Serotonin Syndrome after Lithium Add-on Medication to Paroxetine

Abstract

A 59-year-old female patient was hospitalized on account of a depressive episode in the course of a long-standing bipolar disorder. On a combination of lithium (400 mg/day) and paroxetine (30 mg/day) she developed symptoms of shivering, high-frequency tremor of the upper and lower limbs, skin flush in the face, agitation, and slight impairment of mental focusing, suggestive of a serotonin syndrome. At this stage serum lithium and paroxetine levels were 0.63 mmol/l, and 693 ng/ml, respectively; the latter was six times higher than the upper concentrations seen in patients on this dosage of the drug. Consequently, the dosage of paroxetine was reduced to 10 mg/day, and lithium was continued. This regimen resulted in a steady-state paroxetine serum level of 390 ng/ml. The patient became symptom-free and the depressive episode attenuated, thus enabling us to discharge the patient.

Lithium inhibits tryptophan catabolism via the inflammation-induced kynurenine pathway in human microglia

“…Co-prescription of lithium and serotonergic antidepressants heightens the risk of serotonin toxicity (Adan-Manes et al, 2006;Prakash et al, 2017;Sobanski et al, 1997).…”

Serotonin syndrome

“…Serotonin toxicity has been reported following lithium augmentation in non-responders to conventional antidepressant drugs such as venlafaxine, trazodone and SSRIs. [23][24][25] Bupropion, although initially developed as an antidepressant, is now used in the UK primarily as an aid to quitting smoking. It has mild serotonergic activity and serotonin toxicity has been reported when it has been used in combination with an SSRI.…”

Syndrome sérotoninergique - Approche analytique en Toxicologie Hospitalière

“…Des syndromes sérotoninergiques ont été rapportés après des surdosages par sertraline, fluoxetine (4), venlafaxine (5), IMAO non sélectifs (4), ISRS ou MAO associés avec le lithium (le lithium facilitant la transmission séro-toninergique) (6,7,8), les morphiniques dont plus récem-ment le Tramadol (9), et les triptans (10).…”