Pentazocine pretreatment suppresses fentanyl-induced cough

This study evaluated the effect of pentazocine pretreatment on fentanyl-induced cough. With ethics committee approval, 277 ASA I-II patients, aged between 19 and 63 years, undergoing various elective surgeries during general anesthesia, were enrolled in this prospective, randomized, double-blind, placebo-controlled clinical trial. All patients were randomly assigned to one of three groups. Group I (n = 92) and Group II (n = 93) received normal saline, while Group III (n = 92) received pentazocine 0.5 mg kg–1 5 min prior to receiving fentanyl, Patients belonging to Groups II and III were administered 2 µg/kg fentanyl intravenously over 2 s after the first injection; Group I served as a negative control for fentanyl. Physiologic indicators such as heart rate (HR), non-invasive blood pressure (NBP) and pulse oximetry oxygen saturation (SpO2) of patients were recorded before giving pentazocine or normal saline 1 minute after fentanyl injections. The incidence of cough was recorded and graded as mild (1–2), moderate (3–5) and severe (> 5), depending on the number of coughs observed [13]. The incidence of cough was 0%, 22.6% and 4.3% in Group I, Group II and Group III, respectively. There was no significant difference in SpO2 for the duration of the trial among the three groups. Premedication with intravenous pentazocine can minimize the incidence of fentanyl-induced cough and has no influence on blood pressure, heart rate, and SpO2 compared with Group II.