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 a number of

bacterial infection Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number ...

s. This includes middle ear infections,

strep throat Streptococcal pharyngitis, also known as streptococcal sore throat (strep throat), is pharyngitis (an infection of the pharynx, the back of the throat) caused by ''Streptococcus pyogenes'' a gram-positive, group A streptococcus. Common sympto ...

pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severi ...

traveler's diarrhea Travelers' diarrhea (TD) is a stomach and intestinal infection. TD is defined as the passage of unformed stool (one or more by some definitions, three or more by others) while traveling. It may be accompanied by abdominal cramps, nausea, fever, ...

, and certain other intestinal infections. Along with other medications, it may also be used for

malaria Malaria is a mosquito-borne infectious disease that affects humans and other animals. Malaria causes symptoms that typically include fever, tiredness, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. S ...

. It can be taken

by mouth Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...

intravenously Intravenous therapy (abbreviated as IV therapy) is a medical technique that administers fluids, medications and nutrients directly into a person's vein. The intravenous route of administration is commonly used for rehydration or to provide nutrie ...

. Common side effects include

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 ...

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 nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...

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 w ...

and upset stomach. An

allergic reaction Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...

, such as

anaphylaxis Anaphylaxis is a serious, potentially fatal allergic reaction and medical emergency that is rapid in onset and requires immediate medical attention regardless of use of emergency medication on site. It typically causes more than one of the foll ...

QT prolongation Long QT syndrome (LQTS) is a condition affecting repolarization (relaxing) of the heart after a heartbeat, giving rise to an abnormally lengthy QT interval. It results in an increased risk of an irregular heartbeat which can result in fainting ...

, or a type of diarrhea caused by ''Clostridium difficile'' is possible. No harm has been found with its use during pregnancy. Its safety during

breastfeeding Breastfeeding, or nursing, is the process by which human breast milk is fed to a child. Breast milk may be from the breast, or may be expressed by hand or pumped and fed to the infant. The World Health Organization (WHO) recommends that br ...

is not confirmed, but it is likely safe. Azithromycin is an azalide, a type of

macrolide The Macrolides are a class of natural products that consist of a large macrocyclic lactone ring to which one or more deoxy sugars, usually cladinose and desosamine, may be attached. The lactone rings are usually 14-, 15-, or 16-membered. Ma ...

antibiotic. It works by decreasing the production of protein, thereby stopping bacterial growth. Azithromycin was discovered in 1980 by the Yugoslav pharmaceutical company

Pliva Pliva d.o.o. is a pharmaceutical company based in Zagreb, Croatia that primarily manufactures and sells generic drugs. It is a subsidiary of Teva Pharmaceuticals. Pliva is one of the world's largest producers of Generic drug, generic Adderall. ...

and approved for medical use under the brand name Sumamed in 1988. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health s ...

. The World Health Organization classifies it as critically important for human medicine. It is available as a generic medication and is sold under many trade names worldwide. In 2020, it was the 68th most commonly prescribed medication in the United States, with more than 10million prescriptions.

Medical uses

Azithromycin is used to treat diverse infections, including: * Prevention and treatment of acute bacterial exacerbations of chronic obstructive pulmonary disease due to ''H. influenzae'', ''M. catarrhalis'', or ''S. pneumoniae''. The benefits of long-term prophylaxis must be weighed on a patient-by-patient basis against the risk of cardiovascular and other adverse effects. * Community-acquired pneumonia due to ''C. pneumoniae'', ''H. influenzae'', ''M. pneumoniae'', or ''S. pneumoniae'' * Uncomplicated skin infections due to ''S. aureus'', ''S. pyogenes'', or ''S. agalactiae'' * Urethritis and cervicitis due to '' C. trachomatis'' or '' N. gonorrhoeae''. In combination with

ceftriaxone Ceftriaxone, sold under the brand name Rocephin, is a third-generation cephalosporin antibiotic used for the treatment of a number of bacterial infections. These include middle ear infections, endocarditis, meningitis, pneumonia, bone and joint ...

, azithromycin is part of the United States Centers for Disease Control-recommended regimen for the treatment of gonorrhea. Azithromycin is active as

monotherapy Combination therapy or polytherapy is therapy that uses more than one medication or modality. Typically, the term refers to using multiple therapies to treat a ''single'' disease, and often all the therapies are pharmaceutical (although it can also ...

in most cases, but the combination with ceftriaxone is recommended based on the relatively low barrier to resistance development in gonococci and due to frequent co-infection with ''C. trachomatis'' and ''N. gonorrhoeae''. * Trachoma due to ''C. trachomatis'' * Genital ulcer disease (chancroid) in men due to ''H. ducrey'' *Acute bacterial sinusitis due to ''H. influenzae'', ''M. catarrhalis'', or ''S. pneumoniae''. Other agents, such as amoxicillin/clavulanate are generally preferred, however. *Acute otitis media caused by ''H. influenzae'', ''M. catarrhalis'' or ''S. pneumoniae''. Azithromycin is not, however, a first-line agent for this condition.

