Tenofovir alafenamide

eMC §4.2 (Vemlidy 25 mg film coated tablets). PRODUCT SCOPE FLAG: the SPC fetched for this id is Vemlidy, the tenofovir alafenamide 25 mg single-agent product for CHRONIC HEPATITIS B (CHB). Tenofovir alafenamide is also a component of several fixed-dose antiretroviral combination products for HIV, which have their own separate SPCs and different strengths and regimens - none of those are covered by this source, so do not apply this 25 mg once-daily figure to an HIV combination product. Therapy should be initiated by a physician experienced in the management of CHB. The SPC dose statement is: 'Adults and paediatric patients at least 6 years of age and older weighing at least 25 kg: one tablet once daily.' TREATMENT DISCONTINUATION may be considered as follows: in HBeAg-positive patients without cirrhosis, treatment should be given for at least 6-12 months after HBe seroconversion (HBeAg loss and HBV DNA loss with anti-HBe detection) is confirmed, or until HBs seroconversion, or until there is loss of efficacy, with regular reassessment after discontinuation to detect virological relapse; in HBeAg-negative patients without cirrhosis, treatment should be given at least until HBs seroconversion or until there is evidence of loss of efficacy, with regular reassessment if treatment continues beyond 2 years. In patients with advanced liver disease or cirrhosis, treatment discontinuation is NOT recommended since post-treatment exacerbation of hepatitis may lead to hepatic decompensation (§4.4); hepatic function should be monitored with clinical and laboratory follow-up for at least 6 months after discontinuation. MISSED DOSE: if less than 18 hours have passed from the usual time, take as soon as possible and resume the normal schedule; if more than 18 hours have passed, skip the missed dose and resume the normal schedule. VOMITING: if the patient vomits within 1 hour of taking the tablet, take another tablet; if more than 1 hour after, no further tablet is needed. ELDERLY: no dose adjustment in patients aged 65 years and older. HEPATIC IMPAIRMENT: no dose adjustment required; there are limited data in HBV-infected patients with decompensated liver disease and a Child-Pugh-Turcotte score above 9 (class C), who may be at higher risk of serious hepatic or renal adverse reactions, so hepatobiliary and renal parameters should be closely monitored. PAEDIATRIC: the licensed population extends to children aged at least 6 years weighing at least 25 kg, who take the same one tablet once daily; safety and efficacy in children younger than 6 years or weighing under 25 kg have not been established and no data are available. This is a fixed 25 mg tablet dose, not a per-kg dose - verify all under-18 dosing against a children's formulary. TRANSMISSION: patients must be advised that this medicine does not prevent transmission of HBV through sexual contact or blood contamination.