Ibuprofen: Dosage, Side Effects & Other Facts
Generic ibuprofen tablets are often brownish-red in color.
Credit: BW Folsom | Shutterstock

Ibuprofen is a non-steroidal anti-inflammatory drug (NSAID) available both over-the-counter and, in greater strength, by prescription. It aims to relieve pain in a variety of cases, including fevers, headaches, toothaches, menstrual cramps, joint pain and backaches. It is sometimes prescribed to relieve the symptoms of osteoarthritis or rheumatoid arthritis, such as stiffness, tenderness and swelling, though it cannot cure arthritis. It works by blocking the body’s enzymes that make chemicals that signal pain.

"It's an anti-inflammatory drug typically prescribed for the treatment of pain and [it's] also effective for fever," said Dr. Aaron Clark, a family medicine physician at The Ohio State University Wexner Medical Center in Columbus, Ohio. 

Ibuprofen is commonly marketed as Advil, Motrin or Midol.

Nonprescription ibuprofen is available in the following forms: tablet, chewable tablet, liquid and drops of concentrated liquid. Adults and children over 12 can take ibuprofen every four to six hours as needed, though they should not take more than six pills in one day unless directed by a doctor. 

Children and infants can usually take ibuprofen every six to eight hours but should not have more than four doses in 24 hours unless directed by a doctor. If you are unsure about how much ibuprofen to give a child, consult a doctor who will determine the dosage based on the child’s weight.

"With children there's quite a bit of variation," Clark said. From birth to age 2, the dosage is dependent on the child's weight. "Their livers are more immature and are less able to metabolize medicine as older children can."

Ibuprofen is typically given in drop form to infants, and liquid form for children. But caregivers should not try to substitute one for the other, Clark said. 

"The infant drops are much more concentrated than the liquid," Clark told Live Science. "Parents will occasionally try to use the infant drops for a child and try to match up what they think the dose should be, and they end up overdosing their child with it."

Prescription ibuprofen should come with a doctor’s instructions. It is usually taken three or four times a day for arthritis symptoms or four to six hours as needed with prescribed for pain.

It is best to take ibuprofen with food or milk to prevent stomach upset. If a dose is missed, it should be taken as soon as the patient remembers, unless it is close to the time to take the next dose. In that case, do not double up on doses — simply skip the missed one.

Be careful when taking multiple medicines that they do not contain ibuprofen. Ibuprofen can be present in other medicines, including nighttime sleep aids, nonprescription cough and cold medicines, so combining them can cause patients to exceed the recommended dosage. The U.S. National Institutes of Health notes that this is especially dangerous for children.

Do not take other NSAID drugs unless given permission by a doctor. Tell the doctor if you are taking aspirin, lithium, water pills, steroids, blood thinner or blood pressure medicine in addition to ibuprofen.

People should not drink alcohol while taking ibuprofen.

Women in the later stages of pregnancy should not take ibuprofen. Patients with bleeding disorders, stomach ulcers, liver disease, advanced kidney disease, or who are about to or have just had coronary artery bypass graft surgery should not take ibuprofen.

Some people may suffer allergic reactions or asthma after taking ibuprofen, aspirin or other NSAIDs. Reaction symptoms may include:

  • Itching
  • Hives
  • Swelling of face or hands
  • Swelling or tingling in mouth or throat
  • Chest tightness
  • Breathing trouble

If such reactions occur, do not take ibuprofen again.

Ibuprofen and other NSAIDs may cause bleeding, holes or ulcers in the stomach or intestines. The risk is higher for people who have taken NSAIDs for a long time, are elderly, in poor health, who smoke or drink regularly or have had a stomach ulcer in the past.

The NIH warns that ibuprofen may increase the risk of heart attack or stroke, especially in those who have already have heart disease.

There are some side effects associated with ibuprofen use. These are less serious side effects that NIH recommends talking to a doctor about if they persist:

  • Constipation, diarrhea, or upset stomach
  • Dizziness or headache
  • Mild nausea, vomiting, gas, stomach pain or heartburn
  • Mild rash or itching skin
  • Ringing in ears

The NIH recommends calling a doctor immediately in the case of the following side effects:

  • Allergic reaction
  • Blistering, peeling or red skin rash
  • Bloody or black, tarry stools
  • Change in amount or frequency of urination 
  • Chest pain, shortness of breath or coughing up blood
  • Dark-colored urine or pale stools
  • Fever, neck pain or stiff neck
  • Numbness or weakness in arm or leg, or on one side of your body
  • Calf pain
  • Problems with vision, speech or walking
  • Rapid weight gain
  • Redness or swelling of the body area where you have pain
  • Severe stomach pain
  • Shortness of breath, cold sweat and bluish-colored skin
  • Skin rash or blisters with fever
  • Sudden or severe headache
  • Swelling in hands, ankles or feet
  • Trouble seeing, change in how you see colors
  • Unusual bleeding, bruising or weakness
  • Vomiting blood or a coffee-ground-like substance
  • Skin yellowing or whites of your eyes turning yellow

According to Columbia University Health, ibuprofen “appears to be slightly stronger” than aspirin when treating soft tissue injuries, dental pain and menstrual cramps. Aspirin is as effective as ibuprofen for headaches, migraines and fever reduction. Aspirin is sometimes recommended to reduce the risk of heart attack or stroke.

Though both ibuprofen and aspirin can irritate the stomach, ibuprofen is less of an irritant. Both drugs also cause an antiplatelet effect, which reduces the function of platelets, cells that help blood clot. This effect is much stronger in aspirin than in ibuprofen, which can be a benefit of aspirin depending on the patient’s needs. The antiplatelet effect can reduce the risk of heart attack.

Acetaminophen is commonly branded as Tylenol or Excedrin.  According to the Cleveland Clinic, it is not as effective for fevers, menstrual cramps or pains caused by inflammation, such as backaches and dental pains, as ibuprofen is. It is, however, considered better for treating headaches and arthritis. It is less likely to cause stomach irritation.

If a pet is in pain, its owners should not give it ibuprofen, said Greg Nelson, a veterinarian with Central Veterinary Associates, in Valley Stream, New York.

"A lot of people assume that it’s a good idea, and it most certainly is not," Nelson said. "In cats, there has never been success with the use of ibuprofen, and with dogs, they have a very narrow therapeutic range."

According to a 2004 report in Veterinary Medicine, "In dogs, cats, and ferrets, ibuprofen has a narrow margin of safety and is a frequent toxicosis reported to the ASPCA Animal Poison Control Center.” Dangers for animals include stomach ulceration, kidney failure and neurological damage.

Ibuprofen works by inhibiting enzymes that cause pain, but these enzymes help protect the mucosal lining of the intestinal tract. While this is generally not a problem for humans, it can cause damage for animals. The same is true for the antiplatelet effect: it is not generally harmful in humans but can lead to abnormal bleeding in animals.

Why can’t dogs take ibuprofen the way that people can? Because of their different sizes and the fact that individual dogs metabolize drugs at vastly different rates. This unpredictable absorption rate means that unexpected drug accumulation and other side effects can occur.

No NSAID, including ibuprofen, should be given to an animal without first consulting a veterinarian, who can prescribe a pet-friendly anti-inflammatory durgs such as meloxicam or carprophen. Furthermore, any dog that is going to take an NSAID should have blood work done first. 

With additional reporting by Laura Geggel, Staff Writer. Follow Laura on Twitter @LauraGeggel. Follow Live Science @livescience, Facebook & Google+.