Amoxicillin Amoxicillin is an antibiotic medication used to treat a number of bacterial infections. These include middle ear infection, strep throat, pneumonia, skin infections, and urinary tract infections among others. It is taken by mouth, or less c ...

or another beta lactam antibiotic is generally preferred. *Pharyngitis or tonsillitis caused by ''S. pyogenes'' as an alternative to first-line therapy in individuals who cannot use first-line therapy Sumamed tablete 091208

Bacterial susceptibility

Azithromycin has relatively broad but shallow antibacterial activity. It inhibits some Gram-positive bacteria, some Gram-negative bacteria, and many atypical bacteria. A strain of gonorrhea reported to be highly resistant to azithromycin was found in the population in 2015. ''Neisseria gonorrhoeae'' is normally susceptible to azithromycin, but the drug is not widely used as monotherapy due to a low barrier to resistance development. Extensive use of azithromycin has resulted in growing

Streptococcus pneumoniae ''Streptococcus pneumoniae'', or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They ar ...

resistance. Aerobic and facultative Gram-positive microorganisms * '' Staphylococcus aureus'' (Methicillin-sensitive only) * ''

Streptococcus agalactiae ''Streptococcus agalactiae'' (also known as group B streptococcus or GBS) is a gram-positive coccus (round bacterium) with a tendency to form chains (as reflected by the genus name ''Streptococcus''). It is a beta- hemolytic, catalase-negative, ...

'' * ''

Streptococcus pyogenes ''Streptococcus pyogenes'' is a species of Gram-positive, aerotolerant bacteria in the genus '' Streptococcus''. These bacteria are extracellular, and made up of non-motile and non-sporing cocci (round cells) that tend to link in chains. They ...

'' Aerobic and facultative anaerobic Gram-negative microorganisms * ''

Haemophilus ducreyi ''Haemophilus ducreyi'' is a fastidious gram-negative coccobacillus bacteria. It causes the sexually transmitted disease chancroid, a major cause of genital ulceration in developing countries characterized by painful sores on the genitalia. Ch ...

'' * ''

Haemophilus influenzae ''Haemophilus influenzae'' (formerly called Pfeiffer's bacillus or ''Bacillus influenzae'') is a Gram-negative, non-motile, coccobacillary, facultatively anaerobic, capnophilic pathogenic bacterium of the family Pasteurellaceae. The bacter ...

'' * ''

Moraxella catarrhalis ''Moraxella catarrhalis'' is a fastidious, nonmotile, Gram-negative, aerobic, oxidase-positive diplococcus that can cause infections of the respiratory system, middle ear, eye, central nervous system, and joints of humans. It causes the inf ...

'' * '' Neisseria gonorrhoeae'' * ''

Bordetella pertussis ''Bordetella pertussis'' is a Gram-negative, aerobic, pathogenic, encapsulated coccobacillus of the genus ''Bordetella'', and the causative agent of pertussis or whooping cough. Like '' B. bronchiseptica'', ''B. pertussis'' is motile and expre ...

'' * '' Legionella pneumophila'' Anaerobic microorganisms * ''

Peptostreptococcus ''Peptostreptococcus'' is a genus of anaerobic, Gram-positive, non-spore forming bacteria. The cells are small, spherical, and can occur in short chains, in pairs or individually. They typically move using cilia. ''Peptostreptococcus'' are slow-g ...

'' species * ''

Prevotella bivia ''Prevotella bivia'' is a species of bacteria in the genus ''Prevotella''. It is gram-negative. It is one cause of pelvic inflammatory disease. Other ''Prevotella'' spp. are members of the oral and vaginal microbiota, and are recovered fro ...

'' Other microorganisms *''

Chlamydophila pneumoniae ''Chlamydia pneumoniae'' is a species of ''Chlamydia'', an obligate intracellular bacterium that infects humans and is a major cause of pneumonia. It was known as the Taiwan acute respiratory agent (TWAR) from the names of the two original isola ...

'' * ''

Chlamydia trachomatis ''Chlamydia trachomatis'' (), commonly known as chlamydia, is a bacterium that causes chlamydia, which can manifest in various ways, including: trachoma, lymphogranuloma venereum, nongonococcal urethritis, cervicitis, salpingitis, pelvic infla ...

