Description of the active substance :.
This information is a reference and it is not enough that the drug was prescribed by a doctor. .
PHARMACHOLOGIC EFFECT
An antiviral agent, a synthetic carbocyclic analogue of nucleosides. Inside the cell, abacavir is converted with the participation of cellular enzymes into the active metabolite of carbovir triphosphate. Carbovir triphosphate is an analogue of deoxyguanosine-5'-triphosphate (dGTF). Carbovir triphosphate inhibits the activity of HIV-1 reverse transcriptase, which is due to competition with the natural substrate of dGTP and a violation of its incorporation into viral DNA. The loss of the 3'-OH group in the built-in nucleoside analog prevents the formation of the 5'- and 3'-phosphoric ester bonds necessary for the elongation of the DNA strand. As a result, the growth of viral DNA ceases.
PHARMACOKINETICS
After ingestion, absorption is high, bioavailability is 83%. C max - 3 Ојg / ml, T max - 1-1.5 hours AUC (within 12 hours after administration) - 6 Ојg / ml / h. Food slows the absorption of abacavir and reduces C max , but does not affect the AUC. Penetrates through the BBB, the concentration of abacavir in the cerebrospinal fluid is 30-44% of that in the plasma. Binding to plasma proteins is low.Metabolised in the liver with the participation of acetaldehyde and the formation of glucuronide conjugates (5'-carboxylic acid and 5'-glucuronide). T 1/2 - 1.5 hours. It is excreted by the kidneys - 83% in the form of metabolites and 2% in unchanged form; the remainder is excreted through the intestine. Do not cumulate.
INDICATIONS
Treatment of HIV infection (as part of combination therapy).
DOSING MODE
In combination with other antiviral agents, adults 300 mg 2 times / day, children aged 3 months to 16 years - 8 mg / kg 2 times / day.
SIDE EFFECT
From the skin and appendages of the skin: a rash (usually maculopapular or urticaria); very rarely - multi-form exudative erythema, including Stevens-Johnson syndrome and toxic epidermal necrolysis.
On the part of the digestive system: loss of appetite, nausea, vomiting, diarrhea, abdominal pain, ulceration of the oral mucosa, increased activity of liver enzymes, liver failure.
On the part of the respiratory system: dyspnea, cough, sore throat, adult respiratory distress syndrome, respiratory failure.
From the nervous system: headache, paresthesia, drowsiness.
On the part of the system of hematopoiesis and lymphatic system: lymphopenia.
about the side of the urinary system: increased serum creatinine concentration, renal failure.
From the osteomuscular system: often - hyperlactatemia; rarely - lactic acidosis, fat accumulation / redistribution, myalgia, rhabdomyolysis, arthralgia, increased activity of CK.
Other: fever, fatigue, malaise, swelling, lymphadenopathy, arterial hypotension, conjunctivitis, anaphylactic reactions.
CONTRAINDICATIONS
Dysfunction of the liver moderate and severe; children age less than 3 months and body weight less than 14 kg; hypersensitivity to abacavir.
PREGNANCY AND LACTATION
Adequate and well-controlled clinical studies of the safety of abacavir use during pregnancy and lactation are not conducted.
If it is necessary to use during pregnancy, the expected benefit of therapy for the mother and the potential risk to the fetus should be weighed.
It is not known whether abacavir is excreted in breast milk. If it is necessary to use during the lactation period, the question of stopping breastfeeding should be solved.
APPLICATION FOR CHILDREN
Children aged 3 months to 16 years - 8 mg / kg 2 times / day.
SPECIAL INSTRUCTIONS
Symptoms of hypersensitivity may appear at any time after initiation of abacavir treatment, but most often they occur within the first 6 weeks.
If patients continue to take abacavir while developing the hypersensitivity reaction, then the clinical manifestations become more pronounced and can take a life-threatening character. In most cases, symptoms disappear when discontinuing abacavir.
There are reports of the development of lactic acidosis, hepatomegaly and fatty liver disease, incl. with a fatal outcome, due to antiretroviral therapy with nucleoside analogs, including abacavir, lamivudine and zidovudine, taken either individually or in combination. In most cases, these complications occur in women.
Symptoms that indicate lactic acidosis include general weakness, decreased appetite, rapid weight loss of unclear etiology, gastrointestinal disturbances and impairments in the respiratory system (dyspnea and tachypnea).
The use of abacavir in any patient requires caution, especially in the presence of risk factors for liver damage. When clinical or laboratory signs of lactic acidosis or hepatotoxicity appear (hepatomegaly and fatty liver dystrophy can appear even in the absence of a marked increase in aminotransferase activity), abacavir treatment should be discontinued.
Combined antiretroviral therapy may be accompanied by the development of lipodystrophy syndrome. When clinically examining patients during the treatment period, attention should be paid to the redistribution of subcutaneous fat. Laboratory examination should include determination of serum lipid concentrations and blood glucose concentrations. If the lipid metabolism is disturbed, an appropriate treatment is prescribed.
In the presence of asymptomatic or asymptomatic opportunistic infections in HIV-infected patients with severe immunodeficiency at the time of initiation of antiretroviral therapy (ART), such therapy may lead to an increase in the symptoms of opportunistic infections or other severe consequences. Typically, these reactions occur within the first weeks or months after the onset of ART. Typical examples are cytomegalovirus retinitis, generalized or focal infection caused by mycobacteria, and pneumonia caused by Pneumocystis jiroveci (formerly P. carinii). The appearance of any symptoms of inflammation requires immediate examination and, if necessary, treatment.
The use of abacavir does not exclude the possibility of developing opportunistic infections or other complications of HIV infection, so patients should remain under the supervision of a doctor who has experience in the treatment of these diseases.
Caution should be given to antiretroviral therapy, including drugs containing abacavir, in patients with a possible risk of developing coronary artery disease. It is necessary to take all measures to minimize all modifiable risk factors (such as hypertension, dyslipidemia, diabetes and smoking).
