As penicillins are only active against proliferating micro-organisms, Sterile Pencillin G Benzathine should not be combined with bacteriostatic antibiotics. Combinations with other antibiotics should only be considered, it their effects can be expected to be synergistic or at least additive. Except it a synergistic action is proven, the combination partners should be fully dosed.
Competitive inhibition of drug elimination should be remembered, whenever antiinflammatories, antirheumatics, antipyretics (particularly indomethacin, phenylbutazone and salicylates in high doses) or probenecid are used concomitantly. Like other antibiotics, Sterile Pencillin G Benzathine may occasionally reduce the efficacy of oral contraceptives.
To preclude undesirable chemical reactions, administration with mixed-content syringes should be avoided.