Please check your internet connection and try again.
# Diclofenac
## Overview
Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) that inhibits cyclooxygenase (COX) enzymes, reducing prostaglandin synthesis. It is available in oral, topical, and injectable formulations.
## Primary Indications
* Pain associated with osteoarthritis
* Rheumatoid arthritis
* Ankylosing spondylitis
* Acute pain (e.g., post-operative, musculoskeletal)
* Migraine
## Adult Dosing
**Oral:**
* **Osteoarthritis:** 150 mg daily in 3 divided doses (e.g., 50 mg TID). Doses of 100 mg daily may be effective for some.
* **Rheumatoid Arthritis/Ankylosing Spondylitis:** 150-200 mg daily in 3-4 divided doses (e.g., 50 mg TID or QID).
* **Acute Pain:** 50 mg every 8 hours as needed.
* **Migraine:** 100 mg as a single dose.
**Topical:**
* **Osteoarthritis (knee):** Apply 1% gel to affected knee 4 times daily.
* **Osteoarthritis (hands/wrists):** Apply 1% gel to affected joints twice daily.
**Injectable:**
* **Acute pain:** 75 mg IM once, may repeat after 6 hours if needed. Do not exceed 150 mg daily.
*Maximum daily oral dose:* 200 mg.
## Pediatric Dosing
* **Rheumatoid Arthritis:** 1-3 years: 0.1-0.15 mg/kg/dose TID. 4-12 years: 25 mg TID or QID.
* **Acute pain/Fever:** Not generally recommended for pediatric use due to limited data and increased risk of adverse events.
## Dose Adjustments
* **Hepatic Impairment:** Use with caution. Mild to moderate impairment may not require adjustment, but monitor closely. Avoid in severe hepatic impairment.
* **Renal Impairment:** Use with caution. Monitor renal function. May require dose reduction in severe impairment, though specific guidelines vary.
## Contraindications
* Hypersensitivity to diclofenac, aspirin, or other NSAIDs.
* History of bronchospasm, asthma, urticaria, or allergic-type reactions after taking aspirin or other NSAIDs.
* Peri-operative pain in the setting of coronary artery bypass graft (CABG) surgery.
* Active gastrointestinal (GI) bleeding or ulceration.
* Inflammatory bowel disease (active).
* Severe heart failure.
## Adverse Effects
* **Common:** GI upset (nausea, diarrhea, abdominal pain), headache, dizziness, rash.
* **Serious:** Cardiovascular thrombotic events (MI, stroke), GI bleeding/perforation, hepatotoxicity, renal toxicity, hypersensitivity reactions, fluid retention, hypertension.
## Key Drug Interactions
* **Anticoagulants (e.g., warfarin):** Increased risk of bleeding.
* **Corticosteroids:** Increased risk of GI ulceration and bleeding.
* **SSRIs/SNRIs:** Increased risk of GI bleeding.
* **Other NSAIDs/Aspirin:** Increased risk of GI and renal toxicity, and other adverse effects.
* **ACE inhibitors/ARBs/Diuretics:** Reduced antihypertensive efficacy, increased risk of renal impairment.
* **Lithium:** Increased lithium levels.
* **Methotrexate:** Increased methotrexate levels and toxicity.
## Monitoring
* **GI:** Signs and symptoms of bleeding (melena, hematemesis), abdominal pain.
* **Renal:** Serum creatinine, BUN, urine output.
* **Hepatic:** Liver function tests (AST, ALT).
* **Cardiovascular:** Blood pressure, signs of fluid retention.
* **Hematologic:** Signs of anemia (if chronic GI bleeding).
## Clinical Pearls
* Use the lowest effective dose for the shortest duration necessary.
* Consider a proton pump inhibitor (PPI) or misoprostol for patients at increased risk of GI complications.
* Topical diclofenac offers a localized effect with potentially lower systemic absorption and reduced GI risk compared to oral formulations.
* Avoid concomitant use with other NSAIDs.
* Monitor closely for signs of cardiovascular and renal toxicity, especially in high-risk patients.
***
**Disclaimer:** This information is intended for healthcare professionals and is not a substitute for professional medical advice. Always consult the most current prescribing information and guidelines before making clinical decisions.
