Emtricitabine

Name: Emtricitabine

Warnings

Black Box Warnings

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) reported with use of nucleoside analogues alone or in combination with other antiretrovirals

Not FDA approved for treatment of chronic hepatitis B virus (HBV) infection, and the safety and efficacy of this drug have not been established in patients co-infected with HBV and HIV

Contraindications

Hypersensitivity

Cautions

All patients with HIV-1 should be tested for presence of chronic Hepatitis B virus (HBV) before initiating antiretroviral therapy; safety and efficacy of emtricitabine not established in patients coinfected with HBV and HIV-1; patients infected with HBV and treated with emtricitabine, the exacerbations of hepatitis B were associated with liver decompensation and liver failure; 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 therapy; if appropriate, initiation of anti-Hepatitis B therapy may be warranted

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, reported with use of nucleoside analogs, either alone or in combination with other antiretrovirals; suspend therapy in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations)

Should not be coadministered with combination antiretroviral agents containing emtricitabine or lamivudine

Dose reduction recommended in patients with impaired renal function

Risk of immune reconstitution syndrome if used in combination with other antiretroviral drugs; autoimmune disorders (such as Graves’ disease, polymyositis, and Guillain-Barré syndrome) reported to occur in the setting of immune reconstitution; however, time to onset is more variable, and can occur many months after initiation of treatment

Why is this medication prescribed?

Emtricitabine is used along with other medications to treat human immunodeficiency virus (HIV) infection. Emtricitabine is in a class of medications called nucleoside reverse transcriptase inhibitors (NRTIs). It works by decreasing the amount of HIV in the blood. Although emtricitabine does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other life-style changes may decrease the risk of transmitting (spreading) the HIV virus to other people.

Emtricitabine Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. 

  • Do not take this medication if you are already taking Atripla, Complera, Truvada, Combivir, Epivir, Epivir-HBV, Epzicom, or Trizivir because these medicines contain the same or similar active ingredients.

Emtricitabine Dosage

  • Dosing in adults: The usual dose of emtricitabine is 1 capsule once a day.
  • Dosing in children: The child's doctor will calculate the right dose of emtricitabine (oral solution or capsule) based on the child's weight.

Emtricitabine Overdose

If you take too much emtricitabine, call your local poison control center or emergency room right away.

 

What is emtricitabine (emtriva)?

Emtricitabine is an antiviral medication that prevents human immunodeficiency virus (HIV) cells from multiplying in your body.

Emtricitabine is for treating HIV, which causes the acquired immunodeficiency syndrome (AIDS). Emtricitabine is not a cure for HIV or AIDS.

Emtricitabine may also be used for purposes not listed in this medication guide.

What should i avoid while taking emtricitabine (emtriva)?

Taking this medication will not prevent you from passing HIV to other people. Do not have unprotected sex or share razors or toothbrushes. Talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

What is the most important information I should know about emtricitabine?

Emtricitabine should not be taken together with any HIV combination medicine that contains emtricitabine or lamivudine. This includes: Atripla, Combivir, Complera, Epivir, Epzicom, Stribild, Trizivir, and Truvada.

Emtricitabine may cause a serious condition called lactic acidosis. Get emergency medical help if you have even mild symptoms such as: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

Emtricitabine may also cause severe liver damage, which can be fatal. Call your doctor at once if you have any of these symptoms of liver problems: nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Emtricitabine side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Early symptoms of lactic acidosis may get worse over time and this condition can be fatal. Get emergency medical help if you have even mild symptoms: muscle pain or weakness, numb or cold feeling in your arms and legs, trouble breathing, stomach pain, nausea with vomiting, fast or uneven heart rate, dizziness, or feeling very weak or tired.

Call your doctor at once if you have nausea, upper stomach pain, itching, loss of appetite, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Emtricitabine may increase your risk of certain infections or autoimmune disorders by changing the way your immune system works. Symptoms may occur weeks or months after you start treatment with emtricitabine. Tell your doctor if you have:

  • signs of a new infection--fever, night sweats, swollen glands, mouth sores, diarrhea, stomach pain, weight loss;

  • chest pain (especially when you breathe), dry cough, wheezing, feeling short of breath;

  • cold sores, sores on your genital or anal area;

  • rapid heart rate, feeling anxious or irritable, weakness or prickly feeling, problems with balance or eye movement;

  • trouble speaking or swallowing, severe lower back pain, loss of bladder or bowel control; or

  • swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence, loss of interest in sex.

