Related Experiment Video
Updated: Aug 29, 2026

Acupoint Application Combined with Acupoint Massage for Treating Constipation in a Patient with Chronic Obstructive Pulmonary Disease
Published on: August 18, 2023
Non-steroidal anti-inflammatory drugs antagonise the constipating effects of tramadol
Eulalia Planas1, Raquel Poveda, Silvia Sánchez
1Department of Pharmacology, Barcelona University School of Odontology, Barcelona, Spain.
Abstract:
We report an antagonistic interaction between tramadol and non-steroidal anti-inflammatory drugs (NSAIDs), on gastrointestinal transit in rats. Transit was evaluated with charcoal and results are expressed as %inhibition. Tramadol and morphine had ED(50)s of 120.70+/-9.54 and 3.20+/-0.26 mg/kg, respectively, while metamizol (85 mg/kg), paracetamol (100 mg/kg) or ibuprofen (50 mg/kg) had no effect. All combinations of tramadol plus an NSAID, resulted in a rightward, non-parallel shift of the curves, which showed (two-way analysis of variance, ANOVA) significant differences from tramadol alone for the dose (P<0.0001), the drug (P<0.0001) and their interaction (P<0.0001), demonstrating antagonism. No interaction was present for morphine plus NSAIDs. The results demonstrate that NSAIDs antagonise the constipating effects of tramadol in rats, a fact that could have clinical relevance when combinations of these drugs are used in pain management in humans.
Related Concept Videos
Drugs Affecting GI Tract Motility: Opioids as Antidiarrheal Agents
Opioids, widely used antidiarrheal agents, mitigate diarrhea by slowing down...
Drugs for Treatment of Constipation-Predominant IBS
Drugs for Treatment of Diarrhea-Predominant IBS
Two specific drugs used in the treatment are alosetron (Lotronex) and eluxadoline (Viberzi). Alosetron, a 5-HT3 antagonist, works by slowing the movement of stools in the gut, reducing bowel...
Drugs for Treatment of Ulcerative Colitis in IBD
Drugs Affecting GI Tract Motility: Adsorbents as Antidiarrheal Agents
Adsorbents...
Drugs Affecting GI Tract Motility: Serotonin Receptor Agonists