Atazanavir and ritonavir are antiretrovirals used to treat HIV/AIDS, in combination with other antiretroviral drugs. They belong to the class of drugs called protease inhibitors and are often used together as ritonavir boosts the action of atazanavir. They are available in most countries by prescription only as HIV therapy requires close monitoring by the treating doctor. Trade names of atazanavir and ritonavir may differ between countries, according to their manufacturers.
Acquired Immune Deficiency Syndrome (AIDS) is an incurable and highly transmissible disease caused by the Human Immunodeficiency Virus (HIV). It is transmitted by body fluids, most often sexually, but also by other methods including from mother to child during pregnancy and by the sharing of needles, a common practice in addicts. While HIV is not curable, it is preventable, by practicing safe sex, using condoms and avoiding high risk behaviors like needle-sharing.
HIV destroys the body’s immune system, making the patient highly susceptible to infections such as tuberculosis (TB) and cryptococcal meningitis. The aim of treatment of HIV is to stop this decline in immunity as soon as possible. The decision to start treatment is usually decided by monitoring the body’s immune status. The aim of treatment is to decrease the viral load of HIV to lower than detectable levels and to increase the CD4 count, that is, to improve the immune system.
Protease inhibitors, including atazanavir and ritonavir, act by inhibiting protease, which is an enzyme used in the replication of HIV. Atazanavir and ritonavir are never used alone to treat HIV. Usually triple therapy is given, with the protease inhibitors being combined with two other antiretroviral drugs. The choice of combination will be decided by the prescribing doctor on a patient-by-patient basis, according to their clinical history.
When using atazanavir and ritonavir in combination with other antiretrovirals to treat HIV, the ritonavir increases the amount of atazanavir in the blood, allowing it to work better. The combination may interact with other medications. For this reason, it is essential to inform the prescribing doctor of any other medications, including over-the-counter, homeopathic or complementary drugs.
The dose of atazanavir and ritonavir when used together is usually 300 mg atazanavir and 100 mg ritonavir daily. The prescribed dosage of all antiretrovirals should be followed and doses should never be skipped as non-adherence can result in the development of resistant virus and failure of the treatment. Side effects may be experienced and these should be discussed with the doctor.