Sodium bicarbonate Erythromycin

Additionally, sodium bicarbonate is used in solutions as a buffering agent for erythromycin, lidocaine, local anesthetic solutions, and total parenteral nutrition (TPN) solutions. In some parenteral formulations, e.g., niacin, sodium bicarbonate is used to produce a sodium salt of the active ingredient that has enhanced solubility. Sodium bicarbonate has also been used as a freeze-drying stabilizer and in toothpastes. 

An established interaction, which can be exploited. Should erythromycin be used to treat urinary tract infections its efficacy can be maximised by making the urine alkaline (for example with acetazolamide or sodium bicarbonate). Treatment with urinary acidifiers will minimise the activity of the erythromycin for urinary tract infections and should be avoided. There is no evidence that the efficacy of erythromycin in other infections is affected by urinary acidifiers or alkalinisers. 

This compound is a complex mixture of the sulfates of gentamycin Ci, gentamycin CiA and gentamycin C2. Pharmaceutical incompatibilites include amphotericin, cephalosporins, erythromycin, heparin, penicillins, sodium bicarbonate, and sulfadiazine sodium [295]... 

---