Keywords: propylene glycol, lorazepam, phenytoin (PubMed Search)
Ever have that alcholic who requires lorazapam doses that start to approach 10mg? 20mg? or even higher. The next step is usually a lorazepam infusion and then send them to the ICU. In the ICU, the patient develops an unexplained anion gap lactic acidosis.
Check a Lactate - lorazepam has 80% propylene glycol (PG). PG is metabolized to lactate which can accumulate when a lorazepam infusion at an elevated dose is running constantly. Hypotension, bradycardia and even other EKG changes have been reported. Simply discontinue the infusion and assess your acid-base status.
Other IV meds that contain PG:
lorazepam - 80% PG
Phenytoin - 40% PG
Phenobarbital - 67.8%
Diazepam - 40% PG