The class of medicines known as COX-2 inhibitors will stay on the market in New Zealand, but with considerably stronger warnings for their use and the requirements for pharmaceutical companies to collect and report information on usage, according to MedSafe, the agency that monitors drug safety in the country. Recommendations made by the Medicines Adverse Reactions Committee (MARC), and accepted by the Ministry of Health, end months of uncertainty for patