ProvocholineŽ (methacholine chloride powder for inhalation) is a parasympathomimetic (cholinergic) bronchoconstrictor agent to be administered in solutiOn only, by inhalation, for diagnostic purposes. Each 20 mL vial contains 100 mg of methacholine chloride powder which is to be reconstituted with 0.9% sodium chloride injection or 0.9% sodium chloride injection containing 0.4% phenol (pH 7.0). See DOSAGE AND ADMINISTRATION for dilution procedures, concentrations and schedule of administration.