Department of Pharmacology and Pharmacy, The University of Hong Kong

Professor Esther W.Y. CHAN 陳慧賢

Dr. Esther WY CHAN


Assistant Dean (Health Sciences Education)

  • BPharm(Hons), MClinPharm, GradCertPharmEc, PhD (Monash), FSHP

Professor Chan’s research focuses on determining the safety and effectiveness of medicines, and expanding knowledge about the application of medicines using big data and innovative study designs. Professor Chan has completed several multi-centre randomised controlled trials (RCT) comparing sedative and antipsychotic drugs for the management of behavioural emergencies. Her research findings have led to the inclusion of drug dosing recommendations in the Australian Therapeutic Guidelines and the addition of olanzapine to the Hong Kong Hospital Authority Accident and Emergency drug formulary. Findings from her latest multi-centre RCT were cited in the Hong Kong Hospital Authority Accident and Emergency Clinical Guidelines 2021 to support the use of intramuscular olanzapine in the management of acute agitation. (Click here for Press Release)

Professor Chan’s research has been published in leading journals including JAMA, JAMA Internal Medicine, Journal of the American College of Cardiology, Gastroenterology, Gut and Annals of Emergency Medicine. Her achievements are recognised with awards from funding bodies including the RGC Early Career Scheme (2013) and National Natural Science Fund of China (NSFC) - Young Scientist Fund (2018); and awards including the Faculty Outstanding Research Output Award (8 awards between 2016-2021) and the Outstanding Young Researcher Award in 2018. In 2020, she was awarded the NSFC Excellent Young Scientist Fund. Professor Chan’s research is featured in the HKU Growing Human Capital through the Strategically Oriented Research Themes (SORT), HKU Bulletin as well as Medical Faculty News. Her adaptation of RCT research methodology in both teaching and research is featured in Teaching and Learning Connections, Centre for the Enhancement of Teaching and Learning (CETL).

Christmas-Party-2023---Group-Photo_L_2x1 ResearchTeam_EstherChan_2018_2x1
 Professor Esther Chan and her research associates with Professor Ian Wong

Professor Chan strives to achieve an enriching nexus between teaching and research. Through translating new knowledge into captivating educational materials, she inspires students towards better clinical practice and patient care. She received the Faculty of Medicine Teaching Medal in 2018 in recognition of her outstanding contribution and promotion of good practices in teaching and learning.


In response to the COVID-19 pandemic, Professor Chan led the set-up of the central dilution area in the Ap Lei Chau Community Vaccination Centre in the Hong Kong SAR. In collaboration with The Society of Hospital Pharmacists of Hong Kong (SHPHK) and the Hong Kong Academy of Nursing, she developed online training programme platforms for the Preparation of BioNTech COVID-19 vaccine and the Preparation of Paediatric BioNTech Vaccine for healthcare professionals across Asia.


  • Elected member, The Hong Kong Young Academy of Sciences
  • Fellow, Society of Hospital Pharmacists of Australia (SHPA, Australia)
  • Registered Pharmacist, Australian Health Practitioner Regulation Agency (AHPRA, Australia)
  • Registered Pharmacist, General Pharmaceutical Council (GPC, UK)
  • Member, International Society of Pharmacovigilance (ISOP)
  • Member, The Pharmaceutical Society of Hong Kong (PSHK, Hong Kong)
  • Member, International Society for Pharmacoeconomics and Outcomes Research (ISPOR)
  • Member, SHPA Committee of Specialty Practice (COSP): Emergency Medicine, Infectious Diseases
Honours and Awards
  • National Natural Science Foundation of China (NSFC) Excellent Young Scientist Fund (Hong Kong and Macau), NSFC; 2020
  • Teaching Exchange Fellowship Scheme, The University of Hong Kong; 2020
  • British Medical Association Award – First Prize in Cardiology for The ESC Textbook of Cardiovascular Medicine (Third Edition) – Chapter 54.8, The European Society of Cardiology, Oxford University Press; 2019
  • Outstanding Young Researcher Award, The University of Hong Kong; 2018
  • Faculty Teaching Medal, Faculty of Medicine, The University of Hong Kong; 2018
  • Best Original Paper Award, Hong Kong Medical Journal, Hong Kong Academy of Medicine; 2017
  • Faculty Outstanding Research Output Award, Faculty of Medicine, The University of Hong Kong; 2016 (as first author), 2017 (as corresponding author), 2018 (as co-author), 2019 (two papers as co-author), 2020 (two papers as co-author), 2021 (as co-author), and 2022 (two papers as co-author)
  • Incentive award for successful RGC/GRF Funding, The University of Hong Kong; 2014-2015
  • Fellowship, Society of Hospital Pharmacists of Australia (SHPA); 2013
  • DBL Hospira Young Pharmacist Award, SHPA; 2009
  • Ian Scott PhD Scholarship, Australian Rotary Health; 2008-2010
  • Academic Prize; top candidate, Master of Clinical Pharmacy, Monash University, Australia; 2007

