Dosing and uses of Descovy (emtricitabine/tenofovir AF)
Adult dosage forms and strengths
emtricitabine/tenofovir alafenamide (AF)
tablet
- 200mg/25mg
HIV Infection
Indicated, in combination with other antiretroviral agents (ARTs), for the treatment of HIV-1 infection in adults and pediatric patients aged ≥12 yr
1 tablet (ie, emtricitabine 200 mg + tenofovir AF 25 mg) PO qDay
Dosage modifications
Renal impairment
- Mild-to-moderate (CrCl ≥30 mL/min): No dosage adjustment required
- Severe (CrCl <30 mL/min): Not recommended
Hepatic impairment
- Mild-to-moderate (Child Pugh class A or B): No dosage adjustment required
- Severe (Child Pugh class C): Not studied
Dosing Considerations
Not indicated for preexposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 infectioin in adults at high risk
Prior to initiating, patients should be tested for hepatitis B virus infection
Estimated CrCl, urine glucose, and urine protein should be assessed before initiating therapy and should be monitored during therapy in all patients
For specific dosing recommendations for coadministered third agents, refer to their respective prescribing information
Pediatric dosage forms and strengths
emtricitabine/tenofovir alafenamide (AF)
tablet
- 200mg/25mg
HIV Infection
Indicated, in combination with other antiretroviral agents (ARTs), for the treatment of HIV-1 infection in adults and pediatric patients aged ≥12 yr
<12 years: Safety and efficacy not established
≥12 years and weight ≥35 kg: 1 tablet (ie, emtricitabine 200 mg + tenofovir AF 25 mg) PO qDay
Dosage modifications
Renal impairment
- Mild-to-moderate (CrCl ≥30 mL/min): No dosage adjustment required
- Severe (CrCl <30 mL/min): Not recommended
Hepatic impairment
- Mild-to-moderate (Child Pugh class A or B): No dosage adjustment required
- Severe (Child Pugh class C): Not studied
Dosing Considerations
Not indicated for preexposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 infection in adults at high risk
Prior to initiating, patients should be tested for hepatitis B virus infection
Estimated CrCl, urine glucose, and urine protein should be assessed before initiating therapy and should be monitored during therapy in all patients
For specific dosing recommendations for coadministered third agents, refer to their respective prescribing information
Descovy (emtricitabine/tenofovir AF) adverse (side) effects
1-10%
Nausea (10%)
Bone mineral density (BMD) decline >5% (10%)
Diarrhea (7%)
Creatine kinase ≥10 x ULN (7%)
Headache (6%)
Fatigue (5%)
LDL-C >190 mg/dL (5%)
Total cholesterol >300 mg/dL (2%)
Warnings
Black box warnings
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs in combination with other ARTs
Emtricitabine/tenofovir AF is not approved for the treatment of chronic hepatitis B virus (HBV) infection, and the safety and efficacy have not been established in patients coinfected with HIV-1 and HBV; severe acute exacerbations of hepatitis B have been reported in patients who are coinfected with HIV-1 and HBV and have discontinued products containing emtricitabine and/or tenofovir disoproxil fumarate (TDF), and may occur with discontinuation of emtricitabine/tenofovir AF
Hepatic function should be monitored closely with both clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue ARTs; if appropriate, initiation of antihepatitis B therapy may be warranted
Contraindications
None
Cautions
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs in combination with other ARTs; a majority of these cases have been in women; obesity and prolonged nucleoside exposure may be risk factors (see Black box warnings)
Patients with HIV-1 should be tested for the presence of chronic HBV infection before initiating ART therapy; emtricitabine/tenofovir AF is not approved for the treatment of chronic HBV infection, and the safety and efficacy have not been established in patients coinfected with HIV-1 and HBV (see Black box warnings)
Redistribution or accumulation of body fat, including central obesity, dorsocervical fat enlargement (buffalo hum), peripheral wasting, facial wasting, breast enlargement, and cushingoid appearance, observed
Immune reconstitution syndrome reported with combination ART therapy, including emtricitabine; during the initial phase of combination ART treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (eg, Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment; autoimmune disorders (eg, Grave disease, polymyositis, Guillain-Barré syndrome) may also emerge
New-onset or worsening renal impairment reported with tenofovir, including cases of acute renal failure and Fanconi syndrome
Decreases in BMD and increases in biochemical markers of bone metabolism suggestive of increased bone turnover reported with tenofovir
Not for administration with other drugs containing emtricitabine or tenofovir disoproxil fumarate, or containing tenofovir alafenamide, including Atripla, Complera, Emtriva, Genvoya, Odefsey, Stribild, or Viread; due to similarities between emtricitabine and lamivudine, do not coadminister with other drugs containing lamivudine, including Combivir (lamivudine/zidovudine), Dutrebis (lamivudine/raltegravir)
Pregnancy
Pregnancy
An ART pregnancy registry has been established (1-800-258-4263)
Lactation
Emtricitabine and tenofovir have been detected in human milk
Because of both the potential for HIV transmission and the potential for serious adverse reactions in nursing infants, mothers should be instructed not to breastfeed
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of Descovy (emtricitabine/tenofovir AF)
Mechanism of action
Emtricitabine: Nucleoside reverse transcriptase inhibitor (NRTI); following phosphorylation, interferes with HIV viral DNA polymerase and inhibits viral replication; cytosine analogue
Tenofovir AF: NRTI prodrug of tenofovir; compared with tenofovir disoproxil fumarate (tenofovir DF, Viread), tenofovir alafenamide (AF) is a more targeted form of tenofovir that has demonstrated high antiviral efficacy at a dose that is 10 times lower than tenofovir DF, as well as an improved renal and bone safety profile; inhibits HIV-1 RT by competing with the natural substrate deoxyadenosine 5′-triphosphate and, after incorporation into DNA, by DNA chain termination
Absorption
Emtricitabine
- Peak plasma time: 3 hr
- Peak plasma concentration: 2.1 mcg/mL
- Trough plasma concentration: 0.1 mcg/mL
- AUC: 11.7 mcg•hr/mL
Tenofovir
- Peak plasma time: 1 hr
- Peak plasma concentration: 0.16 mcg/mL
- AUC: 0.21 mcg•hr/mL
Distribution
Emtricitabine
- Protein Bound: <4%
Tenofovir
- Protein Bound: 80%
- Vd: 1.2-1.3 L/kg
Metabolism
Emtricitabine
- Not significantly metabolized
- Metabolized by oxidation
Tenofovir
- Tenofovir AF (TAF) is hydrolyzed within cells to form tenofovir (major metabolite), which is phosphorylated to the active metabolite, tenofovir diphosphate
- In vitro studies have shown that TAF is metabolized to tenofovir by cathepsin A in PBMCs and macrophages and by CES1 in hepatocytes
- Upon coadministration with the moderate CYP3A inducer probe efavirenz, TAF exposure was unaffected
Elimination
Emtricitabine
- Half-life: 10 hr
- Dialyzable: 30% removed by hemodialysis
- Excretion: 70% urine; 13.7% feces
Tenofovir
- Half-life: 0.51 hr
- Excretion: 31.7% feces; <1% urine
Administration
Oral Administration
For oral use only
Swallow 1 capsule once daily with or without food
Storage
Store <30°C (86°F)
Keep container tightly closed
Dispense only in original container
