Generic name: Isosorbide mononitrateBrand names: Monoket, Ismo, Imdur
Imdur is prescribed to prevent angina pectoris (crushing chest pain that results when partially clogged arteries restrict the flow of needed oxygen-rich blood to the heart muscle). This medication does not relieve angina attacks already underway.
Imdur may cause severe low blood pressure (possibly marked by dizziness or fainting), especially when you are standing or if you sit up quickly. People taking blood pressure medication or those who have low blood pressure should use Imdur with caution.
To maintain Ismo's protective effect, it is important that you take it exactly as prescribed.
Take Imdur once a day, when you get up in the morning. It may be taken with or without food. Imdur tablets should not be crushed or chewed. Swallow them with half a glass of liquid.
Do not switch to another brand of isosorbide mononitrate without consulting your doctor or pharmacist.
Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Imdur.
Headache is the most common side effect; usually, aspirin or acetaminophen will relieve the pain. The headaches associated with Imdur usually subside within a short time after treatment with the drug begins. Check with your doctor if your headaches persist or become more intense. Another common side effect is dizziness.
You should not take Imdur if you have had a previous allergic reaction to it or to other heart medications containing nitrates or nitrites. Your doctor will probably not prescribe Imdur if you have had a recent heart attack or congestive heart failure. If the doctor decides that Ismo is essential, your heart function and blood pressure will need to be closely monitored to avoid potential side effects.
Do not abruptly stop taking Ismo. Follow your doctor's plan for a gradual withdrawal.
Since Imdur can cause dizziness, you should be careful while driving, operating machinery, or performing other tasks that demand concentration.
Nitrate-type medications such as Imdur may aggravate angina caused by certain heart conditions.
Do not try to avoid a headache by changing your dose. If your headache stops, it may mean the drug has lost its effectiveness.
Be sure to tell your doctor about any medical conditions you have before starting Imdur therapy.
If Imdur is taken with certain other drugs, the effects of either could be increased, decreased, or altered. Extreme low blood pressure with dizziness and fainting upon standing up may occur if Imdur is taken with the impotence drug sildenafil or calcium-blocking blood pressure medications such as diltiazem, nifedipine, and verapamil.
Alcohol may interact with Imdur and cause a swift decrease in blood pressure, possibly resulting in light-headedness.
The effects of Imdur during pregnancy have not been adequately studied. If you are pregnant or plan to become pregnant, tell your doctor immediately. Imdur should be used during pregnancy only if it is clearly needed.
It is not known whether Imdur appears in breast milk. If the drug is essential to your health, your doctor may advise you to stop nursing until your treatment is finished.
The usual starting dose is 30 milligrams (taken as a single 30-milligram tablet or as one-half of a 60-milligram tablet) or 60 milligrams once a day.
After several days, your doctor may increase the dose to 120 milligrams (a single 120-milligram tablet or two 60-milligram tablets) once daily.
Your doctor may further adjust the dosage according to your response to the medication.
Safety and effectiveness of Imdur in children have not been established.
Any medication taken in excess can have serious consequences. Severe overdosage of Imdur can be fatal. If you suspect an overdose, seek medical help immediately.