STRIBILD FILM COATED TABLET 150MG/150MG/200MG/245MG

Product Information

Registration Status: Active

STRIBILD FILM COATED TABLET 150MG/150MG/200MG/245MG is approved to be sold in Singapore with effective from 2015-08-25. It is marketed by GILEAD SCIENCES SINGAPORE PTE LTD, with the registration number of SIN14835P.

This product contains Cobicistat 150mg,Elvitegravir 150mg,Emtricitabine 200mg , and Tenofovir Disoproxil 245mg in the form of TABLET, FILM-COATED. It is approved for ORAL use.

This product is manufactured by Patheon in UNITED STATES, Inc. in CANADA, andGilead Sciences Ireland UC in IRELAND.

It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.

Cobicistat
Elvitegravir
Emtricitabine
Tenofovir Disoproxil

Description

Cobicistat, trade name Tybost (formerly GS-9350), is a licensed drug for use in the treatment of infection with human immunodeficiency virus (HIV). Although it does not have any anti-HIV activity, cobicistat acts as a pharmacokinetic enhancer by inhibiting cytochrome P450 3A isoforms (CYP3A) and therefore increases the systemic exposure of coadministered agents that are metabolized by CYP3A enzymes. More specifically, cobicistat is indicated to increase systemic exposure of atazanavir or darunavir (once daily dosing regimen) in combination with other antiretroviral agents in the treatment of HIV-1 infection. Increasing systemic exposure of anti-retrovirals (ARVs) without increasing dosage allows for better treatment outcomes and a decreased side effect profile.

Indication

Cobicistat is a CYP3A inhibitor indicated to increase systemic exposure of atazanavir or darunavir (once daily dosing regimen) in combination with other antiretroviral agents in the treatment of HIV-1 infection. It is not interchangeable with ritonavir to increase systemic exposure of darunavir 600 mg twice daily, fosamprenavir, saquinavir, or tipranavir due to lack of exposure data. The use of cobicistat is not recommended with darunavir 600 mg twice daily, fosamprenavir, saquinavir or tipranavir. Complex or unknown mechanisms of drug interactions preclude extrapolation of ritonavir drug interactions to certain cobicistat interactions. Cobicistat and ritonavir when administered with either atazanavir or darunavir may result in different drug interactions when used with concomitant medications.

Mechanism of Action

Cobicistat is a mechanism-based inhibitor of cytochrome P450 3A (CYP3A) isoforms. Inhibition of CYP3A-mediated metabolism by cobicistat increases the systemic exposure of CYP3A substrates atazanavir and darunavir and therefore enables increased anti-viral activity at a lower dosage. Cobicistat does not have any anti-HIV activity on its own.

Pharmacokinetics

Absorption
Median peak plasma concentrations were observed at 3.5 hours post-dose.
Distribution
Metabolism
Cobicistat is metabolized by CYP3A and to a minor extent by CYP2D6 enzymes and does not undergo glucuronidation.
Elimination

Toxicity

The most common adverse reactions reported during clinical trials were jaundice (13%), ocular icterus (15%), and nausea (12%).

Active Ingredient/Synonyms

1,3-thiazol-5-ylmethyl [(2R,5R)-5-{[(2S)-2-({[(2-isopropyl-1,3-thiazol-4-yl)methyl](methyl)carbamoyl}amino)-4-(morpholin-4-yl)butanoyl]amino}-1,6-diphenylhexan-2-yl]carbamate | Cobicistat |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


Description

Elvitegravir is a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor (INSTI) used for the treatment of HIV-1 infection in antiretroviral treatment-experienced adults. Because integrase is necessary for viral replication, inhibition prevents the integration of HIV-1 DNA into the host genome and thereby blocks the formation of the HIV-1 provirus and resulting propagation of the viral infection. Although available as a single dose tablet, elvitegravir must be used in combination with an HIV protease inhibitor coadministered with ritonavir and another antiretroviral drug. It was developed by the pharmaceutical company Gilead Sciences, which licensed EVG from Japan Tobacco in March 2008. The drug gained approval by the U.S. Food and Drug Administration on August 27, 2012 for use in adult patients starting HIV treatment for the first time as part of the fixed dose combination known as Stribild. On September 24, 2014 the FDA approved Elvitegravir (tradename Vitekta) as a single pill formulation.

Indication

Elvitegravir in combination with an HIV protease inhibitor coadministered with ritonavir and with other antiretroviral drug(s) is indicated for the treatment of HIV-1 infection in antiretroviral treatment-experienced adults.

