Generic Name: aspirin (AS-pir-in) (Oral route)
Medically reviewed by Drugs.com. Last updated on June 12, 2020.
Commonly used brand name(s)
In the U.S.
- Norwich Aspirin
Available Dosage Forms:
- Capsule, Extended Release, 24 HR
- Tablet, Chewable
- Tablet, Enteric Coated
Therapeutic Class: Platelet Aggregation Inhibitor
Pharmacologic Class: NSAID
Chemical Class: Salicylate, Aspirin
Uses for Halfprin
Aspirin extended-release capsules are used to lower risk of heart attack in patients with chronic coronary artery disease, such as patients with history of heart attack or angina (severe chest pain). It is also used to lower risk of recurrent stroke in patients who had an ischemic stroke or transient ischemic attack.
This medicine is available only with your doctor's prescription.
Before using Halfprin
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 aspirin extended-release capsules 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 aspirin extended-release capsules in the elderly.
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.
- Influenza Virus Vaccine, Live
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.
- Alipogene Tiparvovec
- Alteplase, Recombinant
- Amtolmetin Guacil
- Choline Salicylate
- Dabigatran Etexilate
- Ethacrynic Acid
- Flufenamic Acid
- Mefenamic Acid
- Niflumic Acid
- Nimesulide Beta Cyclodextrin
- Pentosan Polysulfate Sodium
- Protein C
- Reteplase, Recombinant
- Salicylic Acid
- Sodium Salicylate
- Tenofovir Disoproxil Fumarate
- Tiaprofenic Acid
- Tolfenamic Acid
- Varicella Virus Vaccine, Live
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.
- Enalapril Maleate
- Valproic Acid
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.
Using this medicine with any of the following may cause an increased risk of certain side effects but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use this medicine, or give you special instructions about the use of 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 nonsteroidal anti-inflammatory drugs (NSAIDs) or
- Asthma with nasal polyps and rhinitis, history of or
- Stomach ulcers or bleeding—Should not be used in patients with these conditions.
- Kidney disease, severe or
- Liver disease, severe—Avoid use in patients with these conditions.
Proper use of Halfprin
This section provides information on the proper use of a number of products that contain aspirin. It may not be specific to Halfprin. Please read with care.
Take this medicine only 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.
Take the capsule with a full glass of water at the same time each day.
Swallow the extended-release capsule whole. Do not crush, break, or chew it.
Do not take Durlaza™ 2 hours before or 1 hour after drinking alcohol.
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 oral dosage form (extended-release capsules):
- To lower risk of heart attack and stroke:
- Adults—162.5 milligrams (mg) (one capsule) once a day.
- Children—Use and dose must be determined by your doctor.
- To lower risk of heart attack and stroke:
If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
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.
Precautions while using Halfprin
It is very important that your doctor check your progress while you are using this medicine. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it.
This medicine can not be used for treatment of a heart attack. Use an immediate-release aspirin in such an event.
Make sure your doctor knows if you are pregnant or breastfeeding. Do not use this medicine during the later part of a pregnancy unless your doctor tells you to.
This medicine may increase risk for bleeding problems, including stomach ulcers or bleeding. This usually occurs if you are taking aspirin with certain medicines (eg, NSAIDs, blood thinner). Check with your doctor right away if you have black, tarry stools, severe or continuing stomach pain, unusual bleeding, bruising, or weakness, or vomiting of blood or material that looks like coffee grounds.
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.
Halfprin side effects
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:
Incidence not known
- Abdominal or stomach pain, cramping, or burning
- black, tarry stools
- bloody or cloudy urine
- change in consciousness
- chest pain or discomfort
- convulsions, severe or continuing
- dark urine
- decreased frequency or amount of urine
- difficult breathing
- fast breathing
- feeling that something terrible will happen
- general tiredness and weakness
- greatly decreased frequency of urination or amount of urine
- increased thirst
- irregular heartbeat
- light-colored stools
- loss of appetite
- loss of consciousness
- lower back or side pain
- muscle cramping and weakness
- muscle tremors
- nausea or vomiting
- numbness or tingling in the hands, feet, or lips
- rapid, deep breathing
- skin rash
- stomach cramps
- swelling of the face, fingers, or lower legs
- unusual bleeding or bruising
- unusual tiredness or weakness
- upper right abdominal or stomach
- vomiting of blood or material that looks like coffee grounds
- weakness or heaviness of the legs
- weight gain
- yellow eyes and skin
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:
Incidence not known
- Acid or sour stomach
- dry mouth
- stomach discomfort, upset, or pain
- trouble sleeping
- unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
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
More about Halfprin (aspirin)
- Side Effects
- During Pregnancy or Breastfeeding
- Dosage Information
- Drug Images
- Drug Interactions
- Drug class: platelet aggregation inhibitors
- FDA Alerts (3)
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.