Comparative study of cardiac safety profiles of loratadine and astemizole in rats

The second [non-sedating] generation antihistamines; terfenadine and astemizole have been reported to produce QTc prolongation and ventricular arrhythmias. With the withdrawal of terfenadine and the warnings for astemizole recommended by U.S.FDA, loratadine becomes one of the currently widely available non-sedating antihistamines. We examined and compared the effects of loratadine and astemizole on the electrocardiographic QT c interval and heart rate in adult albino rats.Two groups, each 6 anaesthetised adult albino rats; loratadine, and astemizole-treated groups were used. Each drug was given in 4 doses about 0.1, 1, 5 and 10 times its antihistaminic ED[50] in rats, with 30-minutes dosing interval. The heart rate and QT c interval [mean values over the dosing interval] were the electrocardiographic parameters measured. Loratadine doses about 0.1, 1 and 5 times the antihistaminic ED[50] produced insignificant changes in the HR and QTc interval, while the loratadine dose about 10 times the ED[50] produced significant minimal increases in the HR and QT c interval versus the control in rats. Astemizole doses about 0.1 and 1 times its ED[50] produced insignificant changes in the HR, while astemizole doses about 5 and 10 times its EDSO produced significant moderate decrease [opposite to loratadine effect] in the HR. All astemizole doses about 0.1, 1, 5 and 10 times its ED[50] produced significant moderate prolongations in the QT c interval versus the control which were much greater than loratadine effect with its dose 10 times the ED[50]. Loratadine has no or little effects on the HR and QTc interval with doses up to 10 times the ED[50] and is considered to have much better cardiac safety profile in comparison to astemizole doses from 0.1 up to 10 times its ED[50] which is cardiotoxic based on the greater QTc interval prolongations

Fiberoptic bronchoscopic study of tracheobronchial arborization

In a trial to study the arborization patterns of tracheo-bronchial tree among a representative sample of Egyptian individuals, 258 subjects who were candidate for fiberoptic bronchoscopy and 10 volunteers were studied in this work. The results confirmed the documented and world wide accepted airways patterns. However unusual patterns were observed in 22.7%, 2.1% and 20.33% of the right upper, middle and right lower lobes bronchi respectively. In addition a subsegmental bronchus was detected in the right lower lobe of one case only 23.3% of left upper lobe proper, lingual and left lower lobe basal bronchi [0.41%]. On the other hand 13.6%, 1.6% and respectively showed unusual patterns. This study might be a pilot mirror of the airways arborization patterns among Egyptians which should be considered during bronchoscopy technique

Pulmonary compliance in smokers with special reference to goza smoking

As a material for this work 150 males were studied. 120 of them were smokers and 30 were non-smokers controls. They were studied through the following methods: a] careful history taking and thorough clinical examination. b] radiologic study. c] spirometry. d] static pulmonary compliance measurements. From this work it can be concluded that: 1- smoking is associated with reduction of the pulmonary compliance in subjects with normal ventilatory function [the mean values of pulmonary compliance in smokers and non-smokers were 0.028 L/CmH[2]O/L V.C. and 0.037 L/CmH[2]O/L.V.C. respectively]. The pulmonary compliance is correlated with the subjects, total consumption of cigarettes, goza and both cigarettes and goza together. Its values differ according to the type of smoking, it has the lowest values in goza smokers [0.043 +/- 0.015] and the highest values in both cigarette and goza consumers [0.062 +/- 0.025]. In cigarette smokers its values occupied intermediate position [0.045 +/- 0.015 L/CmH[2]O/L. V.C.]. 2- Reversed relationship was found between the pulmonary compliance and each of MBC% and FEV% in all subjects of the study while a direct relationship was found between the pulmonary compliance and FVC in subjects with normal ventilatory function. 3- The subjects of total consumption of each of cigarettes, goza and both cigarettes and goza were found to be directly related to the severity of dyspnea and reversely related to each of FEV% and MBC%