Brands, Medical Use, Clinical Data
- Analgesics, Opioid
Brands / Synonyms
Antalgin; Aromarone; Cetarin; Dea No. 9220; Dea No. 9733; Dromoran; Lemoran; Levo-Dromoran; Levorfanol [Inn-Spanish]; Levorfanolo [Dcit]; Levorphan; Levorphanal; Levorphanol; Levorphanol Dl-Form; Levorphanol Tartrate; Levorphanolum [Inn-Latin]; Methorfinan [Czech]; Methorphinan; Orphan; Racemethorphanum; Racemic Dromoran; Racemorfano [Inn-Spanish]; Racemorphan; Racemorphan [Ban:Inn]; Racemorphane [Inn-French]; Racemorphanum [Inn-Latin]
For the management of moderate to severe pain or as a preoperative medication where an opioid analgesic is appropriate
Levorphanol is a potent synthetic opioid analgesic indicated for the management of moderate to severe pain or as a preoperative medication where an opioid analgesic is appropriate. Levorphanol is similar to morphine in its actions, however it is up to 8 times more potent than morphine. Levorphanol produces a degree of respiratory depression similar to that produced by morphine at equianalgesic doses, and like many mu-opioid drugs, levorphanol produces euphoria or has a positive effect on mood in many individuals.
Mechanism of Action
Like other mu-agonist opioids it is believed to act at receptors in the periventricular and periaqueductal gray matter in both the brain and spinal cord to alter the transmission and perception of pain.
Levorphanol is well absorbed after PO administration with peak plasma concentrations occurring approximately 1 hour after dosing.
LD50=150 mg/kg (orally in rats). Signs of overdose include nausea, emesis, dizziness, respiratory depression, hypotension, urinary retention, cardiac arrhythmias, allergic reactions, skin rash, and uticaria.
Biotrnasformation / Drug Metabolism
Levorphanol is extensively metabolized in the liver and is eliminated as the glucuronide metabolite.
Levo-Dromoran is contraindicated in patients hypersensitive to levorphanol tartrate.
Interactions with Other CNS Agents: Concurrent use of Levo-Dromoran with
all central nervous system depressants (eg, alcohol, sedatives, hypnotics, other opioids, general anesthetics,
barbiturates, tricyclic antidepressants, phenothiazines, tranquilizers, skeletal muscle relaxants and antihistamines)
may result in additive central nervous system depressant effects. Respiratory depression, hypotension, and profound
sedation or coma may occur. When such combined therapy is contemplated, the dose of one or both agents should be
reduced. Although no interaction between MAO inhibitors and Levo-Dromoran has been observed, it is not recommended
for use with MAO inhibitors.
Most cases of serious or fatal adverse events involving Levo-Dromoran reported to the manufacturer or the FDA have
involved either the administration of large initial doses or too frequent doses of the drug to nonopioid tolerant
patients, or the simultaneous administration of levorphanol with other drugs affecting respiration. The initial dose
of levorphanol should be reduced by approximately 50% or more when it is given to patients along with another drug
Interactions with Mixed Agonist/Antagonist Opioid Analgesics: Agonist/antagonist analgesics
(eg, pentazocine, nalbuphine, butorphanol, dezocine and buprenorphine) should NOT be administered to a patient who
has received or is receiving a course of therapy with a pure agonist opioid analgesic such as Levo-Dromoran. In
opioid-dependent patients, mixed agonist/antagonist analgesics may precipitate withdrawal symptoms.