Treating HIV With Genvoya

Genvoya is a single-tablet, fixed-dose combination drug used in the treatment of HIV, which is comprised of four different antiretroviral drugs:

• Elvitegravir, an integrase inhibitor
• Cobicistat, an HIV "booster" drug
• Emtricitabine, a nucleotide reverse transcriptase inhibitor (NtRTI)
• Tenofovir alafenamide (TAF), another NtRTI

Genvoya is the first combination pill to use TAF, an "improved" version of tenofovir disoproxil fumarate (TDF) found in the drugs Truvada, Atripla, and Complera. As such, it can be considered an improvement on Stribild, the single-tablet formulation comprised of elvitegravir + cobicistat + emtricitabine + TDF. 

TAF is regarded as superior to TDF as it is able to deliver the active drug more effectively to cells and at far smaller doses—meaning that there is less build-up of the drug in the bloodstream and far less chance of developing drug-related kidney toxicities.

(While the risk of TDF-associated kidney toxicity is considered low in developed countries, that risk is seen to rise considerably in developing countries where there is a greater incidence of pre-existing kidney dysfunction.)

Treatment Indication

Genvoya was approved by the U.S. Food and Drug Administration on November 5, 2015, for use in both adults and children over the age of 12 who have never been on HIV therapy and weigh over 77 lbs (35 kgs). It is also approved for adults on therapy who have a fully suppressed (undetectable) viral load.

Formulation

Genvoya is a green, oblong, film-coated tablet, comprised of 150mg of elvitegravir, 150mg of cobicistat, 200mg of emtricitabine and 10mg of TAF. It is embossed with "GSI" on one side and with a "510" on the other.

Dosage

One tablet is taken daily with food. Genvoya should not be taken with any other antiretroviral drug used to treat HIV.

Side Effects

A number of drug side effects have been noted in clinical trial patients taking Genvoya. The most common adverse events, reported in 5% or more of patients, are:

• Nausea
• Diarrhea
• Fatigue
• Headache

Side effects were typically transient, resolving over the course of 1-2 weeks, with few patients discontinuing as a result of treatment intolerance.

Contraindications

Genvoya should not be taken with the following drugs or supplements:

• Anti-migraine medications: Cafergot, Migergot, Ergostat, Medihaler Ergotamine, Wigraine, Wigrettes, Ergotrate, Methergine, DHE 45
• Anti-psychotic medication: Orap
• Cholesterol-lowering statin drugs: Zocor, Simcor, Vytorin, Mevacor, Advicor, Altoprev, Mevacor
• Hepatitis B medication: Hepsera, Preveon
• Prokinetic agents: Propulsid, Propulsid Quicksolv
• Prostate medications: Uroxatral
• Pulmonary hypertension medications: Revatio
• Anti-tuberculosis medications: Mycobutin, Rifater, Rifamate, Rimactane, Rifadin, Priftin
• Sedatives: Versed, Halcion
• St. John's Wort

Other Considerations

Genvoya is not recommended for patients with kidney impairment (defined as having an estimated creatinine clearance of less than 30mL per minute). Please advise your doctor if you have been or are being treated for any kidney disorder by another physician.

Genvoya is not recommended for patients with liver impairment or for those with chronic hepatitis B (HBV) infection as it can severely exacerbate liver problems. It is advised that persons with HIV be screened for HBV before prescribing Genvoya. Please advised your doctor if you have any liver problems and/or history of hepatitis.