229 articles
Metabromsalan
Metabromsalan (3,5-dibromosalicylanilide, CAS 2577-72-2) is a halogenated salicylanilide formerly used in antibacterial soaps; a potent photosensitizer, its US drug products were removed in 1975 and cosmetics containing it are deemed adulterated.
Methacycline
Methacycline (metacycline, Rondomycin, methyleneoxytetracycline) is a broad-spectrum semisynthetic tetracycline antibiotic made by Pfizer from oxytetracycline; ATC J01AA05, oral, 60-70% absorbed, discontinued.
Methenamine
Methenamine (hexamethylenetetramine, hexamine, urotropine) is a urinary antiseptic, discovered 1859, used as hippurate salt since 1895; hydrolyzed to formaldehyde in acid urine to prevent recurrent UTIs without bacterial resistance.
Metronidazole
Metronidazole (Flagyl) is a synthetic 5-nitroimidazole antibiotic and antiprotozoal drug developed at Rhône-Poulenc in 1957 from azomycin, used against obligate anaerobes, trichomoniasis, amebiasis, and giardiasis, with an 8-hour half-life and alcohol interaction.
Mezlocillin
Mezlocillin (Mezlin, Baypen, BAY-F-1353) is a semisynthetic ureidopenicillin beta-lactam antibiotic developed by Bayer, FDA approved in 1981, given parenterally for serious gram-negative infections, and discontinued in the U.S.
Minimum inhibitory concentration
Minimum inhibitory concentration (MIC): the lowest antimicrobial concentration inhibiting visible microbial growth, measured by broth microdilution (ISO 20776-1, CLSI M07) and interpreted with clinical breakpoints S, I, R.
Minocycline
Minocycline (Minocin) is a semisynthetic second-generation tetracycline antibiotic, FDA-approved 1971, used for acne vulgaris, rosacea (Emrosi 40 mg ER, 2024), and bacterial infections; more adverse effects than doxycycline, including pigmentation and drug-induced lupus.
Morinidazole
Morinidazole (吗啉硝唑), sold as Mailinda, is a third-generation nitroimidazole antibacterial drug developed by Jiangsu Hansoh Pharmaceutical and approved in China in 2014 for anaerobic infections, mainly pelvic inflammatory disease.
Moxifloxacin
Moxifloxacin (Avelox, Vigamox) is a fourth-generation fluoroquinolone antibiotic developed by Bayer, approved in 1999, inhibiting DNA gyrase and topoisomerase IV, given as 400 mg once daily for respiratory, skin, intra-abdominal infections, plague, and conjunctivitis.
Mupirocin
Mupirocin (pseudomonic acid A, Bactroban, Centany), a topical antibiotic from Pseudomonas fluorescens discovered in 1971, inhibits isoleucyl-tRNA synthetase; used for impetigo and MRSA nasal decolonization, with mupA/mupB-mediated resistance.
Murepavadin
Murepavadin (POL7080), a Polyphor cyclic peptide antibiotic and first OMPTA, targets LptD to block LPS transport in Pseudomonas aeruginosa; IV phase 3 development ended in 2019 over kidney injury, inhaled development continues.
Nadifloxacin
Nadifloxacin (Acuatim, Nadoxin, OPC-7251) is a topical fluoroquinolone antibiotic for acne and superficial bacterial skin infections; it inhibits bacterial DNA gyrase and topoisomerase IV, is active against MRSA, and was developed by Otsuka.
Nafcillin
Nafcillin is a semisynthetic, penicillinase-resistant penicillin used to treat infections caused by penicillinase-producing staphylococci, and remains a first-line therapy for methicillin-susceptible S. aureus infections despite higher adverse-event rates than cefazolin.
Nafithromycin
Nafithromycin (WCK 4873, brand Miqnaf) is a lactone ketolide antibiotic by Wockhardt for community-acquired bacterial pneumonia; approved in India January 2025, 800 mg once daily for 3 days, non-inferior to moxifloxacin.
Nalidixic Acid
Nalidixic acid is a synthetic antibacterial drug and the founding member of the quinolone antibiotics, introduced in 1964 for urinary tract infections and later abandoned as resistance grew.
