PRODUCTS

EMTRICITABINE

EC / List no.: 604-363-1
CAS no.: 143491-57-0

Emtricitabine (commonly called FTC, systematic name 2',3'-dideoxy-5-fluoro-3'-thiacytidine[1]), with trade name Emtriva (formerly Coviracil), is a nucleoside reverse-transcriptase inhibitor (NRTI) for the prevention and treatment of HIV infection in adults and children.

Emtricitabine is also marketed in a fixed-dose combination with tenofovir disoproxil (Viread) under the brand name Truvada, and with tenofovir alafenamide (Vemlidy) under the brand name Descovy.

A fixed-dose triple combination of emtricitabine, tenofovir and efavirenz (Sustiva, marketed by Bristol-Myers Squibb) was approved by the U.S. Food and Drug Administration (FDA) on July 12, 2006, under the brand name Atripla.

Emtricitabine makes up one fourth of the Quad pill (brand names: Stribild and Genvoya).

In fixed-dose combinations with tenofovir or with efavirenz and tenofovir it is on the World Health Organization's List of Essential Medicines.
In 2017, it was the 224th most commonly prescribed medication in the United States, with more than two million prescriptions.

Medical uses
HIV infection
Emtricitabine is indicated in combination with other antiretroviral agents for the prevention and treatment of HIV-1 infection.

HBV infection
Emtricitabine exhibits clinical activity against the hepatitis B virus (HBV), but is not approved by the U.S. Food and Drug Administration (FDA) for the treatment of HBV infection.
Among individuals with chronic HBV infection, emtricitabine treatment results in significant histologic, virologic, and biochemical improvement.
The safety profile of emtricitabine during treatment is similar to that of a placebo. Emtricitabine, like all other FDA approved drugs, cures neither HIV nor HBV infection.
In a study involving individuals with HBV infection, symptoms of infection returned in 23% of emtricitabine-treated individuals who were taken off therapy.
In studies involving individuals with chronic HIV infection, viral replication also resumes when study subjects are taken off therapy.
As with drugs used to treat HIV infection, drugs used to treat HBV infection may have to be used in combination to prevent the evolution of drug resistant strains.
The effectiveness of emtricitabine in combination with other anti-HBV drugs has not been established.

Mechanism of action
Emtricitabine is an analogue of cytidine.
The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA.
By interfering with this process, which is central to the replication of HIV, emtricitabine can help to lower the amount of HIV, or "viral load", in a patient's body and can indirectly increase the number of immune system cells (namely T cells/CD4+ T-cells).
Both of these changes are associated with healthier immune systems and decreased likelihood of serious illness.

History
Emtricitabine was discovered by Dr. Dennis C. Liotta, Dr. Raymond F. Schinazi, and Dr. Woo-Baeg Choi of Emory University and licensed to Triangle Pharmaceuticals by Emory in 1996.
Triangle Pharmaceuticals was acquired in 2003 by Gilead Sciences, who completed development and now market the product with the brand name Emtriva.

Emtricitabine was approved by the FDA July 2, 2003.
Emtricitabine is very similar to lamivudine (3TC) and cross-resistance between the two is near-universal.

Description
Emtricitabine is a nucleoside reverse transcriptaseinhibitor (NRTI) which has been marketed for the prevention and treatment of HIV infection.
Emtricitabine also exhibits clinical activity against the hepatitis B virus (HBV) (not yet approved by FDA).
Emtricitabine is a synthetic nucleoside analogue of cytidine.
Emtricitabine can be phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate, which competes with the natural substrate deoxycytidine 5'-triphosphate and incorporates into nascent viral DNA, causing early chain termination.
Through doing this, it not only lowers the amount of HIV, but also indirectly increases the number of immune system cells (called T cells or CD4+ T-cells).

