Indomethacin is available as an immediate-release capsule, an extended-release capsule, a suppository, or a liquid.

This medication can cause side effects and may interact with other over-the-counter or prescription medications.

Common Side Effects

If you are experiencing a side effect of this medication, call your healthcare provider. Depending on the severity of the side effect, you may need a simple dose adjustment or you may need to switch to another medication. 

The most common reported side effect of Indocin is headache, followed by: 

Dizziness Indigestion Nausea Diarrhea Decreased appetite Upper abdominal pain Hyponatremia (low blood sodium level) Constipation Rectal irritation Always feeling the need to empty your bowels Tinnitus (ringing or unexplained noise in one or both ears) Feeling discouraged, sad, or empty Weight gain

Serious Side Effects

While any side effect can be distressing, a serious side effect is classified by the potential to become life-threatening, lead to hospitalization, disability, or create permanent damage. 

If you feel you are experiencing a serious side effect, get prompt medical attention. If you are experiencing life-threatening symptoms, call 911 immediately.

Some of the more serious side effects of indomethacin are:

Shortness of breathTightness in chestDifficulty breathing or swallowingNoisy, rattling breathingSwelling in the abdomen, ankles, feet, hands, or legsSwelling of the face, tongue, lips, throat, or eyesNumbness in hands, feet, or lipsFeverBlistersRashHivesIntense itchingHoarse throatPale skinFast heartbeatSevere fatigue and lack of energyUnusual bleeding or bruisingStomach painVomitingDouble visionLoss of bladder controlDifficulty urinatingFainting

Symptoms of an Overdose

The following symptoms indicate a potential overdose. It is essential to call 911 and get help immediately if you are experiencing these symptoms.

Confusion about who you are, where you are, or the date and timeSevere headache, possibly the worse headache you’ve ever experiencedAn unusually strong feeling of sluggishness or drowsiness

Warnings

Black Box Warning

Indomethacin comes with a black box warning. The black box warning is the strongest warning level issued by the FDA. This warning alerts patients and healthcare providers of any serious risks associated with taking the medication.

The FDA issued a black box warning due to potential stomach bleeding and an increased heart risk with indomethacin. All NSAIDs, including indomethacin, run a risk of creating problems in the stomach, specifically with an increased risk of bleeding or developing an ulcer. In some cases, these side effects can be fatal.

NSAIDs like indomethacin are also known to increase heart attack risk, heart failure, or stroke. Factors such as how long you take the medication, the dose you take, or a history of heart issues may increase your risk.

Interactions

With any medication, vitamin, or supplement, there is a risk of interactions. Before starting Indocin, tell your healthcare provider and your pharmacist about all medications, vitamins, and supplements you take so they can be aware of potential interactions or contraindications.

The best way to take Indocin is with food. Taking an NSAID with food reduces the risk of nausea, bleeding in the gastrointestinal system, and ulcers.

A few known warnings and interactions when taking indomethacin:

Alcohol: Drinking alcohol while taking an NSAID such as indomethacin increases your risk for side effects—specifically bleeding in your stomach and intestines. Age: If you are older than 65 years of age, talk to your healthcare provider or pharmacist about the risks of taking this medication. Asthma: If you have asthma, primarily if you are known to have aspirin-sensitive asthma, you should inform your healthcare provider before taking Indocin. Taking this medication may cause a fatal reaction. Heart Conditions: If you have a history of heart problems or high blood pressure, indomethacin might not be the right medication for you. This medication is known to increase the risk of heart attack and stroke. It may also raise your blood pressure to a dangerous level. Gastrointestinal Issues: If you have a history of stomach ulcers or bleeding anywhere in the GI tract, there is an increased risk of new or worsening ulcers, swelling, and bleeding in the gastrointestinal system. Rectal Irritation: If you have a history of rectal irritation or rectal bleeding, inform your healthcare provider—especially if you intend to take indomethacin in suppository form.   Kidney Problems: This medication can damage your kidneys. If you experience any swelling in your feet or ankles, shortness of breath, or change in urine, contact your healthcare provider. Pregnancy: This medication is not safe for pregnant women since it can affect the baby’s heart’s development. Other NSAID Medications: Taking another NSAID such as ibuprofen, naproxen, or aspirin can be dangerous while taking Indocin. Taking two medications from the same category increases your chance of an overdose, as well as other side effects.

A Word From Verywell

Talk to your healthcare provider about any side effects you may be experiencing. If these side effects are bothersome, you may be able to try another medication that is less likely to cause you problems.

At Verywell, our goal is to provide you with accurate and relevant information. However, there is no guarantee all complications and interactions are listed. Always take time to speak with your healthcare provider about possible interactions or concerns about taking any medication.