A case of resistant schizophrenia responding at a higher than recommended dose of risperidone without significant side effects
A 28 year old man presented with active paranoid delusion and auditory hallucination since the last six years. He also gave a history of poly-substance abuse for more than ten years with two previous hospitalizations for aggravation of symptoms, but they were not adequately controlled even after treatment. His psychiatric symptoms could not be directly attributed to the substance abuse as the temporal relationship could not be established. On routine investigations and physical examination, all the parameters were normal (FBS- 106mg/ dl, PPBS- 128mg/dl, urea- 28mg/dl, cr-0.9mg/dl) except that the patient was overweight. He was diagnosed with schizophrenia as per Diagnostic and Statistical Manual - Text Revision (DSM- IV-TR) and was prescribed olanzapine 15 mg and sodium valproate 1000 mg for one month which resulted in only modest improvement of symptoms. The dose was escalated to 20mg without significant improvement. Considering the patient's weight, the regime was augmented with aripiprazole 5mg for two weeks and then switched to 10mg for four weeks with no improvement, and no clinical side effect was noted except a slight weight gain. A third antipsychotic, risperidone 3mg with trihexyphenidyl 2mg was added to the regime and improvement was seen within three weeks. Dose titration of risperidone upto 8mg (with trihexyphenidyl 4mg) was done and olanzapine was tapered off (considering the patient's weight). Complete symptom remission could not be achieved despite continuing risperidone 8mg, aripiprazole 10mg and sodium valproate 1000mg for the next six weeks. As the recommended dose of risperidone was already reached, dose of aripiprazole was raised to 15mg resulting in aggravation of symptoms. Olanzapine 15mg was restarted along with risperidone 12mg (along with trihexyphenidyl 6mg) in divided doses, and continued for more than three months. Improvement in patient's symptoms was seen with no tremors, EPS or other clinically notable side effects except weight gain. However, persistence of auditory hallucinations and delusional belief was noted though the frequency and intensity was reduced. Insight was not present.\nTo achieve complete symptom remission, the issue of raising the dose of risperidone was discussed with the patient's family members where lack of such case reports and available trials were weighed against advantage of higher dosage and lack of side effects in the specific patient and verbal consent was given for trial of higher dose of risperidone. Risperidone, 16mg (along with trihexyphenidyl 8mg) for four weeks showed further improvement but 20mg of risperidone (along with trihexyphenidyl 10mg) resulted in complete symptom remission after four weeks. Slowly all the concomitant medications (olanzapine and sodium valproate) were tapered off, but the symptom remission was maintained. The patient did not develop any tremors, other extrapyramidal symptoms or cognitive decline. However, a weight gain of 15 kgs was seen. The laboratory parameters were normal and elevation in prolactin levels was noted (59.3 mg/dl), which is expected in a case treated with risperidone at a normal recommended dose.\nThe patient has been on risperidone alone for the last two years with complete remission and no further episodes of symptom recurrence. The dose was slowly tapered to 10mg in search of an effective maintenance dose without reappearance of symptoms. His addictions are also under control.