Mofebutazone (or monophenylbutazone) is a 3,5-pyrazolinedione derivative study for treating asthma and muscular pain. It was found that there was no increase in the incidence or severity of the asthmatic attacks during the course of mofebutazone treatment. The drug tended to improve the tested pulmonary ventilatory functions or at least to leave them unchanged. All the mofebutazone-treated individuals showed a dramatic reduction in the concentrations of PGE2, PGF2alpha, and LTs in their BAL, but there was no consistent correlation between the extent of reduction and the degree of benefit or worsening sustained by an individual patient. Mofebutazone was found to be excreted almost exclusively via the kidney