Dear friend,
Thank you for your query at DoctorSpring.com

I can understand your concerns. Many over-the-counter medications can trigger acute intravascular hemolysis in children. Many drugs such as paracetamol fall under the LOW RISK category and can be used in routine doses. You should avoid a few drugs. Check the product label for phenazopyridine, chlorpheniramine, dextromethorphan or phenylephrine. Avoid aspirin, ibuprofen, etc. Also avoid Tylenol and sulfa drugs.
When in doubt, avoid the drug. Even paracetamol is considered unsafe by a few experts, but it has one of the lowest risks of triggering a hemolysis in your nephew. So, if he can avoid drugs altogether and use measures like steam inhalation or saline gargling, that would be the best way out.
Regards
Dr. Saptharishi L G