Intropin (dopamine hydrochloride) intravenous admixture compatibility. Part 2: stability with some commonly used antibiotics in 5% dextrose injection.

The stability of dopamine hydrochloride (Intropin) and several commonly used antibiotics was studied as admixtures in 5% Dextrose Injection USP. The antibiotic-dopamine-dextrose 5% admixtures were assayed for dopamine by colorimetric and chromatographic procedures. The antibiotics were assayed by standard microbiological methods. Kanamycin sulfate, tetracycline hydrochloride, carbenicillin disodium and chloramphenicol sodium succinate were stable in the Intropin-5% dextrose admixture for a period of 24 hours at room temperature in fluorescent and natural (western exposure) light. Gentamicin sulfate, penicillin G potassium and cephalothin sodium were stable in Intropin-5% dextrose admixture for six hours. Ampicillin sodium was stable in the Intropin admixture for only one hour. Amphotericin B was physically unstable in the Intropin-dextrose 5% solution upon admixture. The potency of dopamine hydrochloride remained substantially unchanged in the presence of the above antibiotics. It is recommended that dopamine not be added to amphotericin B or ampicillin sodium admixtures. Further, in order to avoid a fixed combination of potent drugs, it is recommended that a "piggyback" administration set or administration into a second injection site be employed when another drug is to be administered with dopamine hydrochloride.