BioavailabilityIn pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via routes other than intravenous, its bioavailability is generally lower than that of intravenous due to intestinal endothelium absorption and first-pass metabolism.
Phases of clinical researchThe phases of clinical research are the stages in which scientists conduct experiments with a health intervention to obtain sufficient evidence for a process considered effective as a medical treatment. For drug development, the clinical phases start with testing for drug safety in a few human subjects, then expand to many study participants (potentially tens of thousands) to determine if the treatment is effective. Clinical research is conducted on drug candidates, vaccine candidates, new medical devices, and new diagnostic assays.
Management of HIV/AIDSThe management of HIV/AIDS normally includes the use of multiple antiretroviral drugs as a strategy to control HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life-cycle. The use of multiple drugs that act on different viral targets is known as highly active antiretroviral therapy (HAART). HAART decreases the patient's total burden of HIV, maintains function of the immune system, and prevents opportunistic infections that often lead to death.
DienogestDienogest, sold under the brand name Visanne among others, is a progestin medication which is used in birth control pills and in the treatment of endometriosis. It is also used in menopausal hormone therapy and to treat heavy periods. Dienogest is available both alone and in combination with estrogens. It is taken by mouth. Side effects of dienogest include menstrual irregularities, headaches, nausea, breast tenderness, depression, and acne, among others.
Power of a testIn statistics, the power of a binary hypothesis test is the probability that the test correctly rejects the null hypothesis () when a specific alternative hypothesis () is true. It is commonly denoted by , and represents the chances of a true positive detection conditional on the actual existence of an effect to detect. Statistical power ranges from 0 to 1, and as the power of a test increases, the probability of making a type II error by wrongly failing to reject the null hypothesis decreases.
CYP2D6Cytochrome P450 2D6 (CYP2D6) is an enzyme that in humans is encoded by the CYP2D6 gene. CYP2D6 is primarily expressed in the liver. It is also highly expressed in areas of the central nervous system, including the substantia nigra. CYP2D6, a member of the cytochrome P450 mixed-function oxidase system, is one of the most important enzymes involved in the metabolism of xenobiotics in the body.
Grapefruit–drug interactionsSome fruit juices and fruits can interact with numerous drugs, in many cases causing adverse effects. The effect is most studied with grapefruit and grapefruit juice, but similar effects have been observed with certain other citrus fruits. The effect was first discovered accidentally in 1991, when a test of drug interactions with alcohol used grapefruit juice to hide the taste of the ethanol. A 2005 medical review advised patients to avoid all citrus juices until further research clarifies the risks.
Post-exposure prophylaxisPost-exposure prophylaxis, also known as post-exposure prevention (PEP), is any preventive medical treatment started after exposure to a pathogen in order to prevent the infection from occurring. In 2021, the FDA has approved bamlanivimab/etesevimab for post-exposure prophylaxis against COVID-19. PEP is commonly and very effectively used to prevent the onset of rabies after a bite by a suspected-rabid animal, since diagnostic tools are not available to detect rabies infection prior to the onset of the nearly always-fatal disease.
F-testAn F-test is any statistical test in which the test statistic has an F-distribution under the null hypothesis. It is most often used when comparing statistical models that have been fitted to a data set, in order to identify the model that best fits the population from which the data were sampled. Exact "F-tests" mainly arise when the models have been fitted to the data using least squares. The name was coined by George W. Snedecor, in honour of Ronald Fisher. Fisher initially developed the statistic as the variance ratio in the 1920s.
Emtricitabine/tenofovirEmtricitabine/tenofovir, sold under the brand name Truvada among others, is a fixed-dose combination antiretroviral medication used to treat and prevent HIV/AIDS. It contains the antiretroviral medications emtricitabine and tenofovir disoproxil. For treatment, it must be used in combination with other antiretroviral medications. For prevention before exposure, in those who are at high risk, it is recommended along with safer sex practices. It does not cure HIV/AIDS. Emtricitabine/tenofovir is taken by mouth.
