Verapamil and breast-feeding

Concentrations of verapamil and norverapamil were measured in the plasma and breast milk of a woman receiving 120 mg verapamil three times daily. Whilst the concentrations of verapamil in breast milk averaged about 64% of those in maternal plasma no drug could be detected in the plasma of the infant. It is concluded that maternal therapy with verapamil does not pose a hazard to the suckling infant.