Baylor University Medical Center Proceedings July 2017 - 357

rier disruption and extravasation of ﬂuid into the brain parenchyma, producing vasogenic edema. PRES has been reported
after intrathecal morphine (6). The interaction of kratom with
μ-subtype opioid receptors could cause similar eﬀects leading to
PRES. Reversible cerebral vasoconstriction syndrome presents
with sudden-onset "thunder clap headache" due to vasospasm
of cerebral arteries. The diagnosis is clinical and supported with
cerebral angiography, which was not performed in this patient.
Our patient also ingested dextroamphetamine. Dextroamphetamine increases dopamine release into the presynaptic
neuron and increases the release of these monoamines into the
extraneuronal space. These eﬀects can increase blood pressure
(4). The patient's blood pressure was elevated upon presentation to his local emergency department, and this likely contributed to the development of his PRES (5, 7). It is possible
that kratom interacted with amphetamines to raise his blood
pressure or caused direct neurotoxicity and produced PRES.
Many individuals, including this patient, reporting adverse effects associated with kratom have also used other drugs (8).
Consequently, the pathogenesis of adverse eﬀects and toxicity
likely involves individual drug eﬀects, synergistic drug eﬀects,
and possible adulterants in unregulated products like kratom.
Fluoxetine and quetiapine have not been associated with PRES.
Three to ﬁve million Americans use kratom, with estimated
sales ﬁgures >$1 billion per year. Anwar et al reported that US
Poison Control Centers received 660 calls about exposure to
kratom between January 2010 and December 2015 (8). Many
of these individuals had taken kratom with other substances,
such as ethanol, benzodiazepines, narcotics, and acetaminophen. Users were mostly males (71.7%) with a median age of
28 years (range 2 months to 69 years). Symptoms and signs
included tachycardia (25.0%), agitation or irritability (23.8%),

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drowsiness (19.4%), nausea (14.7%), and hypertension
(11.7%). Kratom use has been associated with seizures, coma,
and several deaths (9). The Drug Enforcement Administration
opened an oﬃcial public comment period which ended on
December 1, 2016, for people to share their experiences using
kratom as a medical treatment and has asked the US Food and
Drug Administration to speed up scientiﬁc research.
1.

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Posterior reversible leukoencephalopathy syndrome after kratom ingestion

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