Depression of transmitter release and postjunctional sensitivity during neuromuscular block produced by antibiotics

Y. N. Singh, I. G. Marshall, A. L. Harvey

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24 Citations (Scopus)


In an attempt to elucidate the mechanisms by which antibiotics induce muscle paralysis, the effects of streptomycin, lincomycin, polymyxin B and clindamycin were investigated in the mouse phrenic nerve-hemidiaphragm preparation. Streptomycin resembled magnesium in reducing miniature endplate potential (m.e.p.p.) amplitude and frequency, whereas lincomycin, clindamycin and polymyxin B resembled tubocurarine in abolishing m.e.p.p. Endplate potential (e.p.p.) quantal content in streptomycin was 9, similar to that found in magnesium (5), whereas quantal contents in lincomycin (42), polymyxin B (37) and clindamycin (32) lay between values found in magnesium and in tubocurarine (123). Control quantal content was 152. In the presence of a mixture of magnesium and tubocurarine, no m.e.p.p. could be recorded and quantal content was 39. Blockade of twitches by a mixture of magnesium and tubocurarine was more successfully reversed by a mixture of calcium and neostigmine (to 70% of control) than by either calcium (to 49% of control) or by neostigmine (to 30% of control) alone. Lincomycin- and polymyxin B-induced blockades were poorly reversed by a mixture of the two reversal agents. It is concluded that streptomycin has a magnesium-like action whereas lincomycin, clindamycin and polymyxin B have relatively greater postjunctional and less prejunctional blocking activities. However, the effects of lincomycin and polymyxin B were not analogous to those of a tubocurarine-magnesium mixture, and their mechanism of action is still unclear. Clindamycin produced effects compatible with local anaesthetic activity.

Original languageEnglish
Pages (from-to)1027-1033
Number of pages7
JournalBritish Journal of Anaesthesia
Issue number11
Publication statusPublished - 1 Nov 1979


  • neuromuscular block
  • antibiotic agent
  • clindamycin
  • lincomycin
  • neostigmine
  • neurotransmitter
  • polymyxin
  • streptomycin
  • tubocurarine chloride
  • drug comparison
  • drug efficacy
  • drug interaction
  • in vitro study
  • neuromuscular blocking
  • peripheral nervous system

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