--- abstract: 'Objective: This case report highlights the risk of Torsade de Pointes (TdP), a life threatening cardiac arrhythmia in a heroin dependent patient receiving methadone substitution therapy who was prescribed erythromycin for upper respiratory tract infection. Method: We report a case of a 35-year-old Malay man on methadone maintenance treatment who developed TdP possibly due to drug interaction between methadone and erythromycin. Results: The patient reported feeling unwell, chest pain and feeling dizzy after consuming 2 doses of erythromycin. ECG monitoring showed prolonged rate-corrected QT interval leading to TdP. The patient was admitted to the ward where the cardiac arrhythmia ceased following methadone discontinuation. This cardiac arrhythmia was most likely due to drug interaction between methadone and erythromycin (an enzyme inhibitor) which led to an increase in methadone concentration and potentiated the adverse effects. Conclusion: As methadone is a beneficial treatment for heroin dependent patients, the risk of cardiac arrhythmia is of great concern. To avoid complications of drug interaction, patients on methadone therapy should be advised to seek medical assessment before taking other drugs. As TdP is life threatening, it is thus important that physicians and psychiatrists involved in the treatment of heroin dependent patients on methadone substitution therapy be made aware of this risk.' altloc: [] chapter: ~ commentary: ~ commref: ~ confdates: ~ conference: ~ confloc: ~ contact_email: ~ creators_id: - noorzurani@gmail.com - ~ creators_name: - family: 'Robson ' given: 'Noorzurani ' honourific: '' lineage: '' - family: Habil given: 'Mohamad Hussain ' honourific: '' lineage: '' date: 2010 date_type: published datestamp: 2012-11-09 19:02:25 department: ~ dir: disk0/00/00/82/50 edit_lock_since: ~ edit_lock_until: 0 edit_lock_user: ~ editors_id: [] editors_name: [] eprint_status: archive eprintid: 8250 fileinfo: /style/images/fileicons/application_pdf.png;/8250/1/ASEAN_3_6_Noorzurani.pdf full_text_status: public importid: ~ institution: ~ isbn: ~ ispublished: pub issn: ~ item_issues_comment: [] item_issues_count: ~ item_issues_description: [] item_issues_id: [] item_issues_reported_by: [] item_issues_resolved_by: [] item_issues_status: [] item_issues_timestamp: [] item_issues_type: [] keywords: 'Methadone, arrhythmia, substitution, Torsade de Pointes (TdP), drug interaction' lastmod: 2012-11-09 19:02:25 latitude: ~ longitude: ~ metadata_visibility: show note: ~ number: 1 pagerange: 1-5 pubdom: TRUE publication: Asean Journal of Psychiatry publisher: ~ refereed: TRUE referencetext: ~ relation_type: [] relation_uri: [] reportno: ~ rev_number: 8 series: ~ source: ~ status_changed: 2012-05-13 12:33:17 subjects: - soc-psy succeeds: ~ suggestions: ~ sword_depositor: ~ sword_slug: ~ thesistype: ~ title: Erythromycin induced Torsade de Pointes in a Methadone maintenance patient:Case Report type: journalp userid: 16139 volume: 11