Fenamic® Capsule: Each capsule contains Mefenamic acid BP 250 mg.
Fenamic® 500 Tablet: Each tablet contains Mefenamic acid BP 500 mg.
Fenamic® Suspension: Each 5 ml contains Mefenamic acid BP 50 mg.
Fenamic contains Mefenamic acid which is a member of the fenamate group of nonsteroidal anti-inflammatory drugs (NSAIDs). Mefenamic acid exhibits anti-inflammatory, analgesic, and antipyretic activities in animal models. It is available as capsule, tablet and suspension form for oral administration.
As with other NSAIDs, the lowest dose should be sought for each patient. Therefore, after observing the response to initial therapy with Fenamic, the dose and frequency should be adjusted to suit an individual patient’s needs.
Administration is by the oral route, preferably with food. A 500 mg dose should be given to adults up to three times (1.5 g total) per day.
Infants over 6 months: 25 mg/kg of body weight daily in divided doses for not longer than 7 days.
Aspirin: As with other NSAIDs, concomitant administration of Fenamic and Aspirin is not generally recommended because of the potential of increased adverse effects.
Methotrexate: NSAIDs have been reported to competitively inhibit Methotrexate accumulation in rabbit kidney slices. This may indicate that they could enhance the toxicity of Methotrexate. Caution should be used when NSAIDs are administered concomitantly with Methotrexate.
ACE inhibitors: Reports suggest that NSAIDs may diminish the antihypertensive effect of ACE inhibitors. This interaction should be given consideration in patients taking NSAIDs concomitantly with ACE inhibitors.
Furosemide: Clinical studies have shown that NSAIDs can reduce the natriuretic effect of Furosemide and Thiazides in some patients. This response has been attributed to inhibition of renal prostaglandin synthesis.
Warfarin: The effects of Warfarin and NSAIDs on GI bleeding are synergistic, such that users of both drugs together have a risk of serious GI bleeding higher than users of either drug alone.
Antacids: Concomitant use with an antacid containing Magnesium Hydroxide with Mefenamic acid increases the $C_{\text{max}}$ and AUC of Mefenamic acid.
In patients taking Fenamic or other NSAIDs, the most frequently reported adverse experiences include: abdominal pain, constipation, diarrhoea, dyspepsia, flatulence, gross bleeding/perforation, heartburn.
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nausea, GI ulcers, vomiting, abnormal renal function, anaemia, dizziness, oedema, elevated liver enzymes, headache, increased bleeding time, pruritus, rash and tinnitus.
In late pregnancy, as with other NSAIDs, Fenamic should be avoided because it may cause premature closure of the ductus arteriosus. In general there are no adequate and well controlled studies in pregnant women. Fenamic should be used during pregnancy only if the potential benefit justifies the potential risk to the foetus. Rated as Pregnancy Category C.
Lactation: Trace amounts of Fenamic may be present in breast milk. Taking into account the importance of the drug to the mother, decision should be made whether to discontinue nursing or to discontinue the drug.
NSAIDs should be prescribed with extreme caution in those with a prior history of ulcer disease or gastrointestinal bleeding. To minimise the potential risk for an adverse GI event, the lowest effective dose should be used for the shortest possible duration. In cases with pre-existing advanced kidney disease, treatment with Fenamic is not recommended.