Physician Preferences for Olanzapine Standard Oral Tablets and Orally Disintegrating Tablets: A Cross-Sectional Survey

Olanzapine, a second-generation antipsychotic, is indicated for the treatment of schizophrenia and bipolar disorder.1 Oral formulations of olanzapine include standard oral tablets (SOT) and orally disintegrating tablets (ODT), which are similar in pharmacokinetic aspects and bioequivalent to each other.2 Studies comparing the effects of olanzapine SOT and ODT have found that the patients treated with either formulation experienced a comparable improvement in their symptoms and quality of life.3 Alternatively, a few studies reported lower rates of hospitalization and relapse in the patients treated with olanzapine ODT as compared to SOT, with the patients preferring to use ODT.3 Despite these reported similarities and differences, it is not clear which factors drive the choice of SOT vs ODT formulation among physicians. Hence, this study was conducted to determine the preference of physicians among two oral formulations of olanzapine (SOT vs ODT). This study was conducted in the form of an online cross-sectional survey in the month of June 2021. The survey was in the form of case vignettes with binary/multiple-choice questions (Table 1). The validity of these vignettes was established based on an extensive review of clinical studies utilizing olanzapine ODT or SOT. Study participants included physicians from the Philippines eligible to prescribe olanzapine. A homogenous convenience sampling approach was utilized for this study. The inclusion criteria included (a) physicians eligible to prescribe olanzapine in the Philippines and (b) willingness to provide consent. Only one response per Internet Protocol (IP) address was allowed. Responses were compiled in a spreadsheet program (Microsoft Excel Version 13). Since data were categorical, frequencies and percentage of frequencies were computed. The survey was attended by 238 unique participants. Their practice characteristics involved private clinics, corporate or government hospitals, and academic institutions. The response rate for the four questions ranged from 53% to 78% (Table 1) with each question receving at least 127 and at most 186 responses. For a case presenting with good insight about their illness, 94.6% of participants responded that they would prefer SOT, and 92.9% respondents agreed that if a patient has a lower score on the Drug Attitude Inventory, they would prefer to switch the patient to ODT from SOT. In terms of an ideal candidate for initiating treatment, 57.7% of participants chose to initiate ODT for young patients presenting with an acute episode. 32.7% participants preferred to initiate ODT for patients presenting with predominantly negative symptoms, while 9.5% participants chose to initiate ODT for elderly patients despite a favorable metabolic profile. When the participants were asked if they were willing to switch a patient, who was responding/was stable on treatment with SOT to ODT, an overwhelming 89% of participants agreed that they would switch treatment if the patient demonstrated weight gain, had a history of noncompliance to antipsychotic medication, or developed swallowing difficulties (Table 1). Olanzapine SOT reportedly improves the awareness to need for treatment and maintain good mental health.1,4 In routine clinical practice, prescribers find it difficult to assess insight and therefore SOT may be prescribed for only those patients who have reasonable awareness of their illness and its prognosis. Good insight fairly improves the attitude toward medication.4 If a patient treated with SOT demonstrates a negative attitude toward medication, prescribers need to consider switching the patient to a more convenient form of medications like ODT or even depot injections.5 Switching to ODT may reduce the caregiver’s burden,6 for example, by avoiding any surreptitious behavior (e.g., cheeking) which might lead to a loss of medication (rapid disintegration of ODT in the oral cavity forces the patient to swallow the amorphous content).6 The preference of ODT in young patients is in agreement with previous studies which reported general precedence for olanzapine ODT in externally aggressive patients and those referred to inpatient treatment.3 Negative symptoms of schizophrenia lead to significant functional impairment, and second-generation antipsychotics remain the primary treatment of choice. Compliance and insight further contribute to the choice of formulation in a patient with predominantly negative symptoms—however, no preference for ODT or SOT was found in this study. With newer and metabolically favorable antipsychotics (e.g., aripiprazole) now available, a small group of participants avoided prescribing olanzapine for elderly patients—despite a favorable metabolic profile. However, the choice of switching to ODT was unobstructed if a patient on olanzapine demonstrated weight gain. The decision to switch to ODT may have been additionally driven because of a concern about noncompliance or swallowing difficulties.5 Limitations of this study include the cross-sectional nature of the survey and nonprobability sampling. In conclusion, the choice of olanzapine formulation (SOT or ODT) in a patient with schizophrenia or bipolar disease is influenced strongly by the patient profile.