A patient shows up at the emergency department for treatment and says he’s on medical marijuana. How should the patient care team handle the situation?
An important first step in patient management is to perform a thorough medication reconciliation. That includes encouraging patients to provide information about all the products they take, including medical cannabis, according to Christine Roussel, PharmD, BCOP, assistant director of pharmacy at Doylestown Hospital in Doylestown, Pa.
“Cannabis is a medication,” she said. “Just like all the other prescription and over-the-counter therapies the patient is taking, it has pharmacologic properties, side effects, and drug interactions.”
Next find out if the patient had obtained the drug through a state medical marijuana program and determine which form of the plant the patient is taking—oral capsule, oral liquid, inhalation product, topical product, or vaginal or rectal suppository.
If the patient has documentation that they’re taking marijuana in compliance with a state-run program, verify the information and then decide if the therapy should continue during hospitalization. That decision is based on several factors, including how medical cannabis is helping to control disease symptoms, how it is modifying a disease, and how it interacts with the other drugs, including medications that treat HIV, cancer, and epilepsy.
“There are times when discontinuing a medical cannabis product could be a greater risk than continuing it, such as when it is impacting the metabolism of other medications the patient is taking or controlling diseases such as certain seizure disorders,” said Dr. Roussel. “But there are also cases when it should be discontinued, such as acute myocardial infarction or visible intoxication.”
Dr. Roussel pointed out that cannabis has over 70 different cannabinoids, and each has an individual degree of pharmacologic activity. “We know more about the physiologic effects of some cannabinoids, such as tetrahydrocannabinol (THC) or cannabidiol (CBD),” she said. “But there are more chemicals we don’t know as much about, such as cannabigerol (CBG), which is known to affect the gastrointestinal system, and cannabinol (CBN), which can be very sedating.”
Most state-run medical marijuana programs require that product labels note THC and CBD content in milligrams or a ratio amount. “That’s very important, because the two chemicals have distinct physiologic effects and drug interactions are often more clinically significant with CBD than with THC due to higher doses of CBD,” said Dr. Roussel.
As was done at Doylestown Hospital, more institutions are adding medical cannabis to drug dictionaries, which list every FDA-approved medication. This allows healthcare providers to accurately document what products a patient is taking at home. “It’s a manual entry for medication reconciliation, but more institutions are recognizing the need to do this for medical cannabis, including documenting the route the product is taken as well as any available information on the THC and CBD content,” said Dr. Roussel.
Pharmacists should present medical cannabis to their hospitals’ pharmacy and therapeutic committees, just like they would for any other drug, advised Dr. Roussel. “This group can then decide how to proceed with patient care,” she added. “But regardless of the management approach, prescribers need to be educated about medical cannabis.”
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