Elvitegravir (EVG) is an

integrase inhibitor Integrase inhibitors (INIs) are a class of antiretroviral drug designed to block the action of integrase, a viral enzyme that inserts the viral genome into the DNA of the host cell. Since integration is a vital step in retroviral replication, bloc ...

used to treat

HIV The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immune ...

infection. It was developed by the pharmaceutical company

Gilead Sciences Gilead Sciences, Inc. () is an American biopharmaceutical company headquartered in Foster City, California, that focuses on researching and developing antiviral drugs used in the treatment of HIV/AIDS, hepatitis B, hepatitis C, influenza, and CO ...

, which licensed EVG from

Japan Tobacco Hepburn: ''Nippon Senbai Kōsha'' , type = 1985-: Public (''kabushiki gaisha'') 1949-1985: Statutory corporation , traded_as = , industry = FoodTobacco , foundation = 1898 (as Imperial Japanese Tobacco Company)1 June 1949 (as Japan Tobacco ...

in March 2008. The drug gained approval by the U.S.

Food and Drug Administration The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...

on August 27, 2012 for use in adult patients starting HIV treatment for the first time as part of the

fixed dose combination A combination drug or a fixed-dose combination (FDC) is a medicine that includes two or more active ingredients combined in a single dosage form. Terms like "combination drug" or "combination drug product" can be common shorthand for a FDC prod ...

known as

Stribild Elvitegravir/cobicistat/emtricitabine/tenofovir, sold under the brand name Stribild, also known as the Quad pill, is a fixed-dose combination antiretroviral medication for the treatment of HIV/AIDS. Elvitegravir, emtricitabine and tenofovir diso ...

. On September 24, 2014 the FDA approved Elvitegravir as a single pill formulation under the trade name Vitekta. On November 5, 2015 the FDA approved the drug for use in patients affected with HIV-1 as a part of a second fixed dose combination pill known as Genvoya. According to the results of the phase II clinical trial, patients taking once-daily elvitegravir boosted by

ritonavir Ritonavir, sold under the brand name Norvir, is an antiretroviral drug used along with other medications to treat HIV/AIDS. This combination treatment is known as highly active antiretroviral therapy (HAART). Ritonavir is a protease inhibitor a ...

had greater reductions in

viral load Viral load, also known as viral burden, is a numerical expression of the quantity of virus in a given volume of fluid, including biological and environmental specimens. It is not to be confused with viral titre or viral titer, which depends on the ...

after 24 weeks compared to individuals

randomized In common usage, randomness is the apparent or actual lack of pattern or predictability in events. A random sequence of events, symbols or steps often has no order and does not follow an intelligible pattern or combination. Individual rand ...

to receive a ritonavir-boosted protease inhibitor.

Medical uses

In the United States, elvitegravir can be obtained either as part of the combination pills

or Genvoya, or as the single pill formulation Vitekta. Vitekta is

FDA The United States Food and Drug Administration (FDA or US FDA) is a federal agency of the Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the control and supervision of food ...

approved to be used for the treatment of HIV-1 infection in adults who have previous treatment experience with

antiretroviral therapy The management of HIV/AIDS normally includes the use of multiple Antiviral drug, antiretroviral drugs as a strategy to control HIV/AIDS, HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life- ...

. It must be used in combination with a protease inhibitor that is coadministered with

as well as additional antiretroviral drug(s)."Vitekta Package Insert"
Foster City, CA: Gilead Sciences, Inc.; 2014. Accessed November 1, 2014

Adverse effects

The most common side effects of taking elvitegravir are

diarrhea Diarrhea, also spelled diarrhoea, is the condition of having at least three loose, liquid, or watery bowel movements each day. It often lasts for a few days and can result in dehydration due to fluid loss. Signs of dehydration often begin wi ...

(in 7% of patients) and

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...

(4%). Other side effects that occurred in more than 1% of people are

headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...

, tiredness,

rashes A rash is a change of the human skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cra ...

, and

vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the Human nose, nose. Vomiting can be the result of ailments like Food-poisoning, foo ...

Interactions and contraindications

Elvitegravir is metabolised via the liver enzyme

CYP3A Cytochrome P450, family 3, subfamily A, also known as CYP3A, is a human gene locus. A homologous locus is found in mice. The CYP3A locus includes all the known members of the 3A subfamily of the cytochrome P450 superfamily of genes. These genes ...

. Substances that induce this enzyme can reduce elvitegravir concentrations in the body, potentially triggering the development of resistant virus strains. Consequently, co-administration of strong CYP3A inducers is contraindicated; examples are

rifampicin Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), mycobacterium avium complex, ''Mycobacterium avium'' complex, leprosy, and Legionnaires’ disease. ...

