Neuromuscular blocking property of minocycline in the rabbit

The neuromuscular blocking property of minocycline hydrochloride (MNC) was studied in 12 rabbits. In 2 of 6 animals, MNC, 60-160 mg/kg, alone caused a decrease in twitch tension. During partial neuromuscular blockade produced by a continuous infusion of pancuronium, the intravenous administration of MNC, 20--60 mg/kg, resulted in a dose-dependent decrease in twitch tension in 6 animals. MNC-induced or combined MNC-pancuronium-induced neuromuscular blockade was antagonized by calcium or by neostigmine.