What is Emtriva?

Also referred to as emtricitabine or FTC, Emtriva belongs to the nucleoside reverse transcriptase inhibitor (NRTI) class of anti-HIV drugs. The US Food and Drug Administration (FDA) approved Emtriva on July 2, 2003 for use in combination with other antiretroviral agents for the treatment of HIV infection in adults aged 18 and older.

Emtriva is not a cure for HIV infection and its use does not prevent infection with HIV.

Safety and effectiveness of Emtriva in children and infants have not been established.

How is Emtriva Used in HIV Infection?

In HIV treatment-experienced patients, the use of Emtriva may be considered for adults whose virus is expected to be susceptible to Emtriva. This is determined by genotypic or phenotypic testing.

What Are There Non HIV-Related Uses of Emtriva?

Researchers are also studying Emtriva for the treatment of chronic hepatitis B virus (HBV) infection.

How is Emtriva Dosed in Adults?

Emtriva comes in capsule form and may be taken with or without food

The recommended dose of Emtriva is 200 mg once daily. Patients with decreased kidney function may need to take Emtriva less frequently. Some patients may benefit from different doses of Emtriva .

In patients with baseline creatinine clearance less than 50 ml/min, the dosing interval of Emtriva should be adjusted. The dosing interval recommendations are: creatinine clearance 30 to 49 ml/min, 200 mg every 48 hours; creatinine clearance 15 to 29 ml/min, 200 mg every 72 hours; and creatinine clearance less than 15 ml/min, 200 mg every 96 hours.

Storage: Store at 25 C (77 F); excursions permitted to 15 C to 30 C (59 C to 86 F)

What are the Contraindications for Taking Emtriva?

Emtriva is contraindicated in patients with previously demonstrated hypersensitivity to any of the components of the drug product. Individuals should tell their doctor about any medical problems they have before taking Emtriva.

What are the Side Effects and Toxicities of Emtriva?

The most frequently reported adverse effects of Emtriva are headache, nausea, skin rash, and skin discoloration on palms and soles.

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogues alone or in combination, including with Emtriva. In some patients coinfected with HIV and hepatitis, exacerbation of hepatitis B has been reported after discontinuing treatment with Emtriva.

Redistribution of body fat, peripheral wasting, facial wasting, breast enlargement, and cushingoid appearance have been observed in patients receiving antiretroviral therapy, including Emtriva.

What are the Drug and Food Interactions with Emtriva?

Emtriva can be taken with or without food: the AUC was unchanged and Cmax decreased by 29% when the drug was administered with a 1,000-calorie, high-fat meal.

Emtriva has been evaluated in healthy volunteers in combination with Viread (tenofovir), Crixivan (indinavir), Famvir (famciclovir), and Zerit (stavudine). Results showed no interactions except for a small increase in plasma trough concentrations of Emtriva when it is administered concurrently with tenofovir.


What are Some Aspects of the Pharmacology of Emtriva?

Emtriva, a synthetic nucleoside analogue of cytosine, undergoes phosphorylation by means of cellular enzymes. The product of phosphorylation, emtricitabine 5'-triphosphate, inhibits viral DNA synthesis by competing with the natural substrate deoxycytidine 5'-triphosphate for incorporation into viral DNA and terminating the DNA chain at the point of incorporation.

Emtriva is rapidly and extensively absorbed following oral administration, reaching peak plasma concentrations (Cmax) at 1 to 2 hours post-dose.

Emtriva is in FDA Pregnancy Category B. Animal studies revealed no increased incidences of fetal variations or malformations in mice and rabbits at 60- and 120-fold higher exposures, respectively, than the human exposure at the recommended daily dose. However, there have been no adequate well-controlled studies in pregnant women. Results of animal studies are not always predictive of human response and emtricitabine should be used during pregnancy only if clearly needed. It is not known whether emtricitabine is distributed into human milk.

The plasma half-life of Emtriva is approximately 10 hours.

HIV isolates with reduced susceptibility to emtricitabine have been recovered from some patients treated with emtricitabine alone or in combination with other antiretroviral agents.

Cross-resistance has been noted among some nucleoside analogues. Emtricitabine-resistant isolates were cross-resistant to lamivudine (Epivir; Epivir-HBV) and zalcitabine (Hivid) but retained susceptibility to abacavir (Ziagen), didanosine (Videx), stavudine (Zerit), tenofovir (Viread), and zidovudine (Retrovir), as well as to the non nucleoside reverse transcriptase inhibitors (NNRTIs) delavirdine (Viracept), efavirenz (Sustiva), and nevirapine (Viramune).

Who Manufactures and Distributes Emtriva?

Gilead Sciences Inc, 333 Lakeside Dr, Foster City, CA, 94404.
1-800-445-3235 www.gilead.com