Emtriva (Emtricitabine)
Antiretroviral nucleoside reverse transcriptase inhibitor (NRTI) for the treatment of HIV-1 infection
Emtriva (emtricitabine) is a prescription antiretroviral medicine belonging to the nucleoside reverse transcriptase inhibitor (NRTI) class. It is used as part of combination antiretroviral therapy (cART) for the treatment of HIV-1 infection in adults, children, and infants aged 4 months and older. Emtriva does not cure HIV but helps suppress viral replication when taken consistently with other antiretroviral medicines.
Quick Facts
Key Takeaways
- Emtriva (emtricitabine) is an NRTI antiretroviral used exclusively in combination with other HIV medicines — it must never be used as a single agent.
- The standard adult dose is one 200 mg hard capsule once daily, taken with or without food, making it convenient for adherence.
- Patients co-infected with HIV and hepatitis B should not stop Emtriva without medical supervision due to the risk of severe hepatitis B flare-ups.
- Common side effects include headache, diarrhea, nausea, and muscle pain; most are mild and manageable with continued treatment.
- Kidney function should be monitored before and during treatment, with dose adjustments considered in patients with renal impairment.
What Is Emtriva and What Is It Used For?
Emtriva contains the active substance emtricitabine, a synthetic nucleoside analogue of cytidine. It is classified as a nucleoside reverse transcriptase inhibitor (NRTI), one of the foundational drug classes in modern HIV therapy. The medication is approved for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adults, adolescents, children, and infants from 4 months of age. The 200 mg hard capsule formulation is suitable for patients weighing at least 33 kg.
Emtricitabine exerts its antiviral effect by interfering with the normal function of reverse transcriptase, an enzyme that HIV requires for replication. Once inside the cell, emtricitabine is phosphorylated to its active form, emtricitabine 5'-triphosphate, which competes with the natural substrate deoxycytidine 5'-triphosphate. When incorporated into the growing viral DNA chain, it causes premature chain termination, effectively halting viral replication. This mechanism helps reduce the amount of HIV in the blood (known as viral load) and allows the immune system to recover, as reflected by an increase in CD4+ T-cell counts.
It is essential to understand that Emtriva must always be taken as part of a combination antiretroviral regimen. Modern HIV treatment guidelines from the World Health Organization (WHO), the European AIDS Clinical Society (EACS), and the U.S. Department of Health and Human Services (DHHS) recommend combination therapy with at least two or three active agents to achieve durable viral suppression and prevent the development of drug resistance. Emtricitabine is frequently combined with tenofovir (either disoproxil fumarate or alafenamide) and a third agent such as an integrase strand transfer inhibitor (INSTI).
While Emtriva is a cornerstone of many recommended regimens, it is crucial to recognize that it does not cure HIV infection. Even with successful viral suppression to undetectable levels, HIV persists in latent reservoirs within the body. Patients on effective antiretroviral therapy may still develop opportunistic infections or other HIV-associated conditions, particularly if treatment is interrupted or immune reconstitution is incomplete. Lifelong adherence to antiretroviral therapy remains essential for sustained viral suppression, immune preservation, and prevention of HIV transmission.
Emtricitabine is also a component of several fixed-dose combination tablets. If you are taking a combination product that already contains emtricitabine (such as Truvada, Atripla, Stribild, Genvoya, Descovy, Odefsey, or Biktarvy), you should not take Emtriva separately, as this would result in double-dosing of emtricitabine.
What Should You Know Before Taking Emtriva?
Contraindications
Emtriva is contraindicated in patients with a known hypersensitivity to emtricitabine or to any of the excipients contained in the capsule formulation. If you have previously experienced an allergic reaction to emtricitabine, you should inform your healthcare provider immediately, as re-exposure could trigger a more severe reaction. Cross-reactivity with other nucleoside analogues has not been established, but caution is advised in patients with a history of hypersensitivity reactions to related compounds.
Warnings and Precautions
Kidney function: Emtricitabine is primarily eliminated through the kidneys. Patients with pre-existing renal impairment may require dose adjustments or extended dosing intervals. Your doctor will typically order kidney function tests (serum creatinine, estimated glomerular filtration rate) before initiating therapy and at regular intervals during treatment. Patients with a creatinine clearance below 50 mL/min may need a reduced dosing frequency, and those on hemodialysis require specific dosing considerations.
