Nitroglycerin

Take no more than the smallest possible amount needed to relieve pain.

Daily headaches may be an indicator of the drug's activity. Do not change your dose to avoid the headache, because you may reduce the drug's effectiveness at the same time.

Before taking nitroglycerin, tell your doctor if you have had a recent heart attack, head injury, or stroke; or if you have anemia, glaucoma (pressure in the eye), or heart, kidney, liver, or thyroid disease.

If you use a patch, dispose of it carefully. There is enough drug left in a used patch to be harmful to children and pets.

Since nitroglycerin can cause dizziness, you should observe caution while driving, operating machinery, or performing other tasks that demand concentration.

The benefits of applying nitroglycerin to the skin of people experiencing heart attacks or congestive heart failure have not been established. If you are using the medication for these conditions, your doctor will monitor you to prevent low blood pressure and pounding heartbeat.

Possible food and drug interactions when taking Nitroglycerin

If nitroglycerin is taken with certain other drugs, the effects of either could be increased, decreased, or altered.

Taken with many high blood pressure drugs, nitroglycerin may cause extreme low blood pressure (dizziness, fainting, numbness). Take particular care with calcium channel blockers such as Calan and Procardia XL, as well as isosorbide dinitrate (Sorbitrate, Isordil, others), isosorbide mononitrate (Ismo, others), blood vessel dilators such as Loniten, and beta-blocker medications such as Tenormin. Nitroglycerin may also cause a severe drop in blood pressure when taken with the impotence drug Viagra.

Aspirin can increase the effects of nitroglycerin.

Alcohol may interact with nitroglycerin and cause a swift decrease in blood pressure, possibly causing dizziness and fainting.

Also be alert for an interaction with dihydroergotamine (D.H.E.). Check with your doctor if you are uncertain about any combination you plan to take.