Last updated: October 20, 2014
Trade Names: Formerly Butazolidin
Drug Class: NSAID, human use in US discontinued
Preparations: 100-mg tablet
Dose: 100 mg three to four times daily
Indications: Ankylosing spondylitis refractory to other treatment
Comments: Phenylbutazone for humans is no longer available commercially in the US. It is not recommended for human use because of hematologic toxicity (agranulocytosis, thrombocytopenia). Some rheumatologists believe it can be useful for some patients with ankylosing spondylitis when other NSAIDs and treatments have failed to control symptoms. The potential risks and benefits must be carefully evaluated with the patient before prescribing phenylbutazone.
Clinical Pharmacology: Rapid absorption; hepatic metabolism; renal elimination. Half-life is 50–100 hours.
Cost: Not available
See NSAIDs for Mechanism of Action, Contraindications, Precautions, Monitoring, Pregnancy Risk, Adverse Effects, Interactions, and Patient Instructions.