Hepatitis B co-infection: This is one of the most critical warnings associated with emtricitabine. Because emtricitabine has activity against both HIV and hepatitis B virus (HBV), discontinuation of emtricitabine in patients co-infected with HIV and HBV can lead to severe, acute exacerbations of hepatitis B. These flare-ups can be life-threatening, particularly in patients with advanced liver disease or cirrhosis. If you have hepatitis B, your doctor will carefully select the most appropriate treatment regimen and will monitor your liver function closely, both during treatment and for several months after any change or discontinuation of emtricitabine-containing therapy.
Lactic acidosis: As with other NRTIs, there is a risk of lactic acidosis and severe hepatomegaly with steatosis, which can be fatal. Although this risk appears to be lower with emtricitabine compared to some older NRTIs, patients should be monitored for signs and symptoms including unexplained fatigue, gastrointestinal distress, unexplained weight loss, and respiratory symptoms.
Immune reconstitution inflammatory syndrome (IRIS): When antiretroviral therapy is initiated in patients with advanced HIV disease (AIDS) or pre-existing opportunistic infections, an inflammatory response to residual or latent infections may occur as the immune system recovers. This can manifest as a worsening of symptoms of a previously treated or unrecognized infection shortly after starting treatment. Conditions such as Mycobacterium avium complex, cytomegalovirus retinitis, Pneumocystis jirovecii pneumonia, and tuberculosis have been reported in the context of IRIS. Additionally, autoimmune disorders such as Graves' disease, polymyositis, and Guillain-Barré syndrome have been described, sometimes occurring months after treatment initiation. Report any new or worsening symptoms to your healthcare provider promptly.
Bone health: Patients receiving long-term combination antiretroviral therapy may be at risk for osteonecrosis (avascular necrosis), a condition in which bone tissue dies due to impaired blood supply. Risk factors include prolonged combination antiretroviral therapy, corticosteroid use, alcohol consumption, severe immunosuppression, and elevated body mass index. Symptoms include joint stiffness and pain, particularly in the hips, knees, and shoulders, with difficulty in movement. Patients experiencing these symptoms should seek medical evaluation promptly.
Elderly patients (over 65 years): Emtriva has not been extensively studied in patients older than 65 years. If prescribed to elderly patients, closer monitoring is recommended due to the higher prevalence of decreased renal function, hepatic impairment, and concomitant medications in this population.
If you are co-infected with HIV and hepatitis B, do not stop taking Emtriva without consulting your doctor. Abrupt discontinuation can cause severe hepatitis B flare-ups that may require hospitalization and can be potentially life-threatening. Your doctor will monitor your liver function closely.
Pregnancy and Breastfeeding
Emtricitabine has been extensively studied during pregnancy and is included among the preferred NRTI backbone options in both WHO and DHHS guidelines for the treatment of HIV during pregnancy. Available data from the Antiretroviral Pregnancy Registry and clinical studies have not shown an increased risk of birth defects associated with emtricitabine use during pregnancy. However, as with all medications during pregnancy, the benefits and risks should be carefully considered in consultation with your healthcare provider.
If you have taken emtricitabine during pregnancy, your doctor may recommend regular blood tests and diagnostic monitoring to assess your baby's development. For children born to mothers who received NRTIs during pregnancy, the benefit of HIV protection generally outweighs the potential risk of adverse effects from antiretroviral exposure.
Breastfeeding is not recommended for women living with HIV, regardless of antiretroviral therapy or viral load status, in settings where safe infant formula is available. This is because HIV can be transmitted through breast milk. Emtricitabine is excreted in human breast milk, which provides an additional reason to avoid breastfeeding. In resource-limited settings where formula feeding carries significant risks, the WHO recommends breastfeeding with concurrent antiretroviral therapy, and your healthcare provider can guide you on the most appropriate feeding choice.
How Does Emtriva Interact with Other Drugs?
Emtricitabine has a relatively favorable drug interaction profile compared to some other antiretroviral agents. It is not significantly metabolized by cytochrome P450 enzymes and does not inhibit or induce these enzymes, which reduces the potential for pharmacokinetic interactions with many other medications. However, several important interactions and precautions should be observed.
Major Interactions
The most important interaction to be aware of is with lamivudine (3TC). Emtricitabine and lamivudine are both cytidine analogues that are phosphorylated intracellularly to the same active moiety. Co-administration of these two drugs provides no additional virological benefit and may increase the risk of adverse effects. Therefore, emtricitabine should not be administered concurrently with lamivudine-containing products unless specifically directed by an HIV specialist in exceptional circumstances.
