ABSTRACT
Levorphanol is injected intramuscularly or subcutaneously for the symptomatic management of pain disorders. Although the injectable formulation may be injected intravenously, intravenous pharmacotherapy generally is reserved for use as a supplement to general anesthesia. Levorphanol primarily elicits its analgesic, CNS depressant, and respiratory depressant actions by binding to the endorphin receptors in the CNS. Levorphanol appears to be well absorbed following intramuscular injection or oral ingestion. Peak blood concentrations are achieved within 1 hour after oral ingestion. Levorphanol is addicting and habituating. Long-term levorphanol pharmacotherapy, or regular personal use, may result in addiction and habituation. Levorphanol pharmacotherapy commonly has been associated with dizziness, nausea, and vomiting. Signs and symptoms of levorphanol overdosage are similar to the signs and symptoms associated with other opiate analgesic overdosage.
