A new drug called repinotan blocks the respiratory depressant effects of morphine-like opioid drugs-without altering their potent pain-relieving effects, according to a study in the October issue of Anesthesia & Analgesia, official journal of the International Anesthesia Research Society (IARS).If the promising results of animal studies are borne out by future research, then repinotan could become an important part of safe, effective pain control after surgery. The new study was led by Dr. Ulf Guenther of University of Ulm, Germany.