Absorption of effervescent paracetamol tablets relative to ordinary paracetamol tablets in healthy volunteers

Abstract

Objectives: The aim of this study was to compare the rate of absorption between ordinary paracetamol tablets and effervescent paracetamol tablets.

Methods: Twenty healthy volunteers participated in an open randomised crossover study and were given a 1000-mg dose of either ordinary paracetamol tablets (2 x 500 mg Panodil tablets, SmithKline Beecham) or effervescent paracetamol tablets (2 x 500 mg Pinex Brusetablett, Alpharma AS) with a 3-week washout period in between. Blood samples were collected for 3 h. Maximum serum concentration (Cmax) and the time to maximum serum concentration (tmax) were recorded and the area under the concentration versus time curve (AUC) was calculated.

Results: The mean tmax was significantly shorter when paracetamol effervescent tablets were taken (27 min) rather than ordinary paracetamol tablets (45 min) (P = 0.004). There was no significant difference between the mean Cmax of 143 micromol/l with effervescent tablets and that of 131 micromol/l with ordinary tablets. The mean AUC(0-3 h) was significantly higher with paracetamol effervescent tablets (223.8 micromol x h x l(-1)) than with ordinary tablets (198.2 micromol x h x l(-1); P = 0.003). After 15 min, 17 (85%) subjects in the effervescent group had a serum concentration of 70 micromol/l (lower therapeutic serum concentration) or higher relative to only 2 (10%) subjects in the ordinary tablet group (P = 0.001).

Conclusion: Paracetamol effervescent tablets are absorbed significantly faster than ordinary paracetamol. Thus, effervescent tablets might offer significantly faster pain relief when paracetamol is used.