What is Ibu: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

IBU is a brand-name version of ibuprofen, but it can only be purchased with a prescription. Each tablet contains high doses of ibuprofen, so healthcare professionals reserve its use for rheumatoid arthritis, osteoarthritis, or other pain that can’t be adequately managed with over-the-counter pain relievers. IBU is a nonsteroidal anti-inflammatory drug or NSAID that can have serious side effects, so high-dose IBU is prescribed at the lowest effective dose for the shortest time possible.

Ibu overview

BRAND NAMES:

  • IBU (Rx), Caldolor (Rx)

Generic Names:

  • Ibuprofen (Rx)

Uses:

  • Treats rheumatoid arthritis, osteoarthritis, painful periods (primary dysmenorrhea), and mild to moderate pain

Therapeutic Classes:

  • Nonsteroidal anti-inflammatory drug (NSAID), analgesic, antipyretic, antirheumatic, central nervous system agent

Forms:

  • Tablet

How it’s taken:

  • By mouth

What is Ibu used for?

Healthcare professionals prescribe IBU to treat the symptoms of rheumatoid arthritis and osteoarthritis. It’s also FDA-approved to treat painful periods and moderate to mild pain.

What form(s) does Ibu come in

  • Tablet

    • 400 mg

    • 600 mg

    • 800 mg

What are common Ibu doses?

  • For rheumatoid arthritis or osteoarthritis: 400, 600, or 800 mg taken every four or six hours

  • For painful periods: 400 mg every four hours as needed

  • For mild to moderate pain: 400 mg every four or six hours as needed

Find more information about ibuprofen dosage, forms, and strengths here.

Common Ibu prescriptions

  • IBU
    400mg tablet

  • IBU
    600mg tablet

  • IBU
    800mg tablet

How to take Ibu

  • Follow all the prescriber’s directions. Do not increase the dose or take IBU tablets more often than prescribed.

  • Take IBU tablets only if they’re needed. IBU should be taken for the shortest time possible.

  • Please read the NSAID Medication Guide that comes with this medicine.

  • Take IBU tablets with food to avoid digestive system problems.

  • Swallow the tablet whole with a glass of water.

  • Store IBU tablets at room temperature in a closed container. Avoid excessive heat.

What to do if you miss a dose of Ibu

  • Take a missed dose when remembered if symptoms persist.

  • Taking a missed dose will reset the dosing clock. Depending on the prescriber's instructions, do not take another dose for four or six hours.

  • Never take two or more IBU tablets to make up for a missed dose.

Ibu contraindications

  • This medicine is not right for everyone. 

  • Do not take ibuprofen if you have had an allergic reaction (including asthma) to ibuprofen, aspirin, naproxen, or any other NSAID.

  • IBU and other NSAIDs should not be taken right before or after coronary artery bypass graft surgery.

Ibu warnings

  • Tell any doctor or other healthcare provider who treats you that you are using this medicine.

  • Your doctor will schedule regular appointments and blood tests to check the effects of this medicine. Keep all appointments.

  • Tell your doctor if you are pregnant or breastfeeding.

    • Because of possible risks to an unborn child, NSAIDs should not be taken after the 20th week of pregnancy.

  • Tell the prescriber if you smoke.

  • Also, tell the prescriber if you have:

    • Heart disease

    • Heart failure

    • A recent heart attack

    • Blood circulation problems

    • Bleeding problems 

    • High blood pressure

    • A history of ulcers or gastrointestinal bleeding

    • Kidney disease

    • Liver disease

    • Asthma

    • Lupus

  • The doctor will avoid IBU in anyone who is dehydrated because of the risk of side effects. 

  • Ibuprofen increases the risk of:

    • Blood clots

    • Heart attack

    • Stroke

    • Heart failure

    • Fluid retention (edema) 

  • Prescription ibuprofen can cause severe gastrointestinal problems, including:

    • Ulcers

    • Bleeding

    • Perforation 

  • Ibuprofen can also cause:

    • Kidney damage

    • Liver damage

    • High blood pressure

    • High potassium

    • Anemia

  • Ibuprofen can delay ovulation in women.

  • Call the prescriber if symptoms get worse or don’t get better.

  • Tell any doctor, dentist, or other healthcare professional who treats you that you are using this medicine, particularly before any medical procedure.

Ibu interactions

  • Because of possible drug interactions, tell healthcare providers you are using this medicine.

  • Avoid taking other NSAIDs such as aspirin or naproxen. The prescription NSAID ketorolac should never be combined with IBU or other ibuprofen products.

  • Avoid drinking alcohol when taking ibuprofen. Having three or more drinks daily, along with regular ibuprofen doses, increases the risk of serious gastrointestinal side effects.

  • Other medications that may cause problems with ibuprofen include:

  • Tell any doctor or dentist who treats you that you are using this medicine.

Find more information about ibuprofen interactions to avoid here.

Ibu side effects

Serious side effects

Talk to a doctor if you notice any signs or symptoms of a possible serious side effect, including:

  • Severe stomach pain, vomiting blood, bloody stools, black and tarry stools

  • Chest pain, trouble breathing, weakness on one side of your body, severe headache, trouble seeing or talking, pain in your lower leg

  • Chest pain that may spread to your arms, jaw, back, or neck, trouble breathing, nausea, unusual sweating, faintness

  • Swelling in your hands, ankles, or feet, rapid weight gain

  • Unusual bleeding and bruising

  • Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes

  • Urinating more or less than usual

  • High blood pressure

  • Trouble seeing or other vision changes

  • Hearing loss

  • Blistering, peeling, or red skin rash

  • Allergic reactions: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

Less serious side effects

  • Heartburn

  • Gas

  • Diarrhea

  • Vomiting

  • Abdominal pain

  • Indigestion

  • Nausea

  • Ringing in the ears

  • Skin rash

  • Itching

  • Headache

  • Dizziness

Find more information about ibuprofen side effects here.

Sources:

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