• Keep this leaflet. You may need to read it again.
• If you have any further questions, ask your doctor or pharmacist.
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their signs of illness are the same as yours.
• If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. See section 4.

1. What Tybost is and what it is used for
2. What you need to know before you take Tybost
3. How to take Tybost
4. Possible side effects
5. How to store Tybost
6. Contents of the pack and other information

• If you are allergic to cobicistat or any of the other ingredients of this medicine (listed in section 6 of this leaflet).
• If you are taking medicines containing any of the following:
  • alfuzosin, used to treat an enlarged prostate gland
  • amiodarone, quinidine, used to correct irregular heartbeats
  • dabigatran, used to prevent and treat blood clots
  • carbamazepine, phenobarbital, phenytoin, used to prevent seizures
  • rifampicin, used to prevent and treat tuberculosis and other infections
  • dihydroergotamine, ergometrine, ergotamine, used to treat migraine headache
  • St. John’s wort (Hypericum perforatum), a herbal remedy used for depression and anxiety
  • lovastatin, simvastatin, used to lower blood cholesterol
  • pimozide, lurasidone, used to treat abnormal thoughts or feelings
  • sildenafil, used to treat pulmonary arterial hypertension – a lung disease that makes breathing difficult
  • orally administered midazolam, triazolam, used to help you sleep and/or relieve anxiety

• If any of these applies to you, you should not take Tybost and you should tell your doctor immediately.

You must remain under the care of your doctor while taking Tybost.

• If you are taking another protease inhibitor. Tybost taken with atazanavir or darunavir should not be used with another antiviral medicine that requires boosting.
• Talk to your doctor or pharmacist if you have or have had kidney disease, or if tests have shown problems with your kidneys. Your doctor will carefully consider whether to treat you with Tybost.
• Talk to your doctor or pharmacist if you have or have had severe liver disease, or if tests have shown problems with your liver. Your doctor will carefully consider whether to treat you with Tybost.

• If any of these applies to you, talk to your doctor before taking Tybost.

Do not give this medicine to children under 12 years of age, or who weigh less than 35 kg (or 40 kg) as explained in section 3 of this leaflet. The use of Tybost in children under 12 years of age or who weigh less than 35 kg has not yet been studied.

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines. Tybost may interact with other substances. As a result, the amounts of Tybost or other medicines in your blood may be affected. This may stop your medicines from working properly, or may make any side effects worse. In some cases, your doctor may need to adjust your dose or check the levels of medicine in your blood.

These are mentioned above under the heading “Do not take Tybost-If you are taking medicines containing any one of the following”.

Medicines used in treating HIV infection:

You should not take Tybost with other medicines containing:

• ritonavir
• cobicistat

Talk to your doctor if you are taking

• another protease inhibitor
• efavirenz
• etravirine
• nevirapine
• maraviroc

• Tell your doctor if you are taking any of these HIV medicines.

• ketoconazole, itraconazole, voriconazole, posaconazole and fluconazole, medicines used to treat fungal infections
• clarithromycin and rifabutin, medicines used to treat bacterial infections including tuberculosis
• dasatinib, nilotinib, vinblastine and vincristine, medicines used to treat cancer
• corticosteroids including betamethasone, budesonide, fluticasone, mometasone, prednisone, triamcinolone. These medicines are used to treat allergies, asthma, inflammatory bowel diseases, inflammatory conditions of the skin, eyes, joints and muscles and other inflammatory conditions. These medicines are generally taken orally, inhaled, injected or applied to the skin or eye. If alternatives cannot be used, its use should only take place after medical evaluation and under close monitoring by your doctor for corticosteroid side effects.
• metformin, medicine used for the treatment of type 2 diabetes
• oral or implanted hormonal contraceptives used to prevent pregnancy
• amlodipine, digoxin, diltiazem, disopyramide, felodipine, flecainide, lidocaine, metoprolol, mexiletine, nicardipine, nifedipine, propafenone, timolol and verapamil, medicines used to treat heart problems
• bosentan, a medicine used to treat pulmonary arterial hypertension
• apixaban, edoxaban, rivaroxaban and warfarin, medicines used to prevent and treat blood clots
• salmeterol, a medicine used to treat asthma
• atorvastatin, fluvastatin, pitavastatin, pravastatin and rosuvastatin, medicines used to lower cholesterol
• sildenafil and vardenafil, medicines used to treat impotence, and tadalafil, a medicine used to treat impotence and pulmonary hypertension
• trazodone, a medicine used to treat depression
• ciclosporin, sirolimus and tacrolimus, medicines used to control your body’s immune response after a transplant
• buspirone, clorazepate, diazepam, estazolam, flurazepam, perphenazine, risperidone, thioridazine, zolpidem, medicines used to treat nervous system disorders
• colchicine, a medicine used to treat gout
• clopidogrel, a medicine used to reduce the risk of blood clots

• Tell your doctor if you are taking any of these medicines.
• Tell your doctor if you are taking these or any other medicines. Do not stop your treatment without contacting your doctor.

