The FDA has approved a generic version of an antihistamine drug developed by Cary-based Cornerstone Therapeutics (Nasdaq: CRTX).

Cornerstone announced the decision Monday and said production of the drug will being “immediately.”

The generic is a version of Tussionex Pennkinetic and is designed to relieve cough and upper respiratory symptoms linked to allergy or colds in adults as well as children age 6 and older.

Cornerstone worked with Coating Place and Neos Therapeutics in developing the compound.

“We are pleased with the FDA’s decision to approve our generic antitussive/antihistamine product,” said Craig Collard, Cornerstone’s chief executive officer, in a statement. “Given the recent industry challenges and changes related to prescription cough and cold medications, this product affords patients an approved generic drug product alternative as well as providing Cornerstone the opportunity for growth.”