ABSTRACT

Background: Drug utilization research facilitates the rational use of drugs and suggests measures to improve prescribing habits. Irrational use of drugs is a global problem affecting patient care. It results in increased mortality, morbidity, adverse drug events, and wastage of economic resources.The success of medication treatment is dependent on a patient’s adherence to the medication regimen and non-adherence amongst psychiatric patients is associated with poor clinical outcomes and high resource utilization.

Objectives: The objectives of this study were to evaluate the pattern of drug utilization and the level of patients’ adherence to psychotropic drugs in a Nigerian Psychiatric Hospital.

Methods: Based on the WHO core indicators of rational drug use, data was obtained retrospectively from a review of 5400 outpatient prescriptions from September 2007 to August 2012. Data evaluation was done using the WHO guideline for assessment of drug use in health facilities. Furthermore, Morisky’s scale, (an eight-item validated questionnaire) was employed to obtain information on adherence of patients to medications from two hundred (200) outpatients. The results were analyzed using the Statistical Package for the Social Sciences (SPSS).

Results: A total number of 5400 prescriptions were used in this study. The pattern of prescription in the facility revealed that an average of 2.88 drugs was prescribed per encounter, 94.38 % of the drugs were prescribed by their generic names, and 36.13% of the prescriptions had injection prescribed. The percentage of encounters with antibiotics prescribed was 2.6% while 99.4% of all the drugs encountered were prescribed from the essential drugs list.

The drugs whose utilization accounted for about 90% of the entire drug use (DU90%) include Haloperidol, Amitriptyline, Benzhexol, Trifluoperazine, Chlorpromazine and Carbamazepine. Haloperidol was the most utilized drug in the setting with a DDD/ 1000 inhabitants /day of 5. In more than 70% of the prescriptions encountered, all the drugs prescribed were available in the hospital pharmacy. With respect to patient adherence, 55.5% of patients were classified as having low adherence, 36% with moderate adherence and 8.5% having high medication adherence level. 

Conclusion: The drug utilization review at the psychiatric hospital, Uselu found that polypharmacy was frequently practiced while haloperidol was the most utilized drug. About 70% of the prescribed drugs were available at the hospital pharmacy. Outpatients’ adherence to medications was very low while socio-demographic features of patients did not affect adherence.

CHAPTER ONE

INTRODUCTION

1.0       BACKGROUND

Drug utilization research has been defined by the World Health Organization (WHO) as “the marketing, distribution, prescription and use of drugs in a society with a special emphasis on the resulting medical, social and economic consequences’’.¹ The principal aim of drug utilization research is to facilitate the rational use of drugs in population and to suggest measures to improve prescribing habit. Irrational use of drugs is a widespread global phenomenon cutting across all levels of care. This results in increased mortality, morbidity, adverse drug reactions and economic wastages. Medicines are pivotal to healthcare delivery and disease prevention therefore, the availability and affordability of good quality drugs coupled with their rational use is fundamental to effective healthcare delivery in any country.² However, irrational use of medicines are regular occurrences in many countries especially developing ones due to irrational prescribing, dispensing and administration of medications.^2,3According to the World Health Organization, more than half of all medicines are prescribed, dispensed or sold inappropriately and that half of all patients fail to take them correctly⁴ giving rise to patients poor clinical outcomes.

The manner of drug use by patients and the outcomes of therapy, however, depend on the quality and level of commitment and professionalism displayed by health care providers. To ensure rational prescribing and drug use, the prescriber should endeavor to follow a standard process of prescribing in accordance with that of standard treatment guidelines and the formulary of the health care institution.

Rational drug dispensing requires that system of drug procurement and supply be performed on a professional and efficient manner. The requirements for rational drug use are that the right drugs shall be used for the right indications in the right dose and dosage form for the right duration. Rational drug use, as an essential element of a national drug policy seeks to avoid the frequent problems of under or over prescription, inappropriate prescribing and the use of new, expensive drugs when equally effective, well tried, safe and cheaper alternatives are available.

The pioneers of drug utilization research understood that a correct interpretation of data on drug utilization requires investigations at the patient level. It became clear that we need to know the answers to the following questions: why drugs are prescribed; who the prescribers are; for whom the prescribers prescribe; whether patients take their medicines correctly; what the benefits and the risks of the drugs are?Drug utilization is in the very focus of discussion from the economic, political and healthcare view points. A comprehensive insight into drug utilization as an economic and primarily a public health issue can only be acquired in the context of overall health state of the respective population.⁵

On the other hand, adherence to medication regimen has been monitored since the time of Hippocrates.⁶ It has become a focus of increasing concern in the treatment of psychiatric disorders in recent years.⁷ Adherence to a medication regimen is generally defined as the extent to which patients take medication as prescribed by their health care providers.⁶ It includes data on dose taking (taking the prescribed number of pills each day) and the timing of doses (taking pills within a prescribed period).Non-adherence to treatment is the degree to which a patient does not carry out the clinical recommendations of the treating physician.⁸ Non-adherence is a significant problem in all patient populations from children⁹ to elderly.¹⁰

Adherence rates are typically higher among patients with acute conditions as compared to those with chronic conditions.¹¹This tends to worsen the longer a patient continues on drug therapy.¹² Adherence to medication regimens necessary for therapeutic benefit is posing a major concern to health care professionals. The promotion of out-patient therapy and responsible self-medication has led to placing greater responsibility on the patients for their own health outcomes. Non-adherence is a polyfaceted problem but a triadic model relating therapeutic relationship between the patient and clinician, factors related to medications and factors related to the patients and their illness help to explain the non-adherent behavior.¹³ Physicians contribute to the non-adherence by failing to prescribe simple regimens, not explaining the benefits and side effects of medication, not considering patients life style or medication cost involved and inadequately eliciting and rectifying the myths and beliefs held by patients.^13,14