Drugmaker Merck & Co. says it now has about 40 experimental drugs in mid-or late-stage development as a result of its recent deal to buy New Jersey neighbor Schering-Plough Corp.

The combined company also has four drugs awaiting approval by regulators. Those include Schering-Plough medicines for asthma, schizophrenia and contraception, and a Merck drug for a dangerous irregular heartbeat.

The drugs in late-stage development include four treatments for heart disease, an injection for dangerous staph infections and a pill — instead of the shots now used — to gradually cut allergy symptoms in those with hay fever.

Merck, based in Whitehouse Station, N.J., says its integration of the two company's pipelines saw overlap in research programs.