Critical
Acetylsalicylic acid × Ketorolac
Antiplatelet agents (low dose) / NSAIDs (analgesic dose)×Non-steroidal anti-inflammatory drugs (NSAIDs)
Mechanism
Ketorolac is the most potent oral and parenteral NSAID. Aspirin irreversibly blocks platelet cyclooxygenase. Co-administration of two NSAIDs adds up the risks: gastrointestinal bleeding, acute kidney injury, sodium and fluid retention. FDA Toradol Section 4.3 specifically lists aspirin and other NSAIDs as contraindications.
Symptoms
Black or tarry stools (melena), vomiting blood or coffee-ground material, epigastric pain. Acute kidney injury and a rise in blood pressure are also possible. Risk of bleeding multiplies in patients over 65 and with prior peptic ulcer disease.
Management
The combination is not prescribed. If aspirin is required for cardioprotection (75–100 mg/day), replace ketorolac with paracetamol, metamizole, or a short opioid course. Ketorolac courses are limited to 5 days under all circumstances.