Prescription pattern of psychotropic medicines for patients with schizophrenia in a tertiary hospital of southeast Nigeria

1. Introduction

1.1. Background of the study

Schizophrenia is a public health burden and a severe type of mental disorder which has a significant distress to the individual, close relatives and the so­ciety at large. Moreover, the global situation of mental disorders seems be worrisome since the prevalence has tripled after the COVID-19 pandemic, making close to 1 billion people struggling with the condition, whereas about 82% of them are in low- and middle-income countries⁽¹⁾.

Nigeria, a lower middle-income country, which is the seventh largest country in the world and the most populous in Africa, with more than 200 million people, is reported to have about one in every four persons with a mental illness, accounting for more than 50 million sufferers of mental disorders⁽²⁾. However, the prevalence of schizophrenia is low (about 0.4%), but the illness is severe compared with other mental illnesses⁽³⁾. This group of patients is two or three times more likely to die early in life, probably due to physical illnesses. Whereby as much as 50% of patients in neuropsychiatric hospitals are diagnosed, only 31.3% receive specialist mental healthcare⁽⁴⁾, whereas a substantial proportion of them are left to cope by themselves⁽⁵⁾. In situations where the conditions of the patients are not properly managed, it can lead to their inability to perform meaningful tasks and to lower contributions to the society⁽⁵⁾.

Pharmacotherapy remains the mainstay of treatment in patients with schizophrenia, and psychotropic medication prescriptions are guided by prescription indicators that were developed by World Health Organization (WHO) to assess areas that include pharmaceutical prescribing practices by healthcare providers⁽⁶⁾. However, there are limited data to show the compliance of the prescribers, considering the recommended prescription guidelines.

Hence, this study evaluated the pattern of prescriptions of psychotropic drugs for schizophrenia patients who visit a tertiary mental health facility in Anambra State, southeastern part of Nigeria. It specifically assessed the commonly used psychotropic medicines, the trends, and their extent of rational use in schizophrenia patients.

2. Methodology

2.1. Study site and study setting

The study was conducted at the Anambra State Neuropsychiatric Hospital, Nawfia, in the southeastern part of Nigeria. The hospital is located on the Enugu-Onitsha old express way, about 4 km from the state capital and about 30 km from the state commercial city center. The hospital has been providing psychiatric services since its establishment in 1991 by the government. In 2023, it had a total of 38 beds, with about 90% to 100% steady occupancy, and the staff was represented by 93 specialists: physicians, pharmacists, nurses, other healthcare professionals, and the support staff. More than 95% of the daily visitors are outpatients that come to fill prescription or visit the physicians for treatment or counseling. The hospital structure consists of: general outpatient department (one), dispensary (two), chief pharmacist office (one), physicians consulting offices (three), medical laboratory (one), medical records office (one), male wards (one for acute patients, one for recovery), female wards (one for acute patients, one for recovery), staff general office (one), and students’ hostel (one).

2.2. Study design 

This was a one-year (from the 1^st of April 2022 to the 31^st of March 2023) retrospective, descriptive, cross-sectional study of psychotropic medicines prescriptions for adult schizophrenia patients who were at least 18 years old and visited the hospital.

2.3. Data collection

A standardized drug use indicators to investigate drug use in healthcare facilities⁽⁶⁾ was employed. According to the report by the hospital health information unit, there were a total of 8321 encounters for various mental disorders. Out of the total number, there were 698 encounters of adult patients with only schizophrenia that were eligible for the study. The prescription records, which contained the patients’ names, ages, gender and the prescribed drugs, were kept manually in the pharmacy unit. Relevant data were collected using a designed prescribing indicator form which contained questions on age, sex, number of drugs per encounter, drugs prescribed by generic name, injection(s) prescribed, and drugs prescribed from the Essential Medicines List. The prescribing indicators were adopted from WHO selected drug use indicators to investigate drug use in healthcare facilities⁽⁶⁾. We evaluated the average number of drugs prescribed per encounter, the percentage of encounters with injection prescribed, the percentage of drugs prescribed by generic name, and the percentage of drugs prescribed from the Essential Medicines List. The WHO core indicators were assessed as follows:

i) Average number of drugs prescribed per encounter = total number of drugs prescribed/total number of encounters surveyed.

ii) Percentage of encounters with an injection prescribed: the number of patient encounters with an injection prescribed/total number of encounters surveyed × 100.

iii) The percentage of drugs prescribed by generic names is expected to be 100%.

iv) Percentage of drugs prescribed from the Essential Medicines List: number of products prescribed from the Essential Medicines List/total number of products prescribed × 100%.

