Fenagesic

Mefenamic acid.

Fenagesic Tablet: Round, yellow, convex, film-coated tablet.
Each tablet contains: 500 mg of Mefenamic Acid per tablet.
Fenagesic Suspension 125 MG/5 ML: Cloudy, white suspension with cherry flavour.
Suspension: 125 mg of Mefenamic Acid per 5 ml.

Pharmacology: Pharmacodynamics: It is a nonsteroidal agent with demonstrated anti-inflammatory, analgesic and antipyretic activity. In animal studies, it was found to inhibit prostaglandin synthesis and to compete for binding at the prostaglandin receptor site. Its exact mode of action is not known.
Pharmacokinetics: Following a single one gram oral dose, peak plasma level of 10 mcg/ml occurred in 2 to 4 hours with a half-life of 2 hours. Following multiple doses, plasma levels are proportional to dose with no evidence of drug accumulation. One gram of Mefenamic Acid given four times daily produces peak blood level of 20 mcg/ml by the second day of administration. Following a single dose, sixty-seven percent of the total dose is excreted in the urine as unchanged drug or as one of two metabolites. Twenty to twenty-five percent of the dose is excreted in the faeces during the first three days.

Mefenamic Acid is indicated for the treatment of primary dysmenorrhea and the relief of moderate pain when therapy will not exceed one week.

Recommended Dosage: The recommended regimen in acute pain for adults and children over 14 years of age is 500 mg three times daily, usually not to exceed one week. For the treatment of primary dysmenorrhoea, the recommended dosage is 500 mg three times daily, starting with the onset of bleeding and associated symptoms.
Mefenamic Acid should not be used for more than 7 days at a time.
After assessing the risk/benefit ratio in each individual patient, the lowest effective dose for the shortest possible duration should be used.
Route of Administration: Oral.

Symptoms and Treatment of Overdose: Symptoms of overdosage include diarrhoea, nausea with or without vomiting, abdominal pain, drowsiness, dizziness, nervousness, headache, blurred vision. Mefenamic Acid has a marked tendency to induce tonic-clonic (grand mal) convulsions in overdosage. Dyskinesia, acute renal failure and coma have been reported. Overdose has led to fatalities. Treatment is symptomatic and supportive. The stomach should be emptied by inducing emesis or by careful gastric lavage followed by the administration of activated charcoal. Vital functions should be monitored and supported. Because Mefenamic Acid and its metabolites are firmly bound to plasma proteins, hemodialysis and peritoneal dialysis may be of little value.

Mefenamic Acid should not be used in patients who have previously exhibited hypersensitivity to it. Because the potential exists for cross-sensitivity to aspirin or other NSAIDs, Mefenamic Acid should not be given to patients in whom these drugs induce symptoms of bronchospasm, allergic rhinitis or urticaria.
Mefenamic Acid is contraindicated in patients with active ulceration or chronic inflammation of either the upper or lower gastrointestinal tract.
Mefenamic Acid should be avoided in patients with pre-existing renal disease. Since Mefenamic Acid is eliminated primarily by the kidneys, the drug should not be administered to patients with significantly impaired renal function.

