Lidocaine, quinidine, and theophylline binding to human milk.

Lidocaine, quinidine, and theophylline binding to normal pooled mature human milk was determined using equilibrium dialysis at 4 degrees C. Binding to milk was compared with binding to pooled human serum. The observed binding was related to the relative lipid solubility of each drug in milk. The potential for the excretion of each drug into milk was also evaluated.