Indinavir belongs to the protease inhibitors. The active medical ingredient is used to treat HIV infection.
What is indinavir?
Indinavir belongs to the protease inhibitors. The medical agent is used for the therapy of HIV infections. Indinavir is the name given to an antiviral drug that belongs to the group of HIV protease inhibitors and is used to treat HIV infection. The HIV protease inhibitors are used as part of a special “Highly Active Antiretroviral Therapy” (HAART) together with other antiretroviral drugs such as NRTI (Nucleoside Reverse Transcriptase Inhibitors) and NNRTI (Non-Nucleoside Reverse Transcriptase Inhibitors). Indinavir was developed by the U.S. pharmaceutical company Merck and Co or MSD Sharp and Drohme (MSD). The company developed oral dosage forms of the protease inhibitor, which were eventually approved by both the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) in 1996. In the 1990s, indinavir was among the most effective antiviral drugs. Over time, however, the drug has been increasingly replaced by better-performing HIV protease inhibitors.
Pharmacologic action
Indinavir causes binding to the viral HIV protease. This is important for replication of the pathogen. The process leads to inhibition of the viral enzyme, which in turn counteracts viral replication. Finally, a decrease in viral load occurs. Indinavir use is considered more useful in type 1 AIDS patients because the drug has a greater affinity for HIV-1 than for HIV-2. In the bloodstream, indinavir binds to plasma proteins at approximately 60 percent. Metabolism and breakdown of the drug occur in the liver. Indinavir has the disadvantage that it must be taken every eight hours. This is the only way to ensure sufficient bioavailability. It is recommended to take indinavir either one hour before a meal or one hour after a meal. If the food is rich in proteins (albumin) and fat, this results in a significant reduction in absorption. Medical experts generally consider it advisable to administer it on an empty stomach.
Medical application and use
Indinavir is administered for the treatment of adults, adolescents, and children four years of age and older for the therapy of HIV infection. In addition, the protease inhibitor is suitable for postexposure prevention in adults. Indinavir is not used as a single drug due to the development of resistance in HIV viruses. Instead, the drug is combined with other antiviral drugs. These may be zidovudine or lamivudine, for example. The recommended dose of indinavir is 3 x 800 milligrams per day. A lower dose risks considerable loss of efficacy. However, the protease inhibitor must not be taken in larger quantities. The capsules are taken every eight hours with a glass of water or skim milk. Alternatively, administration with tea, coffee or juice is also possible. To counteract kidney stones, it is advisable to provide the body with at least six glasses of water per day. If the drug is to be administered together with a meal, light meals such as cornflakes or toast with jam are recommended. It is also important to protect indinavir from heat and moisture.
Risks and side effects
Taking indinavir can sometimes result in unwanted side effects. In approximately six percent of all patients, severe side effects even necessitate discontinuation of therapy. In most cases, there are disturbances of the digestive tract such as diarrhea, abdominal pain and nausea. A rather rare undesirable side effect is the development of a bull’s neck, in which there is an abnormal redistribution of fat in the neck area. Other conceivable side effects include changes in metabolism such as hyperglycemia, hypercholesterolemia or hypertriglyceridemia, headache, fatigue, feelings of weakness, bleeding in the case of hemophilia, skin rash, lipid elevations, changes in taste perception, nephrotoxicity, sicca syndrome associated with dry eye mucous membranes, dry mouth, and dry skin, ingrown toenails, nail bed inflammation, hair loss, and liver dysfunction.Kidney stones develop in up to 25 percent of patients. Indinavir should not be administered at the same time as certain other medications such as benzodiazepines, cisapride, rifampicin, terfenadine, or astemizole due to cytochrome system interactions. This could result in changes in blood plasma levels as well as pronounced side effects.
