China
Africa
Explore chapters and articles related to this topic
Antimicrobials during Pregnancy
Published in “Bert” Bertis Britt Little, Drugs and Pregnancy, 2022
Metronidazole (a nitroimidazole) was first introduced as an antiparasitic and used primarily to treatment trichomoniasis. Later it was discovered to be effective in the treatment of serious anaerobic infections. Use in pregnancy is limited primarily to treatment of trichomonal vaginitis. Metronidazole interferes with nucleic acid synthesis and causes cell death. It is a small molecule and crosses the placenta, reaching significant concentrations in fetal blood (Heisterberg, 1984).
New Developments in Drug Treatment
Published in Lloyd N. Friedman, Martin Dedicoat, Peter D. O. Davies, Clinical Tuberculosis, 2020
Alexander S. Pym, Camus Nimmo, James Millard
The development of nitroimidazoles to the point where there are two currently in clinical use and clinical trials; delamanid (OPC-67683)83 and pretomanid (PA-824),84 is an example of drug development by chemical modification of an existing structure.85,86 The first clinically active nitroimidazole was metronidazole (MTZ) discovered in the mid-1950s in a screen for drugs active against trichominiasis. MTZ was subsequently found to be effective therapy against a wide range of anaerobes. Since M. tuberculosis anaerobically adapts to survive in hypoxic granulomas,87 it was rational to try and engineer nitroimidazoles to be more active against mycobacteria. MTZ itself has a maximal effect on M. tuberculosis under anaerobic conditions in vitro,88 but it exhibits inconsistent activity in animal models of TB.87,89–91 Some early attempts to develop a new generation of nitroimidazoles were thwarted by problems of mutagenesis.92 But two independent initiatives succeeded by side-chain modification of the nitroimidazole structure, resulting in a nitroimidazo-oxazine (pretomanid) and a nitroimidazo-oxazole (delamanid). Both of these compounds have good activity against M. tuberculosis grown aerobically and anaerobically, and are active in the mouse and guinea-pig models of TB when given as monotherapy or in combination with other anti-TB drugs.83,84,93–97
Treatment and Prevention of Amebiasis
Published in Roberto R. Kretschmer, Amebiasis: Infection and Disease by Entamoeba histolytica, 2020
Chemical structure — Metronidazole is the 1-(β-hydroxyethyl) 2-methyl-5-nitroimi-dazole, derived from 2-nitroimidazole. The structure is shown in Figure 3. Many nitroimidazoles of similar structure and activity are now in use. They include trinidazole, flunidazole, ronidazole, dimetridazole, and satranidazole. Some patients respond poorly to metronidazole. This has been observed in subjects undergoing treatment with phenobarbital, such as epileptic children.28 A possible explanation is a shortening of the half-life of metronidazole29 resulting from a more intense hydroxylation due to the excessive stimulation of microsomal enzymes by this barbiturate.
Iatrogenic factors of Helicobacter pylori eradication failure: lessons from the frontline
Published in Expert Review of Anti-infective Therapy, 2023
Jinliang Xie, Dingwei Liu, Jianxiang Peng, Shuang Wu, Dongsheng Liu, Yong Xie
Patients used nitroimidazoles mainly included metronidazole, tinidazole and ornidazole. Quinolones mainly include levofloxacin, antofloxacin, and moxifloxacin. We evaluated whether the dose of bismuth, antibiotics, and PPI was appropriate or not according to the ‘Fifth Chinese national consensus report on the management of Helicobacter pylori infection’ [9]. Standard doses of various drugs are defined as follows: amoxicillin 1000 mg twice a day (b.i.d), clarithromycin 500 mg b.i.d, metronidazole 400 mg thrice a day (t.i.d) or four times a day (q.i.d), tetracycline 500 mg t.i.d or q.i.d, furazolidone 100 mg b.i.d, levofloxacin 500 mg q.d or 200 mg b.i.d, esomeprazole 20 mg b.i.d, omeprazole 20 mg b.i.d, lansoprazole 30 mg b.i.d, pantoprazole 40 mg b.i.d, ilaprazole 5 mg b.i.d, and bismuth potassium citrate 220 mg b.i.d.
Novel therapeutic opportunities for Toxoplasma gondii, Trichomonas vaginalis, and Giardia intestinalis infections
Published in Expert Opinion on Therapeutic Patents, 2023
Francesca Arrighi, Arianna Granese, Paola Chimenti, Paolo Guglielmi
Giardia intestinalis infection shares with T. vaginalis the employment of the 5-nitroimidazole class for its management, albeit no standardized treatment is still recommended for giardiasis [25]. Another class of drugs employed in giardiasis treatment is benzimidazoles, with albendazole and mebendazole being the most used ones (Figure 2) [58]. Even in this case, the employment of these drugs is not devoid of side effects; over the above reported ones for 5-nitroimidazoles, benzimidazoles, often employed in a single dose for 7 days, provoke side effects such as nausea, vomiting, diarrhea, and abdominal pain, and its use requires attention during pregnancy because it could have teratogenic outcomes. Along with side effects, multiple resistance mechanisms have developed. In the light of the above, the search for novel effective drugs able to eradicate trichomoniasis as well as giardiasis is still an urgent need.
Impact of insufficient doses of medications on Helicobacter pylori eradication: a retrospective observational study
Published in Postgraduate Medicine, 2022
Xiaoye Shi, Chunmei Wang, Fanjun Meng, Shaoze Ma, Guangqin Xu, Tingwei Liu, Xiaozhong Guo, Hongyu Li, Xingshun Qi
Antibiotics. The types, doses, and frequency of antibiotics prescribed in our patients included clarithromycin (500 mg qd [n = 3], 500 mg bid [n = 1008]), levofloxacin (200 mg qd [n = 1], 200 mg bid [n = 6], 500 mg qd [n = 103], 500 mg bid [n = 1]), amoxicillin (500 mg bid [n = 2], 500 mg tid [n = 5], 1000 mg bid [n = 890], 1000 mg tid [n = 3]), metronidazole (400 mg bid [n = 70], 400 mg tid [n = 2], 400 mg qid [n = 3]), ornidazole (500 mg bid [n = 7], 500 mg tid [n = 1]), azithromycin (500 mg bid [n = 1]), tetracycline (500 mg tid [n = 1]), and furazolidone (100 mg bid [n = 1]). Antibiotics, including clarithromycin plus amoxicillin (87%), clarithromycin plus levofloxacin (8%), and other combinations (5%), were prescribed at their standard doses in 978 patients. Antibiotics, mainly including nitroimidazoles (86%), were prescribed at their insufficient doses in 71 patients. Antibiotics were prescribed at their high doses in four patients. Azithromycin, which was not recommended by the national consensus, was prescribed in one patient.