Hi,
Corex syrup contains
chlorpheniramine,
dextromethorphan and menthol that is used in the treatment of common cold, cough, flu or allergy and their associated symptoms like runny nose, watery eyes, sneezing, itching, sinus congestion etc. But like other medications this medication has some side effects of its own. It may cause dizziness,
hallucinations, drowsiness, nervousness,
restlessness, blurring of vision, vertigo, ataxia, allergic reactions etc. But these side effects are temporary and usually go away after stop taking this medication. But if these side effects persist for long or bother your friend after stop taking this medication, then he should inform his doctor immediately for
medical help.
Take care. Hope I have answered your question. Let me know if I can assist you further.
Regards,
Dr. Zubayer Alam, General And Family Physician,