Table 6.

Representative studies on the effects of paracetamol (acetaminophen) on platelets.

NSAID Drug (s)	Study Design	Effects on Platelets	Ref
Paracetamol (Acetaminophen) and meloxicam	In vitro Platelets from human blood samples from six healthy humans. Dose: 214 μg/mL the standard dose, 1T), 4T, 8T, 10T, 12T, 16T, and 20T acetaminophen. Similar dosages were used for the meloxicam. The Food and Drug Administration (FDA)-approved standard dose for acetaminophen is 15 mg/kg every 6h. The FDA-approved standard dose for meloxicam is 0.2 mg/kg	Notable suppression of AA-induced platelet aggregation in PAWB of healthy subjects was noted with acetaminophen and/or meloxicam, even at their standard therapeutic doses. Similarly, collagen-induced platelet aggregation was inhibited by acetaminophen (inhibition 72 +/− 10%of control) or meloxicam (inhibition 72+/− 5% of control), starting from doses as low as 1 or 4 of the recommended doses. Both acetaminophen and meloxicam, whether administered individually or together, demonstrated the ability to hinder platelet aggregation, even at typical doses.	[96]
2-acetamidophenol (a positional isomer of paracetamol)	In vitro in human platelets Dose: 1, 5, 50, and 100 µM concentrations of 2-acetamidophenol. Adverse effects: with minimal or no risk of gastric ulcer.	2-acetamidophenol exhibited notable activity against AA (inhibition 93.8 +/− 2.9% for dose 1 μM)-induced platelet aggregation in PRP of healthy subjects 2-acetamidophenol exhibited lower sensitivity against the ADP (inhibition 52+/− 1.4% for dose 50 μM)-induced platelet aggregation, an effect which however was of greater potency and efficacy than that of aspirin’s against ADP Additionally, 2-acetamidophenol showed significantly higher potency than paracetamol.	[97]

Abbreviations: NSAID(s) = non-steroidal anti-inflammatory drug(s); AA = arachidonic acid; ADP = adenosine 5′ diphosphate; PRP = platelet-rich plasma; PAWB = platelet-rich whole blood.