Many medicines can cause constipation. Medicines that are most likely to cause constipation include:

• Antihistamines, such as diphenhydramine (Benadryl), found in over-the-counter cold medicines.
• Antidiarrheal medicines, such as Lomotil.
• Antispasmodics, such as atropine and scopolamine.
• Narcotics, such as codeine and hydrocodone.
• Chemotherapy, such as vincristine and vinblastine.
• Anticonvulsants, such as carbamazepine and valproic acid.
• Tricyclic antidepressants, such as amitriptyline or doxepin.

If constipation occurs following the start of a medicine:

• For prescription medicine, before your child's next dose (the same day), call the health professional who prescribed it to determine whether your child should stop taking the medicine or take a different one. An appointment may not be necessary.
• For nonprescription medicine, stop giving your child the medicine. If you feel your child needs to continue taking the medicine, call your health professional.