The components of the drug are well absorbed in the gastrointestinal tract.
Metamizol sodium: in the intestinal wall it hydrolyses to form an active metabolite, 4-methyl-amino-antipyrine, which in turn is metabolized to 4-formyl-amino-antipyrine and other metabolites.The level of binding of the active metabolite with proteins is 50-60%. Excretion of metabolites passes through the kidneys. In addition, metabolites are excreted in breast milk.
Paracetamol: paracetamol quickly and almost completely absorbed from the gastrointestinal tract. It binds to plasma proteins at 15 %. Paracetamol penetrates through blood-brain barrier. Less than 1% of the dose of paracetamol taken by the lactating mother penetrates into breast milk. The therapeutically effective concentration of paracetamol in plasma
is reached at its or his appointment in a dose of 10-15 mg / kg of weight. The half-life is 1-4 hours.
Paracetamol is metabolized in the liver and excreted in the urine, mainly in the form of glucuronides and sulfonated conjugates, less than 5% is excreted unchanged in the urine.
Caffeine: well absorbed in the intestine, half-life - 5 hours (sometimes - up to 10 hours). It is excreted mainly by kidneys in the form of metabolites, about 10% - in unchanged form. Codeine: slightly binds to plasma proteins. It is subject to biotransformation in the liver (10% by demethylation passes into morphine). Excreted by the kidneys (5-15% - unchanged).
Phenobarbital: bioavailability is 80%. In plasma it binds to proteins by 50%, it penetrates well through the placenta. Biotransformatsya in the liver. The main metabolite does not have pharmacological activity. It is excreted by the kidneys, including 20-25% - unchanged.