'' * ''

Mycoplasma genitalium ''Mycoplasma genitalium'' (''MG'', commonly known as Mgen) is a sexually transmitted, small and pathogenic bacterium that lives on the mucous epithelial cells of the urinary and genital tracts in humans. Medical reports published in 2007 and 2 ...

'' * ''

Mycoplasma pneumoniae ''Mycoplasma pneumoniae'' is a very small bacterium in the class Mollicutes. It is a human pathogen that causes the disease mycoplasma pneumonia, a form of atypical bacterial pneumonia related to cold agglutinin disease. ''M. pneumoniae'' is c ...

'' * '' Ureaplasma urealyticum''

Pregnancy and breastfeeding

No harm has been found with use during pregnancy. However, there are no adequate well-controlled studies in pregnant women. The safety of the medication during

is unclear. It was reported that because only low levels are found in breast milk and the medication has also been used in young children, it is unlikely that breastfed infants would have adverse effects. Nevertheless, it is recommended that the drug be used with caution during breastfeeding.

Airway diseases

Azithromycin appears to be effective in the treatment of chronic obstructive pulmonary disease through its suppression of inflammatory processes. And potentially useful in asthma and sinusitis via this mechanism. Azithromycin is believed to produce its effects through suppressing certain immune responses that may contribute to inflammation of the airways.

Adverse effects

Most common adverse effects are diarrhea (5%), nausea (3%), abdominal pain (3%), and vomiting. Fewer than 1% of people stop taking the drug due to side effects. Nervousness, skin reactions, and

have been reported. Clostridium difficile infection, ''Clostridium difficile'' infection has been reported with use of azithromycin. Azithromycin does not affect the efficacy of birth control unlike some other antibiotics such as rifampin. Hearing loss has been reported. Occasionally, people have developed cholestatic hepatitis or delirium. Accidental intravenous overdose in an infant caused severe heart block, resulting in residual encephalopathy. In 2013 the FDA issued a warning that azithromycin "can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm." The FDA noted in the warning a 2012 study that found the drug may increase the risk of death, especially in those with heart problems, compared with those on other antibiotics such as amoxicillin or no antibiotic. The warning indicated people with preexisting conditions are at particular risk, such as those with QT interval prolongation, low blood levels of potassium or magnesium, a slower than normal heart rate, or those who use certain drugs to treat abnormal heart rhythms. It has been reported that azithromycin blocks autophagy and may predispose cystic fibrosis patients to mycobacterial infection.

Pharmacology

Mechanism of action

Azithromycin prevents bacterium, bacteria from growing by interfering with their protein synthesis. It binds to the 50S subunit of the bacterial ribosome, thus inhibiting translation (biology), translation of mRNA. Nucleic acid synthesis is not affected.

Pharmacokinetics

Azithromycin is an acid-stable antibiotic, so it can be taken orally with no need of protection from gastric acids. It is readily absorbed, but absorption is greater on an empty stomach. Time to peak concentration (T_max) in adults is 2.1 to 3.2 hours for oral dosage forms. Due to its high concentration in phagocytes, azithromycin is actively transported to the site of infection. During active phagocytosis, large concentrations are released. The concentration of azithromycin in the tissues can be over 50 times higher than in plasma due to ion trapping and its high lipid solubility. Azithromycin's half-life allows a large single dose to be administered and yet maintain bacteriostatic levels in the infected tissue for several days. Following a single dose of 500 mg, the apparent terminal elimination half-life of azithromycin is 68 hours. bilirubin, Biliary excretion of azithromycin, predominantly unchanged, is a major route of elimination. Over the course of a week, about 6% of the administered dose appears as an unchanged drug in urine.

History

A team of researchers at the pharmaceutical company

in Zagreb, Croatia,—Gabrijela Kobrehel, Gorjana Radobolja-Lazarevski, and Zrinka Tamburašev, led by Slobodan Đokić—discovered azithromycin in 1980. The company

patented it in 1981. In 1986, Pliva and Pfizer signed a licensing agreement, which gave Pfizer exclusive rights for the sale of azithromycin in Western Europe and the United States. Pliva put its azithromycin on the market in Central and Eastern Europe under the brand name Sumamed in 1988. Pfizer launched azithromycin under Pliva's license in other markets under the brand name Zithromax in 1991. Patent protection ended in 2005.

Society and culture

Available forms

Azithromycin is available as a generic medication. Azithromycin is commonly administered in film-coated tablet, capsule, oral suspension (chemistry), suspension, intravenous therapy, intravenous injection (medicine), injection, granules for suspension in sachet, and ophthalmic solution.

