May cause CNS depression. Concurrent use of other CNS depressants may potentiate CNS depression. Possible tolerance, psychological dependence, and physical dependence following prolonged administration. Some formulations contain sulfites, or the dye tartrazine (FD&C yellow No. 5). Potential for increased respiratory-depressant effects and elevation of CSF pressure in increased intracranial pressure, head trauma, or other intracranial lesions. Administration may complicate assessment of acute abdominal conditions. Use may result in obstructive bowel disease, especially in underlying intestinal motility disorder. Possible dose-related respiratory depression. Potential for increased viscosity of bronchial secretions and suppression of cough reflex, with subsequent respiratory insufficiency, in asthma or pulmonary emphysema. Suppression of cough reflex following thoracotomy or laparotomy may lead to postoperative retention of secretions. Use with caution in debilitated patients and in those with hypothyroidism, Addison’s disease, and prostatic hypertrophy or urethral stricture. Risk of overdosage and toxicity (including death) in children <2 years of age receiving preparations containing antihistamines, cough suppressants, expectorants, and nasal decongestants alone or in combination for relief of symptoms of upper respiratory tract infection. Use with caution in geriatric patients. Use with caution in severe hepatic or renal impairment.