Before my life-transforming heart by-pass operation, I controlled angina pain by taking tablets containing nitroglycerine. Since this is a highly explosive substance, one of my friends speculated that I might be banned from flying if I got too close to the sniffer dogs at the airport!

Nitroglycerine is so easy to detonate that it wasn’t widely used until a Swedish chemist discovered how to make it relatively safe. Alfred Nobel, the founder of the famous Nobel Prizes, mixed nitroglycerine with a clay to make dynamite. So a very useful heart drug contains the same stuff from which dynamite is made!

The use of nitroglycerine as both an explosive and a drug is an interesting example of the way many chemicals have very different functions. How they act depends largely on the concentration and the conditions. The concentration of nitroglycerine in medication, and the moist environment in the body, make it impossible for it to explode.

The low concentration of nitroglycerine that’s absorbed by the body is sufficient to dilate the blood vessels, increase the blood supply to the heart, and reduce the workload of sending blood around a body. Angina pain is avoided as the heart muscle receives the oxygenated blood it needs for good functioning.

So next time you see someone taking heart pills, don’t feel that you need to take cover.

Bob