Among specific forms of asthma, exercise-induced asthma (EIA) is the most common. One of the most important factors released in this form of asthma is leukotriens. The place and role of leukotrien modifiers in treating EIA is still not clearly defined. Ten children 5-15 years of age were included in this study. We followed up different lung parameters in children exposed to exertion before and after montelukast by using spirometry. All children included in the study were submitted to the prick test. Results obtained in our study showed that montelukast statistically significantly reduced lung parameters on exertion, when compared with the results obtained before it. Montelukast did not completely block EIA.

Cytotoxic and genotoxic examinations were performed of the effect of levamisole hydrochloride (2.2 mg/kg bm, 4.4 mg/kg bm, LD50-25% mg/kg bm and LD50-75% mg/kg bm) on bone marrow cells of mice of the BALB/c strain. The effect of levamisole hydrochloride on kinetics of the cellular cycle and the appearance of structural and numerical changes in chromosomes of bone marrow cells were followed. The therapeutic dose of levamisole of 2.2 mg/kg bm showed the ability to increase the mitotic activity of the observed cells, thus confirming knowledge of the immunostimulative effect of this dose of the medicine under in vivo conditions. The other tested doses of levamisole in this experiment, observed in comparison with the control group, had an opposite effect, i.e. they caused a reduction in the mitotic activity of bone marrow cells. All the examined doses in vivo showed the ability of inducing numeric (aneuloid and polyploid) and structural (lesions, breaks and insertions) chromosomal aberrations. On this basis, it can be concluded that the examined doses have a genotoxic effect.