Objective: To probe into the incompatibility between bromhexine hydrochloride and azithromycin for injection in clinical practice

and to further find out the causes and provide evidence for clinical safe medication. Methods: The two drugs were dissolved separately

and the pH was measured according to the mixture of clinical proportion. Results: The pH of bromhexine hydrochloride solution was 4.38

and the pH of two different concentrations of azithromycin solution was 7.93 and 7.91

respectively. There were turbidity after mixing the two solutions. Conclusion: Bromhexine hydrochloride for injection is contraindicated with azithromycin for injection