Drug Class: Antiviral combinations
1. How it works
- Genvoya is a combination tablet that contains four different medications: elvitegravir, emtricitabine, tenofovir alafenamide (TAF), and cobicistat that may be used as a complete treatment regimen for human immunodeficiency virus (HIV)-1. HIV-1 is the virus that causes AIDS (Acquired Immune Deficiency Syndrome).
- Genvoya works by inhibiting the replication of the HIV-1 virus in cells. Elvitegravir, emtricitabine, and tenofovir alafenamide are antivirals. Elvitegravir is an HIV-1 integrase strand transfer inhibitor (INSTI) that blocks the action of the enzyme integrase that facilitates the insertion of the HIV-1 virus into the cell. Emtricitabine and tenofovir alafenamide are both HIV-1 nucleoside analog reverse transcriptase inhibitors (NRTIs) that block the action of reverse transcriptase and inhibit viral replication. Cobicistat is known as a pharmacokinetic enhancer that works by inhibiting hepatic enzymes CYP3A and 2D6 which helps boost blood levels of elvitegravir. It is not an antiviral medication and will not treat HIV infection.
- Genvoya belongs to the class of medicines known as antiviral combination medicines.
2. Upsides
- Used to treat human immunodeficiency virus (HIV) in adults and children who are at least 12 years old and who weigh at least 55 pounds (25 kilograms). It may be given to patients who have never received antiretroviral treatment or to patients who have been on a stable regimen for at least six months, have an undetectable viral load, and no history of HIV treatment failure or known resistance to any of the components of Genvoya.
- Available in tablet form. Each tablet contains a combination of four agents: 150 mg of elvitegravir, 150 mg of cobicistat, 200 mg of emtricitabine, and 10 mg of tenofovir alafenamide.
- Considered a complete treatment regimen in one pill.
- One pill is taken once a day with food.
- No other medications for HIV are needed.
- Contains a newer form of tenofovir called tenofovir alafenamide (TAF). TAF is a prodrug of tenofovir that has been designed to enter HIV-infected cells more efficiently than tenofovir disoproxil fumarate (TDF). It can be given at a much lower dose (less than one-tenth) than TDF. TAF is also associated with less kidney toxicity and decreases in bone density than TDF.
- Genvoya slows down the growth, replication, and amount of HIV in the blood (reduces the viral load). This increases the CD4 count, reduces the risk of infections, boosts the immune system, and lowers the risk of progression to AIDS. Most people with HIV achieve undetectable viral loads and live close to a normal life span.
- Well tolerated. Only 1% of patients (1 out of every 100) stopped Genvoya due to side effects.
3. Downsides
If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:
- Headache, diarrhea, nausea, and fatigue. Insomnia has also been reported and Genvoya can also cause elevations in creatine kinase, LDL-cholesterol, total cholesterol, amylase, ALT, AST, and urine red blood cells. Long-term use of Genvoya has been associated with greater than normal reductions in bone mineral density and greater increases in lipid levels.
- Although weight gain is not listed as a side effect on the product information, a large meta-analysis suggested all integrase inhibitors such as elvitegravir (found in Genvoya) may be linked with some weight gain. Over 96 weeks, elvitegravir was associated with a mean weight gain of 2.72 kg [6 lbs] (95% CI, 2.45–3 kg).
- Immune reconstitution syndrome has been reported in people treated with combination antiviral regimens, including Genvoya. Other serious side effects include new-onset or worsening renal impairment, such as acute renal failure, proximal renal tubulopathy, and Fanconi syndrome; lactic acidosis, and severe hepatomegaly with steatosis.
- Cobicistat, contained in Genvoya, is a potent inhibitor of hepatic enzymes CYP3A and CYP2D6 as well as P-glycoprotein (P-gp), BCRP, OATP1B1, and OATP1B3. Elvetigravir is a modest inducer of CYP2C9. Emtricitabine and tenofovir are excreted by the kidneys and coadministration of Genvoya with any medications that reduce renal function or compete for active tubular secretion may increase concentrations of emtricitabine, tenofovir, and other renally excreted medications. As a result, Genvoya interacts with over 570 other medications.
- Not recommended in people with severe hepatic or renal impairment or with end-stage renal disease.
- Severe exacerbations of hepatitis B have been reported in patients coinfected with HIV-1 and HBV who discontinue Genvoya. Monitor hepatic function closely on discontinuation and consider anti-hepatitis B therapy. Test for hepatitis B before initiation.
- Regular monitoring of creatinine, urinary glucose and protein, and phosphorus (in patients with chronic kidney disease) is required.
- Genvoya interacts with several medications (such as statins, birth control pills, erectile dysfunction treatments, and nasal corticosteroids) because it contains the booster, cobicistat which inhibits CYP3A4 liver enzymes.
- Genvoya is not a cure for HIV or AIDS and must be taken daily for the rest of somebody's life to help prevent HIV resistance.
- Not recommended during pregnancy because exposures to cobicistat and elvitegravir are substantially lower in women who are pregnant during the second and third trimesters. If a woman inadvertently becomes pregnant while taking Genvoya, register the woman on the antiretroviral pregnancy registry at 1-800-258-4263 and consult with an HIV specialist about switching to an alternative regimen. HIV-infected mothers should not breastfeed to avoid passing the HIV-1 virus to their newborns.
- Genvoya is considered a new and improved version of Stribild because it contains tenofovir alafenamide (TAF) instead of tenofovir disoproxil fumarate (TDF). TAF is a prodrug of TDF and it can enter HIV-infected cells much more efficiently than TDF, which means it can be given at a much lower dose and has been associated with less kidney toxicity and decreases in bone marrow density than TDF.
Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects
4. Tips
- Take it with food to help increase its absorption into your body. This may also lower the risk of nausea.
- Genvoya is taken once a day, every day. Do not miss a dose. If you forget a dose, take your missed dose right away unless it is almost time for your next dose, then only take your scheduled dose. Do not take a double dose to make up for a forgotten dose.
- Don’t change your dose, stop your medication, or skip any doses without checking with your doctor first. The amount of virus in your blood may increase and develop resistance to treatment if the medicine is stopped, even for a short time. Be sure to get your refills on time and keep your scheduled doctor appointments.
- Genvoya is considered a complete treatment regimen in one pill for HIV. You do not need to use other HIV medicines with Genvoya.
- Tell your doctor and pharmacist about all the medicines you take, including over-the-counter medicines, vitamins, herbals, and dietary supplements. Genvoya interacts with many other medications, including indigestion remedies that contain aluminum hydroxide, magnesium hydroxide, or calcium carbonate. Take these at least 2 hours before or 2 hours after you take Genvoya. Also, avoid grapefruit and grapefruit products.
- Be sure to tell your doctor if you have kidney or liver disease. Genvoya carries a Boxed Warning of a build-up of lactic acid in the blood and the possibility of severe liver problems. If you have kidney or liver impairment you may not be able to use Genvoya.
- Before you start taking Genvoya your doctor will test you for hepatitis B virus (HBV) infection. This is because any underlying HBV infection should be treated before Genvoya is started.
- Report any serious or worrying side effects to your doctor, such as symptoms of an infection (such as fever, shortness of breath, swelling), abdominal discomfort, decreased appetite, unusual tiredness, skin yellowing, cold hands or feet, tea-colored urine, or light-colored stools.
- Not recommended during pregnancy but if you inadvertently become pregnant while taking Genvoya, your doctor should register you on the antiretroviral pregnancy registry at 1-800-258-4263 and consult with an HIV specialist about switching to an alternative regimen. HIV-infected mothers should not breastfeed so that they don't pass the HIV-1 virus to their newborns.
5. Response and effectiveness
- Several large clinical trials have investigated the effectiveness of Genvoya compared to existing HIV-1 treatment regimens.
- Pooled virologic outcomes reported 84% of people given Genvoya compared to 80% of those given Stribald had HIV-1 RNA copies of less than 50 copies/mL after 144 weeks of treatment.
- Other studies report 93% of Genvoya patients had HIV-1 RNA copies < 50 copies/mL after 96 weeks compared to 89% given alternative regimens.
6. Interactions
Medicines that interact with Genvoya may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Genvoya. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.
Over 570 medications interact with Genvoya; most of these interactions are considered major or moderate. Common medications that may interact with Genvoya include:
- alfuzosin (contraindicated due to the potential for serious or life-threatening reactions such as hypotension)
- aluminum-containing antacids
- anti-anxiety medications such as diazepam and oxazepam
- antibiotics, such as clarithromycin, or erythromycin
- anticoagulants, such as apixaban, rivaroxaban, or dabigatran
- anticonvulsants, such as carbamazepine or phenytoin (avoid)
- antidepressants, such as tricyclic antidepressants (eg, amitriptyline, imipramine, nortriptyline), or SSRIs such as paroxetine
- antifungals, such as fluconazole, itraconazole, or ketoconazole
- antihistamines that cause sedation, such as diphenhydramine or azelastine
- antiplatelet agents, such as clopidogrel or ticagrelor
- antipsychotics, such as lurasidone, pimozide, quetiapine, risperidone
- aprepitant
- atorvastatin
- beta-blockers, such as metoprolol or timolol
- biologics, such as imatinib or nilotinib
- bosentan
- buprenorphine
- buspirone
- calcium carbonate
- calcium channel blockers, such as amlodipine, diltiazem, or verapamil
- cannabis
- cisapride
- colchicine
- corticosteroids, such as betamethasone, budesonide, or dexamethasone
- CYP3A4 moderate or strong inhibitors (such as amprenavir, ciprofloxacin, cyclosporine, clarithromycin, erythromycin, diltiazem, itraconazole, ketoconazole, ritonavir, verapamil, goldenseal, or grapefruit). Avoid
- CYP3A4 inducers (such as carbamazepine, efavirenz, modafinil, prednisone, rifampin, St. John's Wort)
- cyclosporine
- duloxetine
- ergot derivatives, such as dihydroergotamine or ergotamine
- ethosuximide
- heart medications, such as amiodarone, digoxin, disopyramide, flecainide, or mexiletine
- herbals, such as echinacea or St. John's Wort
- other HIV medications such as atazanavir, indinavir, or ritonavir
- hormonal contraceptives, such as levonorgestrol, ethinylestradiol, or drospirenone
- grapefruit juice and products
- lithium
- magnesium
- medications for diabetes, such as metformin
- metoclopramide
- naloxone
- opioid analgesics such as fentanyl or tramadol
- PDE5 inhibitors, such as sildenafil, tadalafil, or vardenafil
- multivitamins
- salmeterol
- sedatives, such as midazolam or triazolam
- sirolimus or tacrolimus
- sleeping pills, such as zolpidem
- other medications used to treat mental illness, such as clozapine and thioridazine
- warfarin.
Indigestion remedies (antacids) that contain aluminum hydroxide, magnesium hydroxide, or calcium carbonate should be taken at least 2 hours before or 2 hours after Genvoya. Antacids decrease absorption and blood levels of elvitegravir, one of the medicines in Genvoya.
Note that this list is not all-inclusive and includes only common medications that may interact with Genvoya. You should refer to the prescribing information for Genvoya for a complete list of interactions.