Similarly, patients should avoid taking Emtriva alongside any other product that already contains emtricitabine. Many fixed-dose combination tablets used in HIV treatment include emtricitabine as one of their components (e.g., Truvada, Descovy, Atripla, Stribild, Genvoya, Odefsey, Biktarvy, Symtuza). Taking Emtriva in addition to these products would result in double-dosing, which increases the risk of toxicity without therapeutic benefit.
Minor Interactions
Drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine. While clinically significant interactions are uncommon, caution is advisable when co-administering emtricitabine with nephrotoxic agents or drugs eliminated by active tubular secretion, such as cidofovir, high-dose non-steroidal anti-inflammatory drugs, and certain aminoglycosides.
| Drug | Interaction Type | Clinical Significance | Recommendation |
|---|---|---|---|
| Lamivudine (3TC) | Overlapping mechanism | Major | Do not co-administer |
| Emtricitabine-containing products | Duplication | Major | Do not co-administer |
| Cidofovir | Renal competition | Moderate | Monitor renal function closely |
| High-dose NSAIDs | Nephrotoxicity | Moderate | Use with caution; monitor kidney function |
| Aminoglycosides | Nephrotoxicity | Moderate | Monitor renal function |
Always inform your healthcare provider about all medications you are currently taking, including prescription drugs, over-the-counter medicines, herbal supplements, and vitamins. Do not start or stop any medication without consulting your doctor, as changes to your drug regimen can affect the efficacy and safety of your antiretroviral therapy.
What Is the Correct Dosage of Emtriva?
Emtriva should always be taken exactly as prescribed by your healthcare provider. The medication is administered orally and can be taken with or without food, offering flexibility in daily dosing. Consistency in timing is important to maintain stable drug levels in the blood and reduce the risk of developing drug resistance.
Adults
Standard Adult Dose
200 mg (one hard capsule) once daily, taken orally with or without food. Swallow the capsule whole with a glass of water. Emtriva must always be taken in combination with other antiretroviral medicines as part of a complete HIV treatment regimen.
Children and Adolescents
Pediatric Dose (Children and Adolescents)
Children and adolescents up to 18 years of age who weigh at least 33 kg and can swallow hard capsules may take one 200 mg capsule once daily. For children weighing less than 33 kg or those unable to swallow capsules, an oral solution formulation is available (consult your doctor for appropriate dosing). Emtriva is approved for use in infants from 4 months of age onwards. Do not give Emtriva capsules to infants under 4 months.
Elderly Patients
Elderly (Over 65 Years)
No specific dose adjustment has been established for patients over 65 years based on age alone. However, since renal function commonly declines with age, kidney function should be assessed before initiating treatment and monitored periodically. Dose adjustments based on creatinine clearance may be necessary.
| Patient Group | Dose | Frequency | Notes |
|---|---|---|---|
| Adults | 200 mg capsule | Once daily | With or without food |
| Children/Adolescents (≥33 kg) | 200 mg capsule | Once daily | Must be able to swallow capsules |
| Children (<33 kg) | Oral solution | Once daily | Dose based on body weight; consult physician |
| Renal impairment (CrCl 30–49) | 200 mg capsule | Every 48 hours | Monitor renal function regularly |
| Renal impairment (CrCl 15–29) | 200 mg capsule | Every 72 hours | Close monitoring required |
| Hemodialysis | 200 mg capsule | Every 96 hours | Administer after dialysis on dialysis days |
Missed Dose
Adherence to your prescribed dosing schedule is critically important for maintaining viral suppression and preventing the development of drug resistance. If you miss a dose of Emtriva:
- Within 12 hours of the usual time: Take the missed dose as soon as you remember, then continue with your regular schedule.
- More than 12 hours late: Skip the missed dose and take your next dose at the regularly scheduled time. Do not take a double dose to compensate.
If you vomit within one hour of taking Emtriva, take another capsule. If vomiting occurs more than one hour after taking the dose, no additional dose is needed as the medication will have been sufficiently absorbed.
Overdose
If you accidentally take more Emtriva than prescribed, contact your healthcare provider or nearest emergency department immediately. Bring the medication packaging with you so medical staff can easily identify what you have taken. Limited clinical experience exists with emtricitabine overdose, but hemodialysis can remove approximately 30% of the emtricitabine dose over a 3-hour dialysis session. Supportive care and monitoring of vital signs and clinical status are the primary management approach.
