The drug enhances the effects of monoamine oxidase inhibitors, sedatives, ethanol.
The risk of hepatotoxic action of paracetamol increases with the simultaneous administration of ethanol, hepatotoxic drugs, inducers of microsomal oxidation enzymes in the liver (phenytoin, barbiturates, rifampicin, phenylbutazone, tricyclic antidepressants, etc.).
The concomitant use of paracetamol in high doses increases the effect of anticoagulant drugs (a decrease in the synthesis of procoagulant factors in the liver). Paracetamol reduces the effectiveness of uricosuric drugs.
Long-term use of barbiturates reduces the effectiveness of paracetamol. Metoclopramide and domperidone increase, and colestramine reduces the rate of absorption of paracetamol. Inhibitors of enzymes of microsomal oxidation (incl. cimetidine) reduce the risk of hepatotoxic effects of paracetamol.
Simultaneous administration of ethanol and paracetamol promotes the development of acute pancreatitis. Long-term combined use of paracetamol and non-steroidal anti-inflammatory drugs increases the risk of developing "analgesic" nephropathy and renal papillary necrosis, the onset of the terminal stage of renal failure.Simultaneous long-term administration of paracetamol in high doses and salicylates increases the risk of developing kidney or bladder cancer. Diflunisal increases the plasma concentration of paracetamol by 50% - the risk of developing hepatotoxicity. Myelotoxic drugs increase the manifestation of hematotoxicity of paracetamol.
Phenylephrine reduces the hypotensive effect of diuretics and hypotensive drugs (including methyldopy, mekamilamin, guanadrel, guanetidine), reduces the antianginal effect of nitrates.
Phenothiazines, alpha-adrenoblockers (phentolamine), furosemide and other diuretics reduce the hypertensive effect of phenyramine. Inhibitors of monoamine oxidase (incl. furazolidone, procarbazine, selegiline), oxytocin, ergot alkaloids, tricyclic antidepressants, methylphenidate, adrenostimulants increase the vasoconstrictive effect and arrhythmogenicity of phenylephrine, against the background of reserpine, hypertension is possible. Ergometrine, ergotamine, methylergomethrin, oxytocin, doxapram increase the severity of the vasoconstrictor effect of phenyramine.
Inhalation anesthetics (including chloroform, enflurane, halothane, isoflurane, methoxyflurane) increase the risk of severe atrial and ventricular arrhythmias. Thyroid hormones increase (mutually) the effect of phenylephrine and the associated risk of coronary insufficiency (especially in coronary atherosclerosis).
Ascorbic acid increases the concentration in the blood of benzylpenicillin and tetracyclines, reduces the effectiveness of heparin and indirect anticoagulants, increases the overall clearance of ethanol, which in turn reduces the concentration of ascorbic acid in the body, reduces the therapeutic effect of antipsychotic drugs - phenothiazine derivatives, tubular reabsorption of amphetamine and tricyclic antidepressants.
With simultaneous use with acetylsalicylic acid, urinary excretion of ascorbic acid increases and the excretion of acetylsalicylic acid decreases. Acetylsalicylic acid, oral contraceptives, fresh juices and alkaline drink reduce the absorption and absorption of ascorbic acid.
Ascorbic acid improves the absorption of iron in the intestine; increases the risk of developing crystalluria in the treatment of salicylates andsulfonamides short-acting, slows the excretion of kidney acids, increases the excretion of drugs that have an alkaline reaction (including alkaloids), reduces the concentration in the blood of oral contraceptives, reduces the chronotropic effect of isoprenaline. With long-term use or use in high doses, it can interfere with the interaction of disulfiram and ethanol, in high doses increases the excretion of mexiletine by the kidneys.
Drugs quinoline series, calcium chloride, salicylates, glucocorticoids with prolonged use deplete the stores of ascorbic acid. Barbiturates and primidon increase the excretion of ascorbic acid in the urine.