Ca2 + ions, as well as phosphates, reduce absorption, and Mg2 + reduce the rate of absorption of tetracycline. The activity of levodopa is reduced by pyridoxine.
B6 vitamins used by patients taking levodopa for the treatment of Parkinson's disease, without the use of a peripheral DOPA-decarboxylase inhibitor, reduce the therapeutic effect of L-DOPA.
Since the compounds of cycloserine, isoniazid and penicillin with pyridoxine do not give active interaction, the content of the latter in the body decreases. Phenytoin reduces the concentration of folic acid, and it, in turn, reduces its anticonvulsant properties. Probenecid reduces the rate of elimination of riboflavin from the body. Since TCAs are derivatives of phenothiazine, they can reduce the therapeutic effects of vitamin B2.
Combine with vitamin C medications that reduce the effects of gastric juice, is not recommended. Salicylic acid, as well as other acid derivatives (eg, acetylsalicylic) interfere with the release of vitamin C, and also reduce its level in the blood plasma. Acidification of the body of vitamin E can interfere with mineral oils, as well as colestipol and cholestyramine.