Drug Class: Antiviral combinations
1. How it works
- Stribild is a combination tablet that contains four different medications: elvitegravir, emtricitabine, tenofovir disoproxil fumarate (TDF), 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).
- Stribild works by inhibiting the replication of the HIV-1 virus in cells. Elvitegravir, emtricitabine, and TDF 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 TDF 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.
- Stribild belongs to the class of medicines known as antiviral combinations.
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 77 pounds (35 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 (HIV-1 RNA less than 50 copies/mL), and no history of HIV treatment failure or known resistance to any of the components of Stribild.
- 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 300 mg of TDF.
- Considered a complete treatment regimen in one pill.
- Was the first single-tablet regimen for HIV-1.
- One pill is taken once a day with food.
- No other medications for HIV are needed.
- Stribild 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 lifespan.
- Well tolerated but some people experience increases in serum creatinine early in treatment that stabilized with time.
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:
- Diarrhea, nausea, abnormal dreams, headache, and fatigue. Insomnia has also been reported and Stribild can also cause elevations in creatine kinase, LDL-cholesterol, total cholesterol, amylase, ALT, AST, and urine red blood cells. Long-term use of Stribild 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 Stribild) 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 Stribild. Other serious side effects include new-onset or worsening renal impairment, such as acute renal failure, proximal renal tubulopathy, lactic acidosis, and severe hepatomegaly with steatosis.
- Cobicistat, contained in Stribild, 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 Stribild 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, Stribild 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 Stribild. 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. Renal impairment, including cases of acute renal failure and Fanconi syndrome, have been reported with the use of TDF.
- Stribild 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.
- Stribild 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 Stribild, 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.
- Stribild is considered inferior to Genvoya because it contains tenofovir disoproxil fumarate (TDF) instead of tenofovir alafenamide (TAF). TAF (contained in Genvoya) 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 Stribild with food to help increase its absorption into your body. This may also lower the risk of nausea.
- Stribild 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.
- Stribild is considered a complete treatment regimen in one pill for HIV. You do not need to use other HIV medicines with Stribild.
- Tell your doctor and pharmacist about all the medicines you take, including over-the-counter medicines, vitamins, herbals, and dietary supplements. Stribild 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 Stribild. Also, avoid grapefruit and grapefruit products.
- Be sure to tell your doctor if you have kidney or liver disease. Stribild carries a Boxed Warning for post-treatment exacerbation of hepatitis B. If you have kidney or liver impairment you may not be able to use Stribild. Before you start taking Stribild your doctor will test you for hepatitis B virus (HBV) infection. This is because any underlying HBV infection should be treated before Stribild 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 Stribild, 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 Stribild compared to existing HIV-1 treatment regimens.
- Studies report 78% to 80% of Stribild patients had HIV-1 RNA copies < 50 copies/mL after 144 weeks compared to 75% given alternative regimens.
- Pooled virologic outcomes reported Genvoya was more effective than Stribild with 84% of people given Genvoya compared to 80% of those given Stribald with HIV-1 RNA copies of less than 50 copies/mL after 144 weeks of treatment.
6. Interactions
Medicines that interact with Stribild may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Stribild. 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 Stribild; most of these interactions are considered major or moderate. Common medications that may interact with Stribild 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 Stribild. Antacids decrease absorption and blood levels of elvitegravir, one of the medicines in Stribild.
Note that this list is not all-inclusive and includes only common medications that may interact with Stribild. You should refer to the prescribing information for Stribild for a complete list of interactions.