A Case Report on Serotonin Syndrome in a Patient With Parkinson’s Disease: Diagnostic and Management Challenges

Abstract

Patients with Parkinson's disease are often at risk of polypharmacy, which can lead to serious medication side effects and interactions. Serotonin syndrome (SS) can develop in this patient population due to a possible drug-drug interaction between antidepressants and antiparkinson drugs with serotoninergic activity. On the other hand, these patients are also at risk of malignant syndrome (MS) secondary to dopaminergic medication withdrawal. In this case report, we present a 71-year-old female with Parkinson's disease who developed symptoms suggestive of SS. The patient was admitted to the medical intensive care unit at the Institute for Pulmonary Diseases of Vojvodina in the Republic of Serbia due to impaired consciousness and a previously witnessed cardiorespiratory arrest. Her chronic antiparkinson medication regimen consisted of levodopa, benserazide, entacapone, ropinirole, and rasagiline. Furthermore, she had been prescribed duloxetine for a remote history of depression, which she had only been taking intermittently. Several days before admission, however, the patient started taking duloxetine again due to low mood. Upon admission, laboratory tests revealed leukocytosis with neutrophilia, elevated C-reactive protein, procalcitonin, lactate, urea, and creatinine. Serum creatine kinase (CK) levels were also elevated at 1250 U/L. Six hours after admission to the ICU, the patient developed hyperthermia, hyperreflexia, spontaneous myoclonus, and tremors. Her CK levels continued to rise, reaching 6900 U/L, and her renal function worsened. Due to the possibility of either SS or MS, external cooling measures with frozen gel packs were administered, resulting in the patient's stabilization over a few hours. Further, serotoninergic medication (rasagiline and duloxetine) was discontinued. On the fifth day of hospitalization, a head CT showed signs of cytotoxic edema. On the 11th day, the patient became hemodynamically unstable and passed away despite all adequate resuscitative measures.The purpose of this case report is to raise awareness of possible SS in patients taking monoamine oxidase-B (MAO-B) inhibitors such as rasagiline. Clinicians should have a high index of suspicion for this complication, especially in patients who are treated for comorbid depression with serotoninergic drugs. Furthermore, we emphasize the importance of correctly differentiating SS from MS, which are both risks for patients with Parkinson's disease. A correct approach to these patients is of utmost importance for adequate management and optimal outcomes.

Serotonergic Medication Error: A Case Report of Serotonin Syndrome

“…A past case report described SS in a patient taking MAO-B inhibitors while taking antidepressants intermittently [ 8 ]. Another case discussed a patient taking a combination of carbidopa-levodopa and sertraline, leading to SS [ 9 ]. There have been even fewer cases of reported SSRI-induced parkinsonism [ 9 - 11 ].…”

“…Another case discussed a patient taking a combination of carbidopa-levodopa and sertraline, leading to SS [ 9 ]. There have been even fewer cases of reported SSRI-induced parkinsonism [ 9 - 11 ]. A case report from India by Dixit et al described a case of SSRI-induced irreversible parkinsonism secondary to inhibitory effects of serotonin on dopamine neurotransmission, which may have altered functioning in the striatum [ 11 ].…”

Autophagy‐associated non‐coding RNAs: Unraveling their impact on Parkinson's disease pathogenesis

“…13 Pramipexole and Rasagiline carry a risk of serotonin syndrome due to potential interactions between antidepressants and anti-PD with serotoninergic activity, emphasizing the importance of monitoring for this adverse effect in clinical practice. 14 Currently, available therapies provide relief for symptoms in some groups of patients, but they do not halt the advancement of the illness or undo underlying impairments. Understanding the cause and evolution of diseases is essential for the advancement of diagnostic methods and therapies for PD.…”

“…Moreover, it can induce drowsiness and pose an elevated risk of seizures, especially in patients with PD who have concurrent vitamin B6 deficiency 13 . Pramipexole and Rasagiline carry a risk of serotonin syndrome due to potential interactions between antidepressants and anti‐PD with serotoninergic activity, emphasizing the importance of monitoring for this adverse effect in clinical practice 14 . Currently, available therapies provide relief for symptoms in some groups of patients, but they do not halt the advancement of the illness or undo underlying impairments.…”