Meftal-Forte®, Blue Cross Laboratories Pvt Ltd
MODE OF ACTION
Mefenamic acid has analgesic, anti-inflammatory, and antipyretic properties. The mechanism of action of mefenamic acid, like that of other NSAIDs, is not completely understood but involves inhibition of cyclooxygenase (COX-1 and COX-2).
Paracetamol has a central analgesic effect that is mediated through activation of descending serotonergic pathways. Debate exists about its primary site of action, which may be inhibition of prostaglandin (PG) synthesis or through an active metabolite influencing cannabinoid receptors.
This drug is indicated for the relief of moderate to severe painful inflammatory conditions when therapy will not exceed one week.
DOSAGE AND ADMINISTRATION
Thrice daily, or as prescribed ; therapy should not exceed one week
– Hypersensitivity to the active substance or any of the excipient.
– Inflammatory bowel disease.
– History of gastrointestinal bleeding or perforation, related to previous NSAIDs therapy.
– Active, or history of recurrent peptic ulcer/haemorrhage (two or more distinct episodes of proven ulceration or bleeding).
– Severe heart failure, hepatic failure and renal failure.
– Because the potential exists for cross-sensitivity to aspirin, ibuprofen, or other non-steroidal anti-inflammatory drugs, mefenamic acid must not be given to patients who have previously shown hypersensitivity reaction (e.g. asthma, bronchospasm, rhinitis, angioedema or urticaria) to these medicines.
– During the last trimester of pregnancy.
– Treatment of pain after coronary artery bypass graft (CABG) surgery.
Hypersensitivity to paracetamol or any of the constituents.
Anti-coagulants: NSAIDs may enhance the effects of anti-coagulants, such as warfarin. Concurrent administration of mefenamic acid with oral anti-coagulant drugs requires careful prothrombin time monitoring.
It is considered unsafe to take NSAIDs in combination with warfarin or heparin unless under direct medical supervision.
Lithium: A reduction in renal lithium clearance and elevation of plasma lithium levels. Patients should be observed carefully for signs of lithium toxicity.
The following interactions have been reported with NSAIDs but have not necessarily been associated with mefenamic acid.
Other analgesics including cyclooxygenase-2 selective inhibitors: Avoid concomitant use of two or more NSAIDs (including aspirin) as this may increase the risk of adverse effects.
Antidepressants: Selective serotonin reuptake inhibitors (SSRIs): increased risk of gastrointestinal bleeding.
Antihypertensives and diuretics: A reduction in antihypertensive and diuretic effect has been observed. Diuretics can increase the nephrotoxicity of NSAIDs.
ACE inhibitors and angiotensin-II-receptor antagonists: A reduction in antihypertensive effect and an increased risk of renal impairment especially in elderly patients. Patients should be adequately hydrated, and the renal function assessed in the beginning and during concomitant therapy.
Aminoglycosides: Reduction in renal function in susceptible individuals, decreased elimination of aminoglycoside and increased plasma concentrations.
Anti-platelet agents: Increased risk of gastrointestinal ulceration or bleeding.
Acetylsalicylic Acid: Experimental data implies that mefenamic acid interferes with the anti-platelet effect of low-dose aspirin when given concomitantly, and thus may interfere with aspirin’s prophylactic treatment of cardiovascular disease. However, the limitations of this experimental data and the uncertainties regarding extrapolation of ex vivo data to the clinical situation imply that no firm conclusions can be made for regular mefenamic acid use.
Cardiac glycosides: NSAIDs may exacerbate cardiac failure, reduce GFR and increase plasma cardiac glycoside levels.
Ciclosporin: The risk of nephrotoxicity of ciclosporin may be increased with NSAIDs.
Corticosteroids: Concomitant use may increase the risk of gastrointestinal ulceration or bleeding.
Oral hypoglycaemic agents: Inhibition of metabolism of sulfonylurea drugs, prolonged half-life and increased risk of hypoglycaemia.
Methotrexate: Elimination of the drug can be reduced, resulting in increased plasma levels.
Mifepristone: NSAIDs should not be taken for 8-12 days after mifepristone administration, NSAIDs can reduce the effects of mifepristone.
Probenecid: Reduction in metabolism and elimination of NSAIDs and metabolites.
Quinolone antibiotics: Animal data indicates that NSAIDs can increase the risk of convulsions associated with quinolone antibiotics. Patients taking NSAIDs and quinolones may have an increased risk of developing convulsions.
Tacrolimus: Possible increased risk of nephrotoxicity when NSAIDS are given with tacrolimus.
Zidovudine: Increased risk of haematological toxicity when NSAIDs are given with zidovudine. There is evidence of an increased risk of haemarthroses and haematoma in HIV(+) haemaophiliacs receiving concurrent treatment with zidovudine and ibuprofen.
Cholestyramine: The speed of absorption of paracetamol is reduced by cholestyramine. Therefore, the cholestyramine should not be taken within one hour if maximal analgesia is required.
Metoclopramide and Domperidone: The absorption of paracetamol is increased by metoclopramide and domperidone. However, concurrent use need not be avoided.
Warfarin: The anticoagulant effect of warfarin and other coumarins may be enhanced by prolonged regular use of paracetamol with increased risk of bleeding; occasional doses have no significant effect.
Chloramphenicol: Increased plasma concentration of chloramphenicol.
DRUG ADVERSE EFFECTS
Adverse effects of paracetamol are rare. Very rare cases of serious skin reactions have been reported. There have been reports of blood dyscrasias including thrombocytopenia purpura, methaemoglobenaemia and agranulocytosis, but these were not necessarily causality related to paracetamol.
Clinical | Pharmacokinetic data
Pregnancy Category: C
Routes of Administration: Oral
Bioavailability: Not available
Protein Binding: Not available
Metabolosim: Not available
Onset of Action: Not available
Elimination Half life: Not available
Excretion: Not available
Legal Status | Dosage forms & Strengths
Prescription only Medicine
Narcotic Drugs and Psychotropic Substances (Control ) Act Schedule:
This drug is not a controlled substance under Narcotic Drugs and Psychotropic Substances (Control ) Act
Dosage Forms | Strengths:
Refer to :
PPB Drug Retention Register