Tolfenamic acid

Tolfenamic acid is used specifically for relieving the pain of migraine headache and also recommended for use as an analgesic in post-operative pain and fever.

Tolfenamic acid (N-(2-methyl-3-chlorophenyl) anthranilic acid) belongs to the fenamate group and is a potent inhibitor of cyclooxygenase enzyme, thus it inhibits the synthesis of important inflammatory mediators such as thromboxane (TX) B2 and prostaglandin (PG) E2. Prostaglandins are responsible for causing swelling pain and inflammation associated with these conditions. It acts not only by inhibiting prostaglandin synthesis, but it also has direct antagonistic action on its receptors.

Pharmacokinetic properties: Absorption Readily absorbed from GI tract. Peak plasma concentration: 60-90 min. Bioavailability 85%. Distribution: Protein-binding: 99% Plasma half-life 2 hours. Metabolism: Metabolised in the liver. Tolfenamic acid undergoes enterohepatic circulation. Excretion: Excreted in urine (90%) and faces.

Adult:

• Acute migraine attacks: 200 mg when symptoms appear may be repeated once after 1-2 hour.
• Mild to moderate pain: 100-200 mg tid
• Renal impairment: Dose adjustments may be needed.
• Severe renal impairment: Avoid.

Children: A pediatric dosage regimen has not yet been established.

Tolfenamic acid should be taken with food. Take water during or immediately after meals.

The rate of absorption of Tolfenamic acid increases with Metoclopramide and Magnesium hydroxide but decreases with Aluminium hydroxide. Risk of bleeding with anticoagulants and other NSAIDS increases when use with Tolfenamic acid. It decreases antihypertensive response to loop diuretics, B-blockers and ACE Inhibitors. Co-administration increases plasma concentration of Lithium Methotrexate and cardiac glycosides. It also increases the risk of nephrotoxicity with ACE inhibitors, Ciclosporin, Tacrolimus or diuretics

Active peptic ulcer or bleeding in the gut. Severe heart, kidney or liver failure.

Dysuria especially in males, diarrhoea, nausea epigastric pain, vomiting, dyspepsia, erythema, headache, tremor, euphoria, fatigue, pulmonary infiltration & haematuria. Potentially fatal: Blood dyscrasias and hepatitis.

This medicine is not recommended for using during pregnancy unless considered essential by doctor Not to be given during the third trimester of pregnancy. NSAID's can appear in breast milk in very low concentrations NSAID's should, if possible, be avoided when breastfeeding.

Precaution should be needed for patients with asthma bronchospasm, bleeding disorders, cardiovascular diseases, peptic ulceration, hypertension, liver infection, cardiac or renal function impairment and elderly. Increase water intake or dose reduction to reduce dysuria.

Symptoms include headache, nausea, vomiting, epigastric pain. gastrointestinal bleeding, diarrhoea excitation, coma, drowsiness dizziness, tinnitus, fainting and convulsions. In cases of significant poisoning, acute renal failure and liver damage are possible. Patients should be treated symptomatically as required.

Drugs used for Rheumatoid Arthritis, Non-steroidal Anti-inflammatory Drugs (NSAIDs), Other drugs for migraine.

Store in a cool and dry place, away from light Keep out of the reach of children.