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

• Tell your doctor immediately if you are pregnant, think you may be pregnant or are planning to have a baby. Pregnant women should not take Tybost with atazanavir or darunavir. The amounts of these medicines in your blood may decrease during pregnancy, which may stop them from working properly.
• Do not breast-feed during treatment with Tybost. It is not known if the active substance in this medicine can pass into human breast milk.
• Breast-feeding is not recommended in women living with HIV because HIV infection can be passed on to the baby in breast milk.
• If you are breast-feeding, or thinking about breast-feeding, you should discuss it with your doctor as soon as possible.

Some patients have reported dizziness when Tybost was taken with atazanavir or darunavir. If you are affected while taking Tybost, do not drive and do not use any tools or machines.

Tell your doctor if you have an allergy to sunset yellow FCF (E110). Tybost contains sunset yellow FCF which may cause allergic reactions.

This medicine contains less than 1 mmol sodium (23 mg) per tablet, that is to say essentially ‘sodium-free’.

• One tablet each day by mouth, with food. Do not chew, crush or split the tablet.
• Tybost must be taken with atazanavir (300 mg) or darunavir (800 mg).

• One tablet each day by mouth, with food. Do not chew, crush or split the tablet.
• When taking Tybost with atazanavir (300 mg), adolescents must weigh at least 35 kg.
• When taking Tybost with darunavir (800 mg), adolescents must weigh at least 40 kg.

Always take the dose recommended by your doctor. This is to make sure that your medicine is fully effective. Do not change the dose unless your doctor tells you to.

If you accidentally take more than the recommended dose of Tybost you may be at increased risk of experiencing side effects with this medicine (see section 4 of this leaflet).

Contact your doctor or nearest emergency department immediately for advice. Keep the tablet bottle with you so that you can easily describe what you have taken.

It is important not to miss a dose of Tybost.

If you do miss a dose and notice:

• within 12 hours of the time you usually take Tybost, you must take the tablet as soon as possible. Always take the tablet with food. Then take the next dose as usual in combination with atazanavir or darunavir.
• 12 hours or more after the time you usually take Tybost, then do not take the missed dose. Wait and take the next dose, with food, at your usual time.

Do not stop taking Tybost without talking to your doctor. Stopping Tybost and atazanavir or darunavir may reduce the success of future treatments prescribed by your doctor.

Always keep enough Tybost so you don’t run out. When your supply of Tybost starts to run low, get more from your doctor or pharmacist.

If you get any side effects, talk to your doctor or pharmacist. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme, Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store

By reporting side effects you can help provide more information on the safety of this medicine.

For more information on the side effects of atazanavir or darunavir see the package leaflets for these medicines.

The active substance is cobicistat. Each film-coated tablet contains 150 mg cobicistat.

Tablet core

Croscarmellose sodium, magnesium stearate, microcrystalline cellulose (E460), silicon dioxide (E551).

Film-coating

Sunset yellow FCF (E110), macrogol 3350 (E1521), polyvinyl alcohol (partially hydrolysed) (E1203), talc (E553b), titanium dioxide (E171), iron oxide yellow (E172) (see section 2 of this leaflet).

Tybost film-coated tablets are orange, round, biconvex tablets, debossed on one side with “GSI” and plain-faced on the other side of the tablet.

Tybost comes in bottles of 30 tablets (with a silica gel sachet or canister that must be kept in the bottle to help protect your tablets). The silica gel desiccant is contained in a separate sachet or canister and should not be swallowed.

The following pack sizes are available: outer cartons containing 1 bottle of 30 film-coated tablets and 90 (3 bottles of 30) film-coated tablets. Not all pack sizes may be marketed.

For any information about this medicine, please contact the local representative of the Marketing Authorisation Holder: