Two of the four prescription pain relief medicines containing dextropropoxyphene, due to be cancelled from the Australian Register of Therapeutic Goods (ARTG) from 1 March 2012, have had a reprieve.

Late last year, the Therapeutic Goods Administration (TGA) decided to cancel four products known by the brand names Capadex, Di-Gesic, Doloxene and Paradex following an extensive review of information about the medicines’ safety and efficacy. The decision was to take effect from 1 March 2012.

However, the manufacturer of two of these brands of medicine - Di-Gesic and Doloxene - has appealed to the Administrative Appeals Tribunal (AAT). The AAT has decided that Di-Gesic and Doloxene should remain available for the time being — at least until the final AAT hearing has taken place, or until a further order of the AAT.

There is no appeal in relation to the other two brands - Capadex and Paradex - so these will no longer be available from 1 March, as planned.

The decision to cancel the four medicines came following an extensive review of the safety and efficacy of the dextropropoxyphene – a medicine in the opioid group - conducted by the TGA. The review found that only limited pain relief is provided by the dextropropoxyphene in Capadex, Di-Gesic, Doloxene and Paradex, and that there are serious safety risks with the use of these medicines.

According to the National Prescribing Service (NPS), the main risks associated with medicines containing dextropropoxyphene are to do with adverse effects on the electrical activity of the heart, including serious heart rhythm problems. These adverse effects on the heart can occur even at recommended doses. 

However people taking high doses of these medicines, such as the elderly and people with kidney problems, are particularly at risk.

In making its decision, the TGA determined that the overall risk of serious adverse reactions from these four medicines outweighs any benefits that may be provided. 

The NPS says evidence shows that the three medicines containing a combination of paracetamol and dextropropoxyphene (Capadex, Di-Gesic and Paradex) are no more effective than taking paracetamol alone.

CEO of the NPS, Dr Lynn Weekes, says that while Di-Gesic and Doloxene will remain on the market for the time being, the advice remains the same for all these medicines — that the potential harms outweigh the possible benefits.

“Given the limited benefit of pain relievers containing dextropropoxyphene, the risks associated with their use, and the fact that we also know dextropropoxyphene can cause dependency, NPS agrees with the TGA’s decision to cancel the four pain relief medicines containing this active ingredient,” says Dr Weekes.

Dr Weekes says that anyone who had been taking any of the medicines containing dextropropoxyphene —Capadex, Di-Gesic, Doloxene or Paradex —should speak to their doctor about alternative pain relief medicines.

However, she warns against abruptly discontinuing these medicines.

“If you have been taking these medicines regularly for chronic pain, talk to your doctor about how to gradually change to a new medicine. Suddenly stopping these medicines is not recommended and can cause a range of unpleasant withdrawal symptoms,” says Dr Weekes.

This TGA position is consistent with medicine regulators in the United States, Europe, New Zealand and elsewhere, where dextropropoxyphene-containing medicines have been removed from the market.