Interactions
Acid inhibitors lower the rate of absorption of penicillins and, when administered in parallel, have a reduced effect. Penicillins should also not be combined with other bacteriostatic drugs, as the principle of action is the same and cannot lead to an improvement in efficacy. Beta-lactam antibiotics can inactivate antibiotics of the substance group aminoglycosides and should also not be given in combination.
The combination of penicillin with antihistamines should be carefully considered, as simultaneous administration may alter the effect of the antihistamine. The simultaneous administration of aspirin and comparable drugs from the group of NSAIDs can increase the penicillin levels in the blood of the patient by molecular displacement and thus cause an increased effect. Administration of Probenecid prevents penicillin excretion and also prolongs the time that penicillin remains in the body.
Displacement of penicillin with a simultaneous increase in penicillin concentration is also caused by the simultaneous administration of sulfonamides. A simultaneous intake of vitamin B1 and vitamin C reduces the effectiveness of penicillin. Penicillins inhibit the function of blood platelets (thrombocytes). If warfarin is taken at the same time, its effect can be altered. Combined administration should only be used if there is a precise indication.
Penicillin and milk
Milk and dairy products have no influence on the effect of penicillin.Penicillin does not combine with milk components, so there is no obstruction of absorption (absorption) by the intestine. The drug also has a wide range of applications in pediatrics. It is very effective against scarlet fever or tonsillitis, which are usually caused by streptococci.
Due to the use of penicillin in these clinical pictures, the rheumatic fever caused by streptococci is almost non-existent in Germany. This prevents life-threatening heart muscle inflammations (myocarditis) with subsequent heart valve defects and kidney damage (glumerulonephritis). It is a widespread opinion that antibiotics should not be taken with milk. However, this concerns only certain antibiotics, namely the tetracyclines and the fluoroquinolones, but not penicillin. With the other antibiotics, the complex formation with calcium ions of milk leads to large “lumps” which cannot be absorbed by the intestine and are thus excreted again without passing into the blood.