCERYL TRINITRATE TRANSDERMAL PATCH IN PRETERM LABOUR: A PROSPECTIVE STUDY

OBJECTIVE: To assess the effectiveness and safety of Glyceryl trinitrate transdermal patch, a nitric oxide donor in the treatment of preterm labor and fetomaternal outcome. METHODS: A prospective study was conducted in the department of obstetrics and gynecology, Karnataka institute of medical sciences, Hubli, from June 2008 to May 2009. Sixty pregnant women at 28-34 weeks of gestation were recruited after they met the inclusion criteria. Fifty out of sixty pregnant women completed treatment and ten patients did not come for follow-up or refused to continue. Patients diagnosed with pre-term labor were given glyceryl trinitrate (GTN) 10 mg/24 hours transdermal patch which was applied on the anterior abdominal wall. The second patch of same dose was given after 24 hours. Arrest of labor, prolongation of pregnancy in days or weeks along with side effects were monitored. Patients were followed till delivery to know the feto-maternal outcome. RESULTS: Prolongation of gestational age by more than 48 hours was seen in 45 patients (90%) out of 50. Five patients delivered within 48hours which was considered as treatment failure. Mean prolongation of gestation was 23.8+/-15.5 days. Maximum prolongation of gestation was 40 days. The average birth weight is 2.1 kgs. In the present study headache was the most common side effect observed in 14 (28%) patients, tachycardia in 6 (12%) patients and hypotension in 3 (6%) patients. CONCLUSION: Glyceryl trinitrate transdermal patch appear to be a safe, well tolerated, and noninvasive method of suppressing uterine contractions in preterm labor. Headache was the most common maternal side effect noticed. However, before its widespread use can be recommended, large double blind multicenter trials are needed to assess optimal dosage, dosage regimes, overall efficacy and fetal safety.