Diclofenac sodium

Diclofenac sodium is a drug from the NSAID group, which is a derivative of α-toluic acid.

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Indications Diclofenac sodium

It is used in the following cases:

• in rheumatoid arthritis, rheumatism, Bechterew's disease, and also in case of inflammation in the area of joints with soft tissues, against the background of which painful sensations are observed (this includes injuries of the musculoskeletal system);
• for arthrosis with neuritis, spondyloarthrosis and radiculitis, as well as during exacerbation of gout, lumbago and neuralgia;
• in primary dysmenorrhea.

The drug is prescribed for a short period of time to eliminate bursitis or tendinitis, as well as pain that develops after surgical interventions.

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Release form

The product is released as an injection solution in 3 ml ampoules. The box contains 5 or 10 ampoules with the solution.

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Pharmacodynamics

The drug has strong anti-inflammatory and analgesic properties, as well as a moderate antipyretic effect. During therapy for rheumatic diseases, it reduces pain in the joints (both during movement and at rest), reduces their swelling and stiffness that occurs in the morning, and at the same time helps to increase the range of motion inside the joints affected by the disease. A stable effect develops after 1-2 weeks of therapy.

The drug in the form of injections is usually prescribed at the initial stages of treatment of rheumatological pathologies, as well as for pain sensations of other origin.

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Pharmacokinetics

Absorption.

When 75 mg of the drug is administered intramuscularly, it immediately begins to be absorbed – peak plasma values are reached after approximately 20 minutes (the average value is approximately 2.5 μg/ml (or 8 μmol/l)). Immediately after reaching this mark, plasma values of the substance rapidly decrease. The amount of the absorbed active component is linearly proportional to the size of the drug dose. AUC values with intramuscular administration of the solution exceed the values of the rectal or oral form of the drug by approximately two times, because in the latter cases, approximately half of all diclofenac undergoes the first hepatic passage.

When the drug is used repeatedly, its pharmacokinetics remain the same.

If the patient observes the intervals between injections as required by the instructions, accumulation of the substance does not occur.

Distribution.

Protein synthesis within the blood serum (mostly with albumin) is 99.7%. At the same time, the average distribution volume reaches 0.12-0.17 l/kg.

Diclofenac is able to pass into the synovium, where its peak values are observed later than in the blood plasma (approximately 2-4 hours). The average half-life from the synovium is 3-6 hours. After 2 hours from obtaining peak plasma values, the level of diclofenac in the synovium will have higher values than in the plasma, and these values will remain higher for a period of up to 12 hours.

Metabolic processes.

Part of the metabolism of diclofenac occurs by glucuronidation of the unchanged molecule, but mainly by single and multiple methoxylation, resulting in the formation of several phenolic breakdown products (31-hydroxy-, as well as 4'-hydroxy- and 5'-hydroxy-, as well as 4',5-dihydroxy- with 3'-hydroxy-4'-methoxydiclofenac), most of which are converted to glucuronide-type conjugates.

Two of these breakdown products are bioactive, although to a significantly lesser extent than the active substance of the drug.

Excretion.

The total plasma clearance of the active ingredient is 263±56 ml/min. The terminal half-life is 1-2 hours. The half-life of 4 decay products, including 2 pharmacoactive ones, is also quite short and is 1-3 hours. The metabolite 3'-hydroxy-4'-methoxy-diclofenac has a longer half-life, but it has no medicinal activity at all.

Approximately 60% of the administered dose of solution is excreted in the urine as glucuronidated conjugates of the unchanged active ingredient, and in addition in the form of decay products, the greater half of which are glucuronidated conjugates. Less than 1% of the dose is excreted unchanged. The remainder of the administered drug is excreted as metabolites together with feces and bile.

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Dosing and administration

For adults, the solution is administered intramuscularly in a dose of 75 mg, 1-2 times a day - during the acute stage of the disease or in the case of exacerbation of chronic pathology.

For children over 6 years of age, the dosage is selected by a doctor (based on 2 mg/kg; the daily dose of the solution must be administered 2 or 3 times).

Often the treatment course lasts for 4-5 days.

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Use Diclofenac sodium during pregnancy

It is prohibited to use the solution during pregnancy or lactation.

Contraindications

Main contraindications:

• an ulcer developing in the gastrointestinal tract;
• history of gastrointestinal bleeding;
• liver/renal pathologies;
• intolerance to the drug;
• acute rhinitis, urticaria, as well as bronchial asthma and other signs of allergy caused by the use of NSAIDs;
• children under 6 years of age.

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Side effects Diclofenac sodium

Side effects may include dyspepsia, bleeding, and erosive-ulcerative lesions within the gastrointestinal tract, as well as allergy symptoms, dizziness, and a feeling of irritability or drowsiness. At the site of intramuscular administration of the drug, abscesses, a burning sensation, and necrosis of fat layers may occasionally occur.

If the patient develops any unusual symptoms, the doctor should be consulted immediately regarding the continuation of the use of Diclofenac sodium.

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Interactions with other drugs

If the patient is using any other medications, he/she must inform his/her doctor about it.

The combination of diclofenac sodium with methotrexate potentiates the toxic properties of the latter. When combined with lithium salts or digoxin, it increases their plasma values.

The drug weakens the effect of antihypertensive drugs and furosemide.

Combination with other NSAIDs (for example, GCS or aspirin) increases the likelihood of bleeding in the gastrointestinal tract.

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Storage conditions

Diclofenac sodium should be stored in a dark place, inaccessible to children. Temperature mark – no more than 25ºС.

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Special instructions

Reviews

Diclofenac sodium in the form of injections has a rapid onset of action - this is noted by many patients in their reviews. A decrease in pain symptoms is felt after 20-30 minutes, while in the case of oral administration, the effect of the effect develops only after 1.5-2 hours.

In the case of intramuscular injection, the absorption of the drug from the muscle occurs gradually, which allows for a single administration. A more detailed treatment plan is determined by the doctor.

Among the disadvantages, there is a fairly frequent development of side effects that affect a variety of body systems - the nervous system, the gastrointestinal tract, skin reactions. The latter sometimes occur as a result of the injection - at the injection site.

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Shelf life

Diclofenac sodium is allowed to be used for 2 years from the date of manufacture of the drug.

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