140 for 140 campaign, HKUMed: Making change for the common good

HKU Excellence Awards 2018

Research Interests

Big Data for Medication Safety and Pharmacoeconomics

  • Big data research: pharmacoepidemiology and medication safety
  • Prospective clinical study design; clinical and practice-based research
  • Pharmacotherapy management of communicable and non-communicable disease areas including behavioural emergencies and mental health; cardiovascular and respiratory health, gastroenterology, infectious diseases and oncology
  • Pharmacoeconomics analyses; decision-analytic models, budget impact studies, willingness-to-pay
  • Pharmacy practice and service development

Publications Highlights

Wan EYF, Mok AHY, Yan VKC, Wang B, Zhang R, Hong SN, Chui CSL, Li X, Wong CKH, Lai FTT, Tan KCB, Lau CS, Wong ICK, Chan EWY*. Vaccine effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 Omicron BA.2 infection, hospitalisation, severe complications, cardiovascular disease and mortality in patients with diabetes mellitus: A case control study. J Infect. 2022 Nov;85(5):e140-e144. doi: 10.1016/j.jinf.2022.08.008.

Patients with diabetes mellitus (DM) have heightened susceptibility to COVID-19 infection and complications. Using a case-control design, this study used electronic health databases from the Hospital Authority and the Department of Health in Hong Kong to investigate the real-world effectiveness of CoronaVac and BNT162b2 vaccine against any COVID-19 infection, COVID-19-related hospital admission, ICU admission, incident cardiovascular disease, and all-cause mortality within 28 days after COVID-19 infection during the local outbreak dominated by Omicron BA.2 sublineage. We found a positive dose-response relationship between the number of BNT162b2 or CoronaVac doses received and VE for all outcomes. Additionally, we found that a heterologous booster dose of BNT162b2 after two doses of CoronaVac may be more effective than three doses of CoronaVac. Overall, these findings shed light on the importance of booster shots for reducing morbidity and mortality after COVID-19 infection in patients with DM.

Impact Factor (2021): 38.637, (Rank: 3/123 Infectious Diseases), 5-year Impact Factor: 19.923.

Yan VKC†, Wan EYF†, Ye X, Mok AHY, Lai FTT, Chui CSL, Li X, Wong CKH, Li PH, Ma T, Qin S, Wong VKC, Tsang TC, Tsui SH, Chui WCM, Cowling BJ, Leung GM, Lau CS, Wong ICK*, Chan EWY*. Effectiveness of BNT162b2 and CoronaVac vaccinations against mortality and severe complications after SARS-CoV-2 Omicron BA.2 infection: a case-control study. Emerg Microbes Infect. 2022 Aug 18:1-48. doi: 10.1080/22221751.2022.2114854.

Data regarding protection against mortality and severe complications after Omicron BA.2 infection with CoronaVac and BNT162b2 vaccines remain limited. We conducted a case-control study to evaluate the risk of severe complications and mortality following 1-3 doses of CoronaVac and BNT162b2 using electronic health records. Vaccine effectiveness against COVID-19-related mortality and severe complications by type and number of doses was estimated using conditional logistic regression and adjusted for comorbidities and medications. Both CoronaVac and BNT162b2 vaccination were shown to be effective against COVID-19-related mortality and severe complications amidst the Omicron BA.2 pandemic, and risks decreased further with the third dose.

Impact Factor (2021): 19.568, (Rank: 8/94 Infectious diseases, 9/161 Immunology), 5-year Impact Factor: 14.211.

Cheng FWT, Fan M, Wong CKH, Chui CSL, Lai FTT, Li X, Wan EYF, Tang SCW, Chan EWY*, Wong ICK*. The effectiveness and safety of mRNA (BNT162b2) and inactivated (CoronaVac) COVID-19 vaccines among individuals with chronic kidney diseases. Kidney Int. 2022 Aug 11:S0085-2538(22)00610-X. doi: 10.1016/j.kint.2022.07.018.

People with chronic kidney disease (CKD) are immunocompromised and therefore suffer from poorer outcomes including increased risk of hospitalization and mortality after COVID-19. Using territory-wide electronic medical records and vaccination records, we conducted a population-based, retrospective study to evaluate the effectiveness and safety of COVID-19 vaccines in the CKD population. The findings demonstrated that both BNT162b2 and CoronaVac were effective against severe outcomes after the COVID-19 infection by reducing hospitalization and mortality; and were safe with no increased risk of adverse events of special interest observed during the study period. These findings suggest that vaccination is strongly encouraged for people with CKD.

Impact Factor (2021): 18.998, (Rank: 3/90 Urology & Nephrology), 5-year Impact Factor: 14.318.

Wei Y, Yan VKC, Kang W, Wong ICK, Castle DJ, Gao L, Chui CSL, Man KKC, Hayes JF, Chang WC, Chan EW*. Association of Long-Acting Injectable Antipsychotics and Oral Antipsychotics with disease relapse, health care use, and adverse events among people with schizophrenia. JAMA Netw Open. 2022 Jul 1;5(7):e2224163. doi: 10.1001/jamanetworkopen.2022.24163.