, the anticonvulsants

carbamazepine Carbamazepine (CBZ), sold under the trade name Tegretol among others, is an anticonvulsant medication used primarily in the treatment of epilepsy and neuropathic pain. It is used as an adjunctive treatment in schizophrenia along with other m ...

phenobarbital Phenobarbital, also known as phenobarbitone or phenobarb, sold under the brand name Luminal among others, is a medication of the barbiturate type. It is recommended by the World Health Organization (WHO) for the treatment of certain types of ep ...

and

phenytoin Phenytoin (PHT), sold under the brand name Dilantin among others, is an anti-seizure medication. It is useful for the prevention of tonic-clonic seizures (also known as grand mal seizures) and focal seizures, but not absence seizures. The intr ...

, as well as

St John's wort ''Hypericum perforatum'', known as St. John's wort, is a flowering plant in the family Hypericaceae and the type species of the genus ''Hypericum''. Possibly a hybrid between '' H. maculatum'' and '' H. attenuatum'', the species can be found a ...

Glucuronidation Glucuronidation is often involved in drug metabolism of substances such as drugs, pollutants, bilirubin, androgens, estrogens, mineralocorticoids, glucocorticoids, fatty acid derivatives, retinoids, and bile acids. These linkages involve glycosid ...

of elvitegravir is facilitated by the enzymes

UGT1A1 UDP-glucuronosyltransferase 1-1 also known as UGT-1A is an enzyme that in humans is encoded by the ''UGT1A1'' gene. UGT-1A is a uridine diphosphate glucuronosyltransferase (UDP-glucuronosyltransferase, UDPGT), an enzyme of the glucuronidation path ...

and 3, resulting in increased blood plasma levels when taken together with strong UGT1A inhibitors such as

and other

HIV protease inhibitor Protease inhibitors (PIs) are medications that act by interfering with enzymes that cleave proteins. Some of the most well known are antiviral drugs widely used to treat HIV/AIDS and hepatitis C. These protease inhibitors prevent viral replicat ...

s. (But ritonavir also increases elvitegravir levels by inhibiting CYP3A.) Furthermore, elvitegravir is a weak to medium inducer of

CYP1A2 Cytochrome P450 1A2 (abbreviated CYP1A2), a member of the cytochrome P450 mixed-function oxidase system, is involved in the metabolism of xenobiotics in the human body. In humans, the CYP1A2 enzyme is encoded by the ''CYP1A2'' gene. Function ...

CYP2C19 Cytochrome P450 2C19 (abbreviated CYP2C19) is an enzyme protein. It is a member of the CYP2C subfamily of the cytochrome P450 mixed-function oxidase system. This subfamily includes enzymes that catalyze metabolism of xenobiotics, including some p ...

CYP2C9 Cytochrome P450 family 2 subfamily C member 9 (abbreviated CYP2C9) is an enzyme protein. The enzyme is involved in metabolism, by oxidation, of both xenobiotics, including drugs, and endogenous compounds, including fatty acids. In humans, the prote ...

, CYP3A, and a number of UGTs; the clinical relevance of these findings is however unclear.

Pharmacology

Mechanism of action

Elvitegravir inhibits the enzyme

integrase Retroviral integrase (IN) is an enzyme produced by a retrovirus (such as HIV) that integrates—forms covalent links between—its genetic information into that of the host cell it infects. Retroviral INs are not to be confused with phage int ...

HIV-1 The subtypes of HIV include two major types, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). HIV-1 is related to viruses found in chimpanzees and gorillas living in western Africa, while HIV-2 viruses are related to viruses found in the sooty mangabey ...

, and of HIV-2 to a lesser extent. The virus needs this enzyme to integrate its genetic code into the host's DNA.

Pharmacokinetics

The drug is taken by mouth. When taken together with ritonavir and a meal, it reaches highest blood plasma concentrations after four hours.

Bioavailability In 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%. H ...

is better with fatty meals. In the bloodstream, 98–99% of the substance are bound to

plasma protein Blood-proteins, also termed plasma proteins, are proteins present in blood plasma. They serve many different functions, including transport of lipids, hormones, vitamins and minerals in activity and functioning of the immune system. Other blood pr ...

s. It is metabolized mainly by CYP3A oxidation, and secondly by UGT1A1 and 3 glucuronidation. Nearly 95% are excreted via the feces, and the rest via urine.

Plasma half-life Biological half-life (also known as elimination half-life, pharmacologic half-life) is the time taken for concentration of a biological substance (such as a medication) to decrease from its maximum concentration ( Cmax) to half of Cmax in the bl ...

when combined with ritonavir is 8.7 to 13.7 hours.

References

External links

* {{Portal bar , Medicine , Viruses Integrase inhibitors Quinolines Chloroarenes Fluoroarenes Japan Tobacco