HBV transmission
Patients must be advised that Stadfovir 25 does not prevent the risk of transmission of HBV to others through sexual contact or contamination with blood. Appropriate precautions must continue to be used.
Patients with decompensated liver disease
There are no data on the safety and efficacy of Stadfovir 25 in HBV infected patients with decompensated liver disease and who have a Child Pugh Turcotte (CPT) score > 9 (i.e. class C). These patients may be at higher risk of experiencing serious hepatic or renal adverse reactions. Therefore, hepatobiliary and renal parameters should be closely monitored in this patient population.
Exacerbation of hepatitis
Flares on treatment
Spontaneous exacerbations in chronic hepatitis B are relatively common and are characterised by transient increases in serum alanine aminotransferase (ALT). After initiating antiviral therapy, serum ALT may increase in some patients. In patients with compensated liver disease, these increases in serum ALT are generally not accompanied by an increase in serum bilirubin concentrations or hepatic decompensation. Patients with cirrhosis may be at a higher risk for hepatic decompensation following hepatitis exacerbation, and therefore should be monitored closely during therapy.
Flares after treatment discontinuation
Acute exacerbation of hepatitis has been reported in patients who have discontinued treatment for hepatitis B, usually in association with rising HBV DNA levels in plasma. The majority of cases are self-limited but severe exacerbations, including fatal outcomes, may occur after discontinuation of treatment for hepatitis B. Hepatic function should be monitored at repeated intervals with both clinical and laboratory follow-up for at least 6 months after discontinuation of treatment for hepatitis B. If appropriate, resumption of hepatitis B therapy may be warranted.
In patients with advanced liver disease or cirrhosis, treatment discontinuation is not recommended since post-treatment exacerbation of hepatitis may lead to hepatic decompensation. Liver flares are especially serious, and sometimes fatal in patients with decompensated liver disease.
Renal impairment
Patients with creatinine clearance < 30 ml/min
The use of Stadfovir 25 once daily in patients with CrCl ≥ 15 ml/min but < 30 ml/min and in patients with CrCl < 15 ml/min who are receiving haemodialysis is based on very limited pharmacokinetic data and on modelling and simulation. There are no safety data on the use of Stadfovir 25 to treat HBV infected patients with CrCl < 30 ml/min.
The use of Stadfovir 25 is not recommended in patients with CrCl < 15 ml/min who are not receiving haemodialysis.
Nephrotoxicity
A potential risk of nephrotoxicity resulting from chronic exposure to low levels of tenofovir due to dosing with tenofovir alafenamide cannot be excluded.
Patients co-infected with HBV and hepatitis C or D virus
There are no data on the safety and efficacy of Stadfovir 25 in patients co-infected with hepatitis C or D virus. Coadministration guidance for the treatment of hepatitis C should be followed.
Hepatitis B and HIV co-infection
HIV antibody testing should be offered to all HBV infected patients whose HIV-1 infection status is unknown before initiating therapy with Stadfovir 25. In patients who are co-infected with HBV and HIV, Stadfovir 25 should be co-administered with other antiretroviral agents to ensure that the patient receives an appropriate regimen for treatment of HIV.
Co-administration with other medicinal products
Stadfovir 25 should not be co-administered with medicinal products containing tenofovir alafenamide, tenofovir disoproxil fumarate or adefovir dipivoxil.
Co-administration of Stadfovir 25 with certain anticonvulsants (e.g. carbamazepine, oxcarbazepine, phenobarbital and phenytoin), antimycobacterials (e.g. rifampicin, rifabutin and rifapentine) or St. John’s wort, all of which are inducers of P-glycoprotein (P-gp) and may decrease tenofovir alafenamide plasma concentrations, is not recommended.
Co-administration of Stadfovir 25 with strong inhibitors of P-gp (e.g. itraconazole and ketoconazole) may increase tenofovir alafenamide plasma concentrations. Co-administration is not recommended.
Lactose intolerance
Stadfovir 25 contains lactose. Patients with rare hereditary problems of galactose intolerance, total lactase deficiency or glucose-galactose malabsorption should not take this medicinal product.
There are no or limited amount of data from the use of tenofovir alafenamide in pregnant women. However, a large amount of data on pregnant women indicate no malformative nor feto/neonatal toxicity associated with the use of tenofovir disoproxil fumarate. The use of Stadfovir 25 may be considered during pregnancy, if necessary.
It is not known whether tenofovir alafenamide is secreted in human milk. There is insufficient information on the effects of tenofovir in newborns/infants. A risk to the breast-fed newborns/ infants cannot be excluded; therefore, Stadfovir 25 should not be used during breastfeeding.
Stadfovir 25 has no or negligible influence on the ability to drive and use machines. Patients should be informed that dizziness has been reported during treatment with Stadfovir 25.