The period of data collection was from the 24^th of September 2023 to the 6^th of November 2023.

 2.4. Eligibility criteria

2.4.1. Inclusion criteria:

• Psychotropic medication prescriptions for confirmed diagnosis of schizophrenia spectrum.

• Prescriptions for patients with ages from 18 to 65 years old.

2.4.2. Exclusion criteria:

• Prescriptions for affective disorders.

• Prescriptions of clear experience of more than one discrete psychotic episode.

• Prescriptions for those on clozapine who require close monitoring.

2.4.3. Sample size determination/ sampling technique

Sample size calculation for a finite population:

S = X²NP (1-P) ⁄d² (N-1) + X²P (1-P)⁽⁷⁾

Where:

X = 1.96 (Z value for 95% confidence interval).

N = 698 (population size).

P = 0.5 (50% population proportion).

d = 0.05 (degree of accuracy/margin of error).

Sample size =
1.96²×698×0.5(1-0.5) ⁄0.05²(698-1) + 1.96²×0.5(1-0.5)

                       =
3.8416×698×0.5(0.5) ⁄0.0025(697) + 3.8416×0.5(0.5)

                       = 670.4⁄ 2.7

                       = 248.

Allowing for 10% drop out rate accounted to a minimum sample size of 273.

Although the minimum number of patients’ prescription needed to be reviewed in a single healthcare facility for more reliable results according to World Health Organization is 100⁽⁸⁾, a systematic random sampling was employed to collect the data from every second prescription of 698 encounters of schizophrenia patients in order to give a more reliable result.

2.5. Data analysis

Data were analyzed with the use of designed Excel worksheet to collect relevant data based on indicators. The data collected were transferred into Excel spreadsheet and analyzed for prescriptions by the number of prescription of drugs by generic names versus brand names, theproportion of prescribed injections, and theproportion of prescriptions from the Essential Medicines List. Other used indicators collected and analyzed were prescriptions by gender and the proportion of the patients’ ages.

2.6. Ethical considerations

A study code for the purpose of data was used to ensure the confidentiality of information. Ethical clearance was obtained from the hospital ethics committee (Ref: NPHN/010). The researcher was made aware that the research process can be terminated if he/she was not following the study protocol.

3. Results

Out of total 698 encounters for patients with schizophrenia spectrum, 21 were excluded, the reason being incomplete prescription. However, 338 encounters were assessed after random sampling of every second prescription in 677 encounters. More male patients (176; 52.07%) were encountered in the prescriptions than females (162; 47.93%; Table 1), while the highest number of patients’ prescriptions were for those aged between 26 and 35 years old, with 63 males (48.09%) and 68 females (51.91%) – Table 1. There was a total of 1122 prescribed psychotropic medicines. However, the average number of prescriptions per encounter was 3.23 (Table 2). The maximum number per prescription was six drugs, while three drugs per prescription were mostly used (61.5%), and the least used was one drug per prescription (2.1%) – Table 6. Moreover, 95.97% of the total number of drugs were prescribed by generic names (Table 2), and in 26.9% of the total number of encounters, there were prescribed injections (Table 2). The antipsychotics were the most prescribed (63.46%), followed by anticholinergics (27.45%), while the least prescribed were anti-anxiety agents (9.09%) – Table 5.

 

Out of the prescribed antipsychotic injections, fluphenazine was mostly used (42; 64.62%), while chlorpromazine was least prescribed (4; 6.15%) – Table 4. However, amongst all the psychotropic injections prescribed, fluphenazine remained the most prescribed (46.1%), followed by biperiden (20.9%), while the least used was chlorpromazine (4.4%) – Table 3.
 

