Enmetines and dehydroemetine

Emetine and dehydroemetine inhibit protein synthesis by blocking ribosomal movement along messenger RNA and blocking chain elongation. These drugs are used parenterally (subcutaneously or intramuscularly) as backup drugs for treatment of severe intestinal or hepatic amebiasis together with a luminal agent in hospitalized patients. The drugs may cause severe toxicity, including gastrointestinal distress, muscle weakness, and cardiovascular dysfunction (arrhythmias and congestive heart failure), neuromuscular weakness, dizziness, rashes. The drugs are restricted to use in severe amebiasis when metronidazole cannot be used.Intramuscular injection is the preferred route. Emetine is concentrated in the liver, where it persists for a month after a single dose. It is slowly metabolized and excreted, and it can accumulate. Its half-life in plasma is 5 days. The use of these ipecac alkaloids is limited by their toxicities (dehydroemetine is less toxic than emetine), and close clinical observation is necessary when these drugs are administered. They should not be taken for more than 5 days.