Evidence for improved clinical outcomes with long-acting injectable antipsychotics (LAIAs) versus oral antipsychotics (OAs) is limited in Asian populations and special patient groups. In this self-controlled case series study, we identified 70,396 individuals with schizophrenia, and 23,719 of them were prescribed both LAIAs and OAs. Compared with OAs, LAIAs were associated with lower risk of all-cause hospitalizations, hospitalizations for psychiatric disorders, hospitalizations for schizophrenia, and suicide attempts. There was also a reduction in hospitalizations for somatic disorders, hospitalizations for cardiovascular diseases, and extrapyramidal symptoms. No significant difference was found for emergency department visits. Similar associations were observed during the subsequent treatment periods (after excluding the first 90 days of each treatment period), and in older people (> 65 years) and people with substance use, except for the increased risk of extrapyramidal symptoms in older people when initiating LAIAs (first 90 days). Early LAIA initiators had a greater reduction in above events than late initiators

Impact Factor (2021): 13.366, (Rank: 15/172 Medicine, general & internal), 5-year Impact Factor: 13.318.

Ye X, Ma T, Blais JE, Yan VKC, Kang W, Chui CSL, Lai FTT, Li X, Wan EYF, Wong CKH, Tse HF, Siu CW, Wong ICK*, Chan EW*. Association between BNT162b2 or CoronaVac COVID-19 vaccines and major adverse cardiovascular events among individuals with cardiovascular disease. Cardiovasc Res. 2022 Jun 22:cvac068. doi: 10.1093/cvr/cvac068.

Impact Factor (2021): 13.081, (Rank: 11/143 Cardiac & cardiovascular systems), 5-year Impact Factor: 11.446.

COVID-19 infection can lead to severe outcomes in patients with pre-existing cardiovascular disease (CVD) but concerns about the cardiovascular safety of COVID-19 vaccines among these patients may lead to vaccine hesitancy. We identified 229,235 patients with CVD, among whom 1,764 patients had a diagnosis of major adverse cardiovascular events (MACE) and received the vaccination (662 BNT162b2 and 1,102 CoronaVac) between February 23, 2021 and January 31, 2022. Using a modified self-controlled case series design, each patient was compared to him/herself by comparing the risk after each dose of vaccination and the baseline non-exposure period. Results showed no evidence of an increased risk of MACE after vaccination with BNT162b2 or CoronaVac. We conclude that pre-existing CVD should not prevent individuals from receiving COVID-19 vaccines. It is important that this population is vaccinated to prevent potentially severe outcomes after COVID-19 infection. Real-world evidence and easy-to-access health information is needed to help individuals weigh the risks and benefits of COVID-19 vaccines to guide their decision making.

This work was selected for press release by the European Society of Cardiology.
COVID vaccines are safe for patients with cardiovascular disease

Kang W, Shami JJP, Yan VKC, Ye X, Blais JE, Li X, Lee VHF, Chui CSL, Lai FTT, Wan EYF, Wong CKH, Wong ICK* and Chan EW*. Safety of two-dose COVID-19 vaccination (BNT162b2 and CoronaVac) in adults with cancer: a territory-wide cohort study. J Hematol Oncol. 2022; 15 (66). DOI: 10.1186/s13045-022-01265-9

Impact Factor (2021): 23.168, (Rank: 4/78 Hematology; 12/245 Oncology), 5-year Impact Factor: 17.520.

Despite reasonable Covid-19 vaccine uptake in Hong Kong, the safety of COVID-19 vaccines remains a concern, especially among the elderly and immunocompromised patients such as those with cancer. This study investigated the association between BNT162b2 and CoronaVac vaccines and the risk of adverse events of special interest (AESI) in adults with cancer. Results showed no increased risk of AESI following two doses of either BNT162b2 or CoronaVac vaccines among patients with active cancer or a history of cancer. The findings provide real-world evidence that reassure patients with cancer of the safety of COVID-19 vaccines and facilitates vaccine uptake in this vulnerable group, thereby reducing severe disease and deaths due to COVID-19.

Fung LWY, Zhao J, Yan VKC, Blais JE, Chan JCH, Li STH, Shami JJP, Kwan C, Yue Wei Y, Wong CKH, Li X, Chui CSL, Wan EYF, Lai FTT, Tse S, Cowling BJ, Wong ICK, Chan EW*. COVID-19 vaccination preferences of university students and staff in Hong Kong. JAMA Netw Open. 2022;5(5):e2212681. DOI:10.1001/jamanetworkopen.2022.12681

Impact Factor (2021): 13.366, (Rank: 15/172 Medicine, General & Internal), 5-year Impact Factor: 13.318.

