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Diclofenac Side Effects

In Summary

More frequently reported side effects include: abdominal pain, constipation, diarrhea, dyspepsia, fluid retention, nausea, and headache. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to diclofenac: oral capsule, oral capsule liquid filled, oral powder for solution, oral tablet, oral tablet enteric coated, oral tablet extended release

Other dosage forms:

In addition to its needed effects, some unwanted effects may be caused by diclofenac. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking diclofenac:

More common:
  • Abdominal or stomach bloating, burning, cramping, or pain
  • belching
  • bloody or black, tarry stools
  • cloudy urine
  • constipation
  • decrease in urine output or decrease in urine-concentrating ability
  • diarrhea
  • dizziness
  • feeling of indigestion
  • headache
  • increased bleeding time
  • itching skin or rash
  • loss of appetite
  • nausea and vomiting
  • pain in the chest below the breastbone
  • pale skin
  • severe stomach pain
  • swelling
  • troubled breathing with exertion
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • vomiting of blood or material that looks like coffee grounds
  • weight loss

If any of the following symptoms of overdose occur while taking diclofenac, get emergency help immediately:

Symptoms of overdose:
  • Agitation
  • blurred vision
  • change in consciousness
  • change in the ability to see colors, especially blue or yellow
  • confusion
  • depression
  • difficult or troubled breathing
  • hives
  • hostility
  • irregular, fast or slow, or shallow breathing
  • irritability
  • loss of consciousness
  • muscle twitching
  • nervousness
  • pain or discomfort in the chest, upper stomach, or throat
  • pale or blue lips, fingernails, or skin
  • puffiness or swelling of the eyelids or around the eyes, face, lips, or tongue
  • rapid weight gain
  • seizures
  • sleepiness
  • slow or fast heartbeat
  • stupor
  • swelling of the face, ankles, or hands
  • tightness in the chest
  • trouble sleeping
  • unusual drowsiness, dullness, or feeling of sluggishness

Minor Side Effects

Some of the side effects that can occur with diclofenac may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Continuing ringing or buzzing or other unexplained noise in the ears
  • excess air or gas in the stomach or intestines
  • hearing loss
  • lack or loss of strength
  • passing gas

For Healthcare Professionals

Applies to diclofenac: compounding powder, intravenous solution, oral capsule, oral delayed release tablet, oral powder for reconstitution, oral tablet, oral tablet extended release


Very common (10% or more): Nausea (up to 24%), constipation (up to 13%)
Common (1% to 10%): Abdominal pain, diarrhea, dyspepsia, flatulence, gross bleeding/perforation, heartburn, gastric and duodenal ulcers, vomiting
Rare (less than 0.1%): Colitis, eructation, pancreatitis
Frequency not reported: Dry mouth, esophagitis, gastritis, glossitis, hematemesis, stomatitis[Ref]

NSAIDs including this drug, can cause serious gastrointestinal (GI) events which can occur at any time, with or without warning. For patients who develop a serious upper GI event, only about 20% were symptomatic. Upper GI ulcers, gross bleeding, or perforation occurred in approximately 1% of patients treated with NSAIDs for 3 to 6 months and 2% to 4% of patients treated for 1 year. Patients with a prior history of peptic ulcer disease and/or GI bleeding had a greater than 10-fold increased risk for developing a GI bleed than patients with neither of these risk factors.[Ref]


Borderline elevations of 1 or more liver tests to less than 3 times the upper limit of the normal (3 x ULN) or greater elevations in transaminases occurred in about 15% of patients treated with this drug. Elevations to greater than 3 x ULN of AST occurred in about 2% (n=5700) of patients at some point during treatment. In an open-labeled trial among patients receiving NSAIDs, a higher incidence of transaminase elevations were observed in patients receiving diclofenac compared with other NSAIDs.[Ref]

Common (1% to 10%): Elevated liver enzymes
Rare (less than 0.1%): Hepatitis, jaundice, liver disorder
Very rare (less than 0.01%): Fulminant hepatitis, hepatic necrosis, hepatic failure
Postmarketing reports: Drug-induced hepatotoxicity[Ref]


Common (1% to 10%): Abnormal renal function, increased serum creatinine
Rare (less than 0.1%): Nephrotic syndrome, interstitial nephritis, renal papillary necrosis, acute renal failure, urinary frequency, nocturia, proteinuria, and hematuria[Ref]


