MEDizzy - A Russian youngster was prescribed erythromycin for a

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Protein Synthesis

A Russian youngster was prescribed erythromycin for a bacterial infection, but he developed hearing loss due to use of this drug. This occurred due to which of the following?

ExplanationOtotoxicity (hearing loss) occurs with a subset of antibiotics because, in addition to affecting prokaryotic ribosomes, the drugs also have an effect on mitochondrial ribosomes. Mitochondria contain their own DNA, RNA polymerase, and protein synthesizing apparatus (recall that it is thought that during evolution, bacteria invaded eukaryotic cells and formed a symbiotic relationship, with the bacteria eventually becoming the mitochondria), which is very similar to the prokaryotic apparatus. Thus, certain drugs will affect mitochondrial protein synthesis, and the effects seem to be greatest on those organs that have high energy needs (such as neuronal tissue). Erythromycin does not affect mitochondrial RNA synthesis or DNA replication. It does not affect the eardrum, nor does it increase neuronal signaling in the inner ear.