Ketorolac vs. Diclofenac: Uses, Dosage, Side Effects, Differences

Ketorolac vs. diclofenac: What’s the difference?

• Ketorolac and diclofenac are nonsteroidal anti-inflammatory drugs (NSAIDs) used to treat varying levels of pain.
• Ketorolac is used for short-term management (up to 5 days) of moderately severe acute pain that otherwise would require narcotics.
• Diclofenac is used to treat mild to moderate pain, fever, and inflammation caused by conditions such as rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, tendinitis, bursitis, and menstrual cramps.
• Brand names for ketorolac include Acuvail, Acular LS, Omidria, and Sprix. The Toradol brand of ketorolac has been discontinued in the U.S.
• Brand names for diclofenac include Voltaren, Cataflam, Voltaren-XR, Cambia, Zipsor, and Zorvolex.
• Side effects of ketorolac and diclofenac that are similar include nausea and fluid retention.
• Side effects of ketorolac that are different from diclofenac include rash, ringing in the ears, headaches, dizziness, drowsiness, abdominal pain, diarrhea, constipation, indigestion, itching, and heartburn.
• Side effects of diclofenac that are different from ketorolac include ulcerations, abdominal burning, pain, cramping, gastritis, serious gastrointestinal bleeding, and liver toxicity.

What are ketorolac and diclofenac?

Ketorolac is a nonsteroidal anti-inflammatory drug (NSAID) used for short-term treatment (5 days or less) of moderately severe acute pain that otherwise would necessitate narcotics. Ketorolac is not used for minor or chronic pain. Other NSAIDs include ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn), but ketorolac is more effective in reducing pain from both inflammatory and non-inflammatory causes. Ketorolac reduces the production of prostaglandins, chemicals that cells of the immune system make that cause pain and inflammation. Ketorolac does this by blocking the cyclooxygenase 1 and 2 enzymes that cells use to make prostaglandins. As a result, pain and inflammation are reduced.

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) used to treat mild to moderate pain, fever, and inflammation caused by conditions such as rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, tendinitis, bursitis, and menstrual cramps. Other NSAIDs include ibuprofen (Advil, Motrin), indomethacin (Indocin), nabumetone (Relafen), and naproxen (Aleve, Naprosyn). NSAIDs work by reducing the production of prostaglandins, chemicals that cause pain, fever, and inflammation. NSAIDs block the enzyme that makes prostaglandins (cyclooxygenase), resulting in lower production of prostaglandins. As a consequence, inflammation, pain, and fever are reduced.

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What are the side effects of ketorolac and diclofenac?

Ketorolac

Common side effects from ketorolac include:

• Rash
• Ringing in the ears
• Headaches
• Dizziness
• Drowsiness
• Abdominal pain
• Nausea
• Diarrhea
• Constipation
• Indigestion
• Itching
• Heartburn
• Fluid retention

Rare side effects of ketorolac include:

• Abnormal thinking
• Serious allergic reactions
• Blurred vision
• Bronchospasm
• Jaundice
• Depression
• Difficulty concentrating
• Taste abnormality
• Euphoria
• Hemolytic-uremic syndrome
• High potassium blood levels
• Low sodium levels

Serious side effects of ketorolac include:

• Stomach ulcers
• Intestinal bleeding
• Reduced kidney function
• Liver failure

Other serious adverse events include:

• NSAIDs reduce the ability of blood to clot and therefore increase bleeding after an injury. Ketorolac may cause ulcers and bleeding in the stomach and intestines, particularly with use for more than five days. Sometimes, stomach ulceration and intestinal bleeding can occur without any abdominal pain. Sometimes, the only signs or symptoms of bleeding may be:
  • Black tarry stools
  • Weakness
  • Dizziness upon standing (orthostatic hypotension)
• NSAIDs reduce the flow of blood to the kidneys and impair function of the kidneys. The impairment is most likely to occur in patients with preexisting impairment of kidney function or congestive heart failure, and use of NSAIDs in these patients should be done cautiously.
• Liver failure has also been associated with ketorolac.
• People who are allergic to aspirin and other NSAIDs should not use ketorolac.
• Individuals with asthma or nasal polyps are more likely to experience allergic reactions to NSAIDs.

