Fusion inhibitors, CCR5 Antag, integrase strand transfer inhib.

U.S. Approval:  2014

Mechanism of Action: Cobicistat is a mechanism-based inhibitor of cytochrome P450 3A (CYP3A). Inhibition of CYP3A-mediated metabolism by cobicistat increases the systemic exposure of CYP3A substrates atazanavir and darunavir.

INDICATIONS AND USAGE:  TYBOST 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. (1)

Limitations of Use:
TYBOST 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 TYBOST is not recommended with darunavir 600 mg twice daily, fosamprenavir, saquinavir, or tipranavir. (5.4).
Complex or unknown mechanisms of drug interactions preclude extrapolation of ritonavir drug interactions to certain TYBOST interactions. TYBOST and ritonavir when administered with either atazanavir or darunavir may result in different drug interactions when used with concomitant medications.

HOW SUPPLIED: Tablets: 150 mg.

INDICATIONS AND USAGE:
TIVICAY is a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor (INSTI) indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults and children aged 12 years and older and weighing at least 40 kg.

The following should be considered prior to initiating TIVICAY:
Poor virologic response was observed in subjects treated with TIVICAY 50 mg twice daily with an INSTI-resistance Q148 substitution plus 2 or more additional INSTI-resistance substitutions including L74I/M, E138A/D/K/T, G140A/S, Y143H/R, E157Q, G163E/K/Q/R/S, or G193E/R.

DOSAGE AND ADMINISTRATION:
May be taken without regard to meals.

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Adult Population:
Recommended Dose:

1] Treatment-naïve or treatment-experienced INSTI-naïve:
550 mg once daily

2] Treatment-naïve or treatment-experienced INSTI-naïve when coadministered with the following potent UGT1A/CYP3A inducers: efavirenz, fosamprenavir/ritonavir, tipranavir/ritonavir, or rifampin:
550 mg twice daily

3] INSTI-experienced with certain INSTI-associated resistance substitutions or clinically suspected INSTI resistance:
50 mg twice daily.
Alternative combinations that do not include metabolic inducers should be considered where possible.

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Pediatric Patients: (Treatment-naïve or treatment-experienced, INSTI-naïve, aged 12 years and older, and weighing at least 40 kg).

1] The recommended dose is TIVICAY 50 mg once daily.

2] If efavirenz, fosamprenavir/ritonavir, tipranavir/ritonavir, or rifampin are coadministered, then the dose is TIVICAY 50 mg twice daily.

DOSAGE FORMS AND STRENGTHS:
Tablets: 50 mg

Local monograph

U.S. Approval:  2014

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.

INDICATIONS AND USAGE:
VITEKTA is a human immunodeficiency virus type 1 (HIV-1) integrase strand transfer inhibitor used in combination with an HIV protease inhibitor coadministered with ritonavir and with other antiretroviral drug(s) indicated for the treatment of HIV-1 infection in antiretroviral treatment-experienced adults. (1)

Limitations of Use:
There are no comparative pharmacokinetic or clinical data evaluating VITEKTA with cobicistat as single entities compared to STRIBILD®. (1)
VITEKTA coadministered with protease inhibitors and cobicistat is not recommended. (1)
Coadministration of VITEKTA with dosage regimens or HIV-1 protease inhibitors other than those presented in Table 1 is not recommended. (1)

HOW SUPPLIED:Tablets: 85 mg and 150 mg

See package insert for pediatric dosing.

Directions for Use
For more detailed instructions, see FUZEON Injection Instructions.

Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration.

Subcutaneous Administration
FUZEON must only be reconstituted with 1.1 mL of Sterile Water for Injection provided in the Convenience Kit. After adding sterile water, the vial should be gently tapped for 10 seconds and then gently rolled between the hands to avoid foaming and to ensure all particles of drug are in contact with the liquid and no drug remains on the vial wall. The vial should then be allowed to stand until the powder goes completely into solution, which could take up to 45 minutes. Reconstitution time can be reduced by gently rolling the vial between the hands until the product is completely dissolved. Before the solution is withdrawn for administration, the vial should be inspected visually to ensure that the contents are fully dissolved in solution, and that the solution is clear, colorless and without bubbles or particulate matter. If the FUZEON is foamy or jelled, allow more time for it to dissolve. If there is evidence of particulate matter, the vial must not be used and should be returned to the pharmacy.

