EMTRICITABINE

EMTRICITABINE
(em-tri'ci-ta-been)
Emtriva
Classifications: antiretroviral; nucleoside reverse transcriptase inhibitor (nrti);
Therapeutic: antiviral; antiretroviral, nrti
Prototype: Zidovudine
Pregnancy Category: D

Availability

200 mg capsules; 10 mg/mL oral solution

Action

Emtricitabine is a synthetic nucleoside reverse transcriptase analogue with inhibitory activity against HIV. It inhibits HIV-1 reverse transcriptase (RT), both by competing with the natural DNA nucleoside and by incorporation into viral DNA, which terminates the formation of the viral DNA chain.

Therapeutic Effect

The viral load is decreased as measured by an increase in CD4 leukocyte count and suppression of viral RNA.

Uses

Treatment of HIV in combination with other antiretroviral agents.

Unlabeled Uses

Treatment of chronic hepatitis B in HIV-positive patients.

Contraindications

Children <3 mo; suicidal ideation; HBV infection; pregnancy (category D); lactation.

Cautious Use

Renal impairment, and with end-stage renal disease; hepatic impairment; history of mental illness including bipolar disorder, psychosis; alcoholism; substance abuse; seizure disorders; hypercholesterolemia, hypertriglyceridemia.

Route & Dosage

HIV
Adult: PO 200 mg once/d
Child (3 mo–17 y): PO 6 mg/kg d (max: 240mg/d) OR if >33 kg, 200 mg qd

Renal Impairment
Cl_cr 30–49 mL/min: 200 mg q48h; 15–29 mL/min: 200 mg q72h; <15 mL/min: 200 mg q96h

Administration

Oral

Give at the same time daily.
Store between 15°–30° C (59°–86°F) in a tightly closed container.

Adverse Effects (≥1%)

Body as a Whole: Asthenia, neuropathy, peripheral neuritis. CNS: Headache, depression, dizziness, insomnia. GI: Diarrhea, nausea, dyspepsia, abdominal pain, hepatomegaly. Metabolic: Lactic acidosis. Musculoskeletal: Arthralgia, myalgia, paresthesias. Respiratory: Cough, rhinitis. Skin: Rash, hyperpigmentation of palms and soles of feet.

Interactions

None yet reported.

Pharmacokinetics

Absorption: 93% reaches systemic circulation. Peak: 1–2 h. Distribution: 4% protein bound. Metabolism: In liver. Elimination: Urine. Half-Life: 10 h (active metabolite has intracellular half-life of 39 h).

Nursing Implications

Assessment & Drug Effects

Note: Persons with a detectable viral load to be switched from lamivudine to emtricitabine should have genotypic testing to determine whether the M184 mutation is present.
Monitor individuals with a history of depression for signs and symptoms of suicidal ideation.
Monitor closely for S&S of lactic acidosis, especially in persons with known risk factors such as female gender, obesity, alcoholism, or hepatic disease.
Withhold drug and notify physician if S&S suggestive of lactic acidosis or hepatotoxicity occur.
Lab tests: Baseline renal function tests; frequent LFTs and serum electrolytes during the last trimester of pregnancy; complete blood chemistry if lactic acidosis is suspected; and periodic lipid profile; serum cholesterol and triglycerides; bone density monitoring for history of osteoporosis.
Monitor closely for severe exacerbation of hepatitis B in coinfected patients if this drug is discontinued.

Patient & Family Education

Inform physician, prior to taking this drug, if you have used lamivudine and developed resistance to it.
May cause serious CNS effects. Avoid driving or operating machinery until individual reaction to the drug is known.
Report any of the following to the physician: difficulty breathing, shortness of breath, fast or irregular heartbeat; weight gain with fullness around waist and/or face; vomiting or diarrhea; unexplained muscle aches, pains, weakness, or fatigue; yellow eyes or skin.
Avoid alcoholic drinks while taking this drug.
Do not self-treat nausea, vomiting, or stomach pain. Contact physician for guidance.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

(35)