| Indication | For the treatment of backache and ankylosing spondylitis |
| Pharmacodynamics | Phenylbutazone is a synthetic, pyrazolone derivative. It is a nonhormonal anti-inflammatory, antipyretic compound useful in the management of inflammatory conditions. The apparent analgesic effect is probably related mainly to the compound's anti-inflammatory properties and arise from its ability to reduce production of prostaglandin H and prostacyclin. Prostaglandins act on a variety of cells such as vascular smooth muscle cells causing constriction or dilation, on platelets causing aggregation or disaggregation and on spinal neurons causing pain. Prostacylcin causes vascular constriction platelet disaggregation |
| Mechanism of action | Phenylbutazone binds to and inactivates prostaglandin H synthase and prostacyclin synthase through peroxide (H2O2) mediated deactivation. The reduced production of prostaglandin leads to reduced inflammation of the surrounding tissues. |
| Absorption | Not Available |
| Volume of distribution | Not Available |
| Protein binding | Not Available |
| Metabolism | Not Available |
| Route of elimination | Not Available |
| Half life | Not Available |
| Clearance | Not Available |
| Toxicity | Oral, LD50 = 238 mg/kg (mouse); Oral, LD50 = 781 mg/kg (rabbit); Oral, LD50 = 245 mg/kg (rat); Oral, LD50 = 375 mg/kg (rat) |