Big-chain pharmacists in New York City are a prescription for disaster – committing 210,000 drug-dispensing errors a year, a new study charges.

Duane Reade, Rite Aid and other such megastores give seniors the wrong medication four times as often as independent pharmacies, said Sen. Jeff Klein (D-Bronx/Westchester), whose office analyzed such complaints to the state Office of Professions between 2005 and 2007.

“In a pharmacist’s work, there can be no room for error,” Klein said. “One small typo can seriously conflict with a patient’s care or even cause death.”