Case report:
A 24-year-old, single, gentleman, with a diagnosis of Carcinoma (CA) Rectum, underwent surgery followed by chemoradiotherapy at our center. While he was on adjuvant chemotherapy of 3rd cycle, with a combination of capecitabine and oxaliplatin (CapOX regimen as per the schedule- Oxaliplatin was given intravenously as an inpatient dose calculated as body weight followed by T.Capecitabine to be taken orally by the patient twice daily for 14 days in each cycle). The oncology team started observing changes in his behavior after 3rdday of the 3rd cycle of chemotherapy. He started having awake nights with a duration of sleep up to three hours per night and overfamiliarity with strangers. Despite resuming his routine work, he was found to be excessively involved in cycling, physical exercise, and studying which wasn’t his usual self. He started believing in various businesses investment while working at the grocery shop and would not be productive with customers due to excessive involvement in the tedious detailing of the transactions. During this week he was found to be overgrooming and expressing increased attraction towards female friends than his usual self. These behavioral changes resulted in frequent reminding by family members and eventually stopped him from attending the shop. Considering changes in his usual self and insistence by the family, he discontinued the oral capecitabine for 4 days this phenomenon was consistent with the self-dechallenge. By the end of 4th day, the family found that he could sleep well at night and he appeared calmer. The patient also noticed that he could fall asleep easily (sleep latency reduced to 10-15 minutes than 45-60 minutes earlier) and could feel fresh the next morning. Barring his biological functions, even after 5 days of stopping the capecitabine, he was over cheerful and overtalkative.
Patient-reported to oncology team and capecitabine was rechallenged as a part of treatment regimen while advising brief inpatient care to note the progression of affective symptoms. After rechallenging with the capecitabine, over the next two days, his behavioral problems worsened and he was referred to the Consultation-Liaison Psychiatry (CLP) team. After a detailed evaluation, it was evident that the patient had no significant past history of any psychiatric illness. A family history of psychiatric illness was suggestive of mood disorder (Depressive illness) in the first-degree relative. On Mental Status Examination (MSE) the findings revealed increased psychomotor activity, elated mood, high distractibility, and subjective reporting of racing thoughts. The score on Young’s Mania Rating Scale (YMRS) at the first visit was 18 points. All the routine investigations were within normal limits including MRI Brain. He was prescribed Tab. Risperidone 2mg H.S. and chemotherapy with capecitabine were resumed in liaison with the oncology team. While on capecitabine and risperidone, his manic symptoms started to resolve over a week. The risperidone was further increased to 3 mg and the patient’s manic symptoms remitted within the next week as evidenced by the drop in the YMRS score from 18 to 6. The patient was discharged and followed up on outpatient care.
The patient was followed up on monthly basis and was found to have premorbid functioning with no psychopathology on MSE (YMRS score of 0). He completed the scheduled chemotherapy cycles under the cover of Tab. Risperidone which was subsequently reduced to 2mg at the end of one month. Both capecitabine and risperidone were continued together to prevent any recurrence of symptoms.
As per the institutional and international guidelines on pharmacovigilance, the rare adverse Drug Reaction (ADR) was reported to the ADR monitoring center in central India. The information was registered using vigiflow and vigibase software under the unique ID for the registered ADR as IN-IPC-30057221010.