Monoket (Oral)

Generic name: isosorbide mononitrate [ eye-soe-SOR-bide-mon-oh-NYE-trate ]
Brand names: Imdur, Imdur ER, Ismo, Monoket
Drug class: Antianginal agents

Medically reviewed by Drugs.com. Last updated on Aug 6, 2024.

Uses for Monoket

Isosorbide mononitrate is used to prevent angina (chest pain) caused by coronary artery disease (heart disease). It does not work fast enough to relieve the pain of an angina attack that has already started.

Isosorbide mononitrate belongs to the group of medicines called nitrates. It works by relaxing the blood vessels and increasing the supply of blood and oxygen to the heart while reducing its workload. When used regularly on a long-term basis, this helps prevent angina attacks from occurring.

This medicine is available only with your doctor's prescription.

Before using Monoket

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies have not been performed on the relationship of age to the effects of isosorbide mononitrate in the pediatric population. Safety and efficacy have not been established.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of isosorbide mononitrate in the elderly. However, elderly patients are more likely to have severe low blood pressure and age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving isosorbide mononitrate.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

• Avanafil
• Riociguat
• Sildenafil
• Tadalafil
• Vardenafil

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

• Allergy to nitrates (eg, amyl nitrate, butyl nitrate) and nitrites—Should not be used in patients with these conditions.

• Congestive heart failure or
• Heart attack, recent or
• Hypertrophic cardiomyopathy (a heart disease) or
• Hypotension (low blood pressure) or
• Hypovolemia (low amount of blood)—Use with caution. May make these conditions worse.

Proper use of Monoket

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This form of nitrate is used to reduce the number of angina attacks over a long time. It will not relieve an attack that has already started because it works too slowly. The extended-release form gradually releases medicine to provide its effect for 8 to 10 hours. Check with your doctor if you also need a fast-acting medicine to relieve the pain of an angina attack.

You should take this medicine first thing in the morning and follow the same schedule each day. This medicine works best if you have a "drug-free" period of time every day when you do not take it. Your doctor will schedule your doses during the day to allow for a drug-free time. Follow the schedule of dosing carefully so the medicine will work properly.

Swallow the extended-release tablet whole with a half glass of water. Do not split, crush, or chew it.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

• For prevention of angina:
  • For oral dosage form (extended-release tablets):
    • Adults—At first, 30 or 60 milligrams (mg) once a day. Take the dose in the morning right after you wake up. Your doctor may increase your dose as needed.
    • Children—Use and dose must be determined by your doctor.
  • For oral dosage form (tablets):
    • Adults—20 milligrams (mg) two times a day. Take the first dose in the morning right after you wake up, and the second dose 7 hours later.
    • Children—Use and dose must be determined by your doctor.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Related/similar drugs

amlodipine, lisinopril, aspirin, metoprolol, furosemide, carvedilol, spironolactone, atenolol, propranolol, diltiazem

Precautions while using Monoket

If you will be taking this medicine for a long time, it is very important that your doctor check your progress at regular visits to make sure that this medicine is working properly. Blood tests may be needed to check for unwanted effects.

Do not take riociguat (Adempas®), sildenafil (Viagra®), tadalafil (Cialis®), or vardenafil (Levitra®) while you are using this medicine. Using these medicines together may lower your blood pressure and cause blurred vision, dizziness, lightheadedness, or fainting. If you are taking these medicines and you experience an angina attack, you must go to the hospital right away.

This medicine may cause headaches. These headaches are a sign that the medicine is working. Do not stop using the medicine or change the time you use it in order to avoid the headaches. If you have severe pain, talk with your doctor.

Dizziness, lightheadedness, or faintness may occur, especially when you get up quickly from a lying or sitting position. Getting up slowly may help.

Dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

Do not stop using this medicine without checking first with your doctor. Your doctor may want you to gradually reduce the amount you are using before stopping it completely.

Make sure any doctor or dentist who treats you knows that you are using this medicine. You may need to stop using this medicine several days before you have medical tests.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Side Effects of Monoket

