Lithium toxicity with prolonged neurologic sequelae following sleeve gastrectomy

Abstract

Rationale: Lithium is the first-line medication for bipolar disorder, given a narrow therapeutic window of 0.8 to 1.2 mEq/L. Change of lithium pharmacokinetics following bariatric surgery may lead to lithium toxicity, which is particularly concerned. Patient concerns: We presented a 39-year-old man with morbid obesity and bipolar affective disorder for 20 years, who was treated with lithium. He developed serious lithium toxicity following sleeve gastrectomy and prolonged neurologic sequelae. Diagnoses: He suffered from persistent watery diarrhea, general weakness, and then drowsy consciousness. Lithium level was checked immediately to be 3.42 mEq/L and lithium toxicity was diagnosed. Interventions: After 3 courses of hemodialysis, his serum lithium level subsequently declined to 0.63 mEq/L, while his consciousness returned normal. Lithium was replaced by lamotrigine. Outcomes: The patient was discharged thirty-five days after admission, while his serum lithium declined to 0.06 mEq/L. Neurologic sequelae were noted by muscle weakness and pain sensation in both feet. The nerve conduction test revealed sensorimotor polyneuropathy with conduction block. He was advised to keep a passive range of motion exercise. Lessons: Although the consensus guideline remains lacking, our report reviewed cases of relevance in the literature and highlighted the awareness of the potential risk of lithium toxicity following bariatric surgery. We suggest close monitoring of the lithium levels and perhaps a dosage adjustment for the postoperative period.

Lithium toxicity following Roux-en-Y gastric bypass: Mini review and illustrative case

“…Toxic Li levels result in neurotoxicity, ranging from temporary altered mental status to permanent neurologic sequelae such as cerebellar impairment, brain stem syndromes, and peripheral neuropathies. 16 This is explained by Li's extensive diffusion within the central and peripheral nervous systems following its thorough absorption. 16 , 18 Mr A developed altered mental status, slurred speech, and an unsteady gait owing to Li toxicity.…”

“… 16 This is explained by Li's extensive diffusion within the central and peripheral nervous systems following its thorough absorption. 16 , 18 Mr A developed altered mental status, slurred speech, and an unsteady gait owing to Li toxicity. He received fluids and appropriate treatment.…”

How bariatric surgery affects psychotropic drug absorption

“…As illustrated in the Table [6][7][8][9][10][11][12][13][14][15][16][17][18][19] (page 42), each type of bariatric surgery may impact drug absorption differently depending on the mechanism by which the stomach is restricted. Drug malabsorption is a concern for clinicians with patients who have undergone bariatric surgery.…”

“…Small pouch is created from top portion of stomach First portion of small intestine is divided and connected to newly created small stomach pouch Decrease in effective surface area for drug absorption 9 Increase in gastric pH 10 Decrease in gastric and distribution volume 10 Shorter absorption time 10 Shortened passage through intestine 10 Reduction in drug concentration absorbed 10 Reduced gastric mixing limiting drug disintegration 7 SSRI AUC levels 1 month after surgery drop and return to baseline for most patients by 6 months 11 No change in AUC, C max , or T max for venlafaxine 12 Potentially less significant reductions in bioavailability of SNRIs than SSRIs due to solubility characteristics 8 Sleeve gastrectomy (vertical sleeve gastrectomy; gastric sleeve procedure) 13 Removes approximately 80% of stomach 6 Performed by making 5 to 6 small incisions in the abdomen; procedure completed laparoscopically 14 Procedure results in a narrow, tubular stomach pouch or "sleeve" 6 Reduces amount of food that can be consumed due to smaller volume of stomach pouch 6 Increased transit time of drugs 15 Increased gastric pH leads to decreased absorption of weakly acidic drugs and increased absorption of basic drugs 16 Reduced bioavailability with extended-release formulations 16 Reduced gastric mixing limits drug disintegration 7 Reduced gastric emptying (reduced rate but not reduced overall magnitude of drug absorption) 7 Lithium: decreased stomach surface area, impaired gastric motility, decreased gastric volume, and reduced GI transit time lead to potential decreased drug dissolution and absorption, which has a significant impact on serum drug levels 17,18 Laparoscopic adjustable gastric band Band is implanted around top part of stomach 6 Creates 2-compartment stomach with food only filling top portion upon eating 6 Reduces hunger, ultimately decreasing calorie intake 6 Least invasive weight loss surgery 6 No reduction in intestines or other absorptive surface area 6 Accelerated gastric emptying 15 Increased gastric pH 7…”