Serious side effects are unlikely to occur. Stop taking chlorpheniramine and phenylpropanolamine and seek emergency medical attention if you experience an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives). Other, less serious side effects may be more likely to occur. Continue to take chlorpheniramine and phenylpropanolamine and talk to your doctor or try another similar medication if you experience dryness of the eyes, nose, and mouth drowsiness or dizziness blurred vision difficulty urinating; or excitation in children Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.