The US Food and Drug Administration (FDA) is investigating two unexplained deaths in patients who received an intramuscular injection of the antipsychotic drug Zyprexa Relprevv (olanzapine pamoate).
The patients died 3-4 days after receiving an appropriate dose of the drug, well after the 3-hour post-injection monitoring period required under the Zyprexa Relprevv Risk Evaluation and Mitigation Strategy (REMS).
Both patients were found to have very high olanzapine blood levels after death. High doses of olanzapine can cause delirium, cardiopulmonary arrest, cardiac arrhythmias, and reduced level of consciousness ranging from sedation to coma.
FDA is providing this information to healthcare professionals while it continues its investigation.
If therapy with Zyprexa Relprevv is started or continued in patients, healthcare professionals should follow the REMS requirements and drug label recommendations.
Patients and caregivers should talk to their healthcare professional(s) about any questions or concerns.
Under the REMS, patients are required to receive the Zyprexa Relprevv injection at a REMS-certified health care facility, to be continuously monitored at the facility for at least 3 hours following an injection, and to be accompanied home from the facility.
The Zyprexa Relprevv label contains warnings about the risk of post-injection delirium sedation syndrome (PDSS), a serious condition in which the drug enters the blood too fast following an intramuscular injection, causing greatly elevated blood levels with marked sedation (possibly including coma) and/or delirium.
In the clinical trials supporting the approval of Zyprexa Relprevv, cases of PDSS were observed within 3 hours after administration of Zyprexa Relprevv, but there were no deaths due to PDSS.
These two patients died 3-4 days after receiving an appropriate dose of the drug, and it is not clear whether they died from PDSS.
At this time, FDA is continuing to evaluate these deaths and will provide an update when more information is available.