Usage

In 2010, azithromycin was the most prescribed antibiotic for outpatients in the US, whereas in Sweden, where outpatient antibiotic use is a third as prevalent, macrolides are only on 3% of prescriptions. In 2017, azithromycin was the second most prescribed antibiotic for outpatients in the United States. It is sold under many trade names worldwide including 3-Micina, A Sai Qi, Abacten, Abbott, Acex, Acithroc, Actazith, Agitro, Ai Mi Qi, Amixef, Amizin, Amovin, An Mei Qin, Ao Li Ping, Apotex, Lebanon, Aratro, Aruzilina, Arzomicin, Arzomidol, Asizith, Asomin, Astidal, Astro, Athofix, Athxin, Atizor, Atromizin, Avalon, AZ, AZA, Azacid, Azadose, Azalid, Azalide, AzaSite, Azath, Azatril, Azatril, Azax, Azee, Azeecor, Azeeta, Azelide, Azeltin, Azenil, Azeptin, Azerkym, Azi, Aziact, Azibact, Azibactron, Azibay, Azibect, Azibest, Azibiot, Azibiotic, Azicare, Azicin, Azicine, Aziclass, Azicom, Azicure, Azid, Azidose, Azidraw, Azifam, Azifarm, Azifast, Azifine, Azigen, Azigram, Azigreat, Azikare, Azilide, Azilife, Azilip, Azilup, Azimac, Azimax, Azimed, Azimepha, Azimex, Azimit, Azimix, Azimon, Azimore, Azimycin, Azimycine, Azin, Azindamon, Azinew, Azinex, Azinif, Azinil, Azintra, Aziom, Azipar, Aziped, Aziphar, Azipin, Azipro, Aziprome, Aziquilab, Azirace, Aziram, Aziresp, Aziride, Azirol, Azirom, Azirox, Azirute, Azirutec, Aziset, Azisis, Azison, Azissel, Aziswift, Azit, Azita, Azitam, Azitex, Azith, Azithral, Azithrin, Azithro, Azithrobeta, Azithrocin, Azithrocine, Azithromax, Azithromed, Azithromicina, Azithromycin, Azithromycine, Azithromycinum, Azithrovid, Azitic, Azitive, Azitome, Azitrac, Azitral, Azitrax, Azitredil, Azitrex, Azitrim, Azitrin, Azitrix, Azitro, Azitrobac, Azitrocin, Azitroerre, Azitrogal, Azitrolabsa, Azitrolid, Azitrolit, Azitrom, Azitromac, Azitromax, Azitromek, Azitromicin, Azitromicina, Azitromycin, Azitromycine, Azitrona, Azitropharma, Azitroteg, Azitrox, Azitsa, Azitus, Azivar, Azivirus, Aziwill, Aziwok, Azix, Azizox, Azmycin, Azo, Azobat, Azocin, Azoget, Azoheim, Azoksin, Azom, Azomac, Azomax, Azomex, Azomycin, Azomyne, Azores, Azorox, Azostar, Azot, Azoxin, Azras, Azro, Azrocin, Azrolid, Azromax, Azrosin, Aztin, Aztrin, Aztro, Aztrogecin, Azvig, Azycin, Azycyna, Azydrop, Azypin, Azytact, Azytan, Azyter, Azyter, Azyth, Azywell, Azza, Ba Qi, Bactizith, Bactrazol, Bai Ke De Rui, Batif, Bazyt, Bezanin, Bin Qi, Binozyt, BinQi, Biocine, Biozit, Bo Kang, Canbiox, Cetaxim, Charyn, Chen Yu, Cinalid, Cinetrin, Clamelle, Clearsing, Corzi, Cozith, Cronopen, Curazith, Delzosin, Dentazit, Disithrom, Doromax, Doyle, Elzithro, Eniz, Epica, Ethrimax, Ezith, Fabodrox, Fabramicina, Feng Da Qi, Figothrom, Floctil, Flumax, Fu Qi-Hua Yuan, Fu Rui Xin, Fuqixing, Fuxin-Hai Xin Pharm, Geozif, Geozit, Gitro, Goldamycin, Gramac, Gramokil, Hemomicin, Hemomycin, I-Thro, Ilozin, Imexa, Inedol, Infectomycin, Iramicina, Itha, Jin Nuo, Jin Pai Qi, Jinbo, Jun Jie, Jun Wei Qing, Kai Qi, Kang Li Jian, Kang Qi, Katrozax, Ke Lin Da, Ke Yan Li, Koptin, Kuai Yu, L-Thro, Laz, Legar, Lg-Thral, Li Ke Si, Li Li Xing, Li