Product Description.:
Nitroglycerin belongs to a class of drugs called nitrates. Other nitrates include isosorbide dinitrate (Isordil) and isosorbide mononitrate (Imdur, Ismo, Monoket). Nitroglycerin is used in the management of angina pectoris (heart pain). Synthesized in 1846, nitroglycerin was first used to treat anginal attacks in 1879. It was granted FDA approval in 1938.
Blood returning from the body in the veins must be pumped by the heart through the lungs and into the arteries against the high pressure in the arteries. In order to accomplish this work, the heart's muscle must produce and use energy (fuel). The production of energy requires oxygen. Angina pectoris (angina) or heart pain is due to an inadequate flow of blood (and oxygen) to the muscle of the heart. It is believed that all nitrates, including nitroglycerin, correct the imbalance between the flow of blood and oxygen to the heart and the work that the heart must do by dilating (widening) the arteries and veins in the body. Dilation of the veins reduces the amount of blood returning to the heart so that the heart does less work and requires less blood and oxygen. Dilation of the arteries also lowers the pressure in the arteries against which the heart must pump. As a consequence, the heart works less and requires less blood and oxygen.
Additionally, in patients with angina, nitroglycerin preferentially dilates blood vessels that supply the areas of the heart where there is not enough oxygen thereby delivering oxygen to the heart tissue that needs it most.
PRESCRIPTION: Yes
GENERIC AVAILABLE: Yes (for some dosage forms)
PREPARATIONS:
* Tablets: 0.3, 0.4, 0.6 mg
* Capsules: 2.5, 6.5, 9 mg Spray: 0.4 mg/spray
* Transdermal Patch: 0.1, 0.2, 0.3, 0.4, 0.6, 0.8 mg/hour
* Ointment: 2%
* Injection: 100, 200, 400 mcg/ml
* Injection solution: 5 mg/ml.
STORAGE: All formulations should be kept at room temperature, 15-30 C (59-86 F). The sublingual tablets are especially susceptible to moisture. They should NOT be kept in bathrooms or kitchens because of the greater moisture in these rooms. Care should be taken to replace the sublingual tablets every six months.
PRESCRIBED FOR: Nitroglycerin is used for the treatment and prevention of angina caused by coronary artery disease. Transdermal nitroglycerin, nitroglycerin ointment and capsules do not act rapidly enough to be used for acute angina attacks. Nitroglycerin also is used intravenously to treat congestive heart failure associated with myocardial infarction (heart attack) and high blood pressure during surgery.
DOSING: For the treatment of acute angina attacks or for acute prevention (for example, immediately before encountering situations likely to bring on an anginal attack), one tablet is allowed to dissolve under the tongue or in the buccal pouch (between the cheek and gums), or one spray is given of the lingual spray. Sublingual, spray and buccal nitroglycerin are rapidly absorbed from the lining of the mouth for immediate effects. This may be repeated every 5 minutes as needed. If angina is not relieved after a total of 3 doses, the patient should be taken to a hospital or a physician should be contacted. If lingual spray is used, the canister of spray should not be shaken prior to use, and it should be sprayed onto or under the tongue and then the mouth closed.
For prevention of angina, ointment may be applied using special dose-measuring application papers provided with the ointment. The usual dose is 1/2 to 2 inches applied every 4-6 hours. The appropriate amount of ointment is squeezed as a thin layer onto the paper, and the paper is used to spread the ointment onto a non-hairy area of the skin. The ointment should not be allowed to come into contact with the hands so that absorption from the hands does not occur.
Transdermal patches also are used for prevention. The usual dose is 0.2-0.8 mg/hr applied for 12 hours and then removed. An additional 12 hours should be allowed before applying the next patch because a 12 hour nitroglycerin free period reduces the occurrence of tolerance to the effects (reduced effectiveness) of nitroglycerin. Patches may be applied to any hairless site but should not be applied to areas with cuts or calluses which can alter absorption. Firm pressure should be used over the patch to ensure contact with the skin. The patch should not be cut or trimmed. Patches are waterproof and should not be affected by showering or bathing.
Capsules of long-acting nitroglycerin also are used for prevention. The usual dose is 2.5-9 mg administered 2 to 3 times per day 1 to 2 hours after a meal. Capsules should be swallowed whole and not chewed.
DRUG INTERACTIONS: Since nitroglycerin can cause hypotension (low blood pressure), other medications which also cause hypotension may produce sever
