In this episode I’ll:
1. Discuss an article about the use of ketamine for agitation in patients with schizophrenia
2. Answer the drug information question “Can oral and IV vancomycin be given at the same time to the same patient?”
Psychiatric Outcomes of Patients With Severe Agitation Following Administration of Prehospital Ketamine
Lead author: Jacob Lebin
Published in Academic Emergency Medicine March 2019
Ketamine’s unique dissociative mechanism of action, analgesic effects, and side effect profile are attractive to many clinicians for a variety of indications. With high rates of efficacy and IM administration, ketamine is an ideal agent to manage patients with severe agitation in many settings, including the prehospital setting.
A theoretical precaution to ketamine use is in patients with a history of schizophrenia out of concern that the drug will exacerbate the psychotic symptoms associated with schizophrenia. This presents a dilemma for the use of ketamine in prehospital settings for treating severe agitation as medical history is often not available and/or patients with schizophrenia may be severely agitated and require sedation.
The authors of this study sought to describe psychiatric outcomes in patients who receive prehospital ketamine for severe agitation.
The study was composed of a retrospective cohort from two tertiary academic medical centers. Chart review was conducted to identify patients who required prehospital sedation for severe agitation and received either intramuscular (IM) versus intravenous (IV) ketamine or IM versus IV benzodiazepine.
The primary outcome was psychiatric inpatient admission with secondary outcomes including ED psychiatric evaluation and nonpsychiatric inpatient admission.
There were 141 patient encounters that met the inclusion criteria and 59 of these received prehospital ketamine. Although the ketamine group had a numerically higher number of patients who required psychiatric inpatient admission (6.8% vs. 2.4%) this was not a statistically significant difference.
Patients with schizophrenia who received ketamine vs benzodiazepine did not require psychiatric inpatient admission or ED psychiatric evaluation at significantly higher rates. Unfortunately, this subgroup of patients was very small at just 16.
One significant difference between groups was the reason for nonpsychiatric admission; the benzodiazepine group had a 63% incidence of requiring admission due to intubation vs just 4% for the ketamine group (p < 0.001).
The authors concluded:
Administration of prehospital ketamine for severe agitation was not associated with an increase in the rate of psychiatric evaluation in the emergency department or psychiatric inpatient admission when compared with benzodiazepine treatment, regardless of the patient’s psychiatric history.
Even though the subgroup of patients with schizophrenia who received ketamine was small, this study does provide important information on this group of patients. A reasonable argument may be made that this study justifies ketamine in the prehospital setting without regard to the patient’s history of schizophrenia. However, I would not extrapolate the results to other clinical scenarios. For analgesia or sedation for indications other than acute agitation in patients with schizophrenia, I would still look for alternative medications to ketamine.
Drug information question
Q: Can oral and IV vancomycin be given at the same time to the same patient?
A: Yes, when a patient has two appropriate indications, such as C diff infection and MRSA pneumonia, it is appropriate for the same patient to receive oral and IV vancomycin at the same time. Dual treatment would be necessary because IV vancomycin does not get to the colon and enteral vancomycin is not absorbed systemically.
When using this combination, be alert for the chance of error with new practitioners (pharmacists and nurses) who may not be aware of the need for both forms of vancomycin to be given together. I have encountered scenarios where a practitioner assumed that an order for oral vancomycin meant they should discontinue an order for IV vancomycin, resulting in erroneously discontinuing important therapy.
Staff education of the appropriateness of this combination should be considered to avoid confusion that could lead to a medication error.
You can get a detailed and referenced pdf on the use of ketamine in critical care by going to my free download section at pharmacyjoe.com/free (it’s download #13).
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.