Emodepside (PF 1022-221) is a cyclooctadepsipeptide with broad-spectrum anthelmintic activity. In Vitro: Emodepside is a semisynthetic derivative of PF1022A, which contains a morpholine attached in para position at each of both D-phenyllactic acids. Emodepside is efficacious against a variety of gastrointestinal nematodes. Emodepside binds to a presynaptic latrophilin receptor in nematodes^[1]. Emodepside produces a slow time-dependent (20 min), 4-aminopyridine sensitive, concentration-dependent hyperpolarization and increase in voltage-activated K currents. Emodepside has an inhibitory effect on spiking. Emodepside significantly inhibits the ryanodine increase in spike frequency between the 20 and 35 min period by 9.8 spikes/min^[2]. In the presence of emodepside, highly increased currents are observed without depolarization up to a threshold of 0 mV and without any additional stimuli to artificially increase [Ca ²⁺]i levels. These novel findings confirm that Slo-1 is a direct target of emodepside^[3]. In Vivo: Emodepside interferes with signaling at the neuromuscular junction on the body-wall muscles, pharynx and egg-laying muscles and thus inhibits three important physiological functions: locomotion, feeding and reproduction^[4].