What side effects can this medication cause?  

Chlorpheniramine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• dry mouth, nose, and throat
• upset stomach
• headache
• chest congestion
• diarrhea

If you experience any of the following symptoms, call your doctor immediately:

• vision problems
• difficulty urinating
• difficulty breathing
• muscle weakness
• prolonged drowsiness
• excitement (especially in children)
• dizziness
• skin rash

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online at http://www.fda.gov/MedWatch/report.htm or by phone 1-800-332-1088.