New anti-HIV drugs
Emtricitabine was a novel nucleoside reverse transcriptase inhibitor successfully developed by Gilead Sciences, Inc., belonging to an anti-viral drugs and exhibits antiviral activity on HIV-1, HIV-2 and HBV.
Its antiviral activity exhibits that it can specifically anti-HIV-1, HIV-2 and HBV while even with its drug concentration being raised to 100 mmol/L, it still exhibit no activity against HSV-1, HSV-2, HCMV, VZV, corona, yellow fever virus, respiratory syncytial virus, Rota, and influenza virus or rhinovirus.
Even at a concentration lower than micromolar, the drug still exhibits potent inhibitor effect against the LAV strain and IIIB 1 of HIV virus and the ROD2 strain and ZY virus strain of HIV-2 with an IC50 value lower being 95 times lower than that of AZT (zidovudine).
Emtricitabine has been increasingly become the focus of the assessment of new drugs that whether new anti-HIV drug will produce cross-resistance to other kinds of antiviral resistant strains such as AZT, etc.
The cross-resistance test of emtricitabine against AZT-resistant strains has demonstrated that although IC50 values ??for these resistant strains have been increased slightly, all kinds of virus strains are still relatively sensitive to emtricitabine.
Instead, emtricitabine-resistant viral strains will exhibit significant cross-resistance to antiviral 3TC (lamivudine), but are still sensitive to AZT.
Studies have shown that the drug can be used together with AZT with synergistic effect.
Emtricitabine exhibited strong antiviral activity in HBV generating cell lines HepG22.2.15 (PSA subspecies).
Emtricitabine can dose-dependently reduce the number of extracellular and intracellular HBVDNA with the IC50 value being 10nmol/L; this value was comparable to another kind of HBV replication inhibitor 3TC.
Interferon α nl (Wellferon), α 2a (Ro feron), α 2b (Intron A) can all the production of inhibit HBV viral particles and the accumulation of the intracellular replication virus in the chronic producing cells intracellular production.
Combination of them associated with emtricitabine can produce a synergistic effect.
The in vivo anti-hepatitis activity of emtricitabine is investigated through the anti-HBV action in a kind of chimeric mouse model as well as the action of anti-woodchuck hepatitis virus (WHV) function in natural infected prairie dogs.
In the mouse model, use different doses for oral administration of this drug to mouse of immune deficiency and carrying human tumors as well as producing human HBV, with the antibody capture/PcR experiment, it was found that the blood HBVDNA (Dane particle) was reduced in a dose-dependent manner with even a low dose of 3.5 mg/(kg • d) also being able to produce significant inhibition while the level of intracellular replicated HBVDNA also exhibited a dose-dependent decrease; however, even at the highest dose (89 mg/(kg • d )), the tumor size remained unchanged, suggesting that the drug has selective anti-HBV activity.
The above information is edited by the Chemicalbook of Dai Xiongfeng.
Pharmacological effects Emtricitabine belongs to chemically synthesized nucleoside cytosine.
Its mechanism of anti-HIV-1 is through multi-step in vivo phosphorylation generating active triphosphate which competitively inhibits the HIV-1 reverse transcriptase while competing with natural 5-phosphate cytosine by for penetrating into the viral DNA synthesis process, which ultimately leads to the synthesis of a DNA strand break.
Its mechanism of HBV is because that the HBV replication process contains target site of emtricitabine, namely reverse transcription process.
Emtricitabine has a low inhibitory effect on mammal DNA polymerases α, β, ε and mitochondrial DNA polymerase γ.
In vitro antiviral activity: in vitro laboratory used and clinical isolate anti-HIV viruses have been assessed in lymphoblastoid cell lines, MAGI-CCR5 cell line, and peripheral blood mononuclear cells.
The 50% inhibitory concentration (IC50) value is in the range of 0.0013~0.158 μg/mL.
In the combination study with nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitors (PI), it exhibited a synergistic effect.
Most kinds of combined clinical study have not been carried out.
In vitro tests have demonstrated that it has antiviral activity against HIV-1 (A, C, D, E, F and G subtypes) (IC50 values in the range of 0.007~0.075 μg/mL) while displaying specific inhibition activity against the HIV-2 type (IC50 values in the range of 0.007~1.5 μg/mL).

