Diclofenac
Summary
Diclofenac is an NSAID (non - steroidal anti inflammatory drug) used to treat the sign and symptoms of Osteroarthritis and reheumatoid arthritis.
Clinical data
Brand Name :
Cataflam , Voltaren - XR, Dyloject, Cambia, Zipsor and Zorvolex.
Generic Name :
diclofenac sodium
Drug class :
Topical skin product
Chemical & physical data :
Formula:
C14H11Cl2NO2
Molar mass :
296.148 g/mol
Structure :
IUPAC Name :
2 - [(2,6 - dichloro anilino) phenyl]acetic acid
Pharmacology
Mechanism of action
Diclofenac inhibit Cyclooxygrnase-1 & -2,the enzyme responsible for production of prostaglandin (pg) G2 which is the precursor to other PGs.These molecules have broad avtivity in pain & inflammation & the inhibitions of their production is the common mechanism linking each effect of Diclofenac.
Dosage information
Usual adult dose for Osteoarthritis
Diclofenac free acid capsule : 35mg orally 3 times a day.
Diclofenac potassium immediate - relase tablet : 50mg orally 2 or 3 times a day.
Diclofenac sodium enteric - coated tablet: 50mg orally 3 or 3 times a day.
75mg orally 2 times a day.
Maximum dose : 150mg daily
Diclofenac sodium extended - relase tablet : 100mg orally 1 time a day.
USES : For the relief of signs & symptoms of Osteroarthritis.
Usual adult dose for Ankylosing spondylitis :
Diclofenac sodium enteric - coated & delayed - relase tablet: 25mg orally 4 times a day. Additional 25mg dose may administered at bedtime, if necessary.
Maximum dose : 125mg per day.
USES : for acute or long - term use in the Relief of signs & symptoms of Ankylosing spondylitis.
Usual adult dose for dysmenorrhea:
Diclofenac potassium immediate release tablet : 50mg orally 3 or 4 times a day.
Diclofenac sodium enteric - coated delayed - relase tablet : 50mg orally 3 to 4 times a day. 75mg orally 2 times a day.
Maximum dose : 225mg a day.
Diclofenac sodium extendend - relase tablet : 100mg orally once a day.
Maximum dose : 100mg orally 2 times a day.
Usual adult dose for Migraines:
Diclofenac potassium for oral solution packet : 50mg (1 packet) orally once.
USES : For acute treatment of migraine with or without aura.
Usual adult dose for pain :
ORAL: Diclofenac potassium liquid - filled capsule : 25mg orally 4 times a day
Diclofenac free acid capsule : 18mg or 35mg orally 3 times a day.
Diclofenac potassium immediate - release tablet : 50mg orally 3 times a day.
Initial dose of 100mg orally followed by 50mg oral dose may provide better Relief in some patient.
PARENTERAL : 37.5mg IV bolus over 15 second every 6 hours as needed for pain.
Maximum dose : 150mg per day.
USES : For the management of mild to moderate acute pain (oral, IV) & moderate to sever pain alone or in combination with opioid analgesic (IV).
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is scheduled dose. Don't take extra medicine to make up the missed dose.
Indication & usage
Diclofenac is indication
- For treatment of primary dysmenorrhea,
- For Relief of mild to moderate pain,
- For relief of signs & symptoms of Osteroarthritis,
- For relief of signs & symptoms of rheumatoid arthritis,
- For relief of symptoms of Ankylosing spondylitis,
- For relief of acute migraine symptoms.
Contraindications
Hypersensitivity against Diclofenac
- History allergic reaction (Bronchospam, shock, rehinitis, urticaria) following the use of other NSAID such as aspirin.
- Meningitis not due to an infection
- Dehydration
- Anemia
- High blood pressure
- High risk of bleeding
- Heart attack
- Chronic heart failure
- Blood clot
- Asthma
- Pregnancy
- Tobacco smoking
Pharmacodynamic :
Protein binding :
In case of Diclofenac sodium, the drug is highly bound to serum protein, mostly to it well known that rehumatoid arthritis patient have lower serum or plasma albumin concentration & drastically different synovial fluid protein pattern compound with then of normal.
Half life :
The terminal half life of Diclofenac is approximately 2h, however the apparebt half life including all metabolism is 25.8 - 33h. Diclofenac has a plasma clearance 16L/h.
Adverse effect :
Oral :
- Swelling
- Vomitting or diarrhea
- Dizzy
- Head ache
- Drowsiness
- Epigastric pain
- Mild rash
- Irritation
- Dryness
- Scaling or peeling
Toxicity
Toxicity can cause nausea, vomiting, Tinnitus, Hallucinations & acute renal failures, headache, drowsiness & abdominal pain are most common symptoms & commonly appear with 4 hours of ingestion.
