"Careful, medicines can also be poisons"

Pharmacology researcher, Prof Alastair Stewart responds to the hydroxychloroquine debate.

Published in The Australian, the op-ed discusses hydroxychloroquine – from its classification by the TGA as a poison, its purported use as a COVID-19 therapy to the importance of science and evidence-based medicine.

Hydroxychloroquine has been widely used as an anti-malaria drug, and with subsets of patients of other diseases including Lupus. More recently attention shifted to its use as a potential COVID-19 treatment – and those seeking to treat the coronavirus stockpiled the drug, creating supply shortages to those patients currently using it.

As a result the Therapeutic Goods Administration (TGA) reclassified Hydroxychloroquine a poison earlier this year, in order to restrict PBS availability, keeping it available for patients who require it for evidence-based medical treatment.

When journalist Terry McCrann (“When one man’s poison is another’s medicine”, August 7) berated the TGA for defining hydroxychloroquine as a poison, Prof Alastair Stewart and colleagues from the School of Biomedical Sciences were quick to respond.

“It is axiomatic to the discipline of pharmacology that all drugs are poisons. We teach our biomedicine and medical students to rationalise this core principle, using evidence to support the truth of a statement that has been cast to protect the community from the harms drugs may cause,” says Alastair.

Objective clinical trial evidence of 'substantial efficacy and safety' on populations of patients is required to persuade the US Food and Drug Administration and our TGA to register a therapeutic.”

“All therapeutic drugs are incorporated into the poisons standard. The Department of Health exercised discretionary power to amend the poisons standard (52D(2) (a), Therapeutic Goods Act 1989), enabling rescheduling of hydroxychloroquine (Schedule 4, Appendix D). Hydroxychloroquine has not been newly classified as a poison by this amendment. We note that salbutamol supplies have been protected by the same amendment, without any expression of concern.”

“In our opinion, the government-TGA action has avoided harms to COVID-19 patients in whom benefit from hydroxychloroquine is unlikely based on the most reliable evidence, and its potential for harm in these patients remains uncertain. The restriction in access has the dual benefits of maintaining supplies for those selected patients with auto-immune conditions who benefit from it, while preventing potential toxicity of off-label use in COVID-19 patients.”

"Our TGA experts have served the Australian community well in providing an effective antidote to the rhetoric of domestic and international politicians and celebrities that regularly poisons community thinking on science and evidence-based medicine. This is not about US President Donald Trump, it is about science and high-quality clinical trial evidence."

The opinion piece was written by Prof Alastair Stewart, Director of the ARC Centre for Personalised Therapeutics Technologies, Department of Pharmacology and Therapeutics, in collaboration with Dr Phillip Reece, Honorary Senior Fellow, Department of Pharmacology and Therapeutics; David Story, Deputy Director, Centre for Integrated Critical Care; and Prof Megan Munsie, Deputy Director, Centre for Stem Cell Systems, School of Biomedical Sciences. It was published in The Australian on 25 August 2020.

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