What is Ibu? Uses, warnings & side effects

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 dosages?

  • 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.

Ibu images - What does Ibu look like?

  • 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 - Who shouldn't take Ibu?

  • 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 & what to avoid when taking Ibu

  • 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 - How does Ibu make you feel?

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.

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