What is the recommended use and dosage of Descovy (emtricitabine and tenofovir alafenamide) for HIV-1 infection treatment?

Recommended Use and Dosage of Descovy for HIV-1 Infection Treatment

Descovy (emtricitabine 200 mg/tenofovir alafenamide 25 mg) is recommended as a once-daily oral tablet in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients weighing at least 35 kg. 1

Dosing Recommendations

• One tablet (emtricitabine 200 mg/tenofovir alafenamide 25 mg) taken orally once daily with or without food 1
• Descovy should be used as part of a complete antiretroviral regimen, typically combined with an integrase strand transfer inhibitor (InSTI), non-nucleoside reverse transcriptase inhibitor (NNRTI), or boosted protease inhibitor 2
• For patients with renal impairment, dosage adjustments are required:
  • No dosage adjustment for creatinine clearance ≥30 mL/min 1
  • Not recommended for patients with creatinine clearance <30 mL/min 1

Recommended Combination Regimens

• Descovy is most commonly used as the nucleoside/nucleotide reverse transcriptase inhibitor (NRTI) backbone in combination with:
  • Integrase strand transfer inhibitors (InSTIs): bictegravir, dolutegravir, or raltegravir 2
  • Boosted protease inhibitors: darunavir/cobicistat or darunavir/ritonavir 2, 3
  • Non-nucleoside reverse transcriptase inhibitors (NNRTIs): rilpivirine or doravirine 2

Pre-Treatment Assessment

• Prior to initiating Descovy, patients should undergo:
  • HIV RNA level testing 2
  • CD4+ cell count 2
  • HIV reverse transcriptase and protease genotype testing 2
  • Hepatitis B surface antigen testing (due to risk of severe acute exacerbation of hepatitis B upon discontinuation) 1
  • Renal function assessment (serum creatinine and estimated creatinine clearance) 1
  • Screening for sexually transmitted infections 2

Monitoring Recommendations

• HIV RNA level: Within 6 weeks of starting therapy, then every 3 months until <50 copies/mL for 1 year, then every 6 months 2
• CD4+ cell count: Every 6 months until >250/μL for 1 year, then can stop as long as virus is suppressed 2
• Renal function: Regular monitoring of creatinine clearance, particularly in patients with risk factors for renal dysfunction 1
• Hepatic function: Close monitoring in patients co-infected with HIV-1 and HBV 1

Clinical Advantages of Descovy

• Compared to tenofovir disoproxil fumarate (TDF)-containing regimens, Descovy (TAF-containing) offers:
  • Improved renal safety profile with less impact on markers of renal tubular function 4
  • Better bone mineral density preservation 4
  • Similar high rates of virologic suppression 4

Important Considerations and Precautions

• Severe acute exacerbations of hepatitis B have been reported in patients co-infected with HIV-1 and HBV who discontinue Descovy 1
• Immune reconstitution syndrome may occur, requiring further evaluation and treatment 1
• Lactic acidosis and severe hepatomegaly with steatosis have been reported with nucleoside analogs 1
• Not recommended for use as pre-exposure prophylaxis (PrEP) in individuals at risk of HIV-1 infection from receptive vaginal sex 5, 6

Special Populations

• Pediatric patients: Recommended for those weighing at least 35 kg who can swallow an intact tablet 1
• Pregnancy: Descovy can be used during pregnancy as part of a complete antiretroviral regimen 6
• Renal impairment: Not recommended for patients with severe renal impairment (creatinine clearance <30 mL/min) 1

By following these dosing recommendations and monitoring guidelines, Descovy provides an effective and generally well-tolerated backbone for HIV-1 treatment regimens with improved renal and bone safety profiles compared to older tenofovir formulations.