A COMPARATIVE STUDY OF INTRAMUSCULAR ACETAMINOPHEN VERSUS INTRAMUSCULAR PENTAZOCINE AS LABOUR ANALGESIA IN ZARIA, NORTHWESTERN NIGERIA

Intramuscular pentazocine is a common labour analgesic in Zaria, Nigeria due to its low cost and availability. Though also cheap and readily available the use of intramuscular acetaminophen is not popular and hence the need for a comparative study. To compare the efficacy of intramuscular acetaminophen versus intramuscular pentazocine on women in labour as well as the effects of both drugs on APGAR scores of their newborn. A randomized, comparative study was conducted on 188 eligible, parturients from June to September, 2013. The subjects were selected during antenatal classes and early active labour, counseled, taught about the pain scoring systems after obtaining written consent from them. Randomization was done using the WINPEPI software by Abrahamson in order for each woman in labour to receive either intramuscular acetaminophen 15mg/kg stat or pentazocine 1mg/kg at cervical dilatation of 4-6cm. The data obtained included the patients demographics, hourly pain scores, APGAR scores, patients' satisfaction and side effects. The mean age was 28.1years ± SD 5.2years. The majority of the subjects (53.5%) were Hausa-Fulani and 70.1% were muslims; 64% were booked for antenatal care while 58.5% had received secondary school education. The average duration of labour was 5.4hours. Acetaminophen was administered to 91(48%) subjects while pentazocine was administered to 97(52%). Sixty-nine percent and 80% experienced adequate pain relief in the acetaminophen and pentazocine groups respectively at one hour. The pain scores was statistically significant at one hour but comparable in both groups afterwards: p=0.01, 0.52, 0.338 and 0.389 at 1(st), 2(nd), 3(rd) and 4(th) hours on the linear/visual analogue scale and comparable on the verbal rating scale. There was no difference in the 1(st) and 5(th) minute APGAR scores of the babies delivered (p=0.24 and 0.63 respectively). Patients' satisfaction was comparable but the pentazocine group experienced more side effects. Intramuscular acetaminophen gave comparable labour analgesia with fewer side effects when compared with pentazocine.