Qi, Lin Bi, Lipuqi, Lipuxin, Lizhu Qile, Loromycin, Lu Jia Kang, Luo Bei Er, Luo Qi, Maazi, Macroazi, Macromax, Macrozit, Maczith, Makromicin, Maxmor, Mazit, Mazitrom, Medimacrol, Meithromax, Mezatrin, Ming Qi Xin, Misultina, Na Qi, Nadymax, Naxocina, Neblic, Nemezid, Neofarmiz, Nifostin, Nobaxin, Nokar, Novatrex, Novozithron, Novozitron, Nurox, Odaz, Odazyth, Onzet, Oranex, Oranex, Ordipha, Orobiotic, Pai Fen, Pai Fu, Paiqi, Pediazith, Portex, Pu He, Pu Le Qi, Pu Yang, Qi Gu Mei, Qi Mai Xing, Qi Nuo, Qi Tai, Qi Xian, Qili, Qiyue, Rarpezit, Razimax, Razithro, Rezan, Ribotrex, Ribozith, Ricilina, Rizcin, Romycin, Rothin (Rakaposhi), Rozalid, Rozith, Ru Shuang Qi, Rui Qi, Rui Qi Lin, Rulide, Sai Jin Sha, Sai Le Xin, Sai Qi, Selimax, Sheng Nuo Ling, Shu Luo Kang, Simpli-3, Sisocin, Sitrox, Sohomac, Stromac, Su Shuang, Sumamed, Sumamox, Tailite, Talcilina, Tanezox, Te Li Xin, Tetris, Texis, Thoraxx, Throin, Thromaxin, Tong Tai Qi Li, Topt, Toraseptol, Tremac, Trex, Tri Azit, Triamid, Tridosil, Trimelin, Tritab, Tromiatlas, Tromix, Trozamil, Trozin, Trozocina, Trulimax, Tuoqi, Udox, Ultreon, Ultreon, Vectocilina, Vinzam, Visag, Vizicin, Wei Li Qinga, Wei Lu De, Wei Zong, Weihong, Xerexomair, Xi Le Xin, Xi Mei, Xin Da Kang, Xin Pu Rui, Xithrone, Ya Rui, Yan Sha, Yanic, Yi Nuo Da, Yi Song, Yi Xina, Yin Pei Kang, Yong Qi, You Ni Ke, Yu Qi, Z-3, Z-PAK, Zady, Zaiqi, Zaret, Zarom, Zathrin, Zedbac, Zeemide, Zenith, Zentavion, Zetamac, Zetamax, Zeto, Zetron, Zevlen, Zibramax, Zicho, Zigilex, Zikti, Zimacrol, Zimax, Zimicina, Zindel, Zinfect, Zirom, Zisrocin, Zistic, Zit-Od, Zitab, Zitax, Zithrax, Zithrin, Zithro-Due, Zithrobest, Zithrodose, Zithrogen, Zithrokan, Zithrolide, Zithromax, Zithrome, Zithromed, Zithroplus, Zithrotel, Zithrox, Zithroxyn, Zithtec, Zitinn, Zitmac, Zitraval, Zitrax, Zitrex, Zitric, Zitrim, Zitrobid, Zitrobiotic, Zithrolect, Zitrocin, Zitrocin, Zitrogram, Zitrolab, Zitromax, Zitroneo, Zitrotek, Ziyoazi, Zmax, Zocin, Zomax, Zotax, Zycin, and Zythrocin. It is sold as a combination drug with cefixime as Anex-AZ, Azifine-C, Aziter-C, Brutacef-AZ, Cezee, Fixicom-AZ, Emtax-AZ, Olcefone-AZ, Starfix-AZ, Zeph-AZ, Zicin-CX, and Zifi-AZ. It is also sold as a combination drug with nimesulide as Zitroflam; in a combination with tinidazole and fluconazole as Trivafluc, and in a combination with ambroxol as Zathrin-AX, Laz-AX and Azro-AM.

Research

COVID-19

Despite early evidence showing azithromycin slowed down coronavirus multiplication in laboratory settings, further research indicates it to be ineffective as a treatment for COVID-19 in humans. After a large-scale trial showed no benefit of using azithromycin in treating COVID-19, the UK's National Institute for Health and Care Excellence (NICE) updated its guidance and no longer recommends the medication for COVID-19.

References

External links

* {{Portal bar, Medicine Antimalarial agents Croatian inventions Dimethylamino compounds Macrolide antibiotics Pfizer brands World Health Organization essential medicines Wikipedia medicine articles ready to translate