Nitroglycerin pills for angina: Is there another option?

Q. For more than a year, I've been carrying a small vial of nitroglycerin pills to use in case of angina. But when I checked the bottle recently, I discovered that the jostling in my pocket had reduced them to a fine dust. How can I avoid this problem?

A. First, it's good news that you haven't needed to use your nitroglycerin pills! But to be on the safe side, you could consider switching to the spray version of this drug, which will eliminate the problem you describe.

Nitroglycerin pills, which are designed to be placed under the tongue, are the most common version of this medication. However, the tablets are sensitive to air, light, and heat. So the bottle should be recapped quickly and stored in a cool, dry place like a drawer. When you're out and about, another option is to carry the tablets in a small vial on a necklace rather than in your pocket. Once you open a bottle, the tablets are good for only a few months. If you don't open the bottle, studies suggest they are good for a year or so.

But the spray version (which you spritz under your tongue) is equally effective and has a shelf life of two to three years. Both forms of the medication cause a sweet, tingling sensation — a sign the drug is working.

Since you haven't needed the drug, that likely means you have not had any angina, the chest discomfort that can occur if the heart's arteries are narrowed from a buildup of plaque. A sudden increase in the heart's demand for oxygen-rich blood (from either physical exertion or mental stress) can trigger angina.

Nitroglycerin can provide rapid relief by widening the arteries that nourish the heart, reducing its workload. Because nitroglycerin also relaxes muscles in the veins, blood tends to pool in the legs. That decreases the amount of blood returning to the heart and reduces blood pressure. This side effect is why men who take erectile dysfunction drugs such as sildenafil (Viagra) or tadalafil (Cialis) must never take nitroglycerin. The combination can cause a severe and possibly fatal drop in blood pressure.

An interesting side note: nitroglycerin is also a key component in dynamite. The drug's discovery allegedly arose from the observation that some workers in a dynamite factory complained of chest pains only when they went home at night. The reason? They were having withdrawal from nitroglycerin in the air at work, which opened their coronary arteries. The regular air at home didn't.

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