Pharmacokinetics
Pharmacokinetic assessment was performed in healthy volunteers and HIV-infected individuals.
The pharmacokinetics of the two groups is similar with each other.
Absorption: oral administration gives rapid absorption with the drug being widely distributed.
After administration of 1 to 2 hours, the plasma concentration reaches peak.
20 cases of HIV infected patients were subject to multiple fold doses of drugs through oral administration (mean ± SD) the plasma concentration peak of emtricitabine (Cmax) is 1.8 ± 0.7μg/mL.
At 24 hours, the plasma drug concentration-time area under the curve (AUC) is 10.0 ± 3.1 (h • μg)/mL.
At 24h hours after administration, the average steady-state plasma concentration is 0.09μg/mL.
The average bioavailability is 93%.
At multiple folds of doses, the pharmacokinetics is in proportion with the dose (25~200mg).
Distribution: In vitro binding rate of emtricitabine to human plasma proteins is < 4%; when the concentration exceeds the range of 0.02~200 μg/mL, it exists in its free state.
At the time of peak concentration, the ratio of plasma drug concentration and blood drug concentration is 1.0, and the ratio of the seminal fluid concentration and plasma drug concentration is 4.0.
Metabolism: In vitro studies have shown that emtricitabine is not an inhibitor of human CYP450 enzymes.
Taking 14C-labeled emtricitabine with the prototype reaching the urine (86%) and it (14%).
13% of the dose is converted into three metabolites.
The biotransformation substances include the oxidized sulfur portion for generating 3'-sulfoxide diastereomers (9%), and binding to glucuronide for formation of 2'-oxy-glucuronide (4%).
Other metabolites have not been determined.
Excretion: The half life of the emtricitabine plasma concentration is about 10 hours.
The renal clearance rate of emtricitabine is higher than the creatinine clearance rate, suggesting that it is excreted through glomerular filtration and tubular secretion, and there may be substance competing with it for the kidneys.

Indications
1. Emtricitabine is combined with other antiviral drugs for treating adult HIV-1 infection.
Patients should be those who haven’t been subject to treatment by reverse transcriptase inhibitors or those who have received reverse transcriptase inhibitors with virus having been suppressed.
2. Emtricitabine can be used for the treatment of chronic hepatitis B.

Precautions
Emtricitabine is mainly excreted by the kidneys, so patients with renal insufficiency should reduce the administered amount upon taking this drug.
Pregnant women, when taking emtricitabine, may get an adverse effect on the fetus and newborn.
Emtricitabine can also be secreted through breast milk which may also affect the infant.
Therefore, it is generally not recommended for pregnant and lactating women to use Emtricitabine unless in situation of considering save the mother's life.
Emtricitabine has not been established of the children's safety basis.
Therefore, it is not recommended for children. Elderly should be cautious when choosing the dose.
They can apply appropriate reduction on the dose according to the actual conditions of liver, kidney, heart function decline, associated diseases and the effects of other kinds of drugs.
The impact of excessive drugs is unknown, if there is drug overdose, monitoring should be carried out.
Apply maintenance dose treatment when necessary.

Uses
Emtricitabine is white, white-like powder or crystalline powder Application: treatment of chronic hepatitis B; Emtricitabine has a strong antiviral activity with the safety and tolerance being good.

Description
Emtricitabine is a synthetic nucleoside inhibitor of HIV-1 reverse transcriptase.
Its mechanism of action entails the phosphorylation of the oxathiolane carbinol function by cellular enzymes to form the corresponding 5′-triphosphate, which competes with the endogenous 2′-deoxycytidine 5′-triphosphate substrate.
The in vitro activity of emtricitabine ranges from IC50 of 0.00013 to 0.64 mM against lymphoblastoid cell lines, MAGI-CCR5 cell lines, and peripheral blood mononuclear cells.
Emtricitabine is prepared in about 16 steps from L-gulose, from which the O–C–S carbon stereochemistry is derived in the formation of substituted key 4-O-Acetyl-1,3- oxathiolane intermediate.
This intermediate is coupled with N-benzoyl-O-trimethylsilyl- 5-fluoro-cytosine in the presence of trimethylsilyl triflate.
The resulting anomeric mixture is separated by silica chromatography and subjected to two deprotection steps.
Emtricitabine resistant isolates (M184V/I) were cross-resistant to lamivudine (desfluoro version of emtricitabine) and zalcitabine but remained sensitive to abacavir, didanosine, stavudine, tenofovir, zidovudine, and non-nucleoside reverse transcriptase inhibitors (delavirdine, efavirenz, and nevirapine).
In a 48-week clinical trial using emtricitabine with didanosine and efavirin versus stavudine, didanosine and efavirenz produced 81 versus 68% responder rate respectively.
In one study, 37.5% of treatment na?¨ve patients that were not achieving successful viral levels were found to exhibit a reduced potency toward emtricitabine.
This resistance was due to M184V/I mutation in the HIV reverse transcriptase gene.
Recommended dosing of emtricitabine is 200 mg (capsule) once per day.
Emtricitabine is 93% bio-available and has a plasma half-life about 10 h, with 86% renal clearance.
Side effects associated with emtricitabine treatment were generally mild to moderate and included headache, diarrhea, nausea, and rash.
A generally mild and asymptomatic hyperpigmentation of the palms and/or soles was also observed.