Over dose
If you take too much Diclofenac, call your healthcare provider or locoal poison control center or seek emergency medical attention right way.
If Diclofenac is administered by a healthcare provider in a medical setting, it is unlikely that an overdose will occur. However, if overdoae is suspected, seek emergency medical attention.
Pharmacokinetic
Adsorption
Diclofenac is 100% absorbed after oral administration compared to IV administered as measured by urine recovery. However, due to 1st pass metabolism, only about 50% of absorbed dose is systemically available. Food has no significant effevt on extent of Diclofenac absorption. However, there is usually a delay in onset of absorption of 1 to 4.5 hours and reduction in peak plasma level of < 20 %.
Distribution
The apparent volume of distribution (V/F) of Diclofenac sodium is 1.4 L/kg.
Diclofenac is more than 99% bound to human serum protein, primarily to albumin.Serum protein binding is constant over the concentration range (0.15 - 105 mcg /ml) achieved with recommended dose.
Diclofenac diffuses into & out of synovial fluid.Diffusion into the joint ocvurs when plasma level as higher than those in synovial fluid, after which the process reverses and synovial fluid level as higher than plasma level. It not known whether role diffusion into joint plays a role in effectiveness of Diclofenac.
Metabolism
Five Diclofenac metabolites have been identified in human plasma and urine. The metabolites include 4'-hydroxy-, 5-hydroxy-, 3'-hydroxy-, 4',5-dihydroxy- and 3'-hydroxy-4'-methoxy-Diclofenac. The major Diclofenac metabolite, 4'-hydroxy-Diclofenac, has very weak pharmacologic activity. The formation of 4'-hydroxy- Diclofenac is primarily mediated by CYP2C9.
Both Diclofenac and its oxidative metabolites undergo glucuronidation or sulfation followed by biliary excretion. Acylglucuronidation mediated by UGT2B7 and oxidation mediated by CYP2C8 may also play a role in Diclofenac metabolism. CYP3A4 is responsible for the formation of minor metabolites, 5-hydroxy- and 3'-hydroxy-Diclofenac. In patients with renal dysfunction, peak concentrations of metabolites 4'-hydroxy- and 5-hydroxyDiclofenac were approximately 50% and 4% of the parent compound after single oral dosing compared to 27% and 1% in normal healthy subjects.
Excretion
Diclofenac is eliminated through metabolism and subsequent urinary and biliary excretion of the glucuronide and the sulfate conjugates of the metabolites. Little or no free unchanged Diclofenac is excreted in the urine. Approximately 65% of the dose is excreted in the urine and approximately 35% in the bile as conjugates of unchanged Diclofenac plus metabolites. Because renal elimination is not a significant pathway of elimination for unchanged Diclofenac, dosing adjustment in patients with mild to moderate renal dysfunction is not necessary. The terminal half-life of unchanged Diclofenac is approximately 2 hours.
Drug interaction
Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:
- other NSAIDs such as aspirin, ibuprofen, or naproxen
- 'blood thinners' such as warfarin (Coumadin, Jantoven)
- voriconazole (Vfend)
- angiotensin-converting enzyme (ACE) blockers such as
- benazepril (Lotensin, Lotensin HCT)
- captopril (Capoten, Capozide)
- enalapril (Vasotec, Vaseretic)
- fosinopril (Monopril, Monopril HCT)
- lisinopril (Prinivil, Prinzide, Zestril, Zestoretic)
- moexipril (Univasc, Uniretic)
- quinapril (Accupril, Accuretic, Quinaretic)
- ramipril (Altace)
- trandolapril (Mavik, Tarka)
- diuretics such as
- acetazolamide (Diamox)
- amiloride (Midamor)
- bumetanide (Bumex)
- chlorothiazide (Diuril)
- chlorthalidone (Thalitone)
- ethacrynic acid (Edecrin)
- furosemide (Lasix)
- hydrochlorothiazide (Microzide, HCTZ)
- metolazone (Zaroxolyn)
- torsemide (Demadex)
- triamterene (Dyrenium, Dyazide, Maxzide)
- methotrexate (Trexall)
- lithium (Eskalith, Lithobid)
- cyclosporine (Gengraf, Neoral, Sandimmune)
This is not a complete list of diclofenac drug interactions. Ask your doctor or pharmacist for more information
Reference
- https://www.rxwiki.com/diclofenac
- https://www.drugs.com/pro/diclofenac.html
- https://go.drugbank.com/drugs/DB00586
Disclaimer :
Information that provided on this site is for educational purposes only and doesn't substitute for professional medical advice.
Users Consult a medical professionals or healthcare providers is they're seeking medical advice or treatment
Comments