Simultaneous use of paracetamol with drugs, inducers of microsomal liver enzymes, such as some hypnotic drugs (barbiturates), antiepileptic drugs (phenobarbital, phenytoin, carbamazepine), rifampicin, ethanol, may increase the risk of toxic damage to the liver, even with therapeutic doses.
Under the influence of paracetamol, the period half-life of chloramphenicol increases 5-fold.
Simultaneous use with metoclopramide or domperidone accelerates the absorption of paracetamol.
Simultaneous use of paracetamol in high doses increases the effect of anticoagulants, which increases the risk of bleeding.
Myelotoxic means reinforce manifestations of hematotoxicity paracetamol.
Simultaneous use with acetylsalicylic acid and other non-steroidal anti-inflammatory drugs increases the risk of kidney damage.
Cholestyramine and antacid drugs reduce the absorption of paracetamol.
The effectiveness of paracetamol may decrease with simultaneous use with cholestyramine, anticholinergics, antidepressants, alkaline substances.
The use of paracetamol together with zidovudine increases the risk of developing neutropenia.
The use of paracetamol can affect the results of analyzes of uric acid and blood glucose levels.
Caffeine accelerates the absorption of ergotamine; reduces absorption of calcium preparations; reduces the effect of narcotic and hypnotics, increases the excretion of lithium preparations; accelerates absorption and enhances the action of cardiac glycosides, increases their toxicity. Simultaneous use of caffeine with beta-blockers can lead to mutual suppression of therapeutic effects, with beta-adrenomimetics to additional stimulation of the central nervous system and other toxic effects. Caffeine reduces the effect of many sedatives, such as barbiturates, antihistamines; strengthens tachycardia, provoked by sympathomimetics, thyroxine.
Oral contraceptives, cimetidine and disulfiram slow the metabolism of caffeine, barbiturates and tobacco speed it up.
Simultaneous use with inhibitors of DNA gyrase (eg, ciprofloxacin) may slow the elimination of caffeine and its metabolite paraxanthin.
Caffeine leads to a slower release of theophylline when they are used simultaneously. Inhibitors of monoamine oxidase, furazolidone, procarbazine, selegiline and large doses of caffeine can cause the development of dangerous cardiac arrhythmias or a marked increase in blood pressure.
Mexiletine reduces the excretion of caffeine by 50%. Caffeine is an adenosine antagonist.
Caffeine can interact with ephedrine, causing clinically significant cardiovascular effects, so their simultaneous use should be avoided.
Propifenazone can increase the effect of oral hypoglycemic agents, sulfonamide drugs, anticoagulants, ulcerogenic effect of glucocorticosteroids, and decrease the effectiveness of potassium-sparing diuretics.