Medsafe reviews dextropropoxyphene-containing medicines: Capadex and Paradex

Medsafe has started a statutory review of the safety and efficacy of all medicines containing dextropropoxyphene, Medsafe’s Group Manager Dr Stewart Jessamine said.

Medicines containing dextropropoxyphene are analgesics used to treat chronic moderate pain. Two medicines containing dextropropoxyphene are currently approved for use in New Zealand. The brand names of these products are Capadex and Paradex. Further information about these medicines is available on their data sheets on the Medsafe website (www.medsafe.govt.nz).

“Should this review show that the balance of risks and benefits is unfavourable, this may lead to the withdrawal of these medicines in New Zealand. At the earliest, a final decision on the outcome will not be available until the last quarter of the year,” Dr Jessamine said.

Medsafe initially reviewed the safety of these medicines in 2005. There were concerns around the risk of fatal heart problems, depression of breathing and coma especially in overdose. It was noted that some overdoses had occurred accidentally. Following consultation with healthcare professionals, Medsafe concluded that there was a clinical need for these products for some patients.

In late 2005, Medsafe introduced prescribing restrictions to limit use of these medicines to those patients most likely to benefit from their use. In addition, Medsafe required the manufacturers of these medicines to conduct a drug utilisation study to determine if the restrictions had produced changes in prescribing behaviour.

Dr Jessamine said the results of the study investigating the use of these medicines was reviewed by the Medicines Adverse Reactions Committee (MARC) in June this year.

“The study showed that over half the prescriptions issued for Paradex were not in accordance with the prescribing restrictions. In addition, a significant number of prescriptions were issued for patients, including children, and the treatment of conditions outside of those assessed and approved by Medsafe.”

The MARC concluded that the restrictions on the use of Capadex and Paradex have not changed prescribing habits and recommended to Medsafe that it review the benefits and risks of the continued availability of these medicines.