FDA-Approved Oximes and Their Significance in Medicinal Chemistry

Despite the scientific advancements, organophosphate (OP) poisoning continues to be a major threat to humans, accounting for nearly one million poisoning cases every year leading to at least 20,000 deaths worldwide. Oximes represent the most important class in medicinal chemistry, renowned for their widespread applications as OP antidotes, drugs and intermediates for the synthesis of several pharmacological derivatives. Common oxime based reactivators or nerve antidotes include pralidoxime, obidoxime, HI-6, trimedoxime and methoxime, among which pralidoxime is the only FDA-approved drug. Cephalosporins are β-lactam based antibiotics and serve as widely acclaimed tools in fighting bacterial infections. Oxime based cephalosporins have emerged as an important class of drugs with improved efficacy and a broad spectrum of anti-microbial activity against Gram-positive and Gram-negative pathogens. Among the several oxime based derivatives, cefuroxime, ceftizoxime, cefpodoxime and cefmenoxime are the FDA approved oxime-based antibiotics. Given the pharmacological significance of oximes, in the present paper, we put together all the FDA-approved oximes and discuss their mechanism of action, pharmacokinetics and synthesis.

A retrospective study of azithromycin and ceftizoxime for the management of children with Mycoplasma pneumoniae pneumonia

The aim of this study was to compare the clinical efficacy of azithromycin and ceftizoxime (AC) and erythromycin and amoxicillin/sulbactam (EAS) in the treatment of children with Mycoplasma pneumoniae pneumonia (MPP).In this retrospective study, a total of 92 eligible children with MPP were included, and they were divided into a treatment group (n = 46) and a control group (n = 46). All patients were treated with intravenous ambroxol, and nebulized inhalation of budesonide and terbutaline. In addition, patients in the treatment group received AC. Patients in the control group underwent EAS. All patients in both groups were treated for a total of 10 days. Outcomes consist of erythrocyte sedimentation rate, C-reactive protein, serum lactate dehydrogenase, and interleukin 6, fever clearance time, time of cough disappearance, time of rale disappearance, time of signs disappeared by X-ray, and adverse events. All outcomes were measured after 10-day treatment.After treatment, patients who received AC exerted better improvements in erythrocyte sedimentation rate (P < .01), C-reactive protein (P < .01), serum lactate dehydrogenase (P < .01), interleukin 6 (P < .01), fever clearance time (P < .01), time of cough disappearance (P < .01), time of rale disappearance (P < .01), and time of signs disappeared by X-ray (P < .01), than those in patients who received EAS. In addition, there were not significant differences in adverse events between 2 groups.The results of this study showed that AC may benefit more than EAS for the children with MPP.

Pharmacokinetics and Efficacy of Ceftriaxone in Staphylococcal Mastitis in Crossbred Cows Following Single Intravenous Administration

BACKGROUND

Clinical mastitis is an important production disease of dairy animals, causing significant economic losses.

OBJECTIVE

Disposition kinetics of ceftriaxone was conducted in healthy lactating and staphylococcal mastitic crossbred cows in field condition following single-dose intravenous administration of only ceftriaxone.

METHODS

A single dose of ceftriaxone at 20 mg kg^-1 body weight was administered intravenously through jugular vein to six clinically healthy and six mastitic crossbred cows after proper diagnosis and three mastitic cows remained untreated (positive control). Blood and milk samples were collected at 0 (pre-dosing), 5, 15, 30 min, and 1, 24, 48, 72, 96 and 120 h post drug administration and analyzed for ceftriaxone and its active metabolite (ceftizoxime) by high-performance liquid chromatography.

RESULTS

Ceftriaxone achieved a peak mean plasma concentration of 131.67±1.83 μg mL^-1 at 5 min, which decreased sharply until 1 h (35.56±0.44 μg mL^-1) and was below detection limit at 24 h post drug administration in mastitic crossbred cows. On the other hand, ceftizoxime (active metabolite of ceftriaxone) achieved a peak level of 55.42±3.34 μg mL^-1 at 72 h and could not be detected at 120 h post drug administration in the milk of those mastitic crossbred cows. The Staphylococcus aureus colony count in mastitic crossbred cows was 49.33±6.55 × 10⁵ c.f.u./mL and the lowest colony count was achieved at 72 h with no colony at 120 h post drug administration. All the staphylococcal mastitis affected crossbred cows were cured on day 5.

CONCLUSION

Ceftriaxone may prove to be effective in the treatment of staphylococcal mastitis in crossbred cows following single-dose intravenous administration at 20 mg kg^-1 body weight.

Marked reduction in haemoglobin levels secondary to ceftizoxime-induced immune haemolytic anaemia in diabetic patients

WHAT IS KNOWN AND OBJECTIVE

Drug-induced immune haemolytic anaemia (DIIHA) is rare and difficult to diagnose. In diabetic patients, the diagnosis of DIIHA is even harder. In the current study, we report on two cases of ceftizoxime-induced immune haemolytic anaemia in diabetic patients.

CASE DESCRIPTION

Two diabetic patients (suffering from type 1 and type 2 diabetes mellitus, respectively) presented with rapid reduction in haemoglobin levels when exposed to ceftizoxime (2g q12h). They both achieved symptom improvement after switching to another antibiotic.

WHAT IS NEW AND CONCLUSION

The persistently reduced haemoglobin levels in diabetic patients may contribute to DIIHA. Reviewing patients' medical records might provide some valuable clues as to the causes of DIIHA.