Twelve analogs of diethylcarbamazine as prepared by acylation of 3- and 8-methyl-3,8-diazabicyclo[3.2.1]octane, 2-methyl-2,5-diazabicyclo[2.2.2]octane, and 2-methyl-2,5-diazabicyclo [2.2.1]heptane with diethylcarbamyl chloride, ethyl chloroformate, ethyl isocyanate, and cyclohexanecarbonyl chloride. These compounds are formally derived from diethylcarbamazine in possessing two- or one-carbon bridges over the piperazine ring. The compounds have utility as antifilarial agents and as bronchodilators.