Atovaquone, sold under the brand name Mepron, is an antimicrobial medication for the prevention and treatment of ''Pneumocystis jirovecii'' pneumonia (PCP). Atovaquone is a chemical compound that belongs to the class of naphthoquinones. Atovaquone is a hydroxy-1,4-naphthoquinone, an analog of both

ubiquinone Coenzyme Q10 (CoQ10 ), also known as ubiquinone, is a naturally occurring Cofactor (biochemistry), biochemical cofactor (coenzyme) and an antioxidant produced by the human body. It can also be obtained from dietary sources, such as meat, fish, ...

and lawsone.

Medical uses

Atovaquone is a medication used to treat or prevent: * For pneumocystis pneumonia (PCP), it is used in mild cases, although it is not approved for treatment of severe cases. * For

toxoplasmosis Toxoplasmosis is a parasitic disease caused by ''Toxoplasma gondii'', an apicomplexan. Infections with toxoplasmosis are associated with a variety of neuropsychiatric and behavioral conditions. Occasionally, people may have a few weeks or month ...

, the medication has antiparasitic and therapeutic effects. * For

malaria Malaria is a Mosquito-borne disease, mosquito-borne infectious disease that affects vertebrates and ''Anopheles'' mosquitoes. Human malaria causes Signs and symptoms, symptoms that typically include fever, Fatigue (medical), fatigue, vomitin ...

, it is one of the two components (along with proguanil) in the drug Malarone. Malarone has fewer side effects and is more expensive than mefloquine. Resistance has been observed. * For

babesia ''Babesia'', also called ''Nuttallia'', is an apicomplexan parasite that infects red blood cells and is transmitted by ticks. Originally discovered by Romanian bacteriologist Victor Babeș in 1888; over 100 species of ''Babesia'' have since ...

, it is often used in conjunction with oral

azithromycin Azithromycin, sold under the brand names Zithromax (in oral form) and Azasite (as an eye drop), is an antibiotic medication used for the treatment of several bacterial infections. This includes otitis media, middle ear infections, strep throa ...

Trimethoprim/sulfamethoxazole Trimethoprim/sulfamethoxazole, sold under the trade names Bactrim, Cotrim (a short form of the British Approved Name, Co-trimoxazole) and Septra, among others, is a fixed-dose combination antibiotic medication used to treat a variety of bacte ...

(TMP-SMX, Bactrim) is generally considered first-line therapy for PCP (not to be confused with sulfadiazine and pyrimethamine, which is first line for toxoplasmosis). However, atovaquone may be used in patients who cannot tolerate, or are allergic to,

sulfonamide In organic chemistry, the sulfonamide functional group (also spelled sulphonamide) is an organosulfur group with the Chemical structure, structure . It consists of a sulfonyl group () connected to an amine group (). Relatively speaking this gro ...

medications such as TMP-SMX. In addition, atovaquone has the advantage of not causing

myelosuppression Bone marrow suppression also known as myelotoxicity or myelosuppression, is the decrease in production of cells responsible for providing immunity (leukocytes), carrying oxygen (erythrocytes), and/or those responsible for normal blood clotting ( ...

, which is an important issue in patients who have undergone

bone marrow transplantation Hematopoietic stem-cell transplantation (HSCT) is the transplantation of multipotent hematopoietic stem cells, usually derived from bone marrow, peripheral blood, or umbilical cord blood, in order to replicate inside a patient and produce a ...

. Atovaquone is given prophylactically to kidney transplant patients to prevent PCP in cases where Bactrim is contraindicated for the patient.

Malaria

Atovaquone, as a

combination In mathematics, a combination is a selection of items from a set that has distinct members, such that the order of selection does not matter (unlike permutations). For example, given three fruits, say an apple, an orange and a pear, there are ...

preparation with proguanil, has been commercially available from

GlaxoSmithKline GSK plc (an acronym from its former name GlaxoSmithKline plc) is a British Multinational corporation, multinational Pharmaceutics, pharmaceutical and biotechnology company with headquarters in London. It was established in 2000 by a Mergers an ...

since 2000 as Malarone for the treatment and prevention of malaria.

Research

COVID-19

Preliminary research found that atovaquone could inhibit the replication of

SARS-CoV-2 Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19, the respiratory illness responsible for the COVID-19 pandemic. The virus previously had the Novel coronavirus, provisional nam ...

in vitro. Clinical trials of atovaquone for the treatment of

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by the coronavirus SARS-CoV-2. In January 2020, the disease spread worldwide, resulting in the COVID-19 pandemic. The symptoms of COVID‑19 can vary but often include fever ...

are planned, and ongoing in United States in December 2021. Atovaquone has also been found to inhibit

human coronavirus OC43 Human coronavirus OC43 (HCoV-OC43) is a member of the species ''Betacoronavirus 1, Betacoronavirus gravedinis'', which infects humans and cattle. The infecting coronavirus is an Viral envelope, enveloped, Sense (molecular biology), positive-sense ...

and feline coronavirus in vitro. In newer researches, atovaquone did not demonstrate evidence of enhanced SARS-CoV-2 viral clearance compared with placebo.

Veterinary use

Atovaquone is used in livestock veterinary cases of

babesiosis Babesiosis or piroplasmosis is a malaria-like parasitic disease caused by infection with a eukaryotic parasite in the order Piroplasmida, typically a ''Babesia'' or '' Theileria'', in the phylum Apicomplexa. Human babesiosis transmission via ...

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

, especially if

imidocarb Imidocarb is a urea derivative used in veterinary medicine as an antiprotozoal agent for the treatment of infection with ''Babesia'' ( babesiosis) and other parasites. Mechanism of action Imidocarb is anticholinergic; it inhibits acetylcholinest ...

resistance is a concern.

References

External links

* {{Authority control Antimalarial agents Antiprotozoal agents 1,4-Naphthoquinones 4-Chlorophenyl compounds Drugs developed by GSK plc Hydroxynaphthoquinones