Nemonoxacin
Nemonoxacin (TG-873870, Taigexyn) is a non-fluorinated C-8 methoxy quinolone antibiotic from TaiGen Biotechnology for community-acquired pneumonia, non-inferior to levofloxacin in phase II/III trials and unusually weak against M. tuberculosis.
Neomycin
Neomycin (neomycin B, framycetin): aminoglycoside antibiotic from Streptomyces fradiae, discovered 1949; binds 30S ribosome; used topically and orally for hepatic coma and bowel prep; nephrotoxic, ototoxic, common contact allergen.
Neomycin/polymyxin B/bacitracin
Neomycin/polymyxin B/bacitracin, or triple antibiotic ointment (Neosporin), is an OTC first aid antibiotic ointment with bacitracin zinc 400 units, neomycin 3.5 mg, and polymyxin B 5,000 units per gram for minor wounds.
Nifuroxazide
Nifuroxazide (Ercefuryl) is an oral nitrofuran intestinal antiinfective antibiotic, ATC A07AX03, C12H9N3O5, CAS 965-52-6, used for colitis and diarrhea, with STAT3/JAK2 activity and EMA-noted possible mutagenic potential.
Nitrofurantoin
Nitrofurantoin, an oral nitrofuran antibiotic approved in the US in 1953, treats uncomplicated lower urinary tract infections. Activated by bacterial NfsA/NfsB nitroreductases, it damages multiple targets, giving low resistance; dosed 100 mg twice daily for 5-7 days.
Nitrofurazone
Nitrofurazone, also known as nitrofural, is a synthetic nitrofuran antibacterial drug applied topically to treat burns, skin grafts, and skin ulcers, in US use since 1944.
Nitroxoline
Nitroxoline (8-hydroxy-5-nitroquinoline, 5-NOK) is an 8-hydroxyquinoline antibiotic used since 1962 for urinary tract infections in Germany and Eastern Europe; it chelates metals, acts as a zinc/copper metallophore, and is repurposed for amoebae, cancer, and NF1.
Norfloxacin
Norfloxacin (NFLX) is the first fluoroquinolone antibiotic, discovered in 1977 at Kyorin Pharmaceutical with fluorine at position 6 and piperazine at position 7; marketed 1986, it treats urinary tract infections via DNA gyrase inhibition and is 10x more active than nalidixic acid.
Noxytiolin
Noxytiolin, also called noxythiolin (Noxyflex), is 1-(hydroxymethyl)-3-methylthiourea, a formaldehyde-releasing thiourea antiseptic used to irrigate infected body cavities and treat burns.
Ofloxacin
Ofloxacin (Floxacin, formerly Floxin) is a second-generation fluoroquinolone antibiotic reported by Daiichi Pharmaceutical in 1982, inhibiting bacterial DNA gyrase and topoisomerase IV; used orally, otically, and ophthalmically, with a notably higher Achilles tendon complication risk than ciprofloxacin or levofloxacin.
Omadacycline
Omadacycline (NUZYRA, PTK-0796) is a semisynthetic aminomethylcycline tetracycline antibiotic approved in 2018 for adult CABP and ABSSSI, given once daily orally or intravenously, active against tetracycline-resistant bacteria via C-7/C-9 modifications.
Omiganan
Omiganan (MBI 226, CLS001) is a synthetic 12-amino-acid cationic antimicrobial peptide, an indolicidin analog from bovine neutrophils, that kills bacteria and fungi by disrupting cytoplasmic membranes and has been tested topically for catheter infections, rosacea, and dermatoses.
Oritavancin
Oritavancin (Orbactiv), a long-acting lipoglycopeptide antibiotic with ~393-hour half-life, is approved as a single 1200 mg IV dose for Gram-positive ABSSSI and studied off-label for osteomyelitis, bacteraemia, and endocarditis.
Oxacillin
Oxacillin is a semisynthetic, penicillinase-resistant penicillin of the isoxazolyl series, once sold as Prostaphlin, used to treat penicillinase-producing staphylococcal infections and used in testing for methicillin resistance (MRSA).
Oxytetracycline
Oxytetracycline (Terramycin) is a broad-spectrum tetracycline antibiotic isolated from Streptomyces rimosus by Pfizer in 1950; a WHO essential medicine (WATCH) for trachoma and eye infections, also used in veterinary medicine and agriculture.