What are good sinus or allergy medicines for post nasal drip?

Depends on the cause: If it's caused by allergies, nasal corticosteroid spray (e.g. Flonase) may help. If a sinus infection is the cause, antibiotics may help. Drip caused by environmental irritants (perfumes, smoke, etc.) can sometimes get better with an anticholinergic nasal spray (e.g. Atrovent nasal). An otc treatment that may help any cause is daily nasal lavage (e.g. Sinus rinse or neti pot). See your md.