Common side effects may include:

  • headache, mild dizziness, strange dreams;

  • mild diarrhea, mild nausea, upset stomach;

  • darkened patches of skin on your palms and/or soles;

  • mild skin rash; or

  • change in the shape or location of body fat (especially in the arms, legs, face, neck, breasts, and trunk).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Emtricitabine dosing information

Usual Adult Dose for HIV Infection:

Capsules: 200 mg orally once a day
Oral solution: 240 mg (24 mL) orally once a day

Approved indication: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Usual Adult Dose for Occupational Exposure:

(Not approved by FDA)

US Public Health Service working group recommendations:
Capsules: 200 mg orally once a day
Duration of therapy: 28 days, if tolerated

Comments:
-Emtricitabine plus tenofovir plus raltegravir is recommended as the preferred regimen for HIV postexposure prophylaxis; emtricitabine is also recommended as a component in various alternative regimens.
-Prophylaxis should be started as soon as possible, preferably within hours after exposure.
-The optimal duration of prophylaxis is unknown and may differ based on the institution's protocol.
-The most current therapeutic guidelines should be consulted for more information.

Usual Adult Dose for Nonoccupational Exposure:

(Not approved by FDA)

CDC recommendations:
Capsules: 200 mg orally once a day
Duration of therapy: 28 days

Comments:
-Emtricitabine should be used in combination with efavirenz plus (tenofovir or zidovudine), or with lopinavir-ritonavir plus zidovudine.
-Prophylaxis should be started as soon as possible, within 72 hours of exposure.

Usual Pediatric Dose for HIV Infection:

Oral solution:
0 to 3 months: 3 mg/kg orally once a day
3 months through 17 years: 6 mg/kg orally once a day
Maximum dose: 240 mg (24 mL)

Capsules:
3 months through 17 years, weighing more than 33 kg, and able to swallow intact capsule: 200 mg orally once a day

Approved indication: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Interactions for Emtricitabine

Emtricitabine does not inhibit CYP1A2, 2A6,2B6, 2C9, 2C19, 2D6, or 3A4.1 Interactions with drugs metabolized by these CYP isoenzymes unlikely.1

Emtricitabine does not inhibit glucuronosyltransferase (uridine diphosphoglucuronosyltransferase, UDP-glucuronate β-d-glucuronosyltransferase [acceptor-unspecific]), an enzyme responsible for glucuronidation.1 Pharmacokinetic interactions unlikely.1

The following drug interactions are based on studies using emtricitabine.1 Interaction studies also have been performed using emtricitabine/tenofovir alafenamide, emtricitabine/tenofovir DF, efavirenz/emtricitabine/tenofovir DF, emtricitabine/rilpivirine/tenofovir alafenamide, or emtricitabine/rilpivirine/tenofovir DF.230 232 233 244 245 When a fixed combinations containing emtricitabine is used, consider interactions associated with each drug in the fixed combination.230 232 233 244 245

Specific Drugs

Drug

Interaction

Comments

Abacavir

In vitro evidence of additive or synergistic antiretroviral effects1

Atazanavir

No in vitro evidence of antagonistic antiretroviral effects203

Darunavir

Pharmacokinetic interaction unlikely204

No in vitro evidence of antagonistic antiretroviral effects204

Delavirdine

In vitro evidence of additive or synergistic antiretroviral effects1

Didanosine

Concomitant use with emtricitabine not recommended in antiretroviral-naive adults (inferior virologic efficacy, limited clinical trial experience, didanosine toxicities);200 considered alternative (not a preferred) dual NRTI in antiretroviral-naive children ≥2 weeks of age201

Efavirenz

In vitro evidence of additive or synergistic antiretroviral effects1

Elbasvir and grazoprevir

Fixed combination of elbasvir and grazoprevir (elbasvir/grazoprevir): Clinically important pharmacokinetic interactions with emtricitabine not expected177

