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Diclofenac Potassium
Diclofenac potassium is a widely used nonsteroidal anti-inflammatory drug (NSAID) primarily prescribed for the treatment of pain, inflammation, and fever. It is a fast-acting formulation of diclofenac, available in oral tablets, making it a popular choice for managing acute pain conditions such as migraines, dental pain, and menstrual cramps. Diclofenac potassium is known for its efficacy in reducing pain and inflammation, but its use requires careful monitoring due to the risk of side effects, particularly gastrointestinal and cardiovascular complications. This article provides a detailed overview of diclofenac potassium, including its mechanism of action, uses, dosage, side effects, precautions, drug interactions, and generic names, referencing authoritative sources such as the British National Formulary (BNF), Lippincott Textbook of Pharmacology, and Lange Basic & Clinical Pharmacology.
Diclofenac potassium exerts its therapeutic effects through its action on the cyclooxygenase (COX) enzymes. Its key mechanisms include:
- Inhibition of Cyclooxygenase (COX) Enzymes:
- Diclofenac potassium inhibits both COX-1 and COX-2 enzymes, which are involved in the synthesis of prostaglandins and thromboxanes.
- COX-1 is responsible for the production of prostaglandins that protect the gastric mucosa and regulate platelet function.
- COX-2 is induced during inflammation and is responsible for the production of prostaglandins that mediate pain, inflammation, and fever.
- Reduction of Prostaglandin Synthesis:
- By inhibiting COX enzymes, diclofenac potassium reduces the production of prostaglandins, leading to decreased inflammation, pain, and fever.
- Antipyretic Effects:
- Diclofenac potassium reduces fever by inhibiting prostaglandin synthesis in the hypothalamus, which regulates body temperature.
Diclofenac potassium is approved for a variety of clinical conditions, including:
- Pain Relief:
- Management of mild to moderate pain, such as headaches, dental pain, menstrual cramps, and musculoskeletal pain.
- Inflammation:
- Treatment of inflammatory conditions, such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis.
- Fever:
- Reduction of fever in adults and children.
- Off-Label Uses:
- Management of acute gout.
- Adjunctive therapy for migraine headaches.
The dosage of diclofenac potassium varies depending on the indication, patient age, and formulation. The following dosing guidelines are based on the British National Formulary (BNF) and clinical pharmacology references:
- Adults:
- Oral: 50 mg two to three times daily, not exceeding 150 mg daily.
- Migraine: 50 mg at the onset of migraine, followed by 50 mg every 8 hours as needed, not exceeding 150 mg daily.
- Children:
- Oral: 1–3 mg/kg daily in divided doses, not exceeding 150 mg daily.
Important Considerations:
- Diclofenac potassium is available in oral tablets.
- Dose adjustments may be necessary for patients with hepatic or renal impairment.
- Diclofenac potassium should be taken with food or milk to minimize gastrointestinal side effects.
Diclofenac potassium is generally well-tolerated, but it is associated with a range of side effects, some of which can be serious. Common side effects include:
- Gastrointestinal:
- Nausea, vomiting, dyspepsia, and abdominal pain.
- Gastric ulcers and gastrointestinal bleeding (rare but serious).
- Cardiovascular:
- Increased risk of myocardial infarction and stroke, particularly with long-term use or high doses.
- Renal:
- Acute kidney injury and interstitial nephritis (rare).
- Other:
- Headache, dizziness, and rash.
Serious Side Effects:
- Gastrointestinal Bleeding: Particularly in elderly patients or those with a history of peptic ulcer disease.
- Hypersensitivity Reactions: Stevens-Johnson syndrome (SJS) and anaphylaxis (rare).
Hepatotoxicity: Elevated liver enzymes and, rarely, severe liver damage
Diclofenac potassium requires careful monitoring and adherence to specific precautions to ensure patient safety:
- Gastrointestinal Risk:
- Use with caution in patients with a history of peptic ulcer disease or gastrointestinal bleeding. Consider concomitant use of a proton pump inhibitor (PPI) for gastroprotection.
- Cardiovascular Risk:
- Use with caution in patients with a history of cardiovascular disease. Regular monitoring of cardiovascular health is recommended.
- Renal Impairment:
- Use with caution in patients with impaired kidney function. Avoid use in severe renal impairment (CrCl <30 mL/min).
- Pregnancy and Lactation:
- Diclofenac potassium should be avoided during the third trimester of pregnancy due to the risk of premature closure of the ductus arteriosus. It is excreted in breast milk, so breastfeeding is generally not recommended.
- Elderly Patients:
- Lower doses may be required due to increased sensitivity to side effects, particularly gastrointestinal and renal.
Diclofenac potassium has a significant potential for drug interactions due to its effects on prostaglandin synthesis and metabolism. Key interactions include:
- Anticoagulants:
- Diclofenac potassium may enhance the anticoagulant effects of warfarin, increasing the risk of bleeding.
- Other NSAIDs:
- Concurrent use with other NSAIDs increases the risk of gastrointestinal side effects.
- Antihypertensives:
- Diclofenac potassium may reduce the efficacy of antihypertensive medications, such as ACE inhibitors and beta-blockers.
- Diuretics:
- Diclofenac potassium may reduce the diuretic and antihypertensive effects of diuretics.
- Lithium:
- Diclofenac potassium may increase lithium levels, increasing the risk of toxicity.
Diclofenac potassium is the generic name for this medication. It is marketed under various brand names, depending on the country and manufacturer. Some examples include:
- Cataflam (a well-known brand in the United States and other regions).
- Voltfast.
- Diclofenac Potassium Accord.
- Diclofenac Potassium Mylan.