Diclofenac

The most common side effects of diclofenac involve the gastrointestinal system, such as:

• Ulcerations
• Abdominal burning
• Pain
• Cramping
• Nausea
• Gastritis
• Serious gastrointestinal bleeding
• Liver toxicity

Sometimes, stomach ulceration and bleeding can occur without any abdominal pain. Black tarry stools, weakness, and dizziness upon standing may be the only signs of internal bleeding. Rash, kidney impairment, ringing in the ears, and lightheadedness are also seen.

Other important side effects include:

• Fluid retention
• Blood clots
• Heart attacks
• Hypertension
• Heart failure

People who are allergic to other NSAIDs should not use diclofenac. NSAIDs reduce the flow of blood to the kidneys and impair function of the kidneys. The impairment is most likely to occur in patients with already reduced kidney function or congestive heart failure, and use of NSAIDs in these patients should be done cautiously. Individuals with asthma are more likely to experience allergic reactions to diclofenac and other NSAIDs.

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What is the dosage of ketorolac vs. diclofenac?

Ketorolac

• Treatment should begin with ketorolac injection.
• Tablets are used only if treatment is continued after patients begin to eat and drink.
• The total duration of therapy should not exceed 5 days because of the potential for gastrointestinal bleeding and other side effects.
• The recommended adult intravenous single dose is 15 to 60 mg.
• Multiple intravenous doses of 15 or 30 mg every 6 hours, not to exceed 60 or 120 mg a day, also may be used.
• Following intravenous therapy, the recommended dose is 1 (10 mg) or 2 (20 mg) tablets initially followed by 1 (10 mg) tablet every 4 to 6 hours, not to exceed 40 mg daily.
• The smaller dose is used for patients with poor kidney function or those older than 65 years.
• Oral ketorolac is not approved for individuals less than 17 years of age.

Diclofenac

Diclofenac should be taken with food to reduce stomach upset. The recommended dose for most conditions is 100 to 200 mg daily. Dosing intervals are 2 to 4 times daily depending on the diclofenac formulation used and the condition being treated.

What drugs interact with ketorolac and diclofenac?

Ketorolac

• Probenecid (Benemid) should not be combined with ketorolac because it reduces the elimination of ketorolac by the kidneys. This may lead to increased levels of ketorolac in the body and increased side effects from ketorolac.
• Ketorolac may increase the blood levels of lithium (Eskalith, Lithobid) by reducing the elimination of lithium by the kidneys. Increased levels of lithium may lead to lithium toxicity.
• Concomitant use of ketorolac and angiotensin converting enzyme (ACE) inhibitors may reduce the function of the kidneys.
• Individuals taking oral blood thinners or anticoagulants — for example, warfarin (Coumadin, Jantoven) — should avoid ketorolac because ketorolac also thins the blood, and excessive blood thinning may lead to bleeding.

Diclofenac

• Concomitant use of diclofenac and aspirin or other NSAIDs is not recommended because of the potential of increased adverse effects.
• The effects of anticoagulants such as warfarin and NSAIDs on GI bleeding are synergistic, such that users of both drugs together have a risk of serious GI bleeding higher than users of either drug alone.
• NSAIDs may diminish the antihypertensive effect of angiotensin converting enzyme (ACE) inhibitors.
• NSAIDs can reduce the natriuretic effect of furosemide and thiazides in some patients.
• NSAIDs have produced an elevation of plasma lithium levels and a reduction in renal lithium clearance. Thus, using NSAIDs, including diclofenac, and lithium concurrently, may lead to lithium toxicity.
• NSAIDs could increase the toxicity of methotrexate.
• Diclofenac, like other NSAIDs, may affect renal prostaglandins and increase the toxicity of certain drugs. Concomitant therapy with diclofenac and cyclosporine may increase toxic effects on the kidneys.

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Are ketorolac and diclofenac safe to use while pregnant or breastfeeding?

Ketorolac

There are no adequate studies in pregnant women. Ketorolac should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. NSAIDs may cause cardiovascular side effects during late pregnancy.

Ketorolac should not be used by nursing mothers because it is excreted in breast milk.

Diclofenac

It is not known whether diclofenac is excreted in breast milk.