Indole Derivative

INDOLE DERIVATIVE

Indomethacin

It is a potent anti-inflammatory drug with prompt antipyretic action. Indomethacin relieves only inflammatory or tissue injury related pain. It is a highly potent inhibitor of PG synthesis and suppresses neutrophil motility. In toxic doses it uncouples oxidative phosphorylation (like aspirin).

Pharmacokinetics

Indomethacin is well absorbed orally, rectal absorption is slow but dependable. It is 90% bound to plasma proteins, partly metabolized in liver to inactive products and excreted by kidney. Plasma t½ is 2–5 hours.

Adverse Effects

A high incidence (up to 50%) of gastrointestinal and CNS side effects is produced.

Gastric irritation, nausea, anorexia, gastric bleeding and diarrhoea are prominent.

Frontal headache (very common), dizziness, ataxia, mental confusion, hallucination, depression and psychosis can occur.

Leukopenia, rashes and other hypersensitivity reactions are also reported.

Increased risk of bleeding due to decreased platelet aggregability.

It is contraindicated in machinery operators, drivers, psychiatric patients, epileptics, kidney disease, pregnant women and in children.

Dose: 25–50 mg BDQID. Those not tolerating the drug orally may be given nightly suppository.

IDICIN, INDOCAP 25 mg cap, 75 mg SR cap, ARTICID 25, 50 mg cap, INDOFLAM 25, 75 mg caps, 1% eye drop. RECTICIN 50 mg suppository.

Uses

Because of prominent adverse effects, indomethacin is used as a reserve drug in conditions requiring potent anti-inflammatory action like ankylosing spondylitis, acute exacerbations of destructive arthropathies, psoriatic arthritis and acute gout that are not responding to better tolerated NSAIDs.

Malignancy associated fever refractory to other antipyretics may respond to indomethacin. It has been the most common drug used for medical closure of patent ductus arteriosus: three 12 hourly doses of 0.1–0.2 mg/kg achieve closure in majority of cases.

Bartter’s syndrome responds dramatically, as it does to other PG synthesis inhibitors.