Generic Name  : Diclofenac.

Trade Name      : Voltaren (diclofenac sodium) , Cataflam (diclofenac potassium), Catafast (diclofenac potassium).

Drug Class      : NSAIDs

Source            : Acetic Acid Derivatives.

Classification: Non-Selective COX Inhibitors.

Forms of The Drug

  1. Tablets: 25mg, 50mg, 75mg.
  2. Capsules: 25mg.
  3. Oral Liquid Suspension.
  4. Topical Gels, Creams, and Solutions.
  5. Transdermal Patches.
  6. Injectable Solutions.
  7. Packet: 50mg/single-dose packet.

Mechanism of Action

Diclofenac inhibits both isoforms of cyclooxygenase, namely COX-1 and COX-2, although its affinity for COX-2 is relatively higher. COX-1 is constitutively expressed in various tissues and is involved in the production of prostaglandins that regulate normal physiological functions, such as gastric mucosal protection and platelet aggregation. COX-2, on the other hand, is an inducible enzyme that is primarily responsible for the production of prostaglandins at the site of inflammation. By inhibiting COX enzymes, diclofenac reduces the production of prostaglandins. Prostaglandins sensitize pain receptors, increase blood flow to the site of injury or inflammation, and cause swelling and redness. Therefore, by decreasing the levels of prostaglandins, diclofenac helps to alleviate pain, reduce inflammation, and lower fever associated with various conditions. Also, It inhibits the migration of white blood cells to the site of inflammation, thereby reducing the inflammatory response. It also inhibits the release of inflammatory mediators, such as cytokines and chemokines, further reducing inflammation.


  1. Pain and inflammation including arthritis, musculoskeletal conditions as sprains, strains, tendonitis, bursitis, and back pain, postoperative pain, dental pain.
  2. Menstrual cramps (dysmenorrhea).
  3. Migraine headaches.
  4. Ankylosing spondylitis.
  5. Fever.


  1. Hypersensitivity or allergic reactions.
  2. Asthma, nasal polyps, and aspirin sensitivity.
  3. Active gastrointestinal bleeding or ulcers.
  4. Severe liver or kidney dysfunction.
  5. Pregnancy and breastfeeding.
  6. Cardiovascular disease including heart attack, stroke, or high blood pressure.
  7. In children under the age of 18.

Side Effects

  1. Edema (33%)
  2. Nausea (27%)
  3. Headache (13%)
  4. Dizziness (1%)
  5. Abdominal pain
  6. Constipation
  7. Diarrhea
  8. Dyspepsia
  9. Flatulence
  10. Heartburn
  11. GI ulcers (gastric/duodenal)

Drug Interaction

Other drugs that can interact with it.

  1. Other NSAIDs such as aspirin, ibuprofen, or naproxen
  2. Anticoagulants and Antiplatelet Drugs: Anticoagulant (e.g., warfarin) and antiplatelet drugs (e.g., clopidogrel).
  3. Corticosteroids such as prednisone.
  4. Selective Serotonin Reuptake Inhibitors (SSRIs) and Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs).
  5. Diuretics include thiazide diuretics.
  6. Lithium.
  7. Methotrexate.
  8. Cyclosporine and tacrolimus.
  9. ACE Inhibitors and Angiotensin Receptor Blockers (ARBs).
  10. Herbal supplements and over-the-counter medications including herbal remedies, vitamins, and other NSAIDs.


  1. Pregnancy: Category C
  2. Lactation: Diclofenac is known to pass into breast milk, and its use during lactation should be approached with caution.


What is the difference between diclofenac sodium and diclofenac potassium?

  • The main difference between the two is that diclofenac potassium is absorbed into the body more quickly than diclofenac sodium. A quick action is useful where immediate pain relief is required, and a prolonged action is more useful in reducing inflammation.

Leave a Reply

Your email address will not be published. Required fields are marked *