A worldwide alert has been raised over the severe side effects that can be caused by the osteoporosis drug alendronate, marketed as Fosamax.
Doctors in America and the UK have already been notified of the possible reactions, which include ulceration of the esophagus (gullet). So far, 31 people on the drug have been admitted to hospital.
Doctors have been asked to notify all their alendronate patients to inform them of the possible side effects and to recommend that they take the drug with a large (200ml) glass of water at least 30 minutes before eating, and not to lie down for about 30 minutes after taking it.
Health officials have been telling doctors to get a full medical history of the patient before prescribing alendronate. They should not use it in patients who have had esophagitis, or abnormalities such as strictures and achalasia (inability of a muscle to relax).
The manufacturer Merck Sharpe & Dohme admits that the numbers suffering esophageal irritation is far higher than the 1.5 per cent reported in the clinical trials.
About 475,000 people worldwide take the bone building drug.