Diclofenac (Voltaren): What Is It Used For?

What is diclofenac?

Diclofenac is an active ingredient used to relieve pain and reduce inflammation. It belongs to the NSAID family.

It appears in different salt forms and formulations, including diclofenac diethylamine, diclofenac epolamine, diclofenac potassium, and diclofenac sodium.

Common brand names in the United States include Voltaren, Cataflam, Cambia, and Zorvolex.

What is diclofenac used for?

According to the source content, diclofenac is used for the treatment of:

• Osteoarthritis
• Rheumatoid arthritis
• Spondyloarthritis and ankylopoyetic spondyloarthritis
• Extraarticular rheumatism
• Renal colic
• Musculoskeletal pain
• Lumbar pain
• Post-operative pain
• Post-traumatic pain
• Mild to moderate pain, such as headache, dental pain, menstrual pain, muscular pain, or back pain
• Primary dysmenorrhoea
• Inflammation and post-traumatic swelling
• Symptomatic treatment of acute gout attacks

The exact indication depends on the formulation and route of administration.

How diclofenac works

Diclofenac works by inhibiting the biosynthesis of prostaglandins. Prostaglandins are substances involved in pain, inflammation, and fever.

Forms and administration

Diclofenac may be given by mouth, rectally, or by intramuscular injection, depending on the product.

Oral use

It is preferably taken before meals and swallowed whole with liquid, without chewing.

Rectal use

Suppositories are generally recommended after bowel evacuation.

Parenteral use

Injectable solution is administered intramuscularly by deep intragluteal injection in the upper outer quadrant.

Therapeutic indications and dosage overview

The following information reflects the source content and may vary by product. Always verify the official leaflet for the exact formulation.

Contraindications listed in the source

• Hypersensitivity to diclofenac
• Asthma, urticaria, or acute rhinitis triggered by ASAAs or other NSAIDs
• Active Crohn’s disease
• Active ulcerative colitis
• Severe renal failure
• Severe liver failure
• Coagulation disorders
• History of gastrointestinal bleeding or perforation related to previous NSAIDs
• Active gastrointestinal ulcer, hemorrhage, or perforation
• Established CHF (NYHA II-IV), ischemic heart disease, peripheral arterial disease, and/or cerebrovascular disease
• Third trimester of pregnancy
• Proctitis for rectal use

Warnings and precautions

• Extra caution is noted in mild to moderate renal or liver failure, older adults, porphyria, and a history of ulcerative colitis or Crohn’s disease.
• Caution is also noted in people with a history of high blood pressure or heart failure.
• Risk assessment is important in people with cardiovascular risk factors such as diabetes, hypercholesterolemia, or smoking.
• Diclofenac should not be used in severe cardiovascular disease such as heart failure, ischemic heart disease, peripheral arterial disease, or cerebrovascular disease.
• The risk of gastrointestinal bleeding, ulcer, or perforation increases with higher NSAID doses.
• With prolonged treatment, there is a risk of atherothrombotic events such as myocardial infarction or stroke.
• Rare allergic reactions may occur, including anaphylactic or anaphylactoid reactions.
• Hypersensitivity reactions may evolve into Kounis syndrome, a severe allergic reaction that can lead to myocardial infarction.
• Diclofenac may mask signs and symptoms of infection and may alter female fertility.
• Avoid using it together with other NSAIDs, including selective COX-2 inhibitors, unless a clinician specifically advises otherwise.
• Monitoring of liver function, kidney function, and blood counts may be needed in prolonged treatment.
• It is not recommended for children under 14 years of age in the source content.
• Use the lowest possible dose for the shortest possible duration consistent with the treatment goal.
• Concomitant use with anticoagulants may increase bleeding risk.
• NSAIDs, including diclofenac, may increase the risk of gastrointestinal anastomotic leakage.
• Extra caution is advised after gastrointestinal surgery.

Liver and kidney considerations

Liver failure

Diclofenac is contraindicated in severe liver failure. In mild to moderate liver failure, caution is advised because liver enzymes may rise, especially with prolonged treatment.

Renal insufficiency

Diclofenac is contraindicated in severe renal insufficiency. In mild to moderate renal insufficiency, renal function monitoring is advised.

Interactions listed in the source

Diclofenac may interact with several medicines. The source content lists the following examples:

• Lithium and digoxin: plasma concentrations may increase
• Cyclosporine: nephrotoxicity may increase
• Diuretics and antihypertensive drugs such as beta-blockers and ACE inhibitors: action may decrease
• Isradipine and verapamil: efficacy may decrease
• Cholestyramine and colestipol: diclofenac efficacy may be reduced
• Methotrexate: action and toxicity may increase
• Anticoagulants: close monitoring is advised
• Other systemic NSAIDs: adverse effects may become more frequent
• Misoprostol and corticosteroids: toxicity may increase
• Potent CYP2C9 inhibitors such as sulfinpyrazone and voriconazole: diclofenac exposure may increase
• CYP2C9 inducers such as rifampicin: plasma concentrations may decrease
• Phenytoin: exposure may increase, so monitoring may be needed

Pregnancy and breastfeeding

The source content advises caution in the last trimester of pregnancy because of possible uterine adinamia and premature closure of the ductus arteriosus.

It also states that diclofenac passes into breast milk in small amounts and should not be administered during lactation to avoid undesirable effects on the infant.

Effects on driving and machinery

If diclofenac causes visual disturbances, dizziness, lightheadedness, drowsiness, or other central nervous system effects, driving or operating machinery should be avoided.

Possible adverse reactions and side effects

The source content lists the following adverse reactions:

• Headache
• Dizziness
• Vertigo
• Nausea
• Vomiting
• Diarrhea
• Dyspepsia
• Abdominal pain
• Flatulence
• Anorexia
• Rash
• Ischemic colitis
• Irritation at the rectal application site
• Injection-site pain, induration, reaction, and other local effects with intramuscular use
• Increased serum transaminases in laboratory tests

For injectable use, the source content also stresses strict adherence to administration instructions to reduce the risk of local complications.

What to verify in the official leaflet

Because diclofenac products differ by formulation, it is important to confirm:

• The exact active ingredient and salt form
• The intended route of administration
• The approved indication for that specific product
• Age limits and formulation-specific warnings
• Interaction warnings for your other medicines
• Pregnancy and breastfeeding guidance

Safety reminder

Frequently asked questions

Sources and references

The content on this page was rewritten from the provided source material and cross-referenced with official drug-information resources. For product-specific details, consult the FDA medication guide and the leaflet for the exact formulation.