Mechanism of Action

Elvitegravir is an HIV-1 integrase strand transfer inhibitor (INSTI). Integrase is an HIV-1 encoded enzyme that is required for viral replication. Inhibition of integrase prevents the integration of HIV-1 DNA into host genomic DNA, blocking the formation of the HIV-1 provirus and propagation of the viral infection. Elvitegravir does not inhibit human topoisomerases I or II.

Pharmacokinetics

Absorption
Following oral administration of elvitegravir and ritonavir with food, in HIV-1 infected subjects, peak elvitegravir plasma concentrations were observed approximately 4 hours post-dose.
Distribution
Metabolism
Elvitegravir undergoes primarily oxidative metabolism via CYP3A, and is secondarily glucuronidated via UGT1A1/3 enzymes. Metabolites are found in the plasma at very low concentrations, displayed considerably lower anti-HIV activity, and did not contribute to the overall antiviral activity of elvitegravir.
Elimination

Toxicity

The most common adverse reactions reported for elvitegravir use during clinical trials include nausea, vomiting, and diarrhea. Less common side effects occurring in <2% of patients, include abdominal pain, dyspepsia, fatigue, insomnia, rash, depression, suicidal ideation, and suicidal attempt.

Active Ingredient/Synonyms

6-(3-chloro-2-fluorobenzyl)-1-[(2S)-1-hydroxy-3-methylbutan-2-yl]-7-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid | elvitégravir | EVG | GS 9137 | Elvitegravir |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


Description

Emtricitabine is a nucleoside reverse transcriptase inhibitor (NRTI) for the treatment of HIV infection in adults. Emtricitabine is an analogue of cytidine. The drug works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA.

Indication

Indicated, in combination with other antiretroviral agents, for the treatment of HIV-1 infection in adults and for postexposure prophylaxis of HIV infection in health care workers and others exposed occupationally or nonoccupationally via percutaneous injury or mucous membrane or nonintact skin contact with blood, tissues, or other body fluids associated with risk for transmission of the virus.

Mechanism of Action

Emtricitabine works by inhibiting reverse transcriptase, the enzyme that copies HIV RNA into new viral DNA. Emtricitabine is a synthetic nucleoside analogue of cytidine. It is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate, which is responsible for the inhibition of HIV-1 reverse transcriptase. It competes with the natural substrate deoxycytidine 5'-triphosphate and incorporates into nascent viral DNA, resulting in early chain termination. Therefore emtricitabine inhibits the activity of HIV-1 reverse transcriptase (RT) both by competing with the natural substrate deoxycytidine 5'-triphosphate and by its incorporation into viral DNA. By inhibiting HIV-1 reverse transcriptase, 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 (called T cells or CD4+ T-cells). Both of these changes are associated with healthier immune systems and decreased likelihood of serious illness.

Pharmacokinetics

Absorption
Rapidly absorbed (mean absolute bioavailability of 93% for capsules, and 75% for solution). Food does not effect absorption.
Distribution
Metabolism
Minimally transformed (13%), most appears unchanged in urine (86%). The biotransformation of emtricitabine includes oxidation of the thiol moiety to form the 3′-sulfoxide diastereomers (~ 9% of dose) and conjugation with glucuronic acid to form 2′-O-glucuronide (~ 4% of dose). In vitro studies indicate emtricitabine is not an inhibitor or cytochrome P450 enzymes.
Elimination

Clearance

* 302 +/- 94 mL/min [Renal Function Creatinine Clearance>80 ml/min] * 168 +/- 10 mL/min [Renal Function Creatinine Clearance 50-80 ml/min] * 138 +/- 28 mL/min [Renal Function Creatinine Clearance 30-49 ml/min] * 99 +/- 6 mL/min [Renal Function Creatinine Clearance<30 ml/min] * 64 +/- 12 mL/min [ESRD patients requiring dialysis]

Toxicity

Symptoms of overdose include serious liver problems (hepatotoxicity, with liver enlargement and fat in the liver called steatosis) or a lactic acidosis (buildup of an acid in the blood).

Active Ingredient/Synonyms

(−)-(2R,5S)-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl]cytosine | (−)-2'-deoxy-5-fluoro-3'-thiacytidine | (−)-cis-4-amino-5-fluoro-1-(2-hydroxymethyl-1,3-oxathiolan-5-yl)-(1H)-pyrimidin-2-one | (−)-FTC | (−)-β-2',3'-dideoxy-5-fluoro-3'-thiacytidine | (2R-cis)-4-amino-5-fluoro-1-(2-(hydroxymethyl)-1,3-oxathiolan-5-yl)-2(1H)-pyrimidinone | 4-amino-5-fluoro-1-((2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl)pyrimidin-2(1H)-one | 4-Amino-5-fluoro-1-((2R,5S)-2-hydroxymethyl-[1,3]oxathiolan-5-yl)-1H-pyrimidin-2-one | 5-fluoro-1-((2R,5S)-2-(hydroxymethyl)-1,3-oxathiolan-5-yl)cytosine | Emtricitabin | Emtricitabina | Emtricitabine | Emtricitabinum | Emtricitabine |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.


