Abametapir, sold under the brand name Xeglyze, is a medication used for the treatment of

head lice infestation Head lice infestation, also known as pediculosis capitis, is the infection of the head hair and scalp by the head louse (''Pediculus humanus capitis''). Itching from lice bites is common. During a person's first infection, the itch may not devel ...

in people six months of age and older. The most common side effects include skin redness, rash, skin burning sensation, skin inflammation, vomiting, eye irritation, skin itching, and hair color changes. Abametapir is a metalloproteinase inhibitor. Abametapir was approved for medical use in the United States in July 2020. 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 ...

(FDA) considers it to be a

first-in-class medication A first-in-class medication is a pharmaceutical that uses a "new and unique mechanism of action" to treat a particular medical condition. While the Food and Drug Administration's Center for Drug Evaluation and Research tracks first-in-class medicat ...

Medical uses

Abametapir is

indicated In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. There can be multiple indications to use a procedure or medication. An indication can commonly be confused with the term diagnosis. A diagnosis ...

for the topical treatment of head lice infestation in people six months of age and older.

Contraindications

Abametapir has no contraindications according to the labeling.Abametapir . Accessed 6 May 2021.

Adverse effects

Common adverse effects are burning skin sensations (in 3% of patients),

contact dermatitis Contact dermatitis is a type of acute or chronic inflammation of the skin caused by exposure to chemical or physical agents. Symptoms of contact dermatitis can include itchy or dry skin, a red rash, bumps, blisters, or swelling. These rashes are ...

(2%), skin redness (4%),

rash 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, cr ...

(3%), and vomiting (2%).

Interactions

Abametapir blocks the liver enzymes

CYP3A4 Cytochrome P450 3A4 (abbreviated CYP3A4) () is an important enzyme in the body, mainly found in the liver and in the intestine. It oxidizes small foreign organic molecules (xenobiotics), such as toxins or drugs, so that they can be removed from t ...

CYP2B6 Cytochrome P450 2B6 is an enzyme that in humans is encoded by the ''CYP2B6'' gene. CYP2B6 is a member of the cytochrome P450 group of enzymes. Along with CYP2A6, it is involved with metabolizing nicotine, along with many other substances. Funct ...

and

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 ...

in vitro ''In vitro'' (meaning in glass, or ''in the glass'') studies are performed with microorganisms, cells, or biological molecules outside their normal biological context. Colloquially called "test-tube experiments", these studies in biology an ...

''. A single application of the drug may lead to increased blood concentrations of drugs that are

metabolized Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cell ...

by these enzymes.

Pharmacology

Mechanism of action

The drug inhibits enzymes called

metalloproteinase A metalloproteinase, or metalloprotease, is any protease enzyme whose catalytic mechanism involves a metal. An example is ADAM12 which plays a significant role in the fusion of muscle cells during embryo development, in a process known as myogen ...

s. In lice, these enzymes play a role in egg development and survival; and consequently, blocking them will disrupt the lice's life cycle.

Pharmacokinetics

After application to the scalp, part of the substance reaches the bloodstream, where most of it (91.3–92.3%) is 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 primarily by the liver enzyme CYP1A2 to abametapir hydroxyl and further to abametapir carboxyl (see structure drawings). Abametapir carboxyl has a plasma protein binding of 96.0–97.5% and is the predominant of the three substances in the circulation, having a C_max 30 times and an

area under the curve In mathematics, an integral assigns numbers to functions in a way that describes displacement, area, volume, and other concepts that arise by combining infinitesimal data. The process of finding integrals is called integration. Along with ...

(AUC) 250 times that of abametapir itself. The

elimination 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 ...

of abametapir is 21 hours. That of abametapir carboxyl is not well known; it is thought to be 71±40 hours or longer. It is not known whether the drug is eliminated via the urine or the faeces. Abametapir metabolites

History

The U.S.

(FDA) approved abametapir based on evidence from two identical clinical trials of 699 participants with head lice. The trials were conducted at fourteen sites in the United States. The benefit and side effects of abametapir were evaluated in two clinical trials that enrolled participants with head lice who were at least six months old. About half of all enrolled participants was randomly assigned to abametapir and the other half to placebo. Abametapir lotion or placebo lotion were applied once as a ten-minute treatment to infested hair. The benefit of abametapir in comparison to placebo was assessed after 1, 7 and 14 days by comparing the counts of participants in each group who were free of live lice.

References

External links

* {{Portal bar , Medicine Antiparasitic agents Lice