Dicofen

Diclofenac sodium.

Pharmacology: Pharmacodynamics: Diclofenac is a nonsteroidal anti-inflammatory agents of the arylcarboxylic acid type derived from phenylacetic acid. It has the following activities: Anti-inflammatory, analgesic, antipyretic. It's mechanism of action is produced by inhibition of prostaglandin synthesis. It also exhibits an inhibitory action on platelet aggregation.
Pharmacokinetics: The pharmacokinetics of diclofenac is linear.
Diclofenac is totally and rapidly absorbed.
The C_maxis attained approximately 3.5 hrs or longer after oral administration of 100 mg SR and is maintained for >12 hrs. It is approximately 2 hrs after oral administration of 50 mg DR and it is approximately 20 min after IM injection of 75 mg and is maintained for >12 hrs. Due to a first passage hepatic clearance effect, some 50% of the orally absorbed dose of a DR tablet and some 60% of the orally absorbed dose of a SR tablet do not reach the systemic circulation. The area under the curve for the plasma concentration is approximately doubled following IM administration of an equivalent dose.
Repeated administration does not induce any accumulation phenomenon.
Protein binding exceeds 99%.
Synovial fluid concentrations reach a maximum 2-4 hrs after attainment of the plasma C_max.
These concentrations are higher than the plasma concentrations observed 4-6 hrs after administration and remain at this level for at least 12 hrs.
Plasma elimination half-life is 110 min. The plasma clearance rate is 263 mL/min in the synovial fluid; the apparent clearance half-life is 3-6 hrs.
90% of the administered oral or IV dose is excreted during a 96-hr period: 0.7% in unchanged form, 5-10% as conjugated product and 60% as conjugated hydroxylated compounds in the urine.
Metabolism involves direct conjugation, or oxidation in the 3' to 4' position of the dichlorophenyl nucleus or in position 5 of the phenyl nucleus linked to the acetic acid radical.
The major metabolite in man is 4'-hydroxydiclofenac.

Maintenance and treatment of chronic rheumatoid disorders requiring a 100-mg daily dosage.

Adults: 1 tab daily, swallowed with a little water, before meals.

Symptoms: Effects on the Central Nervous System (CNS) (headaches, dizziness, hyperventilation, clouding of consciousness, motor agitation, increased irritability, ataxia, vertigo, myoclonic seizures in children and convulsions especially in young children; effects on the gastrointestinal tract (epigastric pain, nausea, vomiting, haematemesis, diarrhoea, peptic ulcer); and functional disturbances of the liver and kidneys (oliguria).
Treatment: Symptomatic Treatment: Increase in elimination, dialysis in case of serious intoxication with renal failure. In Case of Convulsion: Diazepam, phenobarbital.

Hypersensitivity to diclofenac sodium; gastric or duodenal ulceration; severe hepatic or renal insufficiency; patients allergic to prostaglandin-synthetase inhibitors; children and adolescents; women during last trimester of pregnancy or during breastfeeding; concurrent use of anticoagulant therapy (risk of haematoma).

Careful monitoring of gastrointestinal symptoms is recommended; in case of gastrointestinal haemorrhage, discontinue treatment.
Diclofenac should be used with precaution in infectious states (decrease natural immunity).

