Simultaneous use with other medicinal products
A drug Tenofovir + Emtricitabine should not be administered in conjunction with other medications containing emtricitabine, tenofovir or other cytidine analogs, for example lamivudine. A drug Tenofovir + Emtricitabine Do not take concomitantly with adefovir.
The simultaneous use of tenofovir and didanosine
The combined use of tenofovir and didanosine is not recommended,since the systemic effect of didanosine increases by 40-60%, which may increase the risk of adverse reactions associated with didanosine. There have been reports of rare cases of pancreatitis and lactic acidosis, sometimes with a fatal outcome. Simultaneous use of tenofovir and didanosine at a dose of 400 mg per day was associated with a significant decrease in the number of cells Cd4, possibly due to intercellular interaction, which increases the phosphorylated (i.e., active) didanosine. The use of didanosine at a reduced dosage of 250 mg, together with tenofovir therapy, was associated with reports of a high incidence of virologic failure in several combinations studied for the treatment of HIV-1 infection.
A regimen comprising three nucleoside analogs
There have been reports of a high incidence of virologically unsuccessful treatment and the emergence of resistance at an early stage in patients with HIV infection, if tenofovir was combined with lamivudine and abacavir, as well as with lamivudine and didanosine according to the regimen of administration once a day. Lamivudine and emtricitabine have close structural similarity, as well as similar pharmacokinetics and pharmacodynamics.Thus, the same problems can be observed when using the drug Tenofovir + Emtricitabine with a third nucleoside analog.
Opportunistic infections
Patients receiving the drug Tenofovir + Emtricitabine or any other antiretroviral drug, may have clinical manifestations of opportunistic infections or complications of HIV infection, and should therefore be observed regularly with a doctor experienced in the treatment of HIV-associated diseases.
Transmission of HIV
Patients should be cautioned that the ability of antiretroviral drugs, including the drug Tenofovir + Emtricitabine, to prevent the risk of HIV transmission to others through sexual contact or through blood, is not proven. Therefore, appropriate measures should be taken to prevent transmission of the virus.
Impaired renal function
Emtricitabine and tenofovir are deduced, mainly, through the kidneys by glomerular filtration and active tubular secretion. When used in clinical practice, tenofovir reported renal failure, impaired renal function, increased creatinine concentration, hypophosphatemia and proximal tubulopathy (including Fanconi syndrome).
It is recommended to evaluate the creatinine clearance in all patients before starting treatment with the drug Tenofovir + Emtricitabine, as well as assess kidney function (creatinine clearance and phosphate concentration in plasma) after 2-4 weeks of treatment, after 3 months of treatment and every 3-6 months after.
In patients with a risk of developing renal dysfunction, including patients with a history of kidney failure, adefovir should be monitored more often by kidney function.
Patients with impaired renal function (CC <80 ml / min), including those who need hemodialysis
Safety data for the preparation Tenofovir + Emtricitabine on the impact on kidney function are limited. For patients with a creatinine clearance of 30-49 ml / min, it is recommended that the interval between doses be corrected. Limited data from clinical studies suggest that a large interval between doses is not optimal and may lead to an increase in toxicity and the probability of an inadequate response. Moreover, in a small clinical study in a subgroup of patients with CK of 50-60 ml / min, who received tenofovir in combination with emtricitabine every 24 hours, there was a 2-4 times higher exposure of tenofovir and impaired renal function. Therefore, when taking the drug Tenofovir + Emtricitabine Patients with CC <60 mL / min need a thorough assessment of the benefit-risk ratio, as well as careful monitoring of kidney function. In addition, in patients taking the drug Tenofovir + Emtricitabine with a long interval between doses, the clinical response to treatment should be monitored continuously. Application of the drug Tenofovir + Emtricitabine is contraindicated in patients with impaired renal function of severe degree (CK <30 ml / min) and those who need hemodialysis, because the corresponding dose reduction is not possible with the combination of a combination tablet.
If any patient receiving the drug Tenofovir + Emtricitabine, the serum phosphate concentration is <1.5 mg / dL (0.48 mmol / L), or the QC is reduced to <50 ml / min, renal function should be re-evaluated for one week, including glucose and potassium concentration in blood, as well as the concentration of glucose in the urine. Consideration should be given to the need to interrupt drug treatment Tenofovir + Emtricitabine in patients with confirmed reduction in CK <50 ml / min or a decrease in serum phosphate concentrations <1.0 mg / dL (0.32 mmol / L).