This cross-sectional online survey study, conducted between July 2021 to September 2021, invited 3,423 students and staff at the University of Hong Kong to quantify 7 attributes of COVID-19 vaccination with a discrete choice experiment. Attributes included risk of a mild or moderate adverse event after vaccination, risk of a severe adverse event after vaccination, efficacy against COVID-19 infection, efficacy against severe manifestation of COVID-19 infection, duration of protection after vaccination, incentive for completing vaccination, and out-of-pocket costs. Quarantine-free travel was preferred, followed by efficacy against any COVID-19 infection, against severe manifestation of COVID-19 infection, and risk of severe adverse events following vaccination. Participants were less concerned about the duration of protection and the risk of mild to moderate adverse events. Preferences of all attributes were significant and considered important by participants for vaccine decision-making. Insights drawn could assist policymakers in future vaccination decisions, such as campus vaccine mandate and requirement of additional dose(s).

Zhao JX, Blais JE, Chui CSL, Suh IH, Chen EYH, Seto WK, Mok MTC, Yan VKC, Lau WCY, Wong ICK, Chan EW*.
Association Between Non-vitamin K Antagonist Oral Anticoagulants or Warfarin and Liver Injury: A Cohort Study. Am J Gastroenterol. 2020; 115(9): 1513-1524. Click to see abstract

Zhao JX, Blais JE, Seto WK, Wong ICK, Chan EW*.
Response to Liu et al., and Björnsson and Björnsson. Am J Gastroenterol. 2021; 116(5): 1091-1092. doi: 10.14309/ajg.0000000000001055. Click to see abstract

Impact Factor (2021): 12.045, (Rank: 9/93 Gastroenterology & Hepatology), 5-year Impact Factor: 13.134

The risk of liver injury in patients with atrial fibrillation (AF) using nonvitamin K antagonist oral anticoagulants (NOACs) has not been previously examined using liver function tests as the primary outcome in the real-world setting. This study assessed the association between NOACs (dabigatran, rivaroxaban, and apixaban) and warfarin and the risk of liver injury, as defined by laboratory tests. Risk of liver injury, defined as laboratory test values >3 times the upper limit of normal of alanine aminotransferase or aspartate aminotransferase and >2 times the upper limit of normal of total bilirubin, was compared between NOAC and warfarin users using Cox proportional hazards regression. Among patients with AF, NOACs as a group, and dabigatran alone were associated with a significantly lower risk of laboratory-based liver injury when compared with warfarin. However, liver injury occurs more frequently in real-world practice than in NOAC randomized controlled trials.

Law SWY, Lau WCY, Wong ICK, Lip GYH, Mok MT, Siu CW, Chan EW*.
Sex-based differences in outcomes of oral anticoagulation in patients with atrial fibrillation. J Am Coll Cardiol, 2018; 72(3): 271-282. Click to see abstract

Law SWY, Lau WCY, Wong ICK, Chan EW*.
In reply: Sex-based differences in outcomes of oral anticoagulation: Does the antiplatelet therapy matter? J Am Coll Cardiol. 2018; 72(20): 2547-2548. doi: 10.1016/j.jacc.2018.09.023. Click to see abstract

Impact Factor (2021): 27.203, (Rank: 5/143 Cardiac & Cardiovascular Systems), 5-year Impact Factor: 26.047

(The University of Hong Kong) 19 November, 2018
Strategic partnership on medication safety using big data, The University of Hong Kong and UCL

(The University of Hong Kong) 19 November, 2018
Using big data to reduce the risk of stroke, The University of Hong Kong and UCL

This study compared the effectiveness and safety outcomes of direct oral anticoagulants (DOACs) versus warfarin in men and women with stratifications for anticoagulation control. DOACs were found to be associated with a lower risk of intracranial hemorrhage [ICH] and all-cause mortality in women only, where the association of lower ICH risk remained when compared with warfarin users with good anticoagulation control.

Of 4,972 men and 4,834 women successfully matched in our cohort, compared with warfarin, DOAC use was associated with a lower risk of ICH (hazard ratio [HR]: 0.16; 95% confidence interval [CI]: 0.06 to 0.40) and all-cause mortality (HR: 0.55; 95% CI: 0.39 to 0.77) in women but not in men. The treatment by sex interaction was significant for ICH only, and a significantly lower risk of ICH remained in the DOAC group when compared with warfarin users with good anticoagulation control (HR: 0.13; 95% CI: 0.02 to 1.00) among women only. The risks of ischemic stroke or systemic embolism and gastrointestinal bleeding with DOACs versus warfarin were comparable in both sexes.

Lau WCY, Chan EW, Cheung CL, Sing CW, Man KKC, Lip GYH, Siu CW, Lam JKY, Lee ACH, Wong ICK*.
Association between dabigatran vs warfarin and risk of osteoporotic fractures among patients with nonvalvular atrial fibrillation. JAMA. 2017; 317(11):1151-1158. Click to see abstract 

Lau WCY, Wong ICK, Chan EW*.
Osteoporotic fractures associated with dabigatran vs warfarin—Reply. JAMA. 2017; 318(1):91. doi:10.1001/jama.2017.6912Click to see abstract 

Impact Factor (2021): 157.335, (Rank: 3/172 Medicine, General & Internal), 5-year Impact Factor: 101.130.

