Why is Isordil prescribed?
Isordil is prescribed to relieve or prevent angina pectoris (suffocating chest pain). Angina pectoris occurs when the arteries and veins become constricted and sufficient oxygen does not reach the heart. Isordil dilates the blood vessels by relaxing the muscles in their walls. Oxygen flow improves as the vessels relax, and chest pain subsides.
In swallowed capsules or tablets, Isordil helps to increase the amount of exercise you can do before chest pain begins.
In chewable or sublingual (held under the tongue) tablets, Isordil can help relieve chest pain that has already started or prevent pain expected from a strenuous activity such as walking up a hill or climbing stairs.
Most important fact about Isordil
Isordil may cause severe low blood pressure (possibly marked by dizziness or fainting), especially when you stand or sit up quickly. People taking diuretic medication or those who have low blood pressure should use Isordil with caution.
How should you take Isordil?
Swallowed capsules or tablets should be taken on an empty stomach. While regular tablets may be crushed for easier use, sustained- or prolonged-release products should not be chewed, crushed or altered.
Chewable tablets should be chewed thoroughly and held in the mouth for a couple of minutes. Do not eat, drink, smoke, or use chewing tobacco while a sublingual tablet is dissolving.
This drug's effectiveness is closely linked to the dose, so follow your doctor's instructions carefully.
--If you miss a dose...
If you are taking Isordil regularly, take the forgotten dose as soon as you remember. If your next dose is within 2 hours--or 6 hours for controlled-release tablets and capsules--skip the one you missed and go back to your regular schedule. Do not take 2 doses at once.
--Storage information...
Store at room temperature in a tightly closed container, away from light.
What side effects may occur?
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Isordil.
Headache is the most common side effect; usually, standard headache treatments with over-the-counter pain products will relieve the pain. The headaches associated with Isordil usually subside within 2 weeks after treatment with the drug begins. Do not change your dose to avoid the headache. At a dose that eliminates headaches, the drug may not be as effective against angina.
Why should Isordil not be prescribed?
You should not take Isordil if you have had a previous allergic reaction to it or to other nitrates or nitrites.
Special warnings about Isordil
You should use Isordil with caution if you have anemia, the eye condition called glaucoma, a previous head injury or heart attack, heart disease, low blood pressure, or thyroid disease.
If you stop using Isordil, you should follow your doctor's plan for a gradual withdrawal schedule. Abruptly stopping Isordil could result in additional chest pain.
Some people may develop a tolerance to Isordil, which causes its effects to be reduced over time. Tell your doctor if you think Isordil is starting to lose its effectiveness.
Possible food and drug interactions when taking Isordil
If Isordil is taken with certain other drugs, the effects of either could be increased, decreased, or altered.
Extreme low blood pressure (marked by dizziness, fainting, and numbness) may occur if you take Isordil with certain other high blood pressure drugs such as Cardizem and Procardia, as well as the impotence remedy Viagra.
Alcohol may interact with Isordil and produce a swift decrease in blood pressure, possibly causing dizziness and fainting.
Special information if you are pregnant or breastfeeding
The effects of Isordil in pregnancy have not been adequately studied. Isordil should be used only when the benefits of therapy clearly outweigh the potential risks to the developing baby. If you are pregnant or plan to become pregnant, inform your doctor immediately. It is not known if Isordil appears in breast milk; therefore, nursing mothers should use Isordil with caution.
Recommended dosage
Because you can develop a tolerance to Isordil, your doctor may schedule a daily period of time when you do not take any drug.
ADULTS
The usual sublingual starting dose for the treatment of angina pectoris is 2.5 milligrams to 5 milligrams. Your doctor will increase this initial dose gradually until the pain subsides or side effects prove bothersome.
The usual sublingual starting dose for the prevention of an impending attack of angina pectoris is usually 5 or 10 milligrams every 2 to 3 hours.
To prevent chronic stable angina pectoris, the usual starting dose for swallowed, immediately released Isordil is 5 to 20 milligrams. Your doctor may increase this initial dose to 10 to 40 milligrams every 6 hours.
To prevent chronic stable angina pectoris with controlled-release Isordil, the usual initial dose is 40 milligrams. Your doctor may increase this dose from 40 to 80 milligrams given every 8 to 12 hours.
CHILDREN
The safety and effectiveness of Isordil have not been established for children.
Overdosage
Any medication taken in excess can have serious consequences. Severe overdosage of Isordil can be fatal. If you suspect an overdose, seek medical help immediately.
• Symptoms of Isordil overdose may include:
Bloody diarrhea, coma, confusion, convulsions, fainting, fever, flushed and perspiring skin (later cold and blue), nausea, palpitations, paralysis, rapid decrease in blood pressure, rapid, then difficult and slow breathing, slow pulse, throbbing headache, vertigo, visual disturbances, vomiting