Stopping Emtriva or other antiretroviral medicines without consulting your doctor can lead to viral rebound, development of drug resistance, and clinical deterioration. If you are co-infected with hepatitis B, stopping Emtriva may cause severe hepatitis flare-ups. Always consult your healthcare provider before making any changes to your treatment.
What Are the Side Effects of Emtriva?
Like all medicines, Emtriva can cause side effects, although not everyone experiences them. Most side effects are mild to moderate in intensity and tend to improve as the body adjusts to the medication. During HIV treatment, changes in body weight and increases in blood lipid and glucose levels may also occur, partly related to improving health and lifestyle, and partly as a potential effect of antiretroviral medications. Your healthcare provider will conduct regular blood tests to monitor for metabolic changes.
Very Common
May affect more than 1 in 10 people
- Headache
- Diarrhea
- Nausea
- Muscle pain and weakness (with elevated creatine kinase)
Common
May affect up to 1 in 10 people
- Dizziness and weakness
- Insomnia and abnormal dreams
- Vomiting and abdominal pain
- Indigestion (dyspepsia)
- Skin rash (including red spots and patches, sometimes with blistering and swelling)
- Itching (pruritus)
- Skin discoloration (hyperpigmentation), including patchy darkening of the skin
- Pain
- Low white blood cell count (increased susceptibility to infection)
- Elevated triglycerides, bilirubin, or blood glucose
- Liver and pancreatic enzyme elevations
Uncommon
May affect up to 1 in 100 people
- Anemia (low red blood cell count)
- Angioedema (swelling of the face, lips, tongue, or throat)
Additional Effects Observed in Clinical Practice
Reported during post-marketing surveillance
- Lactic acidosis (rare but potentially serious)
- Hepatic steatosis (fatty liver)
- Immune reconstitution inflammatory syndrome (IRIS)
- Osteonecrosis (with long-term combination therapy)
Side Effects in Children
Children receiving emtricitabine may experience similar side effects as adults. However, skin discoloration (hyperpigmentation) has been reported as a very common side effect in pediatric patients, and anemia (low red blood cell count) is a common side effect in children. If a child's red blood cell production is reduced, symptoms such as fatigue, pallor, and shortness of breath may occur. Parents and caregivers should monitor for these signs and report them to the child's healthcare provider.
Metabolic Effects
During HIV treatment, weight gain and increases in blood lipid and glucose levels may occur. These changes are partially related to the recovery of health and improvement in lifestyle that accompanies effective viral suppression, but may also be associated with the antiretroviral medications themselves. Your doctor will perform regular blood tests to monitor for these metabolic changes and may recommend dietary modifications, exercise, or additional medication if necessary.
Contact your healthcare provider or seek emergency medical attention immediately if you experience: swelling of the face, lips, tongue or throat (angioedema), severe skin rash with blistering, unexplained fatigue with nausea and abdominal pain (possible lactic acidosis), or yellowing of the skin and eyes (jaundice). These may indicate serious adverse reactions requiring urgent medical intervention.
How Should You Store Emtriva?
Emtriva hard capsules should be stored at room temperature and do not require any special storage conditions. There is no need for refrigeration. Keep the capsules in their original container or blister packaging to protect them from moisture and light until ready to use.
Always store medicines out of the sight and reach of children. Check the expiry date on the bottle, blister pack, and outer carton before taking any capsule. The expiry date refers to the last day of the indicated month. Do not use Emtriva after this date, as the safety and efficacy of expired medication cannot be guaranteed.
Unused or expired medicines should not be disposed of via wastewater or household waste. Return them to your pharmacist or local medicines disposal facility. Proper disposal of pharmaceutical products helps protect the environment and prevents accidental ingestion by children, pets, or others.
What Does Emtriva Contain?
Each Emtriva 200 mg hard capsule contains the following:
Active Ingredient
Emtricitabine 200 mg — a synthetic nucleoside analogue of cytidine with activity against HIV-1 reverse transcriptase.
Inactive Ingredients (Excipients)
- Capsule contents: Microcrystalline cellulose (E460), crospovidone, magnesium stearate (E572), povidone (E1201)
- Capsule shell: Gelatin, indigo carmine (E132), titanium dioxide (E171)
- Printing ink: Black iron oxide (E172), shellac (E904)
Appearance and Packaging
Emtriva 200 mg hard capsules have a white opaque body with a light blue opaque cap. Each capsule is imprinted with “200 mg” on the cap and “GILEAD” with the Gilead logo on the body in black ink. Emtriva is available in bottles or blister packs containing 30 capsules.