(香港電台) 11 April 2017
研究指長期使用傳統薄血藥可致骨折 嚴重或增死亡率

(東網) 11 April 2017
新型薄血藥可減骨折風險 港大倡病人轉用

(The University of Hong Kong) 11 April 2017
HKU discovers that traditional blood thinner drug is associated with a higher risk of osteoporotic fracture compared to newer drug

This paper was selected for press conference held on 11th April 2017 at The University of Hong Kong and the research findings were disseminated through over 20 media sources.

The risk of osteoporotic fracture with dabigatran use in patients with nonvalvular atrial fibrillation (NVAF) is unknown. The aim of our study was to investigate the risk of osteoporotic fractures with dabigatran vs warfarin in patients with NVAF. We performed a retrospective cohort study using a population-wide database managed by Hong Kong Hospital Authority. Patients newly diagnosed with NVAF from 2010 through 2014 and prescribed dabigatran or warfarin were matched by propensity score at a 1:2 ratio with follow-up until July 31, 2016. Risk of osteoporotic hip fracture and vertebral fracture was compared between dabigatran and warfarin users using Poisson regression. The corresponding incidence rate ratio (IRR) and absolute risk difference (ARD) with 95% CIs were calculated. Results of Poisson regression analysis showed that dabigatran use was associated with a significantly lower risk of osteoporotic fracture compared with warfarin. The association with lower risk was statistically significant in patients with a history of falls, fractures, or both (dabigatran vs warfarin, but not in those without a history.

Cheung KS, Chan EW, Wong AY, Chen L, Wong ICK, Leung WK*.
Long-term proton pump inhibitors and risk of gastric cancer development after treatment for H. pylori: A population-based study. Gut. 2018; 67:28-35. doi: 10.1136/gutjnl-2017-314605. Click to see abstract

Impact Factor (2021): 31.840, (Rank: 43/93 Gastroenterology & Hepatology), 5-year Impact Factor: 27.827.

(頭條日報) 14 November 2017

(星島日報) 14 November 2017
PPI胃藥增胃癌風險 長服三年高逾七倍

(The University of Hong Kong) 13 November 2017
HKU Finds that Long-term Use of Proton Pump Inhibitors is Associated with an Increased Risk of Stomach Cancer

Although Helicobacter pylori eradication has been shown to reduce the risk of gastric cancer development, a considerable proportion of these individuals continues to progress to gastric cancer even after successful eradication of H. pylori. This study investigated the association between PPIs use and gastric cancer (GC) among H. pylori-infected subjects who had received HP therapy. The results showed that long-term PPIs use was associated with a 2.4-fold increase in gastric cancer risk in H. pylori-infected subjects who had received eradication therapy, and that the risk of gastric cancer increased with the dose and duration of PPIs use.

This work was awarded the Faculty of Medicine Outstanding Research Output Award 2018.

Wong AYS, Wong ICK, Chui CSL, Lee EHM, Chang WC, Chen EYH, Leung WK, Chan EW*.
Association between acute neuropsychiatric events and Helicobacter pylori therapy containing Clarithromycin. JAMA Intern Med. 2016; 176(6):828-834. Click to see abstract

Impact Factor (2021): 44.460, (Rank: 7/172 Medicine, General & Internal), 5-year Impact Factor: 32.310.

Clarithromycin is used for the treatment of respiratory infections, including community-acquired pneumonia. It is also commonly prescribed in combination with amoxicillin or metronidazole, plus proton pump inhibitors (PPIs) as a first-line standard treatment for Helicobacter pylori eradication. Among potential adverse events associated with the use of clarithromycin, neuropsychiatric symptoms in patients with or without other long-term comorbidities, such as renal disease, hypertension, and obstructive airway disease remains a concern. Apart from clarithromycin monotherapy, neuropsychiatric symptoms were also observed in patients receiving H pylori therapy containing clarithromycin. This study investigated the association between H pylori therapy containing clarithromycin and acute neuropsychiatric events. The results showed that there is evidence of a short-term increased risk of neuropsychiatric events associated with H pylori therapy containing clarithromycin, which will usually resolve after cessation of treatment and psychiatric intervention can be avoided.

This work was awarded the Faculty of Medicine Outstanding Research Output Award 2017.

Chan EW, Lau WCY, Leung WK, Mok MTC, He Y, Tong TSM, Wong ICK*.
Prevention of dabigatran --related gastrointestinal bleeding with gastroprotective agents: A population-based study. Gastroenterology 2015;149(3):586-595.e3. Click to see abstract

Impact factor (2021): 33.883, (Rank 3/135; Gastroenterology & Hepatology), 5-year impact factor: 29.175.

The use of dabigatran, an inhibitor of thrombin, increases risk of gastro intestinal bleeding (GIB). However, it is not clear whether gastroprotective agents (GPA’s) prevent GIB in dabigatran users. This study investigated the risk of GIB and the role of GPA’s (including proton pump inhibitors and histamine type-2 receptor antagonists) in patients using dabigatran. This study showed that in the Hong Kong population, the use of GPAs was associated with a reduced risk of GIB in patient taking dabigatran. The association was stronger for upper GIB than lower GIB, and in patients with prior history of peptic ulcer or GIB.

This work was awarded the Faculty of Medicine Outstanding Research Output Award 2016.

Chan EW, Taylor DMcD*, Knott JC, Phillips GA, Castle DJ, Kong DCM.
Intravenous droperidol or olanzapine as an adjuncts to midazolam for the acutely agitated patient: A multi-centre, randomised, double-blind, placebo-controlled clinical trial. Ann Emerg Med. 2013; 61(1):72-81. Click to see abstract

Impact Factor (2021): 6.762, (Rank: 2/32; Emergency Medicine), 5-year Impact Factor: 6.805.

This multicentre clinical randomised controlled trial was the first rigorous study to compare two IV drug combinations (droperidol and midazolam or olanzapine and midazolam) with a commonly used control (midazolam alone) regimen. This study provided the first evidence that olanzapine by intravenous (IV) administration may be a useful and safe option for the management of acute agitation. Both combinations produced significantly more rapid and effective sedative with similar safety profile. Droperidol remains a safe and effective drug for sedation despite concerns following the FDA black-box warning. Subsequent to publication of this paper, IV olanzapine was added to the Australian Therapeutic Guideline 2013 as an option for the management of behavioural emergencies. This paper was the feature article, selected for media release in Sept 2012 by American College of Emergency Physicians, Reuters, and Monash University. This article was among the top 25 downloads via ScienceDirect in 2013.

Selected Publications
  • Blais JE, Wei Y, Yap KKW, Alwafi H, Ma TT, Brauer R, Lau WCY, Man KKC, Siu CW, Tan KC, Wong ICK, Wei L, Chan EW*. Trends in lipid-modifying agent use in 83 countries. Atherosclerosis, 2021 doi: 10.1016/j.atherosclerosis.2021.05.016.Click to see abstract
  • Zhao JX, Wang H, Li X, Yang H, Yan VKC, Wong KH, Guo Y, Cheung MK, Lip G, Siu CW, Tse HF, Chan EW*. Importance of attributes and willingness-to-pay for oral anticoagulant therapy in patients with atrial fibrillation in China: A discrete choice experiment. PLOS Medicine, 2021 doi: 10.1371/journal.pmed.1003730.Click to see abstract
  • Chan EW*, Lao KSJ, Lam L, Tsui MSH, Lui CT, Wong ACP, Graham CA, Cheng RCH, Chung TS, Lam HF, Ting SM, Knott JC, Taylor DMcD, Kong DCM, Leung LP, Wong ICK*. Intramuscular midazolam, olanzapine, or haloperidol for the management of acute agitation in the emergency department: a multi-center, double-blind, randomized clinical trial. EClinicalMedicine. 2021; (32)100751. doi:10.1016/j.eclinm.2021.100751.Click to see abstract
    This work led to the inclusion of olanzapine in the HA formulary at the Accident and Emergency Department (A&E) of Queen Mary Hospital (one of two public teaching hospitals in Hong Kong) two months following publication. The A&E of other hospital clusters in Hong Kong are in the process of submission for approval.
  • Lao KSJ, Zhao JX, Blais JE, Lam L, Wong ICK, Besag FMC, Chang WC, Castle DJ, Chan EW*. Antipsychotics and Risk of Neuroleptic Malignant Syndrome: A Population-Based Cohort and Case-Crossover Study, CNS Drugs. 2020 Nov; (34) 11:1165-1175. doi:10.1007/s40263-020-00767-9.Click to see abstract
  • Lau WCY, Douglas IJ, Wong ICK, Smeeth L, Lip GYH, Leung WK, Siu CW, Cheung BMY, Mok MTC, Chan EW*. Thromboembolic, bleeding, and mortality risks among patients with nonvalvular atrial fibrillation treated with dual antiplatelet therapy versus oral anticoagulants: a population-based study. Heart Rhythm. 2020; 17(1): 33-40. doi:10.1016/j.hrthm.2019.07.034.Click to see abstract
  • Man KKC, Chan EW, Coghill D, Ip P, Simonoff E, Chan PKL, Lau WCY, Schuemie MJ, Sturkenboom MCJM, Wong ICK*. Prenatal antidepressant use and risk of attention-deficit/ hyperactivity disorder in offspring: a population-based cohort study. BMJ. 2017; 357:j2350:1-9. doi: 10.1136/bmj.j2350.Click to see abstract
  • Lau WCY, Li X, Wong ICK, Man KKC, Lip GYH, Leung WK, Siu CW, Chan EW*. Bleeding-related hospital admissions and 30-day readmissions in patients with non-valvular atrial fibrillation treated with dabigatran versus warfarin. J Thromb Haemost. 2017; 15(10): 1923-1933. doi: 10.1111/jth.13780. Click to see abstract
  • Lao KSJ, He Y, Wong ICK, Besag FMC, Chan EW*. Tolerability and safety profile of cariprazine in treating psychotic disorder, bipolar disorder and major depressive disorder: a systematic review with meta-analysis of randomised controlled trials. CNS Drugs. 2016, 30(11):1043-1054. doi: 10.1007/s40263-016-0382-z.Click to see abstract
  • Chan EW, Lau WCY, Siu CW, Lip GYH, Leung WK, Anand S, Man KKC, Wong ICK*. Effect of suboptimal anticoagulation treatment with antiplatelet therapy and warfarin on clinical outcomes in patients with non-valvular atrial fibrillation: A population-wide cohort study. Heart Rhythm. 2016; 13(8):1581-1588. doi: 10.1016/j.hrthm.2016.03.049.Click to see abstract
  • Chan EW, He Y, Chui CSL, Wong AYS, Lau WCY, Wong ICK*. Efficacy and safety of lorcaserin in obese adults: a meta-analysis of 1-year randomized controlled trials (RCTs) and narrative review on short-term RCTs. Obes Rev. 2013; 14(5):383-392. doi: 10.1111/obr.12015.Click to see abstract


