Ritonavir
What is Ritonavir?
Ritonavir is a medication used in combination with other medications to treat human immunodeficiency virus (HIV) infection (2)(4). It belongs to a class of medications called protease inhibitors, which work by decreasing the amount of HIV in the blood (2). Ritonavir is not a cure for HIV, but it may decrease the chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer (2). Ritonavir is also used as a pharmacokinetic boosting agent to increase the plasma concentration of other protease inhibitors, which helps these medications work better (2)(4).
Also, ritonavir is used in Paxlovid
Dosage
The dosage of ritonavir depends on the specific medication it is being used in combination with and the patient's medical condition (2). It is usually taken with or without food two times a day (2). Patients taking ritonavir, with or without other medications, should be monitored for drug-related toxicities (1).
Side Effects
Ritonavir may cause side effects, including liver problems, loss of appetite, stomach pain, tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes), changes in sense of taste, diarrhea, elevated blood pressure, and others (2)(6). Ritonavir affects the immune system, which may cause certain side effects even weeks or months after taking the medication (6). If you experience any serious side effects, such as an allergic reaction, seek medical attention immediately (2).
Interactions
Ritonavir interacts with many medications, including cobicistat, disulfiram, orlistat, and others (2). Ritonavir can slow down or speed up the removal of other medications from your body, which may affect how they work (2). Other medications can affect the removal of ritonavir from your body, which may affect how ritonavir works (2). Patients taking ritonavir, with or without other medications, should be monitored for drug-related toxicities (1).
Time of Day and With or Without Food
Ritonavir can be taken with or without food (1)(2). The tablets should be swallowed whole and not chewed, broken, or crushed (2).
Human Studies
Ritonavir has been used in combination with other medications to treat HIV infection for many years (2). It is also used as a pharmacokinetic boosting agent to increase the plasma concentration of other protease inhibitors (2). The safety and efficacy of ritonavir have been evaluated in clinical trials, and the results have shown that it can decrease the amount of HIV in the blood and decrease the chance of developing AIDS and HIV-related illnesses such as serious infections or cancer (2).
Citations:
(1) https://www.mayoclinic.org/drugs-supplements/nirmatrelvir-and-ritonavir-oral-route/precautions/drg-20528231?p=1
(2) https://www.webmd.com/drugs/2/drug-8436-1138/ritonavir-oral/ritonavir-oral/details
(3) https://medlineplus.gov/druginfo/meds/a696029.html
(4) https://www.ncbi.nlm.nih.gov/books/NBK544312/
(5) https://labeling.pfizer.com/ShowLabeling.aspx?id=19599
(6) https://www.drugs.com/mtm/nirmatrelvir-and-ritonavir.html