Overlap of extrapyramidal syndrome subtypes in a 47-year-old patient with metastatic rectal cancer on prochlorperazine

Sir, Extrapyramidal side effects (EPS) are a well-known adverse effects of dopamine-receptor-blocking agents, including certain antipsychotics and antiemetics. A variety of movement phenotypes have been described along the EPS spectrum, including dystonia, akathisia, and parkinsonism, which occur more acutely, as well as more chronic manifestations of tardive akathisia and tardive dyskinesia.[1] Typically associated with antipsychotics with a strong D2 blocking, they have been observed in other classes of drugs as well.[2] We present a case where a male patient developed a rare concurrent presentation of these three symptoms together. In our case, the offending agent was Prochlorperazine. A 47-year-old male with a diagnosis of rectal cancer was hospitalized due to persistent pancreatitis, further complicated by a pancreatic mass. During his hospital stay, the patient experienced significant gastrointestinal symptoms, particularly nausea and vomiting. He was initially prescribed Ondansetron. However, the response was limited, prompting the substitution of Ondansetron with Prochlorperazine. He was administered 10 mg of Prochlorperazine every 6 h for 20 days. Within two weeks of starting the Prochlorperazine, the patient started developing side effects that were akin to extrapyramidal symptoms. Clinical presentation included a masked and emotionless face with a twitching movement on the upper lips, along with generalized tremulousness, and shuffling gait. There was also a flexed posture of the neck. Physical examination was significant for hypertonia (most pronounced in the neck muscles), cogwheel rigidity, slight dysdiadochokinesia, and masked facies. Fasciculation was evident in the tongue muscles. In terms of mental status, the patient had a muttering speech; however, his affect was largely stable, with a clear and coherent thought process, he did profess to a constant urge to move, and the interview was interrupted multiple times, with efforts of standing up and walking attempts. These correspond to symptoms of three extrapyramidal syndrome variants: acute dystonia, akathisia, and pseudo-parkinsonism. A thorough medication review was done where Prochlorperazine was found to be the only agent with anti-dopaminergic action; henceforth, it was promptly discontinued. Additionally, Benztropine IV was administered to counter the cholinergic hyperactivation emanating from the dopamine-blocking properties of Prochlorperazine, in conjunction with IV Lorazepam as a muscle relaxant, this caused a steady improvement in his clinical status. Two days later, the patient's motor tone was overall supple, no hypertonicity was noted, neck flexion was better, and shuffling gait had improved, as well as speech which became more spontaneous. The Benztropine 2 mg was switched from IV to a PO route upon discharge, and he took it for another week, as well as Propranolol 10 mg three times a day for Akathisia. Ultimately, his symptoms resolved without complications. This case emphasizes the importance of recognizing and managing EPS in patients receiving dopamine-receptor-blocking agents. Healthcare professionals should be aware of the potential for concurrent presentation of different EPS and promptly address these adverse effects to ensure optimal patient care. Individual risk factors should also be considered to minimize the occurrence of such complications in the future. Consent to participation This communication is based on the neuropsychiatric side effect from a prescribed chemotherapeutic regimen, all patient data was deidentified, and as this was an inpatient undergoing cancer treatment, consent was intrinsic and implied. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.