Neuromuscular blockade induced by flunarizine alone and in combination with pancuronium, suxamethonium or neomycin: studies in isolated rat phrenic-hemidiaphragm preparations.
The in vitro effects of flunarizine on indirectly- and directly-elicited contractions in rat phrenic-hemidiaphragm preparations were studied. The interactions of flunarizine with non-depolarizing and depolarizing neuromuscular blocking drugs (pancuronium and suxamethonium) and with an aminoglycoside antibiotic (neomycin) were also evaluated. Flunarizine induced a slowly developing concentration-dependent reduction of indirectly-elicited diaphragm twitch height, but only slightly reduced directly-elicited contractions. Flunarizine 1 and 5 mumol.l-1 produced a concentration-dependent enhancement of pancuronium-induced neuromuscular blockade, whereas suxamethonium blockade was significantly increased by flunarizine 5 mumols.l.-1 only. Moreover, both flunarizine 1 and 5 mumols.l-1 also increased the neuromuscular blockade induced by neomycin. In conclusion, flunarizine induced neuromuscular blockade and enhanced the effects of several neuromuscular blocking agents to varying degrees in vitro.
del Pozo
E
E
Department of Pharmacology and Anesthesiology, School of Medicine, University of Granada, Spain.
Baeyens
J M
JM
D000818:Animals; D003964:Diaphragm / Q000187:drug effects; D004347:Drug Interactions; D005260:Female; D005444:Flunarizine / Q000008:administration & dosage / Q000494:pharmacology; D066298:In Vitro Techniques; D009355:Neomycin / Q000008:administration & dosage / Q000494:pharmacology; D009466:Neuromuscular Blocking Agents / Q000008:administration & dosage; D009469:Neuromuscular Junction / Q000187:drug effects*; D010197:Pancuronium / Q000008:administration & dosage / Q000494:pharmacology; D010791:Phrenic Nerve / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D013390:Succinylcholine / Q000008:administration & dosage / Q000494:pharmacology
D009466:Neuromuscular Blocking Agents; D009355:Neomycin; D013390:Succinylcholine; D010197:Pancuronium; D005444:Flunarizine