Diclofenac- NSAID and its pharmacology

Diclofenac is a type of Non-steroidal anti-inflammatory drugs prescribed for musculoskeletal pain. NSAIDs are a collective class of compounds widely used in several different indications. The drugs under this class have effects ranging from analgesic, antipyretic, anti-inflammatory, cardio-protection, with varying effectiveness levels. Some are also being used for cancer chemoprevention. These are some of the most commonly available OTC (over the counter) drugs.

The most common of them include paracetamol, diclofenac, and aspirin. They are sometimes, also referred to as non-narcotic, non-opioid, or aspirin-like analgesics.

Parameters	Details
Category of Drug	Diclofenac is an Analgesics, Antipyretics, Non-Steroidal Anti-Inflammatory Drugs
Mechanism of Action	Diclofenac inhibits cyclooxygenase (COX-1 and COX-2). Diclofenac is a potent inhibitor (1)of prostaglandin synthesis in vitro. Prostaglandins are mediators of inflammation.
Indications	Diclofenac is used for 1. Acute musculoskeletal pain 2. Arthritis 3. Gout 4. Spondylitis 5. Migraine 6. Post-operative pain.
Well Known Pharmaceutical Brands	DYNAPAR- TROIKAA PHARMA VOVERAN-NOVARTIS DICLOTAL- BLUE CROSS DOLOKIND AQ- MANKIND
Structure
Molecular details	Weight: 296.149 Chemical Formula- C14H11Cl2NO2
IUPAC Name	2-[2-(2,6-dichloroanilino)phenyl]acetic acid
Available dosage forms	1. TABLETS 2. CAPSULES 3. INJECTION 4. EYE/EAR DROP 5. SUPPOSITORIES 6. GEL
Storage conditions	Store protected from light
Dose	100 to 150 mg daily in 2 to 3 divided doses, (max 150 mg/day) maintenance by 50 to 100 mg in divided doses
Contraindications	1.  Porphyria 2. Avoid injections containing benzyl alcohol in neonates 3. History of gastric ulcers, 4. Bleeding or perforation.
Pharmacokinetic properties	1. Absorption- completely absorbed from the GI tract  2. Vd- 5-10 L or 0.1-0.2 L/kg 3. 99.7% bound to serum proteins 4. The primary metabolite is 4′-hydroxy diclofenac 5. 60-70% is eliminated in the urine 6. half-life – 2 h approx. 7. plasma clearance- 16 L/h
Precautions	1. NSAIDs should be used with caution in the elderly 2. Interactions 3. Pregnancy 4. Patients with coagulation disorders 5. Hepatic, renal and cardiac impairment 6. History of gastrointestinal lesions
Adverse Effects	1. Injection site reactions 2. Transient epigastric pain 3. Risk of thrombotic events 4. Toxic epidermal necrolysis 5. Abnormality in kidney function.
Pregnancy Category	B

References:

• National Formulary
• Diclofenac and combinations: most popular brands
• NSAIDs: Pain Relief, Classification, Uses
• Drug profile of diclofenac