Among the oral antipsychotics, haloperidol (54.8%) and olanzapine (43.8%) were the most prescribed typical and atypical antipsychotics, respectively, while trifluoperazine (14.8%) and aripiprazole (14.6%) were the least prescribed typical and atypical antipsychotics, respectively (Table 4). However, biperiden and trihexyphenidyl were the only prescribed injectable and oral anticholinergics, respectively, while diazepam injection was the only prescribed injectable benzodiazepine (Table 3). Furthermore, the most prescribed oral benzodiazepine was clonazepam (46.3%), followed closely by diazepam (40%), while nitrazepam was the least prescribed (13.7%) – Table 4.
 

4. Discussion

Psychotropic medicines are essential in the management of schizophrenia. We found in our study that three classes of psychotropic drugs were used, and they include antipsychotics, anxiolytics, and anticholinergics. However, antipsychotics remain the mainstay which can be seen in the result where these drugs (oral and injections) accounted for 63.46%, out of the classes of psychotropics prescribed (Table 5). This result is similar to that of a study conducted in a South West Ethiopia on schizophrenia patients prescriptions⁽⁹⁾.
 

In psychiatry, polypharmacy can be defined as the use of two or more psychiatric medications in a patient⁽¹¹⁾, or the use of two or more medications that have the same pharmacological actions to treat the same condition⁽¹²⁾. The reference value for the average number of drugs per encounter to assess poly­pharmacy is between 1.6 and 1.8, and in our study, we found that the value of the average number of drugs per encounter was 3.32, which is quite higher than the reference value (Table 2). 

Trihexyphenidyl is an anticholinergic that reduces the side effects of antipsychotics, especially of the typical ones, which are associated with extrapyramidal effects. Our study shows that trihexyphenidyl is the only anticholinergic used, and the majority (27.45%) of the prescriptions contained this drug (Table 5.) Furthermore, the antipsychotic injections are mostly used in patients with schizophrenia to improve adherence and in patients with irregular contacts with outpatient psychiatric services⁽¹⁰⁾. The reference value for WHO prescribing indicators for the use of injections is in the range of 13.4-24.1, but the results of our study revealed 26.9 (Table 2). We also found that fluphenazine decanoate accounted for 46.1% of the psychotropic injections (Table 3) and for 64.6% of the antipsychotics injections (Table 4), making it the most used psychotropic agent in our study. This formulation is less expensive and has a long-lasting effect, and this may be the reason for the result.

Less than 100% (93.3%) of the prescriptions were prescribed by generic names which is contrary to the WHO recommendation and reference value. The reason may be that some of the healthcare providers lack trust on the quality of some brands of psychotropic products. This result is similar to that of a study conducted in a tertiary hospital in Belagavi, India⁽¹³⁾. Moreover, it was observed that all the psychotropic medicines used were in both the local and theWHO essential lists.

Conclusions

It was concluded that there were issues of polypharmacy, some reluctance in prescribing drugs with generic names, and overuse of injections.  

Limitations of the study

Although the research was diligently performed, there were some limitations. Firstly, the prescribers were not approached to know the rationale for the prescriptions, and secondly, only one hospital was used. This does not reflect the prescriptions of other hospitals.

Recommendations

Further studies should be done in all the psychiatry hospitals in the country to know and compare the psychotropic medications prescription patterns for patients with schizophrenia. Furthermore, there is a need to create a structured way that will be consistent in knowing the medication adherence rate and quality of life of the patients.  

Acknowledgement. Authors thank all the staff of the institution for their support. Special thanks go to Mrs. Ndukwe Charity for her willingness to assist and render information where necessary.  

Corresponding author: Amala Chukwunwike Ofor E-mail: ofachcurepharm@gmail.com

CONFLICT OF INTEREST: none declared.

FINANCIAL SUPPORT: none declared.

This work is permanently accessible online free of charge and published under the CC-BY.