Action and Spectrum

Drug Interaction

Adverse Reaction

Frequency defined 

>10% 

Edema (33%) 

Nausea (27%) 

Headache (13%)  

1-10% 

Dizziness (10%) 

Flatulence (3%) 

Pain in extremities (3%) 

Vomiting (9%) 

Constipation (8%) 

Pruritus (7%) 

Dyspepsia (2%) 

<1% 

Flushing (0.2%) 

Utricaria (0.2%) 

Black Box Warning

Black Box Warning: 

NSAIDs increase the risk of myocardial infarction, stroke, and severe CV thrombotic agents. They increase the risk with more extended usage. NSAIDs increase the risk of serious gastrointestinal events.

Contraindication / Caution

Contraindication/Caution: 

Contraindications 

• Hypersensitivity 
• Pregnancy  
• Lactation 
• Peptic ulcer 
• Asthma 
• Nasal polyps 
• Cardiovascular disease 
• Renal impairment 
• Hepatic impairment 

Pregnancy / Lactation

Pregnancy consideration:  

Not recommended for fertile females.  

Breastfeeding warnings:  

No data is available regarding the excretion of drugs in breast milk. 

Pregnancy category: 

Category A: well-controlled and satisfactory studies show no risk to the fetus in the first or later trimester. 

Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 

Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.    

Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits.    

Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women.    

Category N: No data is available for the drug under this category. 

Pharmacology

Pharmacology: 

• diclofenac has anti-inflammatory and antipyretic properties. Its pharmacological effects are primarily mediated through inhibiting cyclooxygenase (COX) enzymes, specifically COX-1 and COX-2. COX enzymes synthesize prostaglandins, mediating pain, inflammation, and fever. 
• By inhibiting COX enzymes, diclofenac reduces the production of prostaglandins, leading to the alleviation of pain, suppression of inflammation, and reduction of fever. It mainly acts by inhibiting the action of COX-2, which is involved in the inflammatory response. 

Pharmacodynamics: 

By inhibiting COX enzymes, diclofenac reduces the production of prostaglandins, leading to the alleviation of pain, suppression of inflammation, and reduction of fever. It mainly acts by inhibiting the action of COX-2, which is involved in the inflammatory response.  

Pharmacokinetics: 

Absorption 

diclofenac can be administered orally, topically, or intravenously. Oral diclofenac is well absorbed from the gastrointestinal tract, but its absorption may be delayed if taken with food. diclofenac undergoes extensive first-pass metabolism in the liver, resulting in a lower systemic bioavailability than intravenous administration. 

Distribution 

diclofenac is highly protein-bound, primarily to albumin. It has a moderate volume of distribution and can penetrate synovial fluid, where it exerts anti-inflammatory effects. 

Metabolism 

diclofenac is extensively metabolized in the liver, primarily by cytochrome P450 enzymes, particularly CYP2C9 and CYP3A4. The significant metabolites include 4-hydroxy diclofenac, 5-hydroxy diclofenac, and glucuronide/sulfate conjugates. The metabolites are mainly eliminated in the urine. 

Elimination and Excretion 

The elimination half-life of diclofenac is approximately 2 to 3 hours.

Adminstartion

Administration: 

Take diclofenac tablets or capsules by mouth with a full glass of water. Taking them with food or milk is usually recommended to help minimize stomach upset. Follow the prescribed dosage instructions provided by your healthcare professional. 

Swallow the extended-release tablets whole without crushing or chewing. Only break the tablets if instructed by your healthcare professional. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: diclofenac 

Pronounced: dye-KLOE-fen-ak 

Why do we use diclofenac?  

diclofenac is primarily used in treating signs and symptoms of rheumatoid arthritis and osteoarthritis in patients at high risk for developing NSAID-induced gastric ulcers. It also helps in dysmenorrhea, postoperative pain, acute gout attacks, and inflammatory conditions.