Onset of analgesia of a paracetamol tablet containing sodium bicarbonate: A double-blind, placebo-controlled study in adult patients with acute sore throat

Objective:The aim of this study was to determine the time to onset of pain relief from a single dose of a tablet formulation of paracetamol (acetaminophen) containing sodium bicarbonate (PSC).Methods:A single oral dose of PSC or placebo was randomly administered to patients with acute sore throat under double-blind conditions. Patients rated their pain relief using a conventional categorical relief scale every 5 minutes during the first hour postdose to determine the time to onset of pain relief. They continued evaluations of pain relief at less frequent intervals to 6 hours postdose to confirm the overall analgesia of PSC compared with placebo. To determine if food had any effect on the onset of action of PSC, time to onset of analgesia by PSC was compared between patients in the fed and fasted states. Patients were randomized 3:1 to PSC:placebo based on whether they had eaten food within 2 hours of baseline. Adverse events were recorded by questioning throughout the study period.Results:A total of 241 patients were enrolled. Both treatment groups were well matched for age (mean, 20 years), sex (male:female ratio, ∼1:1.5), sore throat duration (mean, 3 days) and severity (mean score, 8). PSC separated significantly from placebo beginning at 15 minutes postdose (P ≤ 0.03). There was no difference for onset of analgesia between PSC in the fed and fasted states. PSC showed significantly greater total pain relief over 30 minutes, 1 hour, and 6 hours compared with placebo (all, P < 0.05). Both treatments were well tolerated and there were no serious adverse events.Conclusion:PSC was effective beginning 15 minutes postdose and well tolerated compared with placebo in this population of adults with acute onset of sore throat pain.