Do not use the drug Tenofovir + Emtricitabine with simultaneous or recent administration of a nephrotoxic drug. If such an application is not possible, weekly renal function should be monitored.
Cases of acute renal failure after initiating high-dose therapy or several non-steroidal anti-inflammatory drugs (NSAIDs) in patients who received tenofovir and having risk factors for renal dysfunction.
Renal function should be monitored appropriately when the drug is administered together Tenofovir + Emtricitabine and NSAIDs.
A high risk of kidney damage has been reported in patients receiving tenofovir in combination with protease inhibitors by enhanced ritonavir or cobicystate. These patients require careful monitoring of kidney function (see section "Interaction with other drugs"). In patients with risk factors for renal dysfunction, joint use of tenofovir with an enhanced protease inhibitor should be carefully analyzed.
Patients with mutations of HIV-1 resistance
A drug Tenofovir + Emtricitabine should not be administered to patients with HIV-1 infection who have a mutation in the codon K65R.
Effects on bone tissue
In a controlled 144-week clinical trial comparing tenofovir with stavudine in combination with lamivudine and efavirenz in HIV-infected adult patients who had not previously received antiretroviral treatment, small decreases in the BMD in the femur and spine were observed in both groups.
Decrease in the BMD of the spine and changes from baseline biomarkers of bone tissue metabolism were significantly more pronounced in the tenofovir group at week 144. The decrease in the BMD of the femur was significantly more pronounced in this group up to 96 weeks. However, after 144 weeks of increased risk of fractures or signs of clinically significant pathologies of bone tissue was not observed.
Pathological changes in bone tissue (occasionally leading to fractures) may be caused by damage to the proximal tubules of the kidneys. If you suspect or detect pathological changes in bone tissue, consult a specialist.
Patients with concomitant HIV infection, hepatitis B viruses or hepatitis C
Patients with chronic viral hepatitis B or C receiving combination antiretroviral therapy are at high risk for severe and potentially fatal liver complications.
Doctors need to follow recommendations for treatment of HIV infection and choose the optimal treatment for patients infected with HIV and hepatitis B virus.
Efficacy and safety of the drug Tenofovir + Emtricitabine with chronic hepatitis B were not studied. In pharmacodynamic studies, the efficacy of emtricitabine and tenofovir has been established in both monotherapy and combination therapy in patients with concomitant HIV infection and hepatitis B virus.
A few data indicate that emtricitabine and tenofovir demonstrate activity against hepatitis B virus. Tenofovir + Emtricitabine in patients with concomitant HIV infection and hepatitis B virus can cause severe exacerbation of hepatitis. For patients infected with HIV and hepatitis B virus,careful monitoring, both clinical and laboratory, should be conducted, at least for several months after discontinuation of therapy with the drug Tenofovir + Emtricitabine. In a number of cases, hepatitis B therapy may need to be resumed.
In patients with severe liver disease or cirrhosis, it is not recommended to cancel treatment, since the aggravation of hepatitis that occurs after cancellation of treatment can lead to decompensation of liver function.
Diseases of the liver
Data on the safety and efficacy of the drug Tenofovir + Emtricitabine for patients in whom serious liver function disorders are the main disease, have not been studied. Data on the pharmacokinetics of the drug Tenofovir + Emtricitabine and emtricitabine in patients with hepatic insufficiency are limited. The study of the pharmacokinetics of tenofovir in patients with hepatic insufficiency showed that dose adjustments in these patients are not required. Emtricitabine is not subjected to significant metabolism by liver enzymes and has a renal excretory pathway, so given the minimal hepatic metabolism and renal excretion pathwayemtricitabine, it can be assumed that patients with hepatic insufficiency do not need a dose adjustment.
In patients with a previously diagnosed liver disease, including chronic active hepatitis, combined antiretroviral therapy may exhibit more frequent liver dysfunction. These patients should be closely monitored in accordance with standard practice. With signs of increased liver disease, such patients should consider the possibility of interrupting or discontinuing treatment.
Lactic acidosis
With the use of nucleoside analogues, lactic acidosis, usually accompanied by fatty liver dystrophy, has been reported.
Early symptoms (symptomatic hyperlactatemia) include mild symptoms on the part of the digestive system (nausea, vomiting, and abdominal pain), nonspecific malaise, loss of appetite, weight loss, respiratory system symptoms (private and / or deep breathing) or neurological symptoms (including motor weakness). Lactic acidosis has a high lethality and may be accompanied by pancreatitis, hepatic or renal insufficiency.Usually, lactic acidosis is observed after several months of treatment.
