NSAIDs, a derivative of phenylacetic acid. It has a pronounced anti-inflammatory, analgesic and moderate antipyretic effect. The mechanism of action is associated with inhibition of the activity of COX, the main enzyme in the metabolism of arachidonic acid, which is a precursor of prostaglandins, which play an important role in the pathogenesis of inflammation, pain and fever. The analgesic effect is due to two mechanisms: peripheral (indirectly, through suppression of prostaglandin synthesis) and central (due to inhibition of prostaglandin synthesis in the central and peripheral nervous system).In vitro, at concentrations equivalent to those achieved in the treatment of patients, does not inhibit the biosynthesis of proteoglycans in cartilage tissue.
In rheumatic diseases, it reduces joint pain at rest and during movement, as well as morning stiffness and swelling of the joints, helps to increase the range of motion. Reduces post-traumatic and postoperative pain, as well as inflammatory edema.
With post-traumatic and postoperative inflammation, it quickly relieves pain (arising both at rest and during movement), reduces inflammatory edema and edema of a postoperative wound.
Suppresses platelet aggregation. With prolonged use, it has a desensitizing effect.
After oral administration, it is absorbed from the gastrointestinal tract. Food intake slows down the rate of absorption, while the degree of absorption does not change. About 50% of the active substance is metabolized during the "first pass" through the liver. With rectal administration, absorption is slower. The time to reach Cmax in plasma after oral administration is 2-4 hours, depending on the dosage form used, after rectal administration - 1 hour, i / m administration - 20 minutes. The concentration of the active substance in plasma is linearly dependent on the size of the applied dose. Does not cumulate. Plasma protein binding is 99.7% (mainly albumin). Penetrates into synovial fluid, Cmax is reached 2-4 hours later than in plasma. It is extensively metabolized to form several metabolites, among which two are pharmacologically active, but to a lesser extent than diclofenac.
The systemic clearance of the active substance is approximately 263 ml / min. T1 / 2 from plasma is 1-2 hours, from synovial fluid - 3-6 hours. Approximately 60% of the dose is excreted in the form of metabolites by the kidneys, less than 1% is excreted in the urine unchanged, the rest is excreted as metabolites in the bile.
Hypersensitivity to diclofenac and excipients of the drug used; "aspirin triad" (attacks of bronchial asthma, urticaria and acute rhinitis when taking acetylsalicylic acid or other NSAIDs); erosive and ulcerative lesions of the gastrointestinal tract in the acute phase; proctitis (only for suppositories); pregnancy (for i / m administration); III trimester of pregnancy (for oral and rectal administration); children and adolescents up to 18 years old (for intramuscular injection and for dosage forms of prolonged action).
With care: suspected gastrointestinal disease; a history of gastrointestinal bleeding and ulcer perforation (especially in elderly patients), Helicobacter pylori infections, ulcerative colitis, Crohn's disease, dysfunction; mild to moderate liver dysfunctions, hepatic porphyria (diclofenac can provoke porphyria attacks); in patients with bronchial asthma, seasonal allergic rhinitis, edema of the nasal mucosa (including with polyps in the nasal cavity), COPD, chronic respiratory tract infections (especially those associated with allergic rhinitis-like symptoms); cardiovascular diseases (including ischemic heart disease, cerebrovascular disease, compensated heart failure, peripheral vascular disease); impaired renal function, including chronic renal failure (CC 30-60 ml / min); dyslipidemia / hyperlipilemia; diabetes; arterial hypertension; a significant decrease in the BCC of any etiology (for example, in the periods before and after massive surgical interventions); violation of the hemostatic system; the risk of thrombosis (including myocardial infarction and stroke); elderly patients, especially those who are weak or have low body weight (diclofenac should be used in the minimum effective dose); in patients receiving drugs that increase the risk of gastrointestinal bleeding, including systemic GCS (including prednisolone), anticoagulants (including warfarin), antiplatelet agents (including clopidogrel, acetylsalicylic acid), selective serotonin reuptake inhibitors (including citalopram, fluoxetine, paroxetine, sertraline); simultaneous treatment with diuretics or other drugs that can impair renal function; in the treatment of smoking patients or patients with alcohol abuse; when administered intramuscularly to patients with bronchial asthma due to the risk of exacerbation of the disease (since sodium bisulfite, which is contained in some dosage forms for injection, can cause severe hypersensitivity reactions).
Pregnancy and lactation
There is insufficient data on the safety of diclofenac use in pregnant women. Therefore, the appointment in the I and II trimesters of pregnancy is possible only in cases where the expected benefit to the mother outweighs the potential risk to the fetus. Diclofenac (like other inhibitors of prostaglandin synthesis) is contraindicated in the third trimester of pregnancy (suppression of uterine contractility and premature closure of the ductus arteriosus in the fetus is possible).Despite the fact that diclofenac is excreted in breast milk in small quantities, use during lactation (breastfeeding) is not recommended. If necessary, use during lactation, breastfeeding should be discontinued. Since diclofenac (like other NSAIDs) can have a negative effect on fertility, it is not recommended for women planning a pregnancy.
For patients undergoing examination and treatment for infertility, the drug should be canceled.
Determination of the frequency of adverse reactions: very often (≥1 / 10), often (≥1 / 100, <1/10) infrequently (≥1 / 1000, <1/100), rarely (≥1 / 10,000, <1 / 1000), very rare (<1/10 000).
