Phenylbutazone


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Rheumatic disorders; Acute gout Rheumatic disorders: Up to 600 mg/day in divided doses. Acute gout: Up to 800 mg/day. Reduce to lowest effective dose after 1-3 days. Usual max: Up to 1 wk.
Dosage Details
Oral
Rheumatic disorders
Adult: Up to 600 mg daily in divided doses. Reduce dose to the lowest effective dose after 1-3 days. Usual max: Up to 1 wk.

Oral
Acute gout
Adult: Up to 800 mg daily may be needed. Reduce to the lowest effective dose after 1-3 days. Usual max duration: Up to 1 wk.
Administration
Should be taken with food. Take w/ or immediately after meals.
Contraindications
Active GI bleeding, ulcer disease, pregnancy.
Special Precautions
CHF, hypertension, renal or hepatic impairment, history of GI disease (bleeding or ulcers), patients receiving anticoagulants, porphyric patients, lactation. Use only when other NSAIDs have failed or discontinue use if no favourable response is seen because of severe hematologic adverse effects. Not recommended for children up to 15 yr.
Adverse Reactions
Tachycardia, hypotension, myocarditis, atrial fibrillation, atrial flutter, angina, CHF, myocardial depression, pericardial effusion/pericarditis, dizziness, drowsiness, headache, fatigue, seizures, gustatory hallucinations, rash, oedema, erythema multiforme, toxic epidermal necrolysis, cutaneous vasculitis, parotitis, GI disorders, anaemia, thrombocytopenia, coagulopathy, leukopenia, neutropenia, agranulocytosis, granulocytopenia, red blood cell aplasia, hepatitis, primary biliary cirrhosis, vision changes, ototoxicity, tinnitus, renal failure, myoglobinuria, glomerulonephritis, renal vasculitis, pulmonary oedema, pulmonary vasculitis, SLE, lymphadenopathy.
Overdosage
Abdominal pain, agitation, ataxia, chest pain, cholestatic jaundice, coagulopathy, colitis, coma, dermatitis, diarrhoea, drowsiness, dysosmia, erythema multiforme, exfoliative dermatitis, faecal discolouration, gastritis, haematuria, GI bleeding, hyperventilation, hypotension, hypothyroidism, jaundice, lichenoid eruptions, pemphigus, periarteritis nodosa, pericarditis, photosensitivity, respiratory arrest, rhabdomyolysis, seizures, stomatitis, toxic epidermal necrolysis, urine discolouration. Treatment is supportive; multiple doses of charcoal may be needed to reduce the risk for delayed toxicities.
Drug Interactions
May reduce phenytoin or warfarin metabolism and methotrexate excretion.
Action
Description: Phenylbutazone is derived from pyrazolone and is an NSAID used only in acute conditions due to its toxicity. It has anti-inflammatory, antipyretic, uricosuric, and analgesic properties; these actions are due primarily to prostaglandin inhibition, leukocyte migration inhibition, and lysosomal enzyme stabilization.
Onset: 30-60 min.
Duration: 3-5 days.
Pharmacokinetics:
Absorption: Oral: Well absorbed from GI tract.
Distribution: Most body tissues and synovial spaces; protein binding: 98%.
Metabolism: Hepatic, to oxyphenbutazone and hydroxyphenbutazone; half-life: 50-100 hr (increases with hepatic impairment); time to peak: within 30-60 min.
Excretion: Via urine as metabolites (99%).
Disclaimer: This information is independently developed by MIMS based on Phenylbutazone from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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