CNS side effect of fexofenadine, A new antihistamine.

Fexofenadine, derivative of Terfenadine has been proved to be not distributed to the CNS, having high selectivity for peripheral histamine H1-receptors. Fexofenadine is an effective antihistamine for the treatment of many allergic diseases. The authors have studied the CNS depressant effects of Fexofenadine in 20 nomal Thai volunteers; 10 males, 10 females, age ranged 25 to 52 years, using the double blind cross-over placebo controlled design comparing with chlorpheniramine. The test methods were both subjective and objective i.e. visual analogue scale, alertness rating scale, card sorting test, glassbead picking test, recording of the reaction time test for light stimulation. There is no CNS side effect caused by Fexofenadine as well as placebo. Chlorpheniramine caused significant CNS side effects.

Dissolution of imported and locally-made terfenadine tablet.

Terfenadine, an effective histamine H1- antagonist, is a popular in Thailand. Both imported and locally-made brands are available in the market. This study was performed to prove the general characteristics and the dissolution profile of one imported terfenadine tablet and five locally-made brands. The tablet from each brand were uniform in weight, thickness and diameter. The dissolution profile of the other three locally-made products do not reach the standard dissolution profile.

Aeroallergens survey in nakornsawan province.

An aeroallergen survey in Nakornswan province, was done prospectively in 1991 using a rotorod sampler. The most common pollen types and mold spores were Cyperaceae and Cladosporium, in order. There were definite differences in the amount and frequency of occurrences of aeroallergens between seasons. Mold spores were found frequently in rainy season.

Effect of allerglobuline injection on serum immunoglobulin levels in ENT patients.

Allerglobuline is a human gammaglobulin preparation which has been reported to have a protective effect against Type I allergic diseases and chronic infection of the upper respiratory tract both in adults and children. This study included 64 patients suffering from perennial allergic rhinitis and/or chronic infection of the nose, paranasal sinuses and pharynx. All patients received Allerglobuline 10 ml intramuscular injection once a week for 5 times then once a month for another 3 times. Blood samples were taken before the first and after the last injections to assay for the levels of Igs G, A, M and E. The therapeutic responses were evaluated after the fifth injections by dividing into 5 grades (from Grade I = excellent to Grade V = no response). Statistical analysis revealed that there was no significant difference between the pre- and post-treatment levels of Igs, G, A and M. But the level of IgE decreased significantly after 8 injections (p less than 0.001). There was no correlation between the level of immunoglobulins and grade of therapeutic responses. But the number of patients who respond satisfactorily to Allerglobuline treatment increased from 62.26% after 5 injections to 77.36% after 8 injections. This difference does not reach the statistically significant level but is noteworthy.

A study on CNS-side effects of mequitazine, an H1-specific antihistamine in healthy Thai volunteers.

Mequitazine is a potent, non-sedative, long-acting H1-specific antihistamine proven to be a better therapeutic drug than other conventional antihistamines. It is also reported by many authors that the drug produces less sedative or other depressive actions on the central nervous system than other antihistamines. In order to evaluate the advantage of this drug in Asian people, an assessment of side effects of mequitazine, in comparison with chlorpheniramine, on the central nervous system was done in 20 healthy Thai volunteers, 10 males and 10 females 23-39 years of age, using a double blind crossover placebo controlled trial. Various subjective tests: alertness scale rating, visual analogue scale rating as well as objective tests: card sorting, glassbead picking and estimation of reaction time, were performed. There were no significant differences in side effects on the central nervous system between mequitazine and the placebo, whereas chlorpheniramine did produce side effects.

Study of the CNS side effect of loratadine, a new antihistamine.

Loratadine, a derivative of the known antihistamine, Azatadine has been proved to be scarcely distributed to the CNS, having high selectivity for peripheral histamine H1-receptore, hence lacking of CNS depressant effects. Lortadine is an effective antihistamine for the treatment of many allergic diseases. The authors have studied the CNS depressant effects of Loratadine in 35 normal Thai volunteers; 17 males, 18 females, age ranged 20 to 40 years, using a double blind cross over placebo controlled design comparing with chlorpheniramine. The test methods were both subjective and objective i.e. visual analogue scale, alertness rating scale, card sorting test, glassbead picking test, recording of the reaction time test for light stimulation. The CNS side effects of loratadine proved to be differ from those caused by placebo and significantly less than the CNS depressive effect by chlorpheniramine.

Study of mechanisms of post-transfusion hypertension in thalassaemic patients.

Post-transfusion hypertension, convulsion and cerebral haemorrhage is a serious complication that may occur in the thalassaemias. In this study we evaluated the effect of blood transfusion on blood pressure, plasma renin activity (PRA), blood viscosity, and urinary vanillylmandelic acid (VMA) and catecholamines in 11 beta-thalassaemia/haemoglobin E patients. The results showed that after each unit of blood transfusion the blood viscosity was increased and correlated with the increased in haematocrit level. At the same time the PRA level was significantly decreased and tended to return to the normal level in a few days after the transfusion. There was no alteration in the urinary VMA and catecholamine levels. During the study two patients developed hypertension and headache. Their PRA were still lower than the pre-transfusion levels and the blood pressure returned to the normal pre-transfusion levels within 30-90 minutes after the intravenous injection of furosemide.

A preliminary study of circulating immune complexes during allergen immunotherapy in Thai patients.

Circulating immune complexes are suspected as a potentially serious adverse effect after prolonged allergen immunotherapy. This study was undertaken to determine whether there were any significant immunological differences between 32 subjects with allergic rhinitis/asthma treated with immunotherapy of various durations and 13 subjects with similar diagnosis who had never been treated by immunotherapy. All patients were carefully examined for symptoms and signs of immune-complex diseases with negative results. The presence of circulating immune complexes was evaluated by the modified 125I-C1q binding test, the solid phase conglutinin (K) binding test and determination of C3, C4 and C3d levels. In addition, urinalysis, and quantitative determination of serum IgG, IgA, IgM and IgE were also performed. The overall results suggested that prolonged allergen immunotherapy did not result in an increase of circulating immune complexes or other adverse immunological consequences.

Intranasal budesonide for the treatment of perennial rhinitis in Thai patients.

The efficacy and tolerability of a new intranasal glucocorticosteroid, budesonide, was evaluated in 28 Thai adult patients with perennial rhinitis. After one week pre-treatment observation period, the nasal spray was given as two puffs into each nostril twice daily (400 micrograms/day) for four weeks. The severity of all nasal symptoms decreased significantly after 1 week treatment reaching a minimal level after 2 weeks. The amounts of antihistamine tablets taken by the patients were also significantly reduced during the treatment with budesonide. Three patients reported adverse effects which were mild and easily tolerated. Morning plasma cortisol levels measured before and after four-week treatment in 15 patients revealed no significant changes. This study suggests that intranasal budesonide is an effective and well-tolerated treatment for perennial rhinitis.

Histamine content in 24-hour urine in patients with dengue haemorrhagic fever.

Twenty-four hour urinary histamine in 12 patients with DHF compared to 12 normal subjects in the comparable age and sex were studied. The results revealed significantly increased urinary excretion in patients with DHF than in normal subjects in both free and total forms. This finding suggests that histamine may be one, if not all, of the mediators released during the course of the disease, especially in the severe cases. Histamine may play an important role for the leakage of intravascular fluid to the various serous spaces resulting in hypovolemia and shock.