Medically reviewed by Drugs.com. Last updated on Jul 29, 2023.
Uses for Nitrek
Nitroglycerin ointment or skin patch is used to prevent angina (chest pain) caused by coronary artery disease. It does not work fast enough to relieve the pain of an angina attack that has already started.
Nitroglycerin 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 work load. 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 Nitrek
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:
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.
Appropriate studies have not been performed on the relationship of age to the effects of nitroglycerin transdermal in the pediatric population. Safety and efficacy have not been established.
Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of nitroglycerin transdermal in the elderly. However, elderly patients are more likely to have low blood pressure and age-related liver, kidney, or heart problems, which may require caution and an adjustment in the dose for patients receiving nitroglycerin transdermal.
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.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Alteplase, Recombinant
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
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. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
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:
- Cardioversion (medical heart procedure) or
- Defibrillation (medical heart procedure)—Use with caution. The patch should be removed before having these procedures.
- 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 Nitrek
Use this medicine exactly as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. It will only work if applied correctly.
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 ointment and patch forms release medicine gradually to provide an effect for 7 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 use 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 use 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.
This medicine comes with a patient information leaflet. Read and follow the instructions in the leaflet carefully. Ask your doctor if you have any questions.
For patients using the ointment:
- Before applying a new dose of ointment, remove any ointment remaining on the skin from a previous dose. This will allow the fresh ointment to release the nitroglycerin properly.
- This medicine comes with papers to help measure the dose. Use them to measure the length of ointment squeezed from the tube and to apply the ointment to the skin. Do not rub or massage the ointment into the skin. Spread it in a thin, even layer, and cover an area of skin that is the same size each time it is applied.
- Apply the ointment to skin with little or no hair that is free of scars, cuts, or irritation.
- Apply each dose of ointment to a different area of skin to prevent irritation.
- If your doctor has ordered an airtight covering or dressing (such as plastic kitchen wrap) be placed over this medicine, make sure you know how to apply it. Airtight dressings will increase the amount of medicine absorbed through the skin and may cause more side effects. Use them only as directed and check with your doctor if you have any questions about this.
For patients using the patch system:
- Wash your hands with soap and water before and after applying a patch. Do not touch your eyes until after you have washed your hands.
- Do not try to trim or cut the adhesive patch to adjust the dosage. Check with your doctor if you think the medicine is not working as it should.
- Apply the patch to a clean, dry skin area with little or no hair that is free of scars, cuts, or irritation.
- Always remove a previous patch before applying a new one.
- Apply a new patch if the first one becomes loose or falls off.
- Apply each patch to a different area to prevent skin irritation.
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 transdermal dosage form (ointment):
- Adults—At first, 7.5 milligrams (mg), one-half inch of ointment, two times a day. Apply the first dose in the morning right after you wake up, and the second dose 6 hours later. Your doctor may increase your dose as needed.
- Children—Use and dose must be determined by your doctor.
- For transdermal dosage form (skin patch):
- Adults—Apply one patch once a day in the morning. Leave the patch in place for a total of 12 to 14 hours.
- Children—Use and dose must be determined by your doctor.
- For transdermal dosage form (ointment):
If you miss a dose of this medicine, apply 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.
If you forget to wear or change a patch, put one on as soon as you can. If it is almost time to put on your next patch, wait until then to apply a new patch and skip the one you missed. Do not apply extra patches to make up for a missed dose.
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.
After removing a used patch, fold it in half with the sticky sides together. Make sure to dispose of it out of the reach of children and pets.
Precautions while using Nitrek
If you will be using 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 use this medicine if you take riociguat (Adempas®), sildenafil (Viagra®), tadalafil (Cialis®), or vardenafil (Levitra®). Using one of these medicines while treated with nitroglycerin may cause severe drops in blood pressure, 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. Ask you doctor if you can take aspirin or acetaminophen to treat the headache.
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 using 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 with your doctor first. Your doctor may want you to gradually reduce the amount you are using before stopping it completely.
Tell the doctor in charge that you are using this medicine before having a magnetic resonance imaging (MRI) scan. Skin burns may occur at the site where the patch is worn during this procedure. Ask your doctor if the patch should be removed before having an MRI scan. You might need to put on a new patch after the procedure.
Side Effects of Nitrek
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:
- Arm, back, or jaw pain
- blurred vision
- chest pain or discomfort
- chest tightness or heaviness
- dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
- fast or irregular heartbeat
- unusual tiredness or weakness
- Bluish-colored lips, fingernails, or palms
- dark urine
- difficulty with breathing
- pale skin
- rapid heart rate
- sore throat
- unusual bleeding or bruising
Incidence not known
- Blistering, burning, crusting, dryness, or flaking of the skin
- difficulty with swallowing
- hives or rash
- itching, scaling, severe redness, soreness, or swelling of the skin
- puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
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
- 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:
- Burning, itching, redness, skin rash, swelling, or soreness at the application site
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.
Frequently asked questions
- How do you take GoNitro to treat an angina attack (chest pain)?
- What is the shelf life of nitroglycerin tablets?
More about Nitrek (nitroglycerin)
- Check interactions
- Compare alternatives
- Drug images
- Side effects
- Dosage information
- During pregnancy
- Drug class: antianginal agents
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.