Clindamycin enhances a nondepolarizing neuromuscular blockade

Area of Science:

• Pharmacology
• Neuroscience
• Anesthesiology

Background:

• Clindamycin is an antibiotic used for serious infections.
• Nondepolarizing neuromuscular blocking agents are used during surgery.
• Interactions between antibiotics and neuromuscular blockers require investigation.

Purpose of the Study:

• To investigate the effects of clindamycin on neuromuscular blockade.
• To determine if clindamycin potentiates or antagonizes neuromuscular blockers like d-tubocurarine and pancuronium.
• To assess the efficacy of neostigmine and calcium in antagonizing clindamycin-induced neuromuscular blockade.

Main Methods:

• In vitro guinea pig lumbrical muscle-nerve preparation.
• Administration of varying concentrations of clindamycin alone and in combination with d-tubocurarine or pancuronium.
• Measurement of twitch tension to assess neuromuscular blockade.
• Evaluation of antagonism by neostigmine and calcium.

Main Results:

• Clindamycin initially increased twitch tension, followed by a decrease at higher concentrations (180-240 mug/ml).
• Neostigmine or calcium partially antagonized clindamycin-induced blockade when twitch tension was depressed by 15-20%.
• Clindamycin (40 mug/ml) potentiated neuromuscular blockade induced by d-tubocurarine or pancuronium.
• Recommended therapeutic plasma concentrations of clindamycin (10-40 mug/ml) fall within the range that potentiates blockade.

Conclusions:

• Clindamycin administration may augment nondepolarizing neuromuscular blockade in humans.
• Antagonism of clindamycin-enhanced blockade by neostigmine and calcium may be incomplete.
• Caution is advised when administering clindamycin concurrently with nondepolarizing neuromuscular blocking agents.