Related Experiment Video
Updated: Feb 18, 2026

An Affordable HIV-1 Drug Resistance Monitoring Method for Resource Limited Settings
Published on: March 30, 2014
Concomitant medication polypharmacy, interactions and imperfect adherence are common in Australian adults on
Krista J Siefried1, Limin Mao, Lucette A Cysique
1aSt Vincent's Centre for Applied Medical Research, St Vincent's Hospital, SydneybCentre for Social Research in HealthcNeuroscience Research Australia, University of New South Wales, SydneydNational Association of People with HIV Australia, NewtowneSchool of Public Health and Community Medicine, University of New South Wales, Sydney, New South WalesfDepartment of Infectious Diseases, Alfred Hospital and Monash UniversitygDepartment of Infectious Diseases, The Royal Women's HospitalhMonash Infectious Diseases, Monash Health, Melbourne, VictoriaiAlbion Centre, South Eastern Sydney Local Hospital Network, Sydney, New South WalesjCentre for Population Health, Burnet InstitutekMelbourne Sexual Health Centre, Alfred HealthlCentral Clinical School, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, VictoriamWestern Sydney Sexual Health Centre, University of Sydney, ParramattanWestmead Clinical School, Sydney Medical School, University of Sydney, Westmead, New South WalesoCentre Clinic, St Kilda, Melbourne, VictoriapHoldsworth House Medical PracticeqThe Kirby Institute, University of New South Wales, Sydney, New South Wales, AustraliarDepartment of Interdisciplinary Social Science, Utrecht University, Utrecht, The Netherlands.
Objectives:
We quantified concomitant medication polypharmacy, pharmacokinetic and pharmacodynamic interactions, adverse effects and adherence in Australian adults on effective antiretroviral therapy.
Design:
Cross-sectional.
Methods:
Patients recruited into a nationwide cohort and assessed for prevalence and type of concomitant medication (including polypharmacy, defined as ≥5 concomitant medications), pharmacokinetic or pharmacodynamic interactions, potential concomitant medication adverse effects and concomitant medication adherence. Factors associated with concomitant medication polypharmacy and with imperfect adherence were identified using multivariable logistic regression.
Results:
Of 522 participants, 392 (75%) took a concomitant medication (mostly cardiovascular, nonprescription or antidepressant). Overall, 280 participants (54%) had polypharmacy of concomitant medications and/or a drug interaction or contraindication. Polypharmacy was present in 122 (23%) and independently associated with clinical trial participation, renal impairment, major comorbidity, hospital/general practice-based HIV care (versus sexual health clinic) and benzodiazepine use. Seventeen participants (3%) took at least one concomitant medication contraindicated with their antiretroviral therapy, and 237 (45%) had at least one pharmacokinetic/pharmacodynamic interaction. Concomitant medication use was significantly associated with sleep disturbance and myalgia, and polypharmacy of concomitant medications with diarrhoea, fatigue, myalgia and peripheral neuropathy. Sixty participants (12%) reported imperfect concomitant medication adherence, independently associated with requiring financial support, foregoing necessities for financial reasons, good/very good self-reported general health and at least 1 bed day for illness in the previous 12 months.
Conclusion:
In a resource-rich setting with universal healthcare access, the majority of this sample took a concomitant medication. Over half had at least one of concomitant medication polypharmacy, pharmacokinetic or pharmacodynamic interaction. Concomitant medication use was associated with several adverse clinical outcomes.
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