What is Diclofenac?
Diclofenac is an active ingredient used for the treatment of osteoarthritis, spondyloarthritis, extraarticular rheumatism, renal colic, musculoskeletal pain, lumbar pain, post-operative and post-traumatic pains, mild to moderate pain and primary dysmenorrhoea.
The brand names of Diclofenac in the United States are: Voltaren, Cataflam, Cambia, Zorvolex.
Diclofenac Mechanism of Action (MOA)
Inhibits the biosynthesis of prostaglandins.
Therapeutic Indications and Dosage of Diclofenac
– Rheumatoid arthritis, ankylopoyetic spondyloarthritis, osteoarthritis, spondyloarthritis, extraarticular rheumatism, symptomatic treatment of acute attack of gout, inflammation and post-traumatic swelling.
Adults: oral: 50 mg/8-12 hours before meals; maximum 150 mg/day.
Retard: 75-150 mg/day.
Rectal: 100 mg/day at bedtime.
Intramuscular: 75 mg/day (exceptionally 75 mg/12 hours on the first day in severe cases).
– Symptomatic treatment of pain associated with renal colic, musculoskeletal pain.
Adults: rectal: 100 mg/day.
Intramuscular: 75 mg/day.
– Symptomatic treatment of severe acute pain associated with lumbar pain, post-operative and post-traumatic pains.
Adults: Intramuscular: 75 mg/day.
– Symptomatic treatment of mild to moderate pain (headache, dental, menstrual, muscular or back pain).
Oral: Adults and children > 14 years: 25 mg followed by 12.5 or 25 mg/4-6 hours; maximum: 75 mg/day.
Duration of treatment for pain relief: 5 days and for febrile states: 3 days.
Rectal: if necessary higher doses, supplement with 50 mg orally.
Intramuscular: maximum 2 days, continue treatment orally or rectally.
– Primary dysmenorrhoea:
Oral and rectal: initial: 50-100 mg/day, adjust individually up to 200 mg/day.
Mode of administration of Diclofenac
Administer preferably before meals. Take whole with some liquid, without chewing.
It is recommended to put the suppositories after the fecal evacuation.
Injectable solution is administered intramuscularly by deep intragluteal injection, in the upper external quadrant.
Contraindications of Diclofenac
- Hypersensitivity to diclofenac.
- When administration of ASAAs or other NSAIDs has triggered asthma attacks, urticaria or acute rhinitis.
- Active Crohn’s disease.
- Active ulcerative colitis.
- Severe renal failure.
- Severe liver failure.
- Coagulation disorders.
- History of gastrointestinal bleeding or perforation related to previous NSAIDs.
- Active gastrointestinal ulcer/hemorrhage/perforation.
- Established CHF (NYHA classification II-IV), ischemic heart disease, peripheral arterial disease, and/or cerebrovascular disease.
- Third trimester of gestation.
- Proctitis (rectal).
Warnings and precautions with Diclofenac
- Mild to moderate renal failure, mild to moderate liver failure, elderly, porphyria, history of ulcerative colitis or Crohn’s disease, history of high blood pressure (BPH) and/or heart failure, concomitant use of oral corticosteroids and SSRI antidepressants.
- In patients with asthma, seasonal allergic rhinitis, inflammation of the nasal mucosa (nasal polyps), chronic obstructive pulmonary disease or chronic respiratory tract infections (allergic rhinitis) are more frequent exacerbations of asthma, Quincke’s edema or urticaria.
With cardiovascular risk factors (diabetes mellitus, BPH, hypercholesterolemia, smoking habit), assess benefit/risk.
- Do not use in patients with severe cardiovascular disease such as heart failure, ischemic heart disease, peripheral arterial disease or cereborovascular disease.
- Risk of gastrointestinal bleeding, ulcer or perforation is greater at increasing doses of NSAIDs.
- In prolonged treatment risk of atherothrombotic events (AMI or stroke).
- Allergic reactions, including anaphylactic/anaphilactoid reactions, may occur in rare cases with diclofenac when there has been no previous exposure to the drug.
- Hypersensitivity reactions may also evolve into Kounis syndrome, a severe allergic reaction that can lead to myocardial infarction; mask signs and symptoms of infection and alter female fertility.
- Avoid concomitant use with other NSAIDs including selective cyclooxygenase-2 inhibitors.
- Liver and kidney control and blood counts.
- Not recommended for children under 14 years of age.
- Use the lowest possible dose and the shortest possible duration of treatment to control symptoms according to the established therapeutic objective.
- Concomitant with anticoagulants may increase the risk of bleeding.
- NSAIDs, including diclofenac, may increase the risk of gastrointestinal anastomotic leakage.
- Close monitoring and caution when using diclofenac after gastrointestinal surgery.
Contraindicated in severe liver failure.
Caution in mild to moderate liver failure, may produce elevations of liver enzymes; prolonged treatment to control liver function.
Contraindicated in severe renal insufficiency.
Caution in mild to moderate renal insufficiency, control of renal function.
Interactions with Diclofenac
- Increases plasma concentration of: lithium and digoxin.
- Increases nephrotoxicity of: cyclosporine.
- Decreases action of: diuretics or antihypertensive drugs such as beta-blockers, ACEi.
- Decreases efficacy of: isradipine, verapamil.
- Reduced efficacy by: cholestyramine, colestipol.
- Increases action and toxicity of: methotrexate.
- Close monitoring with: anticoagulants.
- Increases frequency of adverse effects with systemic NSAIDs.
- Potency of toxicity of: misoprostol and corticoids.
- Plasma concentration increased by: potent inhibitors of CYP2C9 (sulfinpyrazone and voriconazole).
- Decreased plasma concentrations with: CYP2C9 inducers (such as rifampicin).
- Increased exposure to: phenytoin (monitor plasma levels).
Pregnancy and Diclofenac
Caution in the last trimester of pregnancy, due to possible uterine adinamia and/or premature closure of the ductus arteriosus.
Diclofenac passes into breast milk, in small amounts. Therefore it should not be administered during lactation to avoid undesirable effects on the infant.
Effects on driving ability
Patients who experience visual disturbances, dizziness, lightheadedness, drowsiness, or other disorders of the central nervous system should avoid driving or operating machinery while under treatment.
Adverse reactions and side effects of Diclofenac
- Abdominal pain.
- Ischemic coclitis.
- Irritation at the place of application (rectal).
- Reaction, pain and induration at the injection site (IM), strict adherence to instructions for intramuscular administration to avoid adverse reactions such as muscle weakness, muscle paralysis, hypoesthesia and necrosis at the injection site.
- Lab: Increased serum transaminase.
⭐⭐⭐⭐⭐ VIDEO OF DICLOFENAC/VOLTAREN (DRUG)
Source: The content of this active ingredient has been written taking into account the clinical and molecular information of all medicines authorised and marketed in the United States under the Unique Ingredient Identifier (UNII) by the Substance Registration System (SRS) of the Food and Drug Administration (FDA) and the United States Pharmacopeia (USP).
In order to know in detail the information authorized by the FDA for each drug, you should consult the corresponding medication guide authorized by the FDA.