Stability and compatibility of tirofiban hydrochloride during simulated Y-site administration with other drugs

The stability and compatibility of tirofiban hydrochloride injection during simulated Y-site administration with various other drugs were studied. Tirofiban hydrochloride, dobutamine, epinephrine hydrochloride, furosemide, midazolam hydrochloride, and propranolol hydrochloride injections were eac h prepared from their respective concentrates in both 0.9% sodium chloride injection and 5% dextrose injection at both the minimum and maximum concent rations normally administered. The high-concentration solutions of midazola m hydrochloride and furosemide were used as is. Morphine sulfate was dilute d in 5% dextrose injection only. Nitroglycerin premixed infusions, atropine sulfate injection, and diazepam injection were used as is. Tirofiban hydro chloride solutions were combined 1:1 with each of the secondary drug soluti ons in separate glass containers. Samples were stored for four hours at roo m temperature under ambient fluorescent light and were assayed for drug con tent and degradation by highperformance liquid chromatography and for pH, a ppearance, and turbidity. All mixtures except those containing diazepam remained clear and colorless, with no visual or turbidimetric indication of physical instability. Mixing of tirofiban hydrochloride and diazepam solutions resulted in immediate pr ecipitation. All remaining mixtures remained clear. There was no significan t loss of any of the drugs tested, no increase in known degradation product s, and no appearance of unknown drug-related peaks. The pH of all test solu tions remained constant. Tirofiban hydrochloride injection 0.05 mg/mL was stable for at least four h ours when combined 1:1 in glass containers with atropine sulfate, dobutamin e, epinephrine hydrochloride, furosemide, midazolam hydrochloride, morphine sulfate, nitroglycerin, and propranolol hydrochloride at the concentration s studied. Tirofiban hydrochloride was incompatible with diazepam.