Drugs That Can Cause Constipation Aluminum antacids Anticonvulsants Antidepressants Antihistamines Antipsychotics Antispasmodics Beta blockers Calcium channel blockers Codeine cough syrups Decongestants Diuretics Iron supplements Muscle relaxants Narcotics Nonsteroidal anti-inflammatory drugs Parkinson’s drugs Sedatives Tranquilizers