The marketing authorization holder and manufacturer is Gilead Sciences Ireland UC, Carrigtohill, County Cork, T45 DP77, Ireland.
Can You Drive While Taking Emtriva?
Dizziness is a known side effect of emtricitabine that affects up to 1 in 10 patients. While many patients tolerate Emtriva without any impairment to their ability to drive or operate machinery, individual responses vary. If you experience dizziness, lightheadedness, or any other symptoms that could impair your concentration or reaction time, you should refrain from driving, using tools, or operating machinery until these effects resolve.
It is advisable to observe how you respond to the medication during the initial weeks of treatment before engaging in activities that require full mental alertness. If dizziness persists or is bothersome, discuss this with your healthcare provider, as it may be possible to adjust the timing of your dose or evaluate whether the symptom is related to Emtriva or another component of your antiretroviral regimen.
Frequently Asked Questions About Emtriva
Emtriva (emtricitabine) is an antiretroviral medicine used for the treatment of HIV-1 infection in adults, children, and infants aged 4 months and older. It belongs to the NRTI (nucleoside reverse transcriptase inhibitor) class and works by blocking HIV reverse transcriptase, an enzyme the virus needs to replicate. Emtriva is always used in combination with other antiretroviral medicines as part of a comprehensive HIV treatment regimen.
No, Emtriva does not cure HIV infection. Antiretroviral therapy, including Emtriva, suppresses viral replication and reduces the viral load in the blood to undetectable levels when taken consistently. This preserves immune function and prevents HIV transmission, but the virus remains in latent reservoirs within the body. Lifelong treatment adherence is essential for maintaining viral suppression.
The most common side effects (affecting more than 1 in 10 people) include headache, diarrhea, nausea, and muscle pain with elevated creatine kinase. Common side effects (up to 1 in 10) include dizziness, insomnia, abnormal dreams, skin rash, skin discoloration (hyperpigmentation), abdominal pain, and elevated blood triglycerides or glucose. Most side effects are mild to moderate and tend to improve over time.
Emtricitabine is considered one of the preferred NRTIs for use during pregnancy by major international guidelines, including those from the WHO and DHHS. Available safety data have not shown an increased risk of birth defects. However, all medication decisions during pregnancy should be made in consultation with your healthcare provider. Breastfeeding is not recommended for women living with HIV in settings where safe formula feeding is available, as HIV can be transmitted through breast milk.
You should never stop Emtriva without consulting your healthcare provider. Discontinuing treatment can lead to viral rebound (the HIV viral load increasing again) and the potential development of drug resistance, which can limit future treatment options. If you are co-infected with hepatitis B, stopping emtricitabine can trigger severe hepatitis B flare-ups, as emtricitabine also suppresses HBV replication. Your doctor may need to monitor your liver function for several months after discontinuation.
Emtriva hard capsules do not require special storage conditions and can be kept at room temperature. Store them out of the sight and reach of children. Do not use capsules after the expiry date stated on the packaging. Unused or expired medicines should be returned to a pharmacy for proper disposal — do not discard them via wastewater or household waste.
References
- European Medicines Agency (EMA). Emtriva — Summary of Product Characteristics. Last updated 2023. Available at: ema.europa.eu/en/medicines/human/EPAR/emtriva
- World Health Organization (WHO). Consolidated Guidelines on HIV Prevention, Testing, Treatment, Service Delivery and Monitoring. Geneva: WHO; 2024. Available at: who.int/publications
- European AIDS Clinical Society (EACS). Guidelines Version 12.0, October 2023. Available at: eacsociety.org/guidelines
- Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV. Department of Health and Human Services (DHHS). Updated 2024. Available at: clinicalinfo.hiv.gov
- Saag MS, et al. Antiretroviral Drugs for Treatment and Prevention of HIV Infection in Adults: 2020 Recommendations of the International Antiviral Society–USA Panel. JAMA. 2020;324(16):1651–1669. doi:10.1001/jama.2020.17025
- British HIV Association (BHIVA). Guidelines for the Treatment of HIV-1-Positive Adults with Antiretroviral Therapy. Updated 2023. Available at: bhiva.org/HIV-1-treatment-guidelines
- Antiretroviral Pregnancy Registry Steering Committee. Antiretroviral Pregnancy Registry International Interim Report. Issued December 2023. Available at: apregistry.com
- Gilead Sciences. Emtriva (emtricitabine) Prescribing Information. Revised 2023.
Medical Editorial Team
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Reviewed by iMedic Medical Review Board according to WHO, EACS, and DHHS guidelines
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