On the part of the digestive system: often - abdominal pain, nausea, vomiting, diarrhea, dyspepsia, flatulence, decreased appetite, anorexia, increased serum aminotransferase activity; rarely - gastritis, gastrointestinal bleeding, vomiting of blood, melena, diarrhea mixed with blood, stomach and intestinal ulcers (with or without bleeding or perforation), hepatitis, jaundice, liver dysfunction; very rarely - stomatitis, glossitis, damage to the esophagus, the occurrence of diaphragmatic strictures in the intestine, colitis (nonspecific hemorrhagic colitis, exacerbation of ulcerative colitis or Crohn's disease), constipation, pancreatitis, fulminant hepatitis, liver necrosis, liver failure.
From the nervous system: often - headache, dizziness; rarely - drowsiness; very rarely - sensory disturbances, including paresthesias, memory disorders, tremors, convulsions, anxiety, acute cerebrovascular accidents, aseptic meningitis; very rarely - disorientation, depression, insomnia, nightmares, irritability, mental disorders.
From the senses: often - vertigo; very rarely - visual impairment (blurred vision), diplopia, hearing impairment, tinnitus, dysgeusia.
Dermatological reactions: often - skin rash; rarely - urticaria; very rarely - bullous rashes, eczema, erythema, erythema multiforme, Stevens-Johnson syndrome, Lyell's syndrome (toxic epidermal necrolysis), exfoliative dermatitis, pruritus, hair loss, photosensitivity reactions; purple, Shenlein-Henoch purple.
From the genitourinary system: very rarely - acute renal failure, hematuria, proteinuria, tubulointerstitial nephritis, nephrotic syndrome, papillary necrosis.
From the hematopoietic system: very rarely - thrombocytopenia, leukopenia, hemolytic anemia, aplastic anemia, agranulocytosis.
Allergic reactions: rarely - hypersensitivity, anaphylactic / anaphylactoid reactions, including decreased blood pressure and shock; very rarely - angioedema (including facial edema).
From the side of the cardiovascular system: very rarely - a feeling of palpitations, chest pain, increased blood pressure, vasculitis, heart failure, myocardial infarction. There is evidence of a slight increase in the risk of developing cardiovascular thrombotic complications (for example, myocardial infarction), especially with long-term use of diclofenac in high doses (daily dose more than 150 mg).
From the respiratory system: rarely - asthma (including shortness of breath); very rarely - pneumonitis.
General reactions: rarely - edema.
Potent CYP2C9 inhibitors - when diclofenac and potent CYP2C9 inhibitors (such as voriconazole) are coadministered, it is possible to increase the concentration of diclofenac in the blood serum and increase the systemic effect caused by inhibition of diclofenac metabolism.
Lithium, digoxin - it is possible to increase the concentration of lithium and digoxin in the plasma curve. Monitoring of the concentration of lithium and digoxin in the blood serum is recommended.
Diuretics and antihypertensive drugs - when used simultaneously with diuretics and antihypertensive drugs (for example, beta-blockers, ACE inhibitors), diclofenac can reduce their hypotensive effect.
Cyclosporine - The effect of diclofenac on the activity of prostate glandins in the kidneys may increase the nephrotoxicity of cyclosporine.
Drugs that can cause hyperkalemia - the combined use of diclofenac with potassium-sparing diuretics, cyclosporine, tacrolimus and trimethoprim can lead to an increase in the level of potassium in the blood plasma (in the case of such a combination, this indicator should be monitored frequently).
Antibacterial agents quinolone derivatives - there are separate reports on the development of seizures in patients who received both quinolone derivatives and diclofecac.
NSAIDs and GCS - with the simultaneous systemic use of diclofenac and other systemic NSAIDs or GCS can increase the incidence of adverse events (in particular, from the gastrointestinal tract).
Anticoagulants and antiplatelet agents - an increase in the risk of bleeding cannot be excluded with the simultaneous use of diclofenac and with drugs of these groups.
Selective serotonin reuptake inhibitors - may increase the risk of gastrointestinal bleeding.
Hypoglycemic drugs - cases of both hypoglycemia and hyperglycemia cannot be excluded, which necessitated a change in the dose of hypoglycemic drugs against the background of the use of diclofenac.
Methotrexate - when using diclofenac within 24 hours before or within 24 hours after taking methotrexate, an increase in the concentration of methotrexate in the blood and an increase in its toxic effect is possible.
Phenytoin - it is possible to enhance the effect of phenytoin.
Dosage and administration
The method of application and dosage regimen of a particular drug depends on its form of release and other factors. The optimal dosage regimen is determined by the doctor. The compliance of the used dosage form of a specific drug with indications for use and dosage regimen should be strictly observed.
The dose is selected individually, it is recommended to use the drug in the minimum effective dose, if possible with the shortest possible treatment period.
It is used with extreme caution in case of liver, kidney, gastrointestinal tract diseases in history, dyspeptic symptoms, bronchial asthma, arterial hypertension, heart failure, immediately after major surgical interventions, as well as in elderly patients.
If there is a history of allergic reactions to NSAIDs and sulfites, diclofenac is used only in urgent cases. In the course of treatment, systematic monitoring of liver and kidney function, and peripheral blood patterns is necessary.
Rectal administration is not recommended in patients with a history of anorectal disease or anorectal bleeding. Externally should be used only on intact skin.
Avoid getting diclofenac in the eyes (with the exception of eye drops) or mucous membranes. Patients using contact lenses should apply eye drops no earlier than 5 minutes after removing the lenses.
Not recommended for use in children under 6 years of age.
During the period of treatment with dosage forms for systemic use, alcohol is not recommended.
Influence on the ability to drive vehicles and mechanisms
During the treatment period, a decrease in the speed of psychomotor reactions is possible. If the clarity of vision deteriorates after using the eye drops, do not drive or engage in other potentially hazardous activities.