Which antibiotic is a member of the lincosamines and may prolong nondepolarizing neuromuscular blockade?

Which antibiotic is a member of the lincosamines and may prolong nondepolarizing neuromuscular blockade?

• A. Gentamicin
• B. Clindamycin
• C. Metronidazole
• D. Tobramycin

Answer: (B)

Nondepolarizing neuromuscular blockers rely on acetylcholine to activate the motor endplate. Some antibiotics can enhance this blockade, making paralysis longer. Clindamycin, a lincosamide, is known to potentiate nondepolarizing neuromuscular blockade, which can prolong the duration of paralysis and delay recovery from anesthesia. This effect is thought to involve reduced acetylcholine release at the neuromuscular junction or altered postsynaptic sensitivity, amplifying the NM blocker’s action. The other antibiotics listed belong to different classes and do not share this lincosamide-related interaction (and while aminoglycosides can prolong blockade, they are not lincosamides, and metronidazole has no such effect). Thus, the correct choice is clindamycin.

Nondepolarizing neuromuscular blockers rely on acetylcholine to activate the motor endplate. Some antibiotics can enhance this blockade, making paralysis longer. Clindamycin, a lincosamide, is known to potentiate nondepolarizing neuromuscular blockade, which can prolong the duration of paralysis and delay recovery from anesthesia. This effect is thought to involve reduced acetylcholine release at the neuromuscular junction or altered postsynaptic sensitivity, amplifying the NM blocker’s action. The other antibiotics listed belong to different classes and do not share this lincosamide-related interaction (and while aminoglycosides can prolong blockade, they are not lincosamides, and metronidazole has no such effect). Thus, the correct choice is clindamycin.