FUZEON contains no preservatives. Once reconstituted, FUZEON should be injected immediately or kept refrigerated in the original vial until use. Reconstituted FUZEON must be used within 24 hours. The subsequent dose of FUZEON can be reconstituted in advance and must be stored in the refrigerator in the original vial and used within 24 hours. Refrigerated reconstituted solution should be brought to room temperature before injection and the vial should be inspected visually again to ensure that the contents are fully dissolved in solution and that the solution is clear, colorless, and without bubbles or particulate matter.

A vial is suitable for single use only; unused portions must be discarded (see FUZEON Injection Instructions).

Patients should contact their healthcare provider for any questions regarding the administration of FUZEON. Information about the self-administration of FUZEON may also be obtained by calling the toll-free number 1-877-4-FUZEON (1-877-438-9366) or at the FUZEON website, www.FUZEON.com. Patients should be taught to recognize the signs and symptoms of injection site reactions and instructed when to contact their healthcare provider about these reactions.

DOSAGE FORMS AND STRENGTHS
Lyophilized powder for injection: 108 mg enfuvirtide per vial

INDICATIONS AND USAGE
SELZENTRY, in combination with other antiretroviral agents, is indicated for treatment-experienced adult patients infected with only CCR5-tropic HIV-1, who have evidence of viral replication and HIV-1 strains resistant to multiple antiretroviral agents.

This indication is based on analyses of plasma HIV-1 RNA levels in two controlled studies of SELZENTRY of 48 weeks duration. Both studies were conducted in clinically advanced, 3-class antiretroviral (NRTI, NNRTI, PI, or enfuvirtide) treatment-experienced adults with evidence of HIV-1 replication despite ongoing antiretroviral therapy.

The following points should be considered when initiating therapy with SELZENTRY:

Tropism testing is required for the appropriate use of SELZENTRY.
Use of SELZENTRY is not recommended in patients with dual/mixed or CXCR4-tropic HIV-1 as efficacy was not demonstrated in a phase 2 study of this patient group.
The safety and efficacy of SELZENTRY have not been established in treatment-naïve adult patients or pediatric patients.

Recommended Dosing Regimen

Supplied: 
Tablets: 150 mg and 300 mg

>During coadministration of ISENTRESS 400 mg film-coated tablets with rifampin, the recommended dosage of ISENTRESS is 800 mg twice daily in adults. There are no data to guide co-administration of ISENTRESS with rifampin in patients below 18 years of age.

>Maximum dose of chewable tablets is 300 mg twice daily.
>Maximum dose of oral suspension is 100 mg twice daily.
>Each single-use packet for oral suspension contains 100 mg of raltegravir which is suspended in 5 mL of water giving a final concentration of 20 mg/mL.

Adults
For the treatment of adult patients with HIV-1 infection, the dosage of ISENTRESS is one 400 mg film-coated tablet administered orally, twice daily.

See package insert for pediatric dosing.

Method of Administration
ISENTRESS Film-Coated Tablets
Film-Coated Tablets must be swallowed whole

ISENTRESS Chewable Tablets
Chewable Tablets may be chewed or swallowed whole

ISENTRESS For Oral Suspension
Each single-use ISENTRESS packet for oral suspension contains 100 mg of raltegravir which is to be suspended in 5 mL of water giving a final concentration of 20 mg/mL.

Pour packet contents of ISENTRESS for oral suspension into 5 mL of water and mix.
Once mixed, measure the recommended volume (dose) of suspension with a syringe and administer the dose orally.
The volume (dose) of suspension should be administered orally within 30 minutes of mixing.
Discard any remaining suspension.
For more details on preparation and administration of the suspension, see Instructions for Use.

DOSAGE FORMS AND STRENGTHS

Film-coated Tablets
400 mg pink, oval-shaped, film-coated tablets with "227" on one side.

Chewable Tablets
100 mg pale orange, oval-shaped, orange-banana flavored, chewable tablets scored on both sides and imprinted on one face with the Merck logo and "477" on opposite sides of the score.
25 mg pale yellow, round, orange-banana flavored, chewable tablets with the Merck logo on one side and "473" on the other side.

For Oral Suspension
100 mg white to off-white, banana flavored, granular powder that may contain yellow or beige to tan particles in a child resistant single-use foil packet.