Analgesic Effect of Paracetamol, Paracetamol + Codeine, Ibuprofen and Their Combination

Pain, Postoperative Clinical Trial

Official title: Analgesic Effect of Ibuprofen 400 mg/Paracetamol 1000 mg, Ibuprofen 400 mg/ Paracetamol 1000 mg/60 mg Codeine, and Paracetamol 1000 mg/Codeine 60 mg: A Single-dose, Randomized, Placebo-controlled and Double-blind Study

Status Completed

Clinical Trial Summary

The purpose of this study is to determine whether the combination of paracetamol (acetaminophen) and other NSAIDs with or without weak opioids can give synergistic analgesic effect.

Clinical Trial Description

Combining paracetamol and other NSAIDs could give a theoretical synergistic analgesic effect according to already known or assumed mechanisms of action. Synergism is defined as an additive or supra-additive effect not achieved by one of the drugs alone. Such synergism is shown in clinical studies between acetaminophen and naproxen in coxarthrosis and rheumatoid arthritis. Later, a significant additive effect of 100 mg diclofenac with 1 g acetaminophen was demonstrated in a dental pain model.

One review article conclude that acetaminophen and NSAIDs may be appropriate to combine, and the combination is superior to acetaminophen, but not to NSAIDs alone. This view is contested by another review article which concludes that paracetamol may enhance the analgesic effect when added to an NSAID. In both reviews the authors also state that the clinical trials are too few, with different drug formulations, and different pain models not allowing definite conclusions.

There seems to be a need for studies investigating the potential synergistic effects of paracetamol combined with another NSAID displaying similar pharmacokinetic characteristics. To the best of our knowledge no published study has investigated the analgesic effect of the combination of ibuprofen and paracetamol, ibuprofen and paracetamol + codeine versus placebo (i.e. negative control to adjust for possible analgesic placebo effects) and the best standard analgesic treatment (i.e. paracetamol + codeine) as a positive control group. ;

Study Design

Allocation: Randomized, Endpoint Classification: Pharmacodynamics Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Pain, Postoperative

• NCT number: NCT00921700
• Study type: Interventional
• Source: Oslo University Hospital
• Status: Completed
• Phase: Phase 4
• Start date: June 2009
• Completion date: April 2015