A Pharmacokinetic Analysis of Hemodialysis for Metformin-Associated Lactic Acidosis

OBJECTIVE: Although hemodialysis is recommended for patients with severe metformin-associated lactic acidosis (MALA), the amount of metformin removed by hemodialysis is poorly documented. We analyzed endogenous clearance and hemodialysis clearance in a patient with MALA. METHODS: A 62-year-old man with a history of type II diabetes mellitus presented after several days of vomiting and diarrhea and was found to have acute kidney injury (AKI) and severe acidemia. Initial serum metformin concentration was 315.34 μmol/L (40.73 μg/mL) (typical therapeutic concentrations 1-2 μg/mL). He underwent 6 h of hemodialysis. We collected hourly whole blood, serum, urine, and dialysate metformin concentrations. Blood, urine, and dialysate samples were analyzed, and clearances were determined using standard pharmacokinetic calculations. RESULTS: The total amount of metformin removed by 6 h of hemodialysis was 888 mg, approximately equivalent to one therapeutic dose. Approximately 142 mg of metformin was cleared in the urine during this time. His acid-base status and creatinine improved over the following days. No further hemodialysis was required. CONCLUSION: We report a case of MALA likely secondary to AKI and severe volume depletion. The patient improved with supportive care, sodium bicarbonate, and hemodialysis. Analysis of whole blood, serum, urine, and dialysate concentrations showed limited efficacy of hemodialysis in the removal of metformin from blood, contrary to previously published data. Despite evidence of acute kidney injury, a relatively large amount of metformin was eliminated in the urine while the patient was undergoing hemodialysis. These data suggest that clinical improvement is likely due to factors besides removal of metformin

Jamaican Susumber Berry Poisoning Mimicking Acute Stroke.

Background: Stroke mimics are non-vascular conditions that present with acute focal neurological deficits, simulating an acute ischemic stroke. Susumber berry (SB) toxicity is a rare cause of stroke mimic with limited case reports available in the literature. Objectives: We report four new cases of SB toxicity presenting as stroke mimic, and we performed a systematic review. Methods: MEDLINE/EMBASE/WoS were searched for "susumber berries," "susumber," or "solanum torvum." Results: 531 abstracts were screened after removal of duplicates; 5 articles and 2 conference abstracts were selected describing 13 patients. A total of 17 patients who ingested SB and became ill were identified, including our 4 patients. All but one presented with acute neurologic manifestation; 16 (94%) presented with dysarthria, 16 (94%) with unstable gait, 8 (47%) with nystagmus/gaze deviation, 10 (59%) with blurry vision, and 5 (29%) with autonomic symptoms. Six (35%) required ICU admission, and 3 (18%) were intubated. Fourteen (82%) had a rapid complete recovery, and 3 were hospitalized up to 1 month. Conclusions: SB toxicity can cause neurological symptoms that mimic an acute stroke typically with a posterior circulation symptom complex. Altered SB toxins (from post-harvest stressors or temperature changes) might stimulate muscarinic/nicotinic cholinergic receptors or inhibit acetylcholinesterase, causing gastrointestinal, neurological, and autonomic symptoms. In cases of multiple patients presenting simultaneously to the ED with stroke-like symptoms or when stroke-like symptoms fail to localize, a toxicological etiology (such as SB toxicity) should be considered.VoRSUNY DownstatePsychiatry and Behavioral SciencesNeurologyN/