A method of treating a warm-blood vertebrate. The vertebrate may be a human being or a lower animal. The treatment method involves administering to the vertebrate in need of such treatment a pharmaceutically effective amount of a complex of halide-free glucosamine and a therapeutic drug having a pK.sub.a of less than 7. Preferably, the complex is stabilized by coating it with at least one pharmaceutically acceptable polymer comprising a water-soluble, water-immiscible and/or water-swellable homopolymer and/or copolymer. Suitable polymers include carboxypolymethylene homopolymers and copolymers; polyethylene glycol homopolymers and copolymers, povidone homopolymers and copolymers, polyacrylic acid homopolymers and copolymers; polyacrylamide homopolymers and copolymers; polysaccharides; and mixtures of two or more of the foregoing polymers. The resultant polymer-coated complex will be stable upon exposure to ambient temperature and/or the atmosphere. Suitable acidic therapeutic drugs may be found in one or more of the following classes of therapeutic drugs: .alpha.- and .beta.-Adrenergic Agonists; Narcotic and Non-Narcotic Analgesics; Anorexics; Antiallergics; Antianginals; Antiarrhythmics; Antiasthmatics; Antibiotics; Anti-coagulants; Anticonvulsants; Antidepressants; Antidiabetics; Antihistaminics; Anti-hypertensives; Nonsteroidal Anti-Inflammatories; Antimigraines; Antineoplastics; Antiparkinsonians; Antipsychotics; Antipyretics; Antispasmodics; Antithrombotics; Anti-ulceratives; Anxiolytics; Decongestants; Diuretics; Hepatoprotectants; Sedatives; and Vasodilators.