A DRUG normally prescribed for asthma could be a successful treatment for the common cold, say researchers from Gothenburg University, Sweden. Their findings, reported in Doctor, show that sodium cromoglycate, used in brand names such as Intal, can banish symptoms such as a sore throat, runny nose and cough three days earlier than a placebo. The drug may offer particularly valuable protection to the chronically sick, the elderly and asthmatics themselves, say the researchers.