Cardiovascular Thrombotic Events: Observational studies have indicated that non-selective NSAIDs may be associated with an increased risk of serious cardiovascular events, principally myocardial infarction, which may increase with dose or duration of use. Patients with cardiovascular disease or cardiovascular risk of an adverse cardiovascular event in patients taking NSAIDs, especially in those with cardiovascular risk factors, the lowest effective doses should be used for the shortest possible duration.
There is no consistent evidence that the concurrent use of aspirin mitigates the possible increased risk of serious cardiovascular thrombotic events associated with NSAID use.
Hypertension: NSAIDs may lead to the onset of new hypertension or worsening pre-existing hypertension and patients taking antihypertensives with NSAIDs may have an impaired anti-hypertensive response. Caution is advised when prescribing NSAIDs to patients with hypertension. Blood pressure should be monitored closely during initiation of NSAID treatment and at regular intervals thereafter.
Heart Failure: Fluid retention and oedema have been observed in some patients taking NSAIDs, therefore, caution is advised in patients with fluid retention or heart failure.
Severe Skin Reactions: Serious skin reactions such as Generalised bullous fixed drug eruption (GBFDE) have been reported very rarely in association with the use of mefenamic acid. Mefenamic acid should be discontinued at the first appearance of the skin rash, mucosal lesions or any other sign of hypersensitivity.
NSAIDs may very rarely cause serious cutaneous adverse events such as exfoliative dermatitis, toxic epidermal necrolysis (TEN) and Stevens-Johnson Syndrome (SJS), which can be fatal and occur without warning. These serious adverse events are idiosyncratic and are independent of dose or duration of use. Patients should be advised of the signs and symptoms of serious skin reactions and to consult their doctor at the first appearance of a skin rash or any other sign of hypersensitivity.
Mefenamic Acid should be used with caution in patients with impaired renal function or a history of kidney or liver disease and it may exacerbate asthma and hypertension.
Caution should be observed when anticoagulants is administered concomitantly with nonsteroidal anti-inflammatory drugs (NSAIDS), to be certain that no change in anticoagulation dosage is required. In addition to specific drug interactions that might affect prothrombin time, NSAIDs can inhibit platelet aggregation, and can cause gastrointestinal bleeding, peptic ulceration and/or perforation. Safety and effectiveness in children below the age of 14 have not been established.
Risk of GI Ulceration, Bleeding and Perforation with NSAIDs: Serious GI toxicity such as bleeding, ulceration and perforation can occur at any time, with or without warning symptoms, in patients treated with NSAIDs therapy. Although minor upper GI problems (e.g. dyspepsia) are common, usually developing early in therapy, prescribers should remain alert for ulceration and bleeding in patients treated with NSAIDs, even in the absence of previous GI tract symptoms.
Studies to date have not identified any subset of patients not at risk of developing peptic ulceration and bleeding. Patients with prior history of serious GI events and other risk factors associated with peptic ulcer disease (e.g. alcoholism, smoking, corticosteroid therapy) are at increased risk. Elderly or debilitated patients seem to tolerate ulceration or bleeding less than other individuals and account for most spontaneous reports for fatal GI events.
Effects on Ability to Drive and Use Machine: Not applicable.

As there are no adequate and well-controlled studies in pregnant women, this drug should be used only if clearly needed. The use of this drug in late pregnancy is not recommended because of the effects on the foetal cardiovascular system. For the same reason, Mefenamic Acid should not be taken by nursing mothers.
Use of NSAIDs at about 20 weeks gestation or later in pregnancy may cause foetal renal dysfunction leading to oligohydramnios and in some cases, neonatal renal impairment. These adverse outcomes are seen, on average, after days to weeks of treatment, although oligohydramnios has been infrequently reported as soon as 48 hours after NSAID initiation. Oligohydramnios is often, but not always, reversible with treatment discontinuation.

Mefenamic Acid may give rise to occasional gastrointestinal upsets or rashes. Gastrointestinal haemorrhage may rarely occur. Other haematological effects include haemolytic anaemia, agranulocytosis, pancytopenia, thrombocytopenia, thrombocytopenic purpura and bone marrow aplasia.
The occurrence of diarrhoea or skin rash is an indication for discontinuing treatment.
Skin and Subcutaneous Tissue Disorders: Generalised bullous fixed drug eruption (GBFDE).

Mefenamic Acid may prolong prothrombin time. Therefore, when the drug is administered to patients receiving oral anticoagulant drugs, frequent monitoring of prothrombin time is necessary.
Mefenamic Acid may reduce the excretion of lithium, leading to significant increase in the steady-state plasma lithium levels. Hence, increased plasma lithium level monitoring is recommended.

Incompatibilities: Reports of incompatibilities are not available.

Store at or below 30ºC. Protect from light.
Shelf life: 3 years.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

M01AG01 - mefenamic acid ; Belongs to the class of non-steroidal antiinflammatory and antirheumatic products, fenamates.

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