Sunday, January 22, 2012

Drugs Made Famous For Their Unintended Effects


Zolpidem, commonly marketed as Ambien, has been around for years now as treatment for insomnia. Although it belongs to a separate class of drug, it has a sedative effect similar to the classic Valium. Zolpidem is known to have an occasional but bizarre side-effect: sleeptalking and sleepwalking. Scientists call it "paradoxical excitation." Instead of sedating the patient, it does the opposite - exciting him or wake him. In 1999, a semi-comatose patient in South Africa was given Ambien by his doctor (and why would a doctor give a sleeping pill to an almost comatose patient is really beyond me) because he thought the patient was suffering from insomnia. Miraculously, the patient "woke up" and later started talking. Since then, many cases were reported around the world of patients in persistent vegetative state who are awaken for a few hours by this wonderful drug.
Here's an example:
The New York Times has an interesting article about this unusual and paradoxical effect of Ambien:
and a formal study in the U.K. published in 2006 arrived to the same conclusion:
Why am I interested in this particular drug and its unusual effect? It's because my youngest sister has been in a persistent vegetative state for at least the past 12 years. This gives me hope that one day I will see my sister smiles back at me or even utter the words "Manong Yuri" that I haven't heard for a long, long time.
Which brings me back to the original issue on this note: how certain drugs became famous for treatment of medical conditions they are not originally intended for.
Take, for example, Minoxidil, popularly known as Rogaine. It was originally marketed as treatment for high blood pressure. Its unusual side-effect: increased growth or darkening of fine body hairs, or in some cases, significant hair growth. Now the topical version of the drug is one of the most popular treatment for balding or hair loss.
Who would have thought that one day doctors will be treating most cases of peptic ulcer with antibiotics like clarithromycin, amoxicillin and metronidazole? For so many years, the gold standard for treatment of peptic ulcer is acid suppression. Antacids and similar drugs ( ranitidine, omeprazole) reduce the acid produce in our stomach and they were the only medical treatment for ulcers. Then, in 1982 two Australian scientists proved to the world that a certain bacterium that survives the acidic environment of the stomach is actually the most common cause of peptic ulcer. They did it in such dramatic fashion (one of them actually ate the bacterium to prove his point) that in 2005 they received the Nobel Prize in Medicine.
Sildenafil, commonly marketed as Viagra, was originally studied for treatment of high blood pressure and chest pain (angina) but the scientists found that its intended effect was weak. However, they also found out that their male subjects experienced sustained erections as side-effect. Pfizer, the drug company, decided to market it for erectile dysfunction in 1996 and the rest is history. A Filipino friend wrongly claimed that Viagra actually was "discovered" in the Philippines, hence its name which she said comes from the word "bayag." :-)
The famous Alexander Fleming was conducting research on the flu and noticed that mold was growing in one of his petri dishes. He realized that the area with the mold had no bacteria. After further inspection, Fleming determined that the drug he called penicillin could be used to fight bacterial infections.
I'm sure more drugs will be discovered accidentally in the future. This tells us that medical science is not a perfect science. Many of its more remarkable discoveries are accidental.

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