Issue 31 / 19 August 2013

TWO leading pharmacologists have called for a boycott on prescribing dextropropoxyphene after its manufacturer successfully appealed the drug’s removal from the Australian Register of Therapeutic Goods.

Dextropropoxyphene, an opioid, was approved for mild-to-moderate pain more than 30 years ago. Since then evidence has accumulated that it is no more efficacious than paracetamol.

A “For Debate” article in the MJA said the drug also carried a significant risk of sudden death from cardiotoxicity in patients with renal impairment, drug interactions and accidental or deliberate overdose. (1)

Despite this, dextropropoxyphene remains on the market in Australia after an appeal to the Administrative Appeals Tribunal (AAT) by the drug’s manufacturer against the Therapeutic Goods Administration (TGA) decision to delist it, the authors wrote.

The drug has been banned in the UK (2004), EU (2009), US (2010), New Zealand (2010) and elsewhere, they wrote.

The TGA delisted dextropropoxyphene in 2011, with the decision reaffirmed in January 2012. (2)

The AAT upheld the appeal by the manufacturer, Aspen Pharmacare, allowing dextropropoxyphene to remain on the market provided “conditions were put in place directed at minimising the risk”. (3)

In its judgment, the AAT said that “the Tribunal has concluded that the quality, safety and efficacy of both Di-Gesic [dextropropoxyphene/paracetamol] and Doloxene [dextropropoxyphene napsylate] is not unacceptable. In consequence, the products will remain on the [Australian Register of Therapeutic Goods]”.

Professor David Henry, CEO of the Institute for Clinical Evaluative Sciences and professor in the Department of Medicine at the University of Toronto, told MJA InSight that more attention needed to be paid to Aspen’s role.

If the TGA and AAT were not able to protect the public, “doctors and pharmacists should take matters into their own hands and stop using this dangerous and useless drug”, Professor Henry said.

He said doctors might also consider whether to use other products from the same manufacturer.

Professor Andrew Somogyi, professor of clinical and experimental pharmacology at the University of Adelaide, said he was convinced the only way to keep the public safe from dextropropoxyphene was if Aspen now voluntarily removed it from the market.

“And the only way the company will remove it is if there are no sales”, Professor Somogyi told MJA InSight.

He called on medical educators to educate their students and peers about therapeutic guidelines that advised against prescribing the drug. “That’s the only way.”

A spokesperson for Aspen Pharmacare told MJA InSight the company’s policy was not to speak to the media.

Professor Somogyi said the AAT decision set “a very dangerous precedent” as well as damaging Australia’s reputation internationally.

“I’m quite embarrassed about it, actually”, he said. “Internationally, people are looking at us and saying ‘what’s going on?’. The TGA is being viewed as foolish and naïve, and the clinical investigators are being made to look foolish as well.

“I feel very sorry for the TGA”, Professor Somogyi said. “They’re doing the best they can to protect the public. They made a very good decision about dextropropoxyphene and then they get this ludicrous decision [from the AAT].”

A spokesperson for the TGA said each party would have an opportunity to consider an appeal to the AAT finding.

The authors of the MJA article said the case highlighted the need to reform the appeal process by drug manufacturers for the sake of public safety and interest.

“When registration can be contrary to TGA advice and based around civil court proceedings rather than scientific interpretation of evidence, the international reputation of Australia’s drug regulatory system could be at stake”, they wrote.

“[The case] should clearly highlight to our government the urgent need to revise the legal appeal processes that in our view inappropriately burden the TGA when it decides to take action to protect the Australian people.”

1. MJA 2013; 199 (4): 257-260
2. TGA 2012; Media release: Update on TGA decision to cancel prescription pain-killers, 6 Sept
3. Administrative Appeals Tribunal of Australia 2013; Aspen Pharmacare Australia Pty Ltd and Minister for Health and Ageing [2013] AATA 197