Emtricitabine should not be given concomitantly with combined preparations containing emtricitabine, as well as with preparations that contain lamivudine (due to its similarity to emtricitabine).
Patients should be warned that treatment with antiretroviral drugs, including emtricitabine, does not prevent the risk of HIV transmission to other people during sexual intercourse or blood transfusion.Therefore, patients should take appropriate precautions.
Opportunistic infections
In patients receiving emtricitabine or other antiretroviral drugs, opportunistic infections or other complications may develop, so they should be carefully monitored by a physician with experience in HIV treatment.
Impaired renal function
In patients with renal insufficiency (with creatinine clearance <50 ml / min) or terminal stage of chronic renal failure requiring dialysis, correction of the dosing regimen of emtricitabine is recommended (see section "Dosage and Administration").
Impaired liver function
The pharmacokinetics of emtricitabine in patients with hepatic impairment have not been studied. But since emtricitabine is slightly metabolized in the liver, no significant effect of liver failure on the pharmacokinetics of the drug is expected.
Lactic acidosis / severe hepatomegaly with fatty liver dystrophy In HIV-infected patients (predominantly in women) who took nucleoside analogues as monotherapy or in combination with other antiretroviral drugs,described cases of lactic acidosis, which was usually accompanied by severe hepatomegaly and fatty liver dystrophy, including fatal. Symptoms that may indicate the development of lactic acidosis include: general weakness, loss of appetite, sudden unexplained weight loss, gastrointestinal and respiratory system disorders (dyspnea), the appearance of neurologic symptoms (including movement disorders). Lactic acidosis leads to high mortality in the absence of emergency treatment and can be associated with pancreatitis, hepatic or renal insufficiency. Lactic acidosis, as a rule, manifests itself after several months of therapy. Patients with concomitant hepatitis C receiving interferon alfa and ribavirin therapy may represent a particular risk group. Such patients require careful observation.
Treatment with emtricitabine always requires caution, and especially if the patient has risk factors for developing liver disease. In the case of clinical or laboratory signs of lactic acidosis or impaired liver function (including gayatomegaly and fatty liver dystocia, even in the absencea marked increase in the level of hepatic transaminases), the use of emtricitabine should be discontinued. Redistribution / accumulation of subcutaneous fat
In some patients, combined antiretroviral therapy may be accompanied by a redistribution / accumulation of subcutaneous fat, incl. decrease in the amount of peripheral fat and increase in visceral fat, weight loss of limbs and face, increase in mammary glands and fat deposition on the back of the neck and back ("buffalo buffalo"), as well as increased serum lipid concentrations and glucose levels in the blood. Although one or more of the above unwanted reactions associated with a common syndrome, often called lipodystrophy, can cause all drugs from classes of protease inhibitors and nucleoside reverse transcriptase inhibitors, the accumulated evidence suggests that there are differences between individual representatives of these classes of drugs in the ability to induce these unwanted reactions.
It should also be noted that lipodystrophy syndrome has a multifactorial etiology; for example, the stage of HIV infection,the elderly age and duration of antiretroviral therapy play an important, possibly synergistic role in the development of this complication. The long-term effects of these undesirable reactions are not currently established. Clinical examination of patients should include an assessment of physical signs of fat tissue redistribution. Serum lipids and glucose concentration in the blood should also be measured. Disorders of lipid metabolism should be adjusted, guided by their clinical manifestations.
Immunodeficiency Syndrome
Patients who received combined antiretroviral therapy, including with the use of emtricitabine, observed the development of immune reconstitution syndrome. Against the background of the restoration of the immune function, exacerbation of asymptomatic or residual opportunistic infections (including those caused by Mycobacterium avium, Mycobacterium tuberculosis, Pneumocystis carinii, Cytomegalovirus), which may require additional examination and treatment. Autoimmune diseases (such as Graves' disease, polymyositis and Guillain-Barre syndrome) were observed against the background of restoration of immunity,However, the time of primary manifestations varied, and the disease could occur many months after the initiation of therapy and have an atypical course.
Osteonecrosis. Although the etiology of osteonecrosis is considered multifactorial (including the use of glucocorticosteroids, alcohol consumption, severe immunosuppression, high body mass index), cases of osteonecrosis in particular in patients with advanced HIV infection and / or long-term combined antiretroviral therapy have been reported. Patients should be advised to consult a doctor if joint pain occurs, joint stiffness, or difficulty in moving.
Mitochondrial dysfunction
In conditions in vitro and in vivo the ability of nucleotide and nucleoside analogs to cause damage to mitochondria of different degrees was revealed. The development of mitochondrial disorders in HIV-negative neonates exposed to prenatal and / or postnatal effects of nucleoside analogues has been reported. The main manifestations of mitochondrial dysfunction are hematologic disorders (anemia, neutropenia) and metabolic disorders (hyperlactatemia, hyperlipazemia).These changes are often transitory. Some distant neurological disorders (hypertension, seizures, behavioral disorders) have been reported. All children exposed to fetal nucleosides or nucleoside analogues, even HIV-negative newborns, should be under close clinical and laboratory supervision and have a thorough examination for possible presence of mitochondrial disorders in case of manifestation of the relevant signs or symptoms.
Patients infected with both HIV and hepatitis B virus or FROM
The risk of hepatotoxic effect of antiretroviral drugs in patients with co-infected HIV infection and the hepatitis B or C virus is higher than in the presence of only HIV infection. Therefore, patients with chronic hepatitis B or C who simultaneously take antiretroviral drugs are at increased risk of adverse effects on the liver with possible fatal outcome. These patients should be carefully monitored, both clinically and laboratory.
The abolition of emtricitabine therapy can provoke severe exacerbation of hepatitis in patients infected with hepatitis B virus (HBV).Therefore, before starting antiregroviral therapy, it is recommended that patients be screened for viral hepatitis B. Patients infected with HIV-1 and HBV need to closely monitor liver function, but at least within a few months after the abolition of emtricitabine. In some cases, it may be necessary to resume therapy for viral hepatitis. In patients with severe liver disease (cirrhosis), it is not recommended to discontinue treatment, since the aggravation of hepatitis that occurs after the abolition of therapy can lead to decompensation of liver function.