In the late 1950s, U.S. drugmaker Upjohn was developing an ulcer treatment. When researchers gave the experimental compound to dogs, it did little for ulcers. Instead, blood vessels dilated and blood pressure dropped sharply. Upjohn shifted its target, ran more tests and developed minoxidil in 1963. In 1979, the compound won U.S. Food and Drug Administration approval as an oral hypertension drug. But patients taking it began growing hair. That side effect led to the idea that applying the drug to the scalp alone could treat hair loss. In 1988, the FDA approved topical minoxidil as a treatment for male-pattern baldness. A compound sought as an ulcer drug had passed through hypertension treatment and been reborn as a baldness remedy.
Similar cases are not rare. Sildenafil, developed as an angina drug, did not work on the heart as well as hoped, but erectile responses observed in male patients gave birth to Viagra in 1998. Finasteride, a treatment for benign prostatic hyperplasia, was found effective against male-pattern baldness and won additional approval as Propecia in 1997. Aspirin, introduced in 1899 as a fever reducer and painkiller, was approved in 1985 as a preventive treatment against recurrent heart attacks after it was found to inhibit platelet aggregation.
Applying drugs that have already won regulatory approval or whose development was halted to other diseases is known as drug repositioning. It is the rediscovery of medicines. Because the drugs have already been used in humans, animal testing and early-stage clinical trials can be skipped, sharply cutting time and cost.
The international journal Nature recently published research showing that elderly female mice given semaglutide, a compound used to treat obesity and diabetes, lived 12% longer than a control group. Their physical performance, muscle function and cognitive function improved, and blood sugar levels stabilized. Semaglutide is the active ingredient in the obesity drug Wegovy and the diabetes drug Ozempic. Whether it can be developed into a breakthrough drug that slows human aging and extends lifespan will require long-term clinical trials to determine, but how far it may evolve is a fascinating question.