Professor Chan has received funding and support from:

  • National Natural Science Foundation of China (NSFC) – Excellent Young Scientist Fund (Hong Kong and Macau), Young Scientist Fund, China
  • Research Grants Council (RGC), Hong Kong SAR
  • Narcotics Division, Security Bureau, Beat Drugs Fund Regular Funding Scheme, Hong Kong SAR
  • Health and Medical Research Fund (HMRF), Hong Kong SAR
  • National Health and Medical Council (NHMRC), Australia
  • Australian Rotary Health, Australia
  • Pharmaceutical industry sponsors
  • The University of Hong Kong (Teaching Development Grant, Small Projects Grant, Seed Funding Scheme), Hong Kong SAR


Selected Grants and Funding as Principal Investigator or Co-Principal Investigator*:

Year Funding Scheme Project Title Approved Amount (HK$)
2023 RGC General Research Fund (GRF) Safety and effectiveness of cardiovascular drugs in the management of atrial fibrillation with mitral stenosis among Chinese patients: a real-world population-based cohort study (Reference number: 17113523) 1,098,000
2022 RGC General Research Fund (GRF) Effectiveness and safety of NOACs and warfarin in Chinese patients with atrial fibrillation and mitral stenosis: evidence from real-world data (Reference number 17103422) 1,028,773
2022 HMRF Importance of attributes and willingness to pay for lipid-lowering agents in patients with hypercholesterolemia in Hong Kong: a discrete choice experiment (Reference number 20211921) 1,122,040
2021 HMRF Research on COVID-19* HKU Optimizing Protection and Effectiveness (HOPE) of COVID-19 Vaccines: Factors associated with COVID-19 vaccine uptake and protection: a population-wide epidemiology study using big data (Reference number COVID1903011) 12,511,372
2021 RGC Collaborative Research Fund (CRF) Coronavirus Disease (COVID-19) and Novel Infectious Disease (NID) Research Exercise* A multinational big data Covid-19 Epidemiological Study on post-infection Outcomes (ACESO) (Reference number C7154-20GF) 9,691,060
2021 RGC General Research Fund (GRF) Anticoagulation strategies for cancer associated thrombosis (Reference number 17108621) 985,412
2021 HMRF Understanding the preferences for low-dose aspirin use in the primary prevention of colorectal cancer among Hong Kong clinicians and residents: a discrete choice experiment (Reference number 18191851) 797,676
2020 NSFC – Excellent Young Scientist Fund (Hong Kong and Macau) Optimising antipsychotic drug management in patients with mental disorders to improve patient outcomes and reduce healthcare resource utilisation (Project number 8202290200) 1,376,173
2018 NSFC – Young Scientist Fund Preferences and willingness to pay for novel oral anticoagulants in patients with atrial fibrillation in China (Approval number 71704149) 209,841
2017 Narcotics Division, Security Bureau, Beat Drugs Fund Regular Funding Scheme Understanding drug abusers and their healthcare pathways: towards better management in Hong Kong (Project number BDF160052) 2,300,115
2015 RGC General Research Fund (GRF) Mortality risk & death cause in patients using haloperidol compared to other antipsychotics: an 11-year real-world, population-based cohort study using big data (Project number 17111615) 1,072,525
2014 HMRF Mother’s preferences and willingness to pay for human papillomavirus vaccination for their daughters: a discrete choice experiment in Hong Kong (Project number 13120652) 378,036
2014 RGC General Research Fund (GRF) Pharmacoepidemiology of oral anticoagulation agents – a comparison of dabigatran, etexilate, warfarin and dual-antiplatelet therapy in patients with atrial fibrillation (Project number 17102314) 213,938
2013 RGC Early Career Scheme (ECS) Intramuscular olanzapine versus haloperidol or midazolam for the management of acute agitation in the emergency department – a multicenter randomized clinical trial (Project number 789813) 1,411,647

Other Information
WARDEN of Richard Charles Lee (R. C. Lee) Hall
Professor Esther Chan is currently the Warden of Richard Charles Lee (R. C. Lee) Hall. She has a vision to promote multiculturalism and diversity in all student activities and empower students to develop their leadership potential. (

Seeking full time PhD candidates and Research Assistants commencing 2022-2023

We are seeking highly driven and organised registered practitioners in nursing, pharmacy, medicine or related disciplines to conduct research in the areas of medication safety, pharmacoepidemiology and pharmacoeconomics. We are also seeking Research Assistants who are skilled in data analysis and interpretation, who enjoy independent work and team-based projects. Experience in working with large data sets, programming and pharmacoeconomic models will be an advantage.
For further information, please email Professor Esther Chan with your research proposal, university transcripts and CV (

Undergraduate training for research exchange 2022-2023

We provide training to undergraduate students to conduct research on a variety of topics as summer research internship or international research exchange throughout the year. The training period will be a minimum of two months. Students in pharmacy, nursing, medicine or related disciplines who wish to enhance research skills or gain exposure in clinical settings are encouraged to apply. For application or enquiries, please email Professor Esther Chan with academic transcripts and CV at

Current Team Members and Students
  • Ms. Fung, Lydia (Research Assistant)
  • Ms. Huang, Callie (Research Assistant)
  • Dr. Yiu, Hei Hang Edmund (Post-Doctoral Fellow)
  • Doctor of Philosophy (PhD)
    • As primary supervisor
      • Yang, Yu Rainee (2022- )
      • Li, Tung Hiu Silvia (2021- )
      • Yan, Ka Chun Vincent (2021- )
      • Zhao, Jesse (2020- )
      • Kang, Wei Faery (2020- )
      • Ye, Xuxiao Chris (2020- )
      • Shami, Jessica (2019-2022 )
      • Wei, Luna (2019- )
      • Blais, Joseph (2018-2022 )
      • Lao, Shi Jian Kim (2014-2018)
      • Lau, Cheuk Yin Wallis (2013-2017)
      • Wong, Yun Sum Angel (2013-2017)
      • Chui, Sze Ling Celine (2013-2017)
      • He, Ying Helen (2012-2015)
    • As co-supervisor
      • Lam, Ivan (2021- )
      • Cheung, Edmund (2020- )
      • Ng, Wai Sei, Vanessa (2019-2023)
      • Gao, Le (2019-2023 )
    • Master of Philosophy (MPhil)
      • Wong, Kai Chung Vincent (2015-2018)
Research Collaborators
  • Neuropsychiatric Diseases Global Epidemiology Network (NeuroGEN), The University of Hong Kong (
  • Department of Geriatric Cardiology, the Second Medical Centre, Chinese PLA General Hospital, Beijing, China
  • The Asian Pharmacoepidemiology Network (AsPEN) (
  • Department of Practice and Policy, UCL School of Pharmacy, UK
  • Centre for Medicine Use and Safety, Faculty of Pharmacy and Pharmaceutical Sciences, Monash University, Melbourne, Australia
  • Hong Kong Poison Information Centre, Hong Kong SAR
  • Department of Accident and Emergency; North District Hospital, Pamela Youde Nethersole Eastern Hospital, Prince of Wales Hospital, Queen Elizabeth Hospital, Queen Mary Hospital, Ruttonjee Hospital, Tuen Mun Hospital, United Christian Hospital, Hospital Authority, Hong Kong SAR
  • Emergency and General Medicine Research, Department of Emergency Medicine, Austin Hospital; Department of Emergency Services, Royal Melbourne Hospital; St. Vincent's Hospital Melbourne Victoria, Australia
  • School of Clinical Medicine (Department of Emergency Medicine; Department of Medicine including Clinical Pharmacology, Endocrinology and Metabolism, Gastroenterology & Hepatology, Infectious Disease; Neurology, Psychiatry, Respiratory Medicine, Rheumatology & Clinical Immunology, Department of Paediatrics and Adolescent Medicine), LKS Faculty of Medicine, HKU; Queen Mary Hospital, Hong Kong SAR
  • Department of Microbiology, Department of Pharmacy, Queen Mary Hospital, Hong Kong SAR
  • Department of Psychiatry, St. Vincent's Hospital Melbourne, Victoria, Australia
  • School of Pharmacy, National Cheng Kung University, Taiwan
  • School of Nursing, LKS Faculty of Medicine, HKU
  • School of Public Health, LKS Faculty of Medicine, HKU
  • HKU Musketeers Foundation Institute of Data Science
Centre for Safe Medication Practice and Research

Web site: CSMPR

1/F, Jockey Club Building for Interdisciplinary Research
5 Sassoon Road, Pokfulam
Hong Kong SAR, China
For appointments email:

Regular Student Consultation Hours
Every Tuesday at 2:00pm - 3:00pm

Department of Pharmacology and Pharmacy
Li Ka Shing Faculty of Medicine
02-56, 2/F Laboratory Block, 21 Sassoon Road, Pokfulam
Hong Kong SAR, China