Erika Prouty, PharmD, is a professional community pharmacist who aids patients in medication management and pharmacy services in North Adams, Massachusetts.
Tybost is a prescription medication that is used to boost the effects of Reyataz (atazanavir) or Prezista (darunavir) once-daily dosing regimen in combination with other antiretroviral drugs in the treatment of HIV-1 infection in adults or children weighing at least 77 pounds (35 kilograms) (with atazanavir) or at least 88 pounds (40 kilograms) (with darunavir).
Tybost is a strong CYP3A4 inhibitor, and it helps increase the levels of specific HIV protease inhibitors (atazanavir and darunavir) in the body by competing with their metabolism through the liver.
Brand Name(s): Tybost
Therapeutic Classification: CYP3A4 inhibitor
Controlled Substance: N/A
Dosage Form(s): Oral tablet
Tybost is used with other antiretrovirals to treat HIV-1 infection in adults or children.
Since the epidemic started, around 84.2 million people have been infected with HIV, and approximately 40.1 million people have died of HIV. By the end of 2021, 38.4 million people worldwide were living with HIV. Africa is the most severely affected part of the world. Nearly one in 25 adults in Africa lives with HIV. This accounts for over two-thirds of the population that lives with HIV globally.
Take Tybost by mouth as prescribed by your healthcare provider, along with food. Do not use more than directed. It would help if you took Tybost at the same time as atazanavir or darunavir. It is essential to take these medicines on a regular dosing schedule. Here are a few things to keep in mind:
Store Tybost at room temperature, away from heat, moisture, and direct light, in its original child-resistant container. Keep the container tightly closed. Do not use Tybost if the seal over the bottle opening is broken or missing.
The off-label uses of Tybost are lacking.
It takes Tybost 3.5 hours to reach peak drug concentrations (Tmax) after taking it by mouth. The time it takes Tybost to work may be different for everyone. Be sure to check with your healthcare provider or pharmacist for any questions.
This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at fda.gov/medwatch or 800-FDA-1088.
Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you have a medical emergency. Serious side effects and their symptoms can include the following:
Long-term effects of Tybost are lacking.
Tybost may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.
If you experience a serious side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).
The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
The following modifications (changes) should be kept in mind when using Tybost:
If you accidentally forgot your Tybost dose, take it as soon as you remember. If your next dose is in less than 12 hours, skip the missed dose and take the following dose at your next scheduled dosing time. Don't try to double up to make up for the missed dose.
Try to find ways that work for you to help yourself remember to keep your appointments and take your medication routinely. If you miss too many doses, your HIV-1 infection may become harder to treat.
There is limited information available about Tybost overdose. Treatment of overdose with Tybost consists of general supportive measures, including monitoring of vital signs, as well as observation of the clinical status of the patient.
If you think you're experiencing an overdose or life-threatening symptoms, seek immediate medical attention.
If you think you or someone else may have overdosed on Tybost, call a healthcare provider or the Poison Control Center (800-222-1222).
If someone collapses or isn't breathing after taking Tybost, call 911 immediately.
Your doctor will want to check your progress at regular visits, especially during the first few weeks that you take this medicine. Blood and urine tests may be needed to check for any unwanted effects.
This medicine should not be used together with atazanavir or darunavir if you are also using any of the following: alfuzosin (Uroxatral®), carbamazepine (Tegretol®), colchicine (Colcrys®), dronedarone (Multaq®), drospirenone/ethinyl estradiol (Yasmin®, Yaz®), indinavir (Crixivan®), irinotecan (Camptosar®), lomitapide (Juxtapid®), lovastatin (Altoprev®, Mevacor®), lurasidone (Latuda®), midazolam (Versed®), nevirapine (Viramune®), phenobarbital (Luminal®), phenytoin (Dilantin®), pimozide (Orap®), ranolazine (Ranexa®), rifampin (Rifadin®), sildenafil (Revatio®), simvastatin (Simcor®, Zocor®), St John's wort, triazolam (Halcion®), or ergot medicines (eg, dihydroergotamine, ergotamine, methylergonovine, Cafergot®, Migranal®). Doing so may cause serious unwanted effects.
Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant during treatment with this medicine. Certain birth control pills may not work as well to prevent pregnancy when used with this medicine. Use another form of birth control (eg, condoms, spermicide) along with your pills. If you think you have become pregnant while using this medicine, tell your doctor right away.
Using this medicine together with tenofovir DF may cause kidney problems (including Fanconi syndrome). Tell your doctor right away if you have bloody urine, decreased frequency or amount of urine, increased thirst, loss of appetite, lower back or side pain, nausea, vomiting, swelling of the face, fingers, or lower legs, trouble breathing, unusual tiredness or weakness, or weight gain.
This medicine does not decrease the risk of transmitting the HIV infection to others through sexual contact or by contaminated blood. Make sure you understand and practice safe sex, even if your partner also has HIV. Avoid sharing needles with anyone.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
You should not take Tybost in certain situations.
If you're allergic to Tybost or any of its ingredients, do not take it. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.
If you take any of the following medications, do not take Tybost:
Please let your healthcare provider know if you have kidney or liver problems because taking Tybost may worsen your condition.
Do not take Tybost with the following medications:
Use caution when taking Tybost with the following medications:
Take antacids at least 2 hours before or after you take this medicine.
This is not a complete list of medications that interact with Tybost.
Taking Tybost with atazanavir or darunavir, along with certain other medicines, can lead to severe or life-threatening side effects or could lead to death. Keep a list of your medications and show it to your healthcare provider and pharmacist when you get a new medicine.
Talk with your pharmacist or healthcare provider for more detailed information about medication interactions with Tybost.
Be sure to talk with your healthcare provider about any other medicines you take or plan to take, including over-the-counter, nonprescription products, vitamins, herbs, or plant-based medicines.
There are no medications that are clinically similar to Tybost.
Tybost is used with other antiretrovirals to treat HIV-1 infection in adults or children.
You need to take Tybost by mouth with food at the same time you take atazanavir or darunavir as prescribed by your healthcare provider.
Do not change your dose or stop taking Tybost without first talking with your healthcare provider. If you stop the medicine even for a short time, your HIV-1 infection may become harder to treat.
If you're taking Tybost, your HIV-1 infection has likely affected your life. You may have tried different approaches or treatments. While living with HIV does have its challenges, there are ways to help improve your quality of life. Refer below for some general tips to support your health:
Verywell Health's drug information is meant for educational purposes only and is not intended as a replacement for medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.
Food and Drug Administration. Tybost Label,
Deeks ED. Cobicistat: a review of its use as a pharmacokinetic enhancer of atazanavir and darunavir in patients with HIV-1 infection. Drugs. 2014 Feb;74(2):195-206. doi: 10.1007/s40265-013-0160-x. PMID: 24343782.
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