Probable and suspected Interactions of Aspirin

Aspirin is linked to several probable and suspected interactions that influence the activity of other drugs. Listed below are some common suspected interactions.

Aspirin can decrease the effects of medications (used for regulating blood pressure) by reducing the levels of blood pressure. This may happen because prostaglandins play a major role in regulating blood pressure.

Aspirin with Methotrexate

When Aspirin is used with aminoglycoside antibiotics or methotrexate the blood levels of aminoglycoside or methotrexate can increase, may be due to their elimination process from the body gets reduced. This leads to many side effects.

Individuals using anticoagulants or oral blood thinners like warfarin should not take aspirin as aspirin also aids blood thinning and can result in severe bleeding.

Some other products that can interact with aspirin are

  • Acetazolamide
  • Blood thinners
  • Mifepristone
  • Cortoicosteroids like valproic acid and other herbal medications like gingko biloba.

Before using Aspirin, speak to your doctor if you had recently taken vaccines like flu vaccine, varicella vaccine etc.,

Check all non prescription and prescription medicine labels properly because many medications comprise of fever reducers, pain relievers called as NSAIDs  like ibuprofen, naproxen etc., to avoid overdose of Aspirin read the labels very carefully before you take other medicines for cold, pain  and make sure these medicines do not contain aspirin.

Using NSAIDs can decrease the aspirin’s potential to prevent heart stroke or heart attack. If you are using Aspirin in low doses for preventing heart stroke or attack, discuss with your pharmacist or doctor for more information and to know about other alternative treatments for fever and pain.

Interactions of Aspirin with Anticoagulants/ Mifepristone

The interactions can be severe. These medicines can interact to yield harmful effects and that’s why should not be used together. Consult your physician for details.

You anticoagulant reduces the blood clot formation ability of your body. This may result in more bleeding and excessive bleeding can be fatal too.

Let your physician know that you are using anticoagulant before you start taking mifepristone. If you have already consumed mifepristone and are also using an anticoagulant, contact your physician immediately. You physician can help treat the problem as he knows the possible risks associated with the drug interaction.

Interactions of Aspirin with Ketorolac(Injectable)

The two medications should not be taken together as this can result in severe effects. The effects of either of the drugs can increase if taken together.  The side effects associated with the other drugs or aspirin can increase and result in stomach pain or stomach upset, bloody stools, drowsiness or dizziness. In some situations even the function of the kidney is affected.

You need to contact your health provider immediately as he can change or adjust your doses accordingly.  Also do not stop, start or change the dosage of medicines you are taking before informing your doctor.
As you do not know the after effects of each drug, it is always better to be safe and consult the physician in advance. You might not know as these effects can be life threatening too.

Facts to know about Aspirin during Pregnancy and Breastfeeding

Aspirin is not recommended during pregnancy as it can have adverse effect on fetus. However, low doses of aspirin have been used safely for preventing pregnancy complications.

FDA has also warned for not using aspirin during pregnancy, especially during the last trimester of pregnancy unless the physicians recommend the use of aspirin as it can cause problems in your unborn child or lead to complications during delivery.

A group of scientists have determined that a developmental toxicant is basically a substance that can harm unborn child. Drugs can lead to dangers to fetus or embryo throughout pregnancy, but the prime concern is during the first three months of pregnancy as vital organs and other systems are in developing phase and during last three months , when there are chances of excessive bleeding that may occur during labor.

As per studies conducted in England, 10-45% of women in first three months of their pregnancy are not aware of their present condition and use the well known OTP medication, aspirin. Aspirin and other medications comprising of salicylate are not safe to be used throughout pregnancy, especially during the last trimester of pregnancy ,except your doctor’s advice.

Since aspirin obstructs the prostaglandin levels, using it in third trimester of your pregnancy can result in premature rerouting of your baby’s blood in uterus and shutting down the ductus arteriousus.

Do not use aspirin when your delivery time is nearing as it can increase the risk of heavy bleeding. Some studies also say that use of aspirin can reduce the fertility as well. If you are using aspirin regularly as part of your treatment and you get pregnant, you should let your doctor know immediately to avoid unwanted effects.

Use of aspirin during first and second trimester of pregnancy has often noticed higher rates of unexpected miscarriages.

Well, in some cases low doses of aspirin are recommended during pregnancy, but after analyzing the possible risks and benefits by a physician only when other alternative and safe treatments aren’t available.

Aspirin and Breastfeeding

Aspirin is believed to be passed through breast milk to the baby and the baby gets 4 to 8 per cent of aspirin dose that mother takes.

Regular exposure of small doses of this medication can be harmful to your baby as aspirin starts building in their body.  Thus the use of aspirin in not recommended in nursing mothers as it there are chances that Reye ’s syndrome can develop in their babies.

Reye ’s syndrome is a medical condition that effects liver and brain and is observed more in children who are on medication for treating viral illness.

To reduce the risks of aspirin, you can check with your doctor if you can take other safe alternative treatments during pregnancy. There are many other alternative treatments available that can help you avoid using aspirin. If your doctor suggests you any other alternative treatment which is safe for you during pregnancy, go for it as it won’t have any side effects and you have a safe pregnancy period and normal delivery.

Dosage instructions that can help you take the right dose- Aspirin

You need to know about the right dosage when taking Aspirin. Knowing about the right dosage can help you know your medicine better.


Aspirin should be consumed with food. Dosage varies between

50 mg – 6000mg on a daily basis depending on the dose prescribed

Normal doses for pain (mild to moderate) – 350mg or 650 mg after every 4 hours

Or 500 mg after every six hours

Rheumatoid Arthritis- Dose

500 mg to be taken after every 4 to 6 hours

650mg after every 4 hours

1000mg – after every 4 to 6 hours

1950mg two times daily

75, 81,162, or 325 mg on a daily basis to prevent heart attack

In case you experience symptoms related to heart attack Aspirin (non-enteric coated) 160- 325mg can be chewed immediately.

For preventing another heart stroke 75-100mg on a daily basis is recommended.

It is recommended that you discard the medicine carefully. Do not flush them in toilet or throw them in drain. You can get in touch with your local waste organizations or pharmacist to know about the right way to dispose the medicine.

What if you missed a dose?

Since Aspirin is meant to be used when needed, you do not need to be on a dosing schedule. If you have maintained a schedule and miss a dose, you can take the missed dose as and when you remember. You can also skip the dose you missed if it is quite late and you need to take medication as per your next schedule. Do not take extra medicine to adjust the missed dose.

What if you overdose?

If you overdose and notice the symptoms of overdose call poison help or emergency medical help. The symptoms of overdose can be hearing loss (temporary), coma or seizure.


If you are using Aspirin for self treatment, you need to follow the directions given on the label.  If you are not sure about the instruction given on the package, speak to your pharmacist or doctor.

You can take this medicine orally with a glass of water. Avoid lying down for minimum 10 minutes after taking this medication. The duration of treatment and dosage entirely depends on your medical condition and how you respond to the treatment.

Do not use this medication for self treatment for pain for more than 10 days. Also avoid using this drug for self treatment of a fever that continues for more than 3 days. You need to consult your doctor in such cases.

If any of the symptoms get worse, seek medical help immediately. Some of the symptoms of overdose are

Mood changes

Pain in throat

Pain in stomach

Rapid breathing



There are different aspirin products available like some come with special coating whereas others are long-acting. Check with your pharmacist or doctor, which one suits you the best.

You need to be aware about how to use the medicine and avoid overdose. Even using the medicine for self treatment has some limitations and you should follow them.

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