An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such infections. They may either kill or inhibit the growth of bacteria. A limited number of antibiotics also possess antiprotozoal activity. Antibiotics are not effective against viruses such as the ones which cause the common cold or influenza; drugs which inhibit growth of viruses are termed antiviral drugs or antivirals rather than antibiotics. They are also not effective against fungi; drugs which inhibit growth of fungi are called antifungal drugs.
Drug resistance is the reduction in effectiveness of a medication such as an antimicrobial or an antineoplastic in treating a disease or condition. The term is used in the context of resistance that pathogens or cancers have "acquired", that is, resistance has evolved. Antimicrobial resistance and antineoplastic resistance challenge clinical care and drive research. When an organism is resistant to more than one drug, it is said to be multidrug-resistant.
Metronidazole, sold under the brand name Flagyl among others, is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat pelvic inflammatory disease, endocarditis, and bacterial vaginosis. It is effective for dracunculiasis, giardiasis, trichomoniasis, and amebiasis. It is an option for a first episode of mild-to-moderate Clostridium difficile colitis if vancomycin or fidaxomicin is unavailable. Metronidazole is available orally, as a cream or gel, and by slow intravenous infusion.
Imidazole (ImH) is an organic compound with the formula C3N2H4. It is a white or colourless solid that is soluble in water, producing a mildly alkaline solution. In chemistry, it is an aromatic heterocycle, classified as a diazole, and has non-adjacent nitrogen atoms in meta-substitution.
Daptomycin, sold under the brand name Cubicin among others, is a lipopeptide antibiotic used in the treatment of systemic and life-threatening infections caused by Gram-positive organisms.
Tinidazole, sold under the brand name Tindamax among others, is a medication used against protozoan infections. It is widely known throughout Europe and the developing world as a treatment for a variety of anaerobic amoebic and bacterial infections. It was developed in 1972 and is a prominent member of the nitroimidazole antibiotic class.
Ornidazole is an antibiotic used to treat protozoan infections. A synthetic nitroimidazole, it is commercially obtained from an acid-catalyzed reaction between 2-methyl-5-nitroimidazole and epichlorohydrin.
Lincosamides are a class of antibiotics, which include lincomycin, clindamycin, and pirlimycin.
Platensimycin, a metabolite of Streptomyces platensis, is an antibiotic, which act by blocking enzymes.
2-Oxazolidone is a heterocyclic organic compound containing both nitrogen and oxygen in a 5-membered ring.
Benznidazole is an antiparasitic medication used in the treatment of Chagas disease. While it is highly effective in early disease, the effectiveness decreases in those who have long-term infection. It is the first-line treatment given its moderate side effects compared to nifurtimox. It is taken by mouth.
Pretomanid is an antibiotic medication used for the treatment of multi-drug-resistant tuberculosis affecting the lungs. It is generally used together with bedaquiline and linezolid. It is taken by mouth.
Beta-lactamases are a family of enzymes involved in bacterial resistance to beta-lactam antibiotics. In bacterial resistance to beta-lactam antibiotics, the bacteria have beta-lactamase which degrade the beta-lactam rings, rendering the antibiotic ineffective. However, with beta-lactamase inhibitors, these enzymes on the bacteria are inhibited, thus allowing the antibiotic to take effect. Strategies for combating this form of resistance have included the development of new beta-lactam antibiotics that are more resistant to cleavage and the development of the class of enzyme inhibitors called beta-lactamase inhibitors. Although β-lactamase inhibitors have little antibiotic activity of their own, they prevent bacterial degradation of beta-lactam antibiotics and thus extend the range of bacteria the drugs are effective against.
A nucleic acid inhibitor is a type of antibacterial that acts by inhibiting the production of nucleic acids. There are two major classes: DNA inhibitors and RNA inhibitors. The antifungal flucytosine acts in a similar manner.
Solithromycin is a ketolide antibiotic undergoing clinical development for the treatment of community-acquired pneumonia and other infections.
Cephalosporins are a broad class of bactericidal antibiotics that include the β-lactam ring and share a structural similarity and mechanism of action with other β-lactam antibiotics. The cephalosporins have the ability to kill bacteria by inhibiting essential steps in the bacterial cell wall synthesis which in the end results in osmotic lysis and death of the bacterial cell. Cephalosporins are widely used antibiotics because of their clinical efficiency and desirable safety profile.
Ceftolozane/tazobactam, sold under the brand name Zerbaxa, is a combination antibiotic medication used for the treatment of complicated urinary tract infections and complicated intra-abdominal infections in adults. Ceftolozane is a cephalosporin antibiotic, developed for the treatment of infections with gram-negative bacteria that are resistant to conventional antibiotics. It was studied for urinary tract infections, intra-abdominal infections and ventilator-associated bacterial pneumonia.
2-Methylimidazole is an organic compound that is structurally related to imidazole with the chemical formula CH3C3H2N2H. It is a white or colorless solid that is highly soluble in polar organic solvents and water. It is a precursor to a range of drugs and is a ligand in coordination chemistry.
A drug class is a group of medications and other compounds that have similar chemical structures, the same mechanism of action, similar modes of action, and/or are used to treat the similar diseases. The Food and Drug Administration (FDA) has worked on classifying and licensing new medications for many years. However, the FDA's Drug Evaluation and Research Center categorizes these new medications based on both their chemical and therapeutic class.
A disulfiram-like drug is a drug that causes an adverse reaction to alcohol leading to nausea, vomiting, flushing, dizziness, throbbing headache, chest and abdominal discomfort, and general hangover-like symptoms among others. These effects are caused by accumulation of acetaldehyde, a major but toxic metabolite of alcohol formed by the enzyme alcohol dehydrogenase. The reaction has been variously termed a disulfiram-like reaction, alcohol intolerance, and acetaldehyde syndrome.