Common (1% to 10%): Pruritus, rashes
Rare (less than 0.1%): Angioedema, toxic epidermal necrolysis, erythema multiforme, exfoliative dermatitis, Stevens-Johnson syndrome, urticaria
Very rare (less than 0.01%): Bullous eruptions, eczema, erythema, erythema multiforme, toxic epidermal necrolysis (Lyell's syndrome), dermatitis exfoliative, loss of hair, photosensitivity reaction
Frequency not reported: Increased sweating[Ref]


NSAIDs inhibit platelet aggregation and have been shown to prolong bleeding time in some patients. Unlike aspirin, the NSAID effect on platelet function is quantitatively less, of shorter duration, and reversible.[Ref]

Common (1% to 10%): Anemia, increased bleeding time
Rare (less than 0.1%): Agranulocytosis, hemolytic anemia, aplastic anemia, lymphadenopathy, pancytopenia
Very rare (less than 0.01%): Thrombocytopenia, leukopenia, positive Coombs' test
Frequency not reported: Ecchymosis, eosinophilia, melena, purpura, rectal bleeding[Ref]


Uncommon (0.1% to 1%): Urticaria, rash, angioedema, bronchospasm
Rare (less than 0.1%): Anaphylactic reactions
Very rare (less than 0.01%): Angioneurotic edema (including facial edema)[Ref]


Rare (less than 0.1%): Changes in appetite, hyperglycemia
Frequency not reported: Weight changes[Ref]

Nervous system

Common (1% to 10%): Dizziness, headaches
Rare (less than 0.1%): Meningitis
Very rare (less than 0.01%): Memory impairment
Frequency not reported: Confusion, drowsiness, insomnia, paresthesia, tremors[Ref]


Clinical trials of several cyclooxygenase (COX)-2 selective and nonselective NSAIDs of up to 3 years duration have shown an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal. All NSAIDs appear to have a similar risk. There is no consistent evidence that concurrent use of aspirin mitigates this increased risk and may be associated with an increased risk of serious gastrointestinal events.

Pharmacoepidemiological data reveal an increased risk of arteriothrombotic events associated with diclofenac use, particularly at a high dose and during long-term treatment. In a meta-analysis of long-term treatment with diclofenac 150 mg/day, compared with placebo use of this drug resulted in approximately 3 additional major vascular events per 1000 participants.[Ref]

Common (1% to 10%): Edema
Uncommon (0.1% to 1%): Cardiac failure, chest pain
Rare (less than 0.1%): Arrhythmia, hypotension, myocardial infarction, palpitations
Very rare (less than 0.01%): Vasculitis
Frequency not reported: Congestive heart failure, tachycardia, syncope, hypertension[Ref]


Rare (less than 0.1%): Hallucinations
Very rare (less than 0.01%): Disorientation, depression, nightmare, irritability, psychotic disorder
Frequency not reported: Anxiety, nervousness[Ref]


Common (1% to 10%): Tinnitus,
Rare (less than 0.1%): Hearing impairment
Frequency not reported: Fever, asthenia, vertigo[Ref]


Rare (less than 0.1%): Conjunctivitis
Very rare (less than 0.01%): Blurred vision, visual disturbance, diplopia
Frequency not reported: Optic neuritis


The most common adverse reactions among patients treated with this drug included; gastrointestinal events of abdominal pain, constipation, diarrhea, dyspepsia, flatulence, gross bleeding,/perforation, heartburn, nausea, gastric and duodenal ulcers, and vomiting; abnormal renal function, anemia, dizziness, edema, elevated liver enzymes, headaches, increased bleeding time, pruritus, rashes, and tinnitus.


Common (1% to 10%): Urinary tract infection
Frequency not reported: Cystitis, dysuria, hematuria, interstitial nephritis, oliguria/polyuria


Frequency not reported: Infection, sepsis


Common (1% to 10%): Local reactions such as itching, burning, and increased bowel movement with suppository use
Very rare (less than 0.01%): Exacerbation of hemorrhoids with suppository use


Common (1% to 10%): Sinusitis, upper respiratory infection, nasopharyngitis, bronchitis
Rare (less than 0.1%): Pneumonia
Frequency not reported: Asthma, dyspnea


1. "Product Information. Voltaren (diclofenac)." Novartis Pharmaceuticals, East Hanover, NJ.

2. Cerner Multum, Inc. "Australian Product Information." O 0

Not all side effects for diclofenac may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

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