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Less common

• Abnormal heart sound
• absence of or decrease in body movement
• arm, back, or jaw pain
• black, tarry stools
• bladder pain
• bleeding after defecation
• bleeding gums
• blood in the urine or stools
• blurred vision
• body aches or pain
• burning while urinating
• burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
• chest pain or discomfort
• chest tightness or heaviness
• chills
• cold sweats
• colds
• confusion
• convulsions
• cough or hoarseness
• decreased urine
• diarrhea
• difficult or labored breathing
• difficult, burning, or painful urination
• dilated neck veins
• dizziness
• dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
• dry mouth
• ear congestion
• extra heartbeats
• fainting
• fast, slow, irregular, pounding, or racing heartbeat or pulse
• fever or chills
• flu-like symptoms
• frequent urge to urinate
• frequent urination
• general feeling of discomfort or illness
• headache
• headache, severe and throbbing
• heart murmur
• increased need to urinate
• increased sweating
• increased thirst
• increased volume of pale, dilute urine
• irregular breathing
• itching, pain, redness, or swelling on the leg
• joint pain, stiffness, or swelling
• lightheadedness
• loss of appetite
• loss of voice
• lower back, side, or stomach pain
• muscle aches and pains
• muscle cramps
• nasal congestion
• nausea or vomiting
• nervousness
• numbness or tingling in the hands, feet, or lips
• pain or discomfort in the arms, jaw, back, or neck
• pain, tension, and weakness upon walking that subsides during periods of rest
• partial or slight paralysis
• passing urine more often
• pinpoint red or purple spots on the skin
• pounding in the ears
• runny nose
• shakiness in the legs, arms, hands, or feet
• shivering
• sneezing
• sore on the leg
• sore throat
• sudden decrease in the amount of urine
• sweating
• swelling
• swelling of the face, fingers, feet, or lower legs
• tightness in the chest
• trembling or shaking of the hands or feet
• trouble sleeping
• troubled breathing
• uncomfortable swelling around the anus
• unusual bleeding or bruising
• unusual tiredness or weakness
• vomiting of blood or material that looks like coffee grounds
• weakness
• weight gain

Rare

• Bluish-colored lips, fingernails, or palms
• dark urine
• pale skin
• rapid heart rate

Get emergency help immediately if any of the following symptoms of overdose occur:

Symptoms of overdose

• Blurred or loss of vision
• bulging soft spot on the head of an infant
• change in consciousness
• change in the ability to see colors, especially blue or yellow
• cold, clammy skin
• disturbed color perception
• double vision
• feeling of constant movement of self or surroundings
• halos around lights
• headache, severe and throbbing
• loss of consciousness
• night blindness
• overbright appearance of lights
• paralysis
• sensation of spinning
• tunnel vision

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

• Acid or sour stomach
• anxiety
• back pain
• belching
• blemishes on the skin
• bloated
• breast pain
• burning feeling in the chest or stomach
• burning, dry, or itching eyes
• change in color vision
• changes in vision
• cold sweats
• congestion
• constipation
• continuing ringing or buzzing or other unexplained noise in the ears
• cough producing mucus
• decreased interest in sexual intercourse
• difficulty seeing at night
• difficulty with moving
• discharge, excessive tearing
• double vision
• drooping upper eyelids
• dull ache or feeling of pressure or heaviness in the legs
• earache
• excess air or gas in the stomach or intestines
• feeling of constant movement of self or surroundings
• feeling of warmth
• feeling unusually cold
• frequent urge to defecate
• frozen shoulder
• full feeling
• hearing loss
• heartburn
• hyperventilation
• inability to have or keep an erection
• increased appetite
• increased sensitivity of the eyes to sunlight
• increased sputum
• indigestion
• irritability
• itching skin near damaged veins
• lack or loss of strength
• loss in sexual ability, desire, drive, or performance
• muscle or bone pain
• muscle stiffness or weakness
• nightmares
• noisy breathing
• pain or tenderness around the eyes and cheekbones
• passing gas
• pimples
• poor concentration
• rash
• redness of the face, neck, arms, and occasionally, upper chest
• redness, pain, swelling of the eye, eyelid, or inner lining of the eyelid
• redness, swelling, or soreness of the tongue
• restlessness
• seeing double
• sensation of spinning
• sleepiness or unusual drowsiness
• small clicking, bubbling, or rattling sounds in the lung when listening with a stethoscope
• small lumps under the skin
• sore mouth or tongue
• stiff neck
• stomach bloating, burning, cramping, or pain
• stomach discomfort or upset
• straining while passing stool
• stuffy nose
• sudden sweating
• swollen feet and ankles
• tender, swollen glands in the neck
• tenderness in the stomach area
• terrifying dreams causing sleep disturbances
• tooth disorder
• trouble swallowing
• uncontrolled twisting movements of the neck
• voice changes
• weight loss
• white patches in the mouth, tongue, or throat

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Commonly used brand name(s)

In the U.S.

• Imdur
• Imdur ER
• Ismo
• Monoket

Available Dosage Forms:

• Tablet, Extended Release
• Tablet

Therapeutic Class: Antianginal

Chemical Class: Nitrate

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer