Pak. J. Pharm. Sci., Vol.29, No.1, January 2016, pp.239-246 239 REPORT Demographic profiles and sleep quality among patients on methadone maintenance therapy (MMT) in Malaysia Zalina Zahari 1,2 *, Lee Chee Siong 3 , Nurfadhlina Musa 2 , Mohd Azhar Mohd Yasin 2,4 , Tan Soo Choon 2 , Nasir Mohamad 2,5 and Rusli Ismail 2,6 1 Department of Pharmacy, Hospital University Sains Malaysia, Kubang Kerian, Kelantan, Malaysia 2 Pharmacogenetics and Novel Therapeutics Cluster, Institute for Research in Molecular Medicine (INFORMM), University Sains Malaysia, Kubang Kerian, Kelantan, Malaysia 3 Department of Emergency Medicine, School of Medical Sciences, University Sains Malaysia, Kubang Kerian, Kelantan, Malaysia 4 Department of Psychiatry, School of Medical Sciences, University Sains Malaysia, Kubang Kerian, Kelantan, Malaysia 5 Faculty of Medicine & Health Sciences, Universiti Sultan Zainal Abidin, Kuala Terengganu, Terengganu, Malaysia 6 Centre of Excellence for Research in AIDS (CERiA), University of Malaya, Kuala Lumpur, Malaysia Abstract: Poor sleep quality was frequently reported by opioid dependence patients during methadone maintenance therapy (MMT). The study investigated a sample of patients on MMT to investigate the severity and prevalence of sleep problems in MMT patients. We evaluated sleep quality and disturbances of 119 Malay male patients from MMT clinics in Kelantan, Malaysia between March and July 2013 using the Pittsburgh Sleep Quality Index (PSQI)-Malay version. Patients’ demographic, clinical data, past drug history and methadone treatment variables were recorded. Patients averaged 37.5 years of age (SD 6.79) and their mean age of first time illicit drug use was 19.3 years (SD 4.48). Their mean age of entering MMT was 34.7 years (SD 6.92) and the mean duration in MMT was 2.8 years (SD 2.13). The mean current daily dosage of methadone was 77.8 mg (SD 39.47) and ranged from 20 to 360 mg. The mean global PSQI score was 5.6 (SD 2.79) and 43.7% patients were identified as ‘poor sleepers’ (global PSQI scores >5). This study confirms the poor overall sleep quality among patients on MMT. The prevalence and severity of sleep problems in MMT patients should not be underestimated. Keywords: clinical, insomnia, outcomes, response, subjective INTRODUCTION Opioid dependence is one of the chronic, relapsing disorders with high social, medical, and economic burdens. This problem is growing and it is also a major concern in public health throughout Malaysia. Methadone is well known in the treatment of opioid dependence. Maintenance treatments are effective in suppressing drug abuse and retaining patients in pharmacological treatment (Amato et al., 2011). Research evaluating costs of healthcare associated with medications used in opioid dependence treatment found that subjects who did not receive pharmacologic therapy had higher hospital utilization and total costs than those who received medication (Baser et al., 2011). However, discontinuation of methadone maintenance therapy (MMT) and continued use of illicit drugs pose challenges to the treatment of opioid dependence. Sleep disorder has been attributed to premature exit from methadone detoxification treatment by many patients with opioid dependence (Beswick et al., 2003; Gossop and Bradley, 1984; Oyefeso et al., 1997). Previous work has documented that 40 to 90% of patients reported use of medications to improve their sleep (Hsu et al., 2012; Liao et al., 2011; Peles et al., 2006). Persistent sleep disorder might promote chronic depressive symptoms (Staedt et al., 1996; Wang et al., 2008). The drug-dependency sleep disturbances could have a negative impact on patients’ health, quality of life, and also could lead to continued drug abuse, if sleep disorders are not treated in these patients (Hsu et al., 2012; Pud et al., 2012; Staedt et al., 1996). The aetiology of sleep disorder among patients in methadone treatment is often multifactorial and complex. Chronic treatment with methadone might result in sleep disturbance. Perceived (subjective) poor sleep quality or sleep problems such as inadequate quality, inadequate latency, inadequate efficiency, sleep disturbance, impaired day-time function, insomnia, excessive day-time sleepiness (Charpentier et al., 2010; Hsu et al., 2012; Liao et al., 2011; Peles et al., 2006, 2009; Pud et al., 2012; Stein et al., 2004; Wang et al., 2008) were frequently reported by opioid dependent patients during maintenance therapy. *Corresponding author: e-mail: zzalina@kb.usm.my