Rexol MF suspension is a combination of paracetamol and mefenamic acid.
Paracetamol is also known as acetaminophen and is widely used as over the counter analgesic and anti-pyretic. It is a mild analgesic which causes relief in mild headaches and other aches and pains. In combination with other drugs like opioid analgesic, paracetamol is used in the management of post surgical pain and severe pain.
Mefenamic acid is a non steroidal anti-inflammatory drug which is used for the treatment of pain, it also includes menstrual pain. It produces its action by inhibition of prostaglandin synthesis.
Antipyretic and analgesic action
25mg/kg in divided doses for 7 days
It inhibits the synthesis of prostaglandin synthesis by competing with arachidonic acid for the active site of COX.
It produces its action by inhibiting COX-1 and COX-2 which causes prostaglandin synthesis. By acting on the activity of these enzymes it causes reduction in the prostaglandin synthesis which causes inflammation and pain process.
It has rapid and complete absorption
The protein binding of the drug is about 25%, it undergoes glucuronidation in liver.
About 80% of acetaminophen is excreted in the urine after conjugation and about 3% of the drug is excreted unchanged.
After oral administration it gets rapidly absorbed with Cmax of 20mcg/ml and Tmax is 2-4hrs.
The drug is about 90% bound to plasma protein with Vd is 1.06 l/kg. Metabolism of the drug is through CYP-450 enzyme CYP2C9 to 3-hydroxymethyl mefenamic acid. These metabolites may undergo glucuronidation.
About 52% of the drug is excreted in urine.
Serious Kidney Problems
Overdose of the Drug Acetaminophen
Chewable tablet may contain sugar or aspartame should not be used in diabetic patients
Mefenamic acid cannot be substituted for corticosteroid therapy
It can also remove the diagnostic signs which are useful for detecting complications associated with disease.