Treatment with analogues of nucleosides should be discontinued in the presence of symptomatic hyperlactatemia and metabolic / lactic acidosis, progressive hepatomegaly or a rapid increase in the level of aminotransferases.
Caution should be exercised when assigning nucleoside analogues to any patient (especially obese women) with hepatomegaly, hepatitis, or other known risk factors for liver disease and fatty liver disease (including certain drugs and alcohol).
Interferon-alpha and ribavirin treatment of patients with concomitant hepatitis C virus infection may present a particular risk.
Patients with an increased risk should be closely monitored.
Lipodystrophy
In patients with HIV infection, combined antiretroviral therapy was associated with the redistribution of adipose tissue in the body (lipodystrophy). The remote consequences of these phenomena are unknown to date. Data on the mechanism of development are incomplete. There is a hypothesis about the relationship between the development of visceral lipomatosis and the intake of protease inhibitors and the development of lipoatrophy with the use of nucleoside reverse transcriptase inhibitors.
The increased risk of lipodystrophy was due to individual factors, such as the elderly age of patients, and factors associated with the drug, such as the long duration of antiretroviral therapy and the resulting metabolic disorders.
Clinical examination should include an assessment of the physical signs of redistribution of adipose tissue in the body. You should pay attention to the indices of lipids of blood serum fasting and the level of glucose in the blood.
Dyslipidemia should be adjusted in accordance with clinical recommendations.
Tenofovir is structurally related to nucleoside analogs, so the risk of developing lipodystrophy can not be ruled out. However, 144-week data obtained from HIV-infected patients who had not previously been treated with antiretroviral drugs indicate that the risk of lipodystrophy in the case of tenofovir was less than with stavudine when they were used in combination with lamivudine and efavirenz.
Mitochondrial disorders
In vitro and in vivo it was shown that nucleoside and nucleotide analogues lead to damage to mitochondria of different degrees.There have been reports of the development of mitochondrial disorders in HIV-negative newborns exposed to intrauterine and / or postnatal effects of nucleoside analogues.
The main undesirable phenomena reported were hematologic disorders (anemia, neutropenia) and metabolic disorders (hyperlactatemia, hyperlipazemia). These phenomena are often short-lived.
There were reports of some neurological disorders that began later (hypertension, seizures, abnormal behavior). To date, it is not known whether neurological disorders are temporary or permanent. All children exposed to prenatal exposure to nucleoside or nucleotide analogues, even HIV-negative newborns, should be under close clinical and laboratory supervision and have a thorough examination for possible presence of mitochondrial changes in case of manifestation of the corresponding signs or symptoms.
Available data do not affect current national recommendations, according to which HIV-positive pregnant women need antiretroviral therapy toprevention of vertical transmission of HIV.
Immunodeficiency Syndrome
At the onset of antiretroviral therapy, HIV-infected patients with severe immunodeficiency may develop an inflammatory response to pathogens of asymptomatic or residual opportunistic infections, and lead to severe clinical conditions or increased severity of symptoms. Typically, such reactions are observed during the first weeks after the start of treatment. Examples are cytomegalovirus retinitis, generalized and / or focal mycobacterial infections and pneumocystis (Pneumocystis jirovecii) pneumonia. You should monitor any symptoms of inflammation and, if necessary, prescribe treatment in a timely manner.
Also reported were autoimmune diseases (such as Graves' disease) that accompanied reactivation of immunity; However, data on the onset of such events vary widely, and these cases may have occurred several months after the start of treatment.
In patients with co-infection with HIV / HBV, a sharp exacerbation of hepatitis caused by the immune reactivation syndrome may occur in response to the initiation of antiretroviral therapy.
Osteonecrosis
Although the etiology of osteonecrosis is considered multifactorial (including the use of glucocorticosteroids, alcohol use, the presence of severe immunosuppression, a higher body mass index), cases of osteonecrosis have been recorded especially frequently in patients with progressive HIV infection and / or with prolonged use of combined antiretroviral therapy. Patients should be advised to seek medical advice if they develop aches or joint pain, joint stiffness, or difficulty walking.
Elderly patients
A drug Tenofovir + Emtricitabine It has not been studied in patients older than 65 years. Older patients are more likely to have reduced renal function, so the drug should be administered with caution in this group of patients.