Chemical Properties
White to Off-White Crystalline Solid

Uses
A reverse transcriptase inhibitor.
A nucleoside analog structurally related too lamivudine.
Emtricitabine is an effective antiviral agent against HIV, HBV, and other viruses replicating in a similar manner.
A nucleoside analog structurally related to Lamivudine (L172500).

anti-Alzheimer’s treatment

Labeled Emtricitabine, intended for use as an internal standard for the quantification of Emtricitabine by GC- or LC-mass spectrometry.

Definition
ChEBI: An organofluorine compound that is 5-fluorocytosine substituted at the 1 position by a 2-(hydroxymethyl)-1,3-oxathiolan-5-yl group (2R,5S configuration).
Emtricitabine is used in combination therapy for the treatment of HIV-1 infect on.

Brand name
Emtriva (Gilead Sciences) [Note—Emtricitabine has appeared in the literature with the trivial names, (-)-FTC and FTC-(-).].

Acquired resistance
Resistance is associated with a substitution in the HIV-1 reverse transcriptase gene at codon 184 (M184V/I). ,
Emtricitabineresistant isolates are cross-resistant to lamivudine. HIV-1 isolates with the K65R substitution in the reverse transcriptase coding region have reduced susceptibility.

General Description
Emtricitabine is an orally active NRTI whose pharmacokineticsare favorable for once-daily administration.

Pharmaceutical Applications
A synthetic nucleoside analog of cytosine, formulated for oral use.

Pharmacokinetics
Oral absorption: capsules 93%
Cmax 200 mg oral once daily: 1.8 ± 0.7 mg/L
Plasma half-life: c. 10 h
Volume of distribution: 1.4 ± 0.3 L/kg
Plasma protein binding: <4%
Absorption and distribution
Emtricitabine is rapidly and extensively absorbed. There is moderate CNS penetration.
The estimated semen:plasma ratio is approximately 4. There are presently no data on levels in breast milk.
Metabolism and excretion
Emtricitabine does not inhibit human cytochrome P450 enzymes. About 80% is excreted in the urine, the rest in feces.
Renal clearance is greater than the estimated creatinine clearance, suggesting elimination by both glomerular filtration and active tubular secretion.
There may be competition for elimination with other compounds that are renally excreted.
Exposure is significantly increased in renal insufficiency, but dose reductions are not generally recommended.
Emtricitabine is unlikely that a dose adjustment would be required in the presence of hepatic impairment.

Clinical Use
Treatment of HIV infection (in combination with other antiretroviral drugs)

Description
Emtricitabine is a nucleoside reverse transcriptaseinhibitor (NRTI) which has been marketed for the prevention and treatment of HIV infection.
Emtricitabine also exhibits clinical activity against the hepatitis B virus (HBV) (not yet approved by FDA).Emtricitabine is a synthetic nucleoside analogue of cytidine.
Emtricitabine can be phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate, which competes with the natural substrate deoxycytidine 5'-triphosphate and incorporates into nascent viral DNA, causing early chain termination.
Through doing this, it not only lowers the amount of HIV, but also indirectly increases the number of immune system cells (called T cells or CD4+ T-cells).

