Two patients were hospitalized with acute kidney injury (AKI) after using synthetic marijuana, according to case reports presented here, and the agent doesn’t always show up on drug screening.
Synthetic cannabinoids, also known as Spice, K2, DOA, and Spice Gold, among other names, are a mix of natural herbs that have been sprayed with chemicals that can mimic the psychoactive effects of natural marijuana from tetrahydrocannabinol, explained Manuel Fernandez Palmer, MD, of the Methodist Dallas Medical Center, and colleagues in a poster presentation at the National Kidney Foundation spring clinical meeting.
But they have common side effects like vomiting, agitation, hallucinations, and even seizures, they added. Fernandez Palmer and colleagues reported on a 19-year-old Mexican-American man who was brought to the medical center after being found unconscious in a parking lot. A urine toxicology report came back negative, and much of the initial exam as unremarkable, the authors said.
The initial lab results revealed that the patient had a blood urea nitrogen (BUN) of 12 mg/dL, a creatinine level of 1.35 mg/dL, and “a high anion gap metabolic acidosis with elevated lactic acid levels,” they wrote.
On the second day of his admission, the patient became anuric; his parents continued to deny that he’d had any exposure to nephrotoxic agents. A workup including urinalysis showed no glomerular disease. A renal sonogram showed normal-sized kidneys.
“We tried to find what was causing this kidney injury, but everything came back negative,” Fernandez Palmer told MedPage Today.
The authors found signs of possible acute tubular necrosis (ATN), and the patient was given hemodialysis on day 3. After several treatments, the patient began to stabilize. At discharge, the patient’s renal function returned to normal with creatinine levels of 0.98 mg/dL, they wrote.
Fernandez Palmer said he found a case report that suggested a link between synthetic marijuana and AKI, and when he approached the patient’s parents about it, they said that their son had been using Spice.
The authors noted that the same patient had been admitted twice during the previous 2 months with synthetic cannabinoid overdose and concomitant AKI. Each time, the patient was discharged with normal creatinine levels, supporting their suspicions that synthetic cannabinoids was responsible for AKI in this patient.
“Widespread use of these agents has increased in the last couple of years, mainly because it is a legal substance that is marketed as ‘safe,’ but also because it is not detected on urine toxicology screens,” Fernandez Palmer and colleagues wrote.
They theorized that some of the compounds in synthetic cannabinoids may have heavy metal residues that have been found in other studies to harm the kidney, but the mechanism of action is still unclear.
“Definitive proof is still lacking,” Fernandez Palmer said. “I think it should be studied in more detail — identifying the chemical that is causing this or seeing what the chemical does to the body hasn’t really been studied yet.”
The CDC reported a possible link between AKI and synthetic marijuana in 2013, but the product remains popular and easy to access.
“You can buy it in a gas station,” Fernandez Palmer pointed out.
They recommended that clinicians ask about exposure to synthetic cannabinoids during an intake of social history, particularly if the patient presents with AKI without an apparent cause.
In the second case report, Chyi Chyi Chong, MD, of Louisiana State University in Shreveport, and colleagues described a 22-year-old patient who presented with nausea, vomiting, and abdominal pain, but with no medical history. He was unarousable, required emergency intubation, and was admitted to the intensive care unit.
The symptoms started about 10 days after he had smoked synthetic marijuana, Chong’s group wrote. The patient had smoked marijuana since he was 14, Chong added, and had a recent 4-year use of synthetic marijuana.
His urine drug test results were negative. A chest CT chest showed pneumomediastinum, bilateral pneumothoraces, and pneumorachis (free intraspinal air). Also, lab results revealed a white blood cell count of 30K/uL, BUN 192mg/dL, and creatinine 16.8mg/dL.
After a trio of dialysis sessions, his urine output and renal functions gradually improved. While on oxygen, the pneumothoraces resolved. Finally, his creatinine was 2.8mg/dL on the day of discharge, the authors reported.
“When a healthy twentysomething patient presents with renal failure, I think we should ask if something is going on,” Chong said. “Synthetic marijuana, for this age group, is very popular. It’s something that we often miss, and we should be asking about drug use anyway.”
Published: 03.30.2015. by Parker Brown
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