Description

Tenofovir disoproxil fumarate (a prodrug of tenofovir), marketed by Gilead Sciences under the trade name Viread, belongs to a class of antiretroviral drugs known as nucleotide analogue reverse transcriptase inhibitors (nRTIs), which block reverse transcriptase, an enzyme crucial to viral production in HIV-infected people. In vivo tenofovir disoproxil fumarate is converted to tenofovir, an acyclic nucleoside phosphonate (nucleotide) analog of adenosine 5'-monophosphate.

Indication

Tenofovir is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and pediatric patients 2 years of age and older. It is also indicated for the treatment of chronic hepatitis B in adults and pediatric patients 12 years of age and older.

Mechanism of Action

Tenofovir inhibits the activity of HIV reverse transcriptase by competing with the natural substrate deoxyadenosine 5'-triphosphate and, after incorporation into DNA, by DNA chain termination. Specifically, the drugs are analogues of the naturally occurring deoxynucleotides needed to synthesize the viral DNA and they compete with the natural deoxynucleotides for incorporation into the growing viral DNA chain. However, unlike the natural deoxynucleotides substrates, NRTIs and NTRTIs (nucleoside/tide reverse transcriptase inhibitors) lack a 3'-hydroxyl group on the deoxyribose moiety. As a result, following incorporation of an NRTI or an NtRTI, the next incoming deoxynucleotide cannot form the next 5'-3' phosphodiester bond needed to extend the DNA chain. Thus, when an NRTI or NtRTI is incorporated, viral DNA synthesis is halted, a process known as chain termination. All NRTIs and NtRTIs are classified as competitive substrate inhibitors.

Pharmacokinetics

Absorption
Tenofovir disoproxil fumarate is the water soluble diester prodrug of the active ingredient tenofoir. The oral bioavailability in fasted patients is approximately 25%. When a single oral dose (300 mg) is given to HIV-1 infected subjects in the fasted state, the maximum serum concentration was achieved in 1.0 ± 0.4 hours (Tmax). Cmax and AUC values are 0.30 ± 0.09 µg/mL and 2.29 ± 0.69 µg∙hr/mL. Administration of food (high fat meal containing 40 to 50% fat) increases the oral bioavailability, with an increase in the AUC of approximately 40%. Cmax is lower in the oral powder, compared to the tablet formulation. However, the mean AUC is similar between the two formulations.
Distribution
* 1.3 ± 0.6 L/kg [tenofovir 1.0 mg/kg IV] * 1.2 ± 0.4 L/kg [tenofovir 3.0 mg/kg IV]
Metabolism
The cytochrome P450 enzyme system is not involved with the metabolism of tenofovir disoproxil or tenofovir.
Elimination

Clearance

The following are renal clearance (CL renal) parameters for subjects with varying degrees of renal function: * 243.5 ± 33.3 mL/min [baseline creatinine clearance >80 mL/min] * 168.6 ± 27.5 mL/min [baseline creatinine clearance 50-80 mL/min] * 100.6 ± 27.5 mL/min [baseline creatinine clearance 30-49 mL/min] * 43.0 ± 31.2 mL/min [baseline creatinine clearance 12-29 mL/min] The following are clearance (CL/F) parameters for subjects with varying degrees of renal function: * 1043.7 ± 115.4 [baseline creatinine clearance >80 mL/min] * 807.7 ± 279.2 [baseline creatinine clearance 50-80 mL/min] * 444.4 ± 209.8 [baseline creatinine clearance 30-49 mL/min] * 177.0 ± 97.1 [baseline creatinine clearance 12-29 mL/min]

Toxicity

Limited clinical experience at doses higher than the therapeutic dose of tenofovir 300 mg is available. In Study 901 tenofovir disoproxil fumarate 600 mg was administered to 8 patients orally for 28 days. No severe adverse reactions were reported. The effects of higher doses are not known.

Active Ingredient/Synonyms

Bis(POC)PMPA | Tenofovir bis(isopropyloxycarbonyloxymethyl) ester | Tenofovir disoproxil |


Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.

References

  1. Health Science Authority of Singapore - Reclassified POM
  2. Drugbank