Pharmacological effects Emtricitabine belongs to chemically synthesized nucleoside cytosine.
Its mechanism of anti-HIV-1 is through multi-step in vivo phosphorylation generating active triphosphate which competitively inhibits the HIV-1 reverse transcriptase while competing with natural 5-phosphate cytosine by for penetrating into the viral DNA synthesis process, which ultimately leads to the synthesis of a DNA strand break.
Its mechanism of HBV is because that the HBV replication process contains target site of emtricitabine, namely reverse transcription process.
Emtricitabine has a low inhibitory effect on mammal DNA polymerases α, β, ε and mitochondrial DNA polymerase γ.
In vitro antiviral activity: in vitro laboratory used and clinical isolate anti-HIV viruses have been assessed in lymphoblastoid cell lines, MAGI-CCR5 cell line, and peripheral blood mononuclear cells.
The 50% inhibitory concentration (IC50) value is in the range of 0.0013~0.158 μg/mL.
In the combination study with nucleoside reverse transcriptase inhibitors (NRTI), non-nucleoside reverse transcriptase inhibitor (NNRTI) and protease inhibitors (PI), it exhibited a synergistic effect.
Most kinds of combined clinical study have not been carried out.
In vitro tests have demonstrated that it has antiviral activity against HIV-1 (A, C, D, E, F and G subtypes) (IC50 values in the range of 0.007~0.075 μg/mL) while displaying specific inhibition activity against the HIV-2 type (IC50 values in the range of 0.007~1.5 μg/mL).

Distribution:
In vitro binding rate of emtricitabine to human plasma proteins is < 4%; when the concentration exceeds the range of 0.02~200 μg/mL, it exists in its free state.
At the time of peak concentration, the ratio of plasma drug concentration and blood drug concentration is 1.0, and the ratio of the seminal fluid concentration and plasma drug concentration is 4.0.
Metabolism: In vitro studies have shown that emtricitabine is not an inhibitor of human CYP450 enzymes.
Taking 14C-labeled emtricitabine with the prototype reaching the urine (86%) and it (14%).
13% of the dose is converted into three metabolites.
The biotransformation substances include the oxidized sulfur portion for generating 3'-sulfoxide diastereomers (9%), and binding to glucuronide for formation of 2'-oxy-glucuronide (4%).
Other metabolites have not been determined.

Excretion: The half life of the emtricitabine plasma concentration is about 10 hours.
The renal clearance rate of emtricitabine is higher than the creatinine clearance rate, suggesting that it is excreted through glomerular filtration and tubular secretion, and there may be substance competing with it for the kidneys.

Precautions
Emtricitabine is mainly excreted by the kidneys, so patients with renal insufficiency should reduce the administered amount upon taking this drug.
Pregnant women, when taking emtricitabine, may get an adverse effect on the fetus and newborn.
Emtricitabine can also be secreted through breast milk which may also affect the infant.
Therefore, it is generally not recommended for pregnant and lactating women to use Emtricitabine unless in situation of considering save the mother's life.
Emtricitabine has not been established of the children's safety basis.
Therefore, it is not recommended for children.
Elderly should be cautious when choosing the dose.
They can apply appropriate reduction on the dose according to the actual conditions of liver, kidney, heart function decline, associated diseases and the effects of other kinds of drugs.
The impact of excessive drugs is unknown, if there is drug overdose, monitoring should be carried out.
Apply maintenance dose treatment when necessary.

Chemical Properties
White to Off-White Crystalline Solid

Uses
anti-Alzheimer’s treatment

Labeled Emtricitabine, intended for use as an internal standard for the quantification of Emtricitabine by GC- or LC-mass spectrometry.

Definition
ChEBI: An organofluorine compound that is 5-fluorocytosine substituted at the 1 position by a 2-(hydroxymethyl)-1,3-oxathiolan-5-yl group (2R,5S configuration). Emtricitabine is used in combination therapy for the treatment of HIV-1 infect on.

Brand name
Emtriva (Gilead Sciences) [Note—Emtricitabine has appeared in the literature with the trivial names, (-)-FTC and FTC-(-).].

Acquired resistance
Resistance is associated with a substitution in the HIV-1 reverse transcriptase gene at codon 184 (M184V/I).
Emtricitabineresistant isolates are cross-resistant to lamivudine. HIV-1 isolates with the K65R substitution in the reverse transcriptase coding region have reduced susceptibility.

General Description
Emtricitabine is an orally active NRTI whose pharmacokineticsare favorable for once-daily administration.