Use is restricted to adults. The minimal effective dose should be administered.
In the following circumstances, particularly careful medical supervision is required: Patients with gastrointestinal symptoms, history of duodenal ulcer, ulcerative colitis or Crohn's disease, haematological or coagulation disorders; elderly patients; major post-surgical procedures; patients with hepatic or renal impairment or arterial hypertension and/or heart failure.
It is recommended to monitor diuresis and kidney function in patients with cardiac failure in cirrhotic or renally-insufficient patients, and in patients receiving diuretics; to monitor haematological, hepatic and renal function during prolonged treatment. Discontinue treatment in case of persistent abnormalities; to exercise particular caution in patients with hepatic porphyria.
The following category of patients should take diclofenac only if emergency facilities are available: Patients who have reacted to previous administration of NSAIDs or any other prostaglandin synthesis inhibitors or analgesics with hypersensitivity reactions eg, asthma attacks, skin reactions or acute allergic rhinitis.
Effects on the Ability to Drive or Operate Machinery: Slight dizziness or other CNS disorders may occur.
Use in pregnancy: No malformation associated with diclofenac therapy in man has been reported. Nevertheless, it is recommended not to prescribe diclofenac during the first 3 months of pregnancy because of a possible teratogenic risk.
Any NSAID intake is absolutely contraindicated in the 3rd trimester of pregnancy.
Use in lactation: Diclofenac should not be prescribed in breastfeeding women.
Use in pregnancy and lactation should be restricted to situations where the potential benefit to the mother justifies the potential risk to the foetus or breastfed infant.
Dosage adjustment is not necessary in the elderly.

Use in pregnancy: No malformation associated with diclofenac therapy in man has been reported. Nevertheless, it is recommended not to prescribe diclofenac during the first 3 months of pregnancy because of a possible teratogenic risk.
Any NSAID intake is absolutely contraindicated in the 3rd trimester of pregnancy.
Use in lactation: Diclofenac should not be prescribed in breastfeeding women.
Use in pregnancy and lactation should be restricted to situations where the potential benefit to the mother justifies the potential risk to the foetus or breastfed infant.
Dosage adjustment is not necessary in the elderly.

Gastrointestinal Disorders: Nausea, vomiting, diarrhoea, eructation, epigastric distress, rare cases of peptic ulcer, digestive or gastrointestinal haemmorhage; lower abdominal pain ie, non-specific haemmorhagic colitis, exacerbation of ulcerative colitis.
Hypersensitivity Reactions: Dermatological; skin reactions: Bullous dermatitis (exceptionally, Stevens-Johnson and Lyell syndrome).
Central Nervous System Effects: Asthenia, insomnia or irritability, agitation, fatigue, dizziness, drowsiness, vertigo and headache, vision disorders (blurred vision, diplopia), tinnitus, obnubilations and convulsions.
Renal Effects: Peripheral oedema (rare), acute renal failure, urinary anomalies (ie, haematuria), interstitial nephritis, hyperkaelemia, hyporeninism, hypotension.
Hepatic Effects: Elevation of liver enzymes, icterus, hepatitis (exceptional) with or without icterus, and fulminant hepatitis.
Haematological Effects: These reaction occur rarely: Leukopenia, agranulocytosis, thrombocytopenia, bone marrow aplasia, haemolytic anaemia.

Inadvisable Concomitant Medications: Other NSAIDs; oral anticoagulants, heparin via parenteral route and ticlopidine; intrauterine device (IUD): Possible diminution of efficacy; lithium (if necessary, closely monitor lithium levels and adopt lithium dosage during concomitant use and after the end of NSAID treatment); methotrexate used at doses >15 mg weekly: Increase in methotrexate haematological toxicity; digoxin.
Concomitant Medications Requiring Precautions for Use: Diuretics: Risk of acute renal failure in the dehydrated patient by decreased glomerular filtration. Rehydrate the patient and monitor renal function during initiation of treatment.
Methotrexate Used at Low Doses (< 15 mg weekly): Weekly monitoring of haematological function during the first weeks of concomitant medications.
Pentoxifylline: Increased risk of haemmorhage.
Concomitant Medications to be Taken into Account: Antihypertensive (β-Blockers, ACE Inhibitors, Diuretics): Reduction of the antihypertensive action.
Interferon-α: Risk of inhibition of action.
Thrombolytic Drugs: Increased risk of haemorrhage.

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

M01AB05 - diclofenac ; Belongs to the class of acetic acid derivatives and related substances of non-steroidal antiinflammatory and antirheumatic products.

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