What is Tybost - cobicistat and what is it used for?
Tybost is a medicine containing the active substance cobicistat . Tybost is used to treat adults with HIV-1 infection, a virus that causes acquired immune deficiency syndrome (AIDS). Tybost does not directly cure HIV infection but is given to enhance the effects of atazanavir or darunavir, which are used with other standard medicines to treat HIV-1 infection.
How is Tybost used - cobicistat?
Tybost can only be obtained with a prescription. Therapy should be started by a doctor experienced in treating HIV infection. Tybost is available as tablets (150 mg). The recommended dose is one tablet a day, taken with food. Tybost is given in combination with 300 mg of atazanavir once a day or 800 mg of darunavir once a day. For more information, see the package leaflet.
How does Tybost - cobicistat work?
The active substance in Tybost, cobicistat, blocks the action of a group of liver enzymes called CYP3A, which participate in the metabolism of medicines in the body. By blocking the action of CYP3A, Tybost slows the rate of metabolization of atazanavir and darunavir, thereby prolonging its duration of action in the body. Tybost is taken in combination with atazanavir or darunavir, both of which are protease inhibitors: they block an enzyme called protease, which is involved in the reproduction of HIV-1. If the enzyme is blocked, the virus is unable to reproduce normally and the spread of the infection is slowed. Treatment with Tybost and atazanavir or duranavir does not cure HIV-1 infection or AIDS, but may delay the damage to the immune system and the development of infections and diseases associated with AIDS, if used in combination with others. standard medicines for the treatment of HIV-1 infection.
What benefit has Tybost - cobicistat shown during the studies?
Tybost was compared with another medicine called ritonavir in one main study involving 698 HIV-1 infected patients. The study compared the use of these two medicines as enhancers of the effects of atazanavir, given in combination with another standard medicine for the treatment of HIV-1 infection containing emtricitabine and tenofovir. The main measure of effectiveness was the reduction of the viral load (the amount of virus found in the blood): it was considered that patients whose viral load was less than 50 HIV-1 RNA copies / ml after 48 had responded to the treatment weeks of treatment. Tybost showed to be as effective as ritonavir: about 85% of patients (293 out of 344) treated with Tybost responded to treatment compared to about 87% of patients (304 out of 348) treated with ritonavir
What is the risk associated with Tybost - cobicistat?
The most common side effects with Tybost (which may affect more than 1 in 10 people) in combination with atazanavir are ocular jaundice (yellowing of the white part of the eyeball), nausea and jaundice (yellowing of the eyes and skin). For the full list of all side effects reported with Tybost, see the package leaflet. Tybost should not be taken with certain medicines that affect the way that Tybost is metabolized in the body or whose mode of action is influenced by Tybost: alfuzosin (used to treat the increase in volume of the prostate gland); amiodarone or quinidine (used to correct heartbeat irregularities); carbamazepine, phenobarbital or phenytoin (used to prevent convulsions); rifampicin (used to prevent and treat tuberculosis and other infections); dihydroergotamine, ergometrine or ergotamine (used in the treatment of headache); cisapride (used to relieve certain stomach problems); St. John's wort (a plant remedy used against depression and anxiety); lovastatin or simvastatin (used to lower blood cholesterol); pimozide (used to treat abnormal thoughts or feelings); sildenafil (used in the treatment of pulmonary arterial hypertension); midazolam or triazolam for oral use (used to promote sleep or relieve anxiety). For the full list of limitations, see the package leaflet.
Why has Tybost - cobicistat been approved?
The Agency's Committee for Medicinal Products for Human Use (CHMP) decided that Tybost's benefits are greater than its risks and recommended that it be approved for use in the EU. Studies have shown that Tybost is as effective as ritonavir as an atazanavir enhancer; based on data on the effect of Tybost on levels of darunavir in the body, a similar effect is expected for darunavir. The CHMP considered that there are no safety concerns that prevent the use of Tybost in combination with atazanavir or darunavir.
What information is still awaited for Tybost - cobicistat?
A risk management plan has been developed to ensure that Tybost is used as safely as possible. Based on this plan, safety information has been included in the summary of product characteristics and the package leaflet for Tybost, including the appropriate precautions to be followed by healthcare professionals and patients.
More information on Tybost - cobicistat
On 19 September 2013, the European Commission issued a marketing authorization for Tybost, valid throughout the European Union. For more information about treatment with Tybost, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist. Last update of this summary: 09-2013.