Pharmaceutical Applications
A synthetic nucleoside analog of cytosine, formulated for oral use.

Emtricitabine is rapidly and extensively absorbed.
There is moderate CNS penetration.
The estimated semen:plasma ratio is approximately 4.
There are presently no data on levels in breast milk.

Metabolism and excretion
Emtricitabine does not inhibit human cytochrome P450 enzymes.
About 80% is excreted in the urine, the rest in feces.
Renal clearance is greater than the estimated creatinine clearance, suggesting elimination by both glomerular filtration and active tubular secretion.
There may be competition for elimination with other compounds that are renally excreted.
Exposure is significantly increased in renal insufficiency, but dose reductions are not generally recommended.
Emtricitabine is unlikely that a dose adjustment would be required in the presence of hepatic impairment.

Clinical Use
Treatment of HIV infection (in combination with other antiretroviral drugs)
Side effects
At least 10% of patients suffer headache, diarrhea, nausea, fatigue, dizziness, depression, insomnia, abnormal dreams, rash, abdominal pain, asthenia, increased cough and rhinitis.
Skin hyperpigmentation is common (≥10%) in pediatric patients.
Emtricitabine competes with lamivudine for the enzymes involved in intracellular phosphorylation; their co- administration is contraindicated.

Chemical Synthesis
Emcitritabine (VII) was discovered by researchers at Emory University and licensed to Triangle Pharmaceuticals, which started the development work before being acquired by Gilead.
Because emcitritabine (VII) belongs to an important structural class of nucleosides with marketed drugs, such as 3TC, several processes for the manufacture of this class of oxathiolane nucleosides have appeared in patents and scientific literature.
However, only the synthesis described in the latest patent filed for the manufacture of emcitritabine (VII) and one other efficient synthesis from the Liotta group will be described .
The synthesis started with diacylation with butyryl chloride (62) of the 2-butene-1,4-diol (61) in methyl t-butylether at 0°C to room temperature in the presence of triethylamine to give diacylated product 63 in 95% yield.
Ozonolysis followed by reduction with thiourea provided a mixture of hemiacetal 64 mixed with acetals, dimers and trimers in 97% yield, which was used in the next step directly.
The hemiacetal mixture was reacted with thioacetic acid in toluene at 85°C for 3 hr to give the crude keto oxathiolane mixture, which was purified by vacuum distillation in a 2-in Pope Scientific wiped film still to remove impurities and collect about 92% pure 66 in 54% yield.
Also mentioned in the patent is the potential use of enzymatic resolution of the isomers as reported previously.
This keto oxathiolane 66 was reduced at 5°C with lithium aluminum t-butoxide, which was prepared in situ via reaction of LAH and t-butanol, and the resulting lactol was trapped with acetic anhydride in the presence of DMAP in the same reaction vessel to give, after workup, 87% yield of the key intermediate acetate 67.
The bis-silyl protected 5- fluorocytosine 68, prepared in situ by reacting 5- fluorocytosine (71) with HMDS, was reacted with acetate 67 in the presence of trimethylsilyliodide at 0°C to room temperature to give a 1:1 mixture of alpha and beta-anomers 69 and 70.
Pure 69 could be isolated by recrystallization from toluene.
Cleavage of the butyryl group with a strongly basic DOWEX SBR resin in methanol at room temperature gave emcitritabine (VII) in 81% yield.
An alternate concise synthesis reported by Liotta et al is worth mentioning.
This synthetic route accessed the key thioxalane acetate 76 as the TBDMS ether in four steps from allyl alcohol 72.
The key step to the preparation of the final compound was the coupling of the bis-silyl 5-fluorocytosine (68) with acetate 76 with tin tetrachloride in a stereoselective manner, after cleavage of the silyl groups and recrystallization, to give pure cis isomer emcitritabine (VII) in excellent yield.

Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) indicated for the treatment of HIV infection in adults or combined with tenofovir alafenamide for the prevention of HIV-1 infection in high risk adolescents and adults.
Emtricitabine is a cytidine analogue.
The drug works by inhibiting HIV reverse transcriptase, preventing transcription of HIV RNA to DNA

Emtricitabine is a synthetic fluoro derivative of thiacytidine with potent antiviral activity.
Emtricitabine is phosphorylated to form emtricitabine 5'-triphosphate within the cell.
This metabolite inhibits the activity of human immunodeficiency virus (HIV) reverse transcriptase both by competing with the natural substrate deoxycytidine 5'-triphosphate and by incorporation into viral DNA causing a termination of DNA chain elongation (due to the lack of the essential 3'-OH group).

Emtricitabine is a nucleoside analogue and reverse transcriptase inhibitor used in combination with other agents for treatment and prevention of human immunodeficiency virus (HIV) infection and the acquired immunodeficiency syndrome (AIDS).
Emtricitabine does not appear to be a significant cause of drug induced liver injury, but may cause flares of disease in patients with underlying chronic hepatitis B virus (HBV) infection.

Emtricitabine is an organofluorine compound that is 5-fluorocytosine substituted at the 1 position by a 2-(hydroxymethyl)-1,3-oxathiolan-5-yl group (2R,5S configuration).
Emtricitabine is used in combination therapy for the treatment of HIV-1 infection.
Emtricitabine has a role as an antiviral drug and a HIV-1 reverse transcriptase inhibitor.
Emtricitabine is a pyrimidone, an organofluorine compound, a monothioacetal and a nucleoside analogue.

Emtricitabine is an orally administered nucleoside reverse transcriptase inhibitor.
Emtricitabine has activity against both human immunodeficiency virus and hepatitis B virus.
Emtricitabine is very similar to lamivudine with respect to activity, convenience and safety, and resistance profile.
The only difference is the longer intracellular half-life of emtricitabine.
Emtricitabine is indicated in combination with other antiretroviral agents for the treatment of HIV infection in adults.
As a component of antiretroviral therapy, emtricitabine effectively reduces and/or maintains suppression of viral load in antiretroviral naïve adults or experienced adults switching from stable combination regimens.
Emtricitabine is also a preferred choice for patients coinfected with HIV and hepatitis B virus when combined with tenofovir, which also has antihepatitis B activity.
Emtricitabine has the convenience of once-daily administration, no dietary restrictions and a favorable drug interaction and tolerability profile.

Emtricitabine is an antiretroviral medicine. Emtricitabine is used for human immunodeficiency virus (HIV) infection.
Emtricitabine slows the progress of HIV infection, but it is not a cure. HIV destroys cells in the body, called CD4 T cells.
These cells are a type of white blood cell and are important because they are involved in protecting your body from infection.
If left untreated, the HIV infection weakens your immune system so that your body cannot defend itself against bacteria, viruses and other germs.
Emtricitabine slows down the progress of HIV infection by reducing the amount of virus in your body. Emtricitabine does this by stopping the virus from copying (replicating) itself.

Emtricitabine will be prescribed for you by a doctor who is a specialist.
Emtricitabine belongs to a group of antiretroviral medicines known as nucleoside reverse transcriptase inhibitors (NRTIs).
Emtricitabine is given alongside a number of other antiretroviral medicines, as part of a combination therapy.
Taking three or more antiretroviral medicines at the same time is more effective than taking one alone.
Taking a combination of different medicines also reduces the risk that the virus will become resistant to any individual medicine.
Some brands of emtricitabine contain other antiretroviral medicines also (see the list in the table above).
Taking one of these brands helps to reduce the number of tablets you need to take each day.
Not all of the information in this leaflet applies to the combination brands - please refer to the manufacturer's printed information leaflet from inside the pack for full details about these brands.

Emtricitabine is vital to take your antiretroviral medicines exactly as prescribed to maintain success and to help to prevent the virus from becoming resistant to the medicines.
These medicines are usually taken for life.