Etravirine

No in vitro evidence of antagonistic antiretroviral effects214

Famciclovir

Pharmacokinetic interaction unlikely1

Indinavir

No effect on pharmacokinetics of either drug1

Lamivudine

In vitro evidence of additive antiretroviral effects1

Do not use concomitantly with emtricitabine1 200 201 (no potential benefit)

Ledipasvir

Fixed combination of ledipasvir and sofosbuvir (ledipasvir/sofosbuvir): Clinically important pharmacokinetic interactions with emtricitabine not expected181

Maraviroc

No in vitro evidence of antagonistic antiretroviral effects224

Nelfinavir

In vitro evidence of additive to synergistic antiretroviral effects1

Nevirapine

In vitro evidence of additive or synergistic antiretroviral effects1

Rilpivirine

Pharmacokinetic interactions unlikely226

No in vitro evidence of antagonistic antiretroviral effects226

Ritonavir

In vitro evidence of additive or synergistic antiretroviral effects1

Saquinavir

In vitro evidence of additive or synergistic antiretroviral effects1

Simeprevir

Clinically important interactions with emtricitabine not expected187

Sofosbuvir

No clinically important pharmacokinetic interactions with emtricitabine188

Dosage adjustments not needed for either drug188

Stavudine

Pharmacokinetic interaction unlikely1

In vitro evidence of additive or synergistic antiretroviral effects1

Concomitant use with emtricitabine not recommended (increased toxicities)200 201

Tenofovir

No clinically important pharmacokinetic interactions1

In vitro evidence of additive to synergistic antiretroviral effects1

No in vitro evidence of antagonistic antiviral effects against HBV1

Tipranavir

In vitro evidence of additive antiretroviral effects211

Zidovudine

In vitro evidence of additive or synergistic antiretroviral effects1

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Capsule, Oral:

Emtriva: 200 mg [contains fd&c blue #2 (indigotine)]

Solution, Oral:

Emtriva: 10 mg/mL (170 mL) [contains edetate disodium, fd&c yellow #6 (sunset yellow), methylparaben, propylene glycol, propylparaben; cotton candy flavor]

Use Labeled Indications

HIV-1 infection, treatment: Treatment of HIV-1 infection in combination with other antiretroviral agents.

Dosing Hepatic Impairment

There are no dosage adjustments provided in the manufacturer’s labeling; however, not hepatically metabolized, so impact of hepatic impairment would be minimal.

Usual Adult Dose for Nonoccupational Exposure

(Not approved by FDA)

CDC recommendations:
Capsules: 200 mg orally once a day
Duration of therapy: 28 days

Comments:
-Emtricitabine should be used in combination with efavirenz plus (tenofovir or zidovudine), or with lopinavir-ritonavir plus zidovudine.
-Prophylaxis should be started as soon as possible, within 72 hours of exposure.

Usual Pediatric Dose for HIV Infection

Oral solution:
0 to 3 months: 3 mg/kg orally once a day
3 months through 17 years: 6 mg/kg orally once a day
Maximum dose: 240 mg (24 mL)

Capsules:
3 months through 17 years, weighing more than 33 kg, and able to swallow intact capsule: 200 mg orally once a day

Approved indication: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Liver Dose Adjustments

No adjustment recommended.

Precautions

Consult WARNINGS section for dosing related precautions.

Other Comments

Administration advice:
-May be taken without regard to food

Storage requirements:
-Oral solution: Should store refrigerated (2C to 8C [36F to 46F]); should not freeze
-Oral solution: May store at room temperature (25C [77F]; excursions permitted to 15C to 30C [59F to 86F]) for up to 3 months; should discard any remaining solution after the 3 months

General:
-Use of emtricitabine in therapy-experienced patients should be guided by laboratory testing and treatment history.

Monitoring:
-Hepatic: For chronic hepatitis B virus (HBV) in all patients (before therapy); hepatic function with clinical and laboratory follow-up in patients coinfected with HIV-1 and HBV (for at least several months after stopping therapy)
-Renal: Renal function with CrCl less than 50 mL/min

(web3)