Phenylbutazone
Phenylbutazone is a congener of aminopyrine and antipyrine, having analgesic, antipyretic, antinflammatory and mild uricosuric properties; rapidly gained favour after its introduction in 1949 for the treatment of inflammatory joint disordes. Phenylbutazone is used in the treatment of gout, ankylosing spondylitis But it has a large number of serious adverse effects.
Primary Characteristics
It is of Synthetic origin and belongs to Pyrazolidine.
It belongs to Cyclo-oxygenase inhibitor pharmacological group on the basis of mechanism of action. It is also classified under Analgesics and Anti-inflammatory Agents .
Molecular Weight: 308.4 · pKa: 4.5 · Solubility in Water: 1 in 11000 · Solubility in Alcohol: 1 in 28 · Non-proprietary name: Phenylbutazone · Isotonic value: 5.34.
Pharmacokinetics
Absorption: Phenylbutazone has an oral bioavailability is 97% (±2%), pre-systemic (first-pass) metabolism accounts for 0.5% (±0.5%).
Distribution: Phenylbutazone has a volume of distribution is 0.172 l/kg. plasma protein binding is 99.4 %.
Elimination: plasma half-life is 49 - 142 hr, renal excretion is < 1 %.
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Indications
Phenylbutazone is primarily indicated in conditions like Acute gout, Advanced prostate cancer, Agitation and restlessness in the elderly, Ankylosing spondylitis, Nausea and vomiting (palliative care), Pain, Schizophrenia and other psychoses.
Phenylbutazone is also indicated for secondary conditions like Bone pain, Gout, Osteoarthritis, Psoriatic arthritis, Reiters disease, Rheumatic fever, Rheumatoid arthritis, Thrombophlebitis.
Contraindications
Phenylbutazone is contraindicated in conditions like Peptic ulcer, Blood dyscrasias, Congestive heart failure, Hepatitis.
Dosage
Phenylbutazone 's dosage details are as follows:
| Dose | Single Dose | Frequency | Route | Instructions |
|---|---|---|---|---|
| Adult Dosage | ||||
| 100 mg | 100 mg | Every 8h | PO | Maintenance, As Required |
| 200 mg | 200 mg | Every 8h | PO | Initially for 2 Days |
| Paediatric Dosage (20kg) | ||||
| 0 – 0 | — | — | Not recommended for this age group | |
| Neonatal Dosage (3kg) | ||||
| 0 – 0 | — | — | Not recommended for this age group | |
Drug Interactions
Always consult your physician for the change of dose regimen or an alternative drug of choice that may strictly be required.
Side Effects
Phenylbutazone in overdosage may give rise to further complications which include Chromosomal damage , Exfoliative dermatitis , Gastric erosions , Goitre , Hepatitis , Peptic ulceration .
Phenylbutazone produces potentially life-threatening effects which include Pulmonary edema , Blood dyscrasias, Bleeding , Cardiac failure, Peptic ulceration, Perforation . Careful monitoring is needed with proper medical management.
The signs and symptoms that are produced after acute overdosage of Phenylbutazone are Acidosis, Acute renal failure, Encephalitis, Death , Neurological syndrome, Acute hepatitis.
Phenylbutazone is known to cause more or less tolerable side effects which are usually transient. These include Hematuria, Increased intracranial pressure, Rashes , Rectal bleeding, Salivary gland swelling, Stomatitis.
Warnings / Precautions
Interference in Pathology
Phenylbutazone may interfere in the diagnosis of Thyroid Function Test.
Available Brands
Storage Conditions
Drug Classification
- 1.2.1.3 — Non steroidal anti-inflammatory drugs (NSAIDs)