Before taking emtricitabine
Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken.
For these reasons, before you start taking emtricitabine it is important that your doctor knows:

If you are pregnant, trying for a baby or breastfeeding.
If you have any problems with the way your liver works, or if you have problems with the way your kidneys work.
If you drink a lot of alcohol.
If you are taking any other medicines. This includes any medicines which are available to buy without a prescription, as well as herbal and complementary medicines.
If you have ever had an allergic reaction to a medicine.
How to take emtricitabine
Before you start the treatment, read the manufacturer's printed information leaflet from inside your pack.
Emtricitabine will give you more information about emtricitabine, and it will also provide you with a full list of the side-effects which you could experience from taking it.
Take emtricitabine exactly as your doctor tells you to.
Emtricitabine is taken once daily.
Adults will usually be prescribed capsules/tablets to take, whereas children are likely to be supplied with liquid medicine.
Your doctor will tell you how much you should take for each dose.
Try to take emtricitabine at the same time of day each day, as this will help you to remember to take it regularly.
You can take emtricitabine either with or without food.
If for any reason you are sick (vomit) within one hour of taking emtricitabine, you should take another dose.
This is because the medicine will not have been absorbed by your body.
If, however, you are sick more than one hour after taking a dose, there is no need to repeat the dose, as the medicine will already have been absorbed.
If you forget to take a dose, take it as soon as you remember, providing it is within 12 hours of the time you should have taken it.
If when you remember, it is more than 12 hours late, do not take the dose you missed but do remember to take your next dose when it is due.
Do not take two doses together to make up for a forgotten dose.
Getting the most fro

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

Emtricitabine is used to treat HIV, the virus that can cause 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.

Emtricitabine is used in combination with other antiviral drugs to treat HIV infection.
There are currently no reported nutrient or herb interactions involving emtricitabine.

IUPAC NAMES:
2'-Deoxy-5-fluoro-3'-thiacytidine
5-Fluor-1-[(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosin
5-fluoro-1-(2R,5S)-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine
gil
Nucleoside analogue

SYNONYMS:
Emtricitabine (200 mg)
4-aMino-5-fluoro-1-[(2R,5S)-2-(hydroxyMethyl)-1,3-oxathiolan-5-yl]-1,2-dihydropyriMidin-2-one
EMtricitabine (EMtriva)
4-Amino-5-fluoro-1-[(2R,5S)-2-hydroxymethyl)-1,3-oxathiolan-5-yl]-2-(1H-pyrimidinone, (-)-FTC, (-)-b-23Dideoxy-5-fluoro-3thiacytidine, 524W91, BW-52491, Coviracil,
Entricitabine
2(1H)-Pyrimidinone, 4-amino-5-fluoro-1-(2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl-
2'-deoxy-5-fluoro-3'-thiacytidine
4-Amino-5-fluoro-1-[(2R,5S)-2-hydroxymethyl)-1,3-oxathiolan-5-yl]-2-(1H-pyrimidinone, (-)-FTC, (-)--2’,3’-Dideoxy-5-fluoro-3’-thiacytidine, 524W91, BW-52491, Coviracil
Emtritabine Hydrochloride
EMtricitabine 15N D2 HCL
BW 1592
BW1592
BW-1592
EMtriva
EMtricitabine Hydrochloride
4-Amino-5-fluoro-1-((2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl)pyrimidin-2(1H)-one
Emtiricitabine
Emtricitabine,4-amino-5-fluoro-1-(2-(hydroxymethyl)-1,3-oxathiolan-5-yl)-(2r-cis)-2(1h)-pyrimidinone
Emtricitabine D2
SM-Q
4-amino-5-fluoro-1-(2-(hydroxymethyl)-1,3-oxathiolan-5-yl)-(2r-cis)-2(1h)-pyrimidinone
(-)-BETA-2',3'-DIDEOXY-5-FLUORO-3'-THIACYTIDINE
EMTRICITABINE
EMTRITABINE
FTC
FUMITREMORGIN C
EMTRICITABIN
EMTRITABINE 98.0+%
4-Amino-5-fluoro-1-[(2R,5S)-2-hydroxymethyl)-1,3-oxathiolan-5-yl]-2-(1H-pyrimidinone,(-)-FTC,(-)-b-23Dideoxy-5-flu
Emtricitabin-d3
Emtricitabine (BW1592)
Emtricitabine Impurity 1
CS-895
Emtricitabine>
Emtricitabine Emtricitabine
((2R-cis)-4-Amino-5-fluoro-1-[2-(hydroxymethyl)-1,3- oxathiolan-5-yl]-2(1H)- pyrimidinone)
Emtricitabine fandachem
Emtricitabine USP/EP/BP
Emtricitabine (1.0 mg/mL in Methanol)