Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1 Pharmacodynamic properties
Pharmacotherapeutic group: Nonsteroidal anti-inflammatory drug (NSAID).
ATC Code: M01A B05
Cataflam tablets contain the potassium salt of diclofenac, a nonsteroidal compound with pronounced and clinically demonstrable analgesic, anti-inflammatory and anti-pyretic properties.
Diclofenac is a potent inhibitor of prostaglandin bio-synthesis and modulator of arachidonic acid release and uptake.
Cataflam tablets have a rapid onset of action and are therefore suitable for the treatment of acute episodes of pain and inflammation.
In migraine attacks Cataflam has been shown to be effective in relieving the headache and in improving the accompanying symptom of nausea.
Diclofenac in vitro does not suppress proteoglycan biosynthesis in cartilage at concentrations equivalent to the concentrations reached in human beings.

Pharmacokinetic Properties

5.2     Pharmacokinetic properties
Absorption:
Diclofenac is rapidly and completely absorbed from sugar coated tablets. Food intake does not affect absorption.

Peak plasma concentration after one 50 mg sugar-coated tablet was 3.9 µmol/l after 20-60 minutes.The plasma concentrations show a linear relationship to the size of the dose.


CAT API 02JUN24                                                                         UK SmPC Feb2023 Diclofenac undergoes first-pass metabolism and is extensively metabolised.
Distribution:
Diclofenac is highly bound to plasma proteins (99.7%), chiefly albumin (99.4%).
Diclofenac was detected in a low concentration (100 ng/mL) in breast milk in one nursing mother. The estimated amount ingested by an infant consuming breast milk is equivalent to a 0.03 mg/kg/day dose (see section 4.6 Pregnancy and lactation).

Elimination:
The total systemic clearance of diclofenac in plasma is 263 ± 56 ml/min (mean ± SD).
The terminal half-life in plasma is 1-2 hours.
Repeated oral administration of Cataflam for 8 days in daily doses of 50 mg t i d does not lead to accumulation of diclofenac in the plasma.
Approx. 60% of the dose administered is excreted in the urine in the form of metabolites, and less than 1% as unchanged substance. The remainder of the dose is eliminated as metabolites through the bile in the faeces.

Biotransformation:
The biotransformation of diclofenac involves partly glucuronidation of the intact molecule but mainly single and multiple hydroxylation followed by glucuronidation.

Characteristics in patients:
The age of the patient has no influence on the absorption, metabolism, or excretion of diclofenac.
In patients suffering from renal impairment, no accumulation of the unchanged active substance can be inferred from the single-dose kinetics when applying the usual dosage schedule. At a creatinine clearance of <10 ml/min the theoretical steady-state plasma levels of metabolites are about four times higher than in normal subjects.
However, the metabolites are ultimately cleared through the bile.
In the presence of impaired hepatic function (chronic hepatitis, non-decompensated cirrhosis) the kinetics and metabolism are the same as for patients without liver disease.