An open, comparative pilot study of thiamphenicol glycinate hydrochloride vs clarithromycin in the treatment of acute lower respiratory tract infections due to Chlamydia pneumoniae

Improved antibacterial efficiency of inhaled thiamphenicol dry powders: Mathematical modelling of in vitro dissolution kinetic and in vitro antibacterial efficacy

Thiamphenicol (TAP) is reported to be effective against many respiratory pathogens including methicillin-resistant Staphylococcus aureus (MRSA). However, its poor solubility in water remains as one of the obstacles hindering the preparation of inhalable TAP formulations. The aim of this study was to improve the dissolution rate of TAP by micronization, and investigate whether variations in the dissolution rates of TAP would affect its in vitro antibacterial activity. Inhalable dry powders composed of TAP microcrystals (MDP) or nanocrystals (NDP) were prepared by using a wet ball milling method followed by spray drying. The morphology, solid state and in vitro dissolution of these dry powders were characterized. In vitro antibacterial activities of the inhalable TAP dry powders against a MRSA strain were evaluated. A dissolution-efficacy model relating antibacterial activity with time and dissolution rate was established via modified time-kill assays. Upon being spray dried, the volumetric mean diameters of MDP and NDP were found to be around 5 µm. Solid state analyses showed that MDP and NDP possess the same crystalline form as the raw materials. NDP exhibited faster in vitro dissolution rate as compared to MDP. The in vitro antibacterial efficiency of NDP and MDP were superior to raw TAP when the test was performed at a TAP concentration of 32 mg/L. Simulated colony forming units predictions were consistent with the result measured in the time-kill experiments with Raw TAP, MDP and NDP. This study characterized the effect of the dissolution rate of TAP dry powders on in vitro antibacterial activity against MRSA, and an enhanced antibacterial activity of TAP was observed with an increase in the dissolution rate of TAP from the dry powders at certain concentration ranges.

A Therapeutic Approach in the Treatment of Infections of the Upper Airways: Thiamphenicol Glycinate Acetylcysteinate in Sequential Treatment (Systemic-Inhalatory Route)

Eight hundred and seventeen patients with upper respiratory tract infections were treated with thiamphenicol glycinate acetylcisteinate (TGA) or other standard antibiotics for 6–10 days in a randomised trial. In 419 out of 817 patients, the symptomatology was severe and they were treated with TGA in sequential therapy (TGA 500 mg- as thiamphenicol- b.i.d. intramuscularly on the first day and TGA 500 mg b.i.d by aerosol during the following days) (n=151), or with antibiotics of comparison (n=268) given intramuscularly. In this group the disappearance of the symptomatology with TGA ranged from 90% of the patients with otitis media to 94% in pharyngotonsillitis and rhinosinusitis; in this latter group TGA was significantly better than cefazolin. In 398 patients with mild symptomatology TGA (250 mg - as thiamphenicol- b.i.d.) was given by aerosol (n=149) and the antibiotics of comparison by oral route (n=249). In TGA patients, the disappearance of symptoms was achieved in 87% of those with rhinosinusitis, in 88% of those with pharyngotonsillitis and in 91% of those with otitis media. S. pyogenes, S. pneumoniae and H. influenzae were the most frequently isolated pathogens, and none of the isolated bacteria proved to be resistant to TGA. Microbiological eradication was obtained in TGA groups in a percentage of patients ranging from 90.2 to 96.0% in those with severe forms, and from 86.2 to 91.6% in those with a mild clinical picture. Investigators rated the TGA efficacy as “excellent” in 96–100% of the patients with severe forms and in 85.5%–100% of the patients with mild forms, whereas in the group of patients with rhinosinusitis the comparison of TGA versus other treatment was significantly in favour of TGA. The Investigator rating of treatment tolerability significantly favoured TGA in sequential treatments in comparison to the other antibiotics. No patient dropped out from the trial because of adverse events.

In vitro activity of thiamphenicol against multiresistant Streptococcus pneumoniae, Haemophilus influenzae and Staphylococcus aureus in Italy

Thiamphenicol is a derivative of chloramphenicol characterized by a spectrum comparable to that of the parent compound against multiresistant pathogens but showing satisfactory tolerability. The in vitro activity of thiamphenicol and of 11 comparative drugs against 397 recently isolated antibiotic-resistant and/or invasive pneumococci and 52 multiply-resistant MRSA including 2 VISA strains was determined. Bactericidal activity against Haemophilus influenzae and the post-antibiotic effect on Streptococcus pneumoniae, H. influenzae, Staphylococcus aureus and Escherichia coli were also assessed. Against invasive pneumococci, thiamphenicol and chloramphenicol were the most potent non-beta-lactam molecules together with vancomycin and rifampin. Against high-level penicillin-resistant strains phenicol activities were superior to those of cefotaxime, ceftriaxone and imipenem. Against MRSA thiamphenicol and chloramphenicol were second only to the glycopetides and also inhibited the VISA strains. Thiamphenicol showed a significant PAE (0.33 to 2.9h) on all pathogens studied and a powerful bactericidal effect against beta-lactamase-positive and -negative H. influenzae. These results indicate a good in vitro activity of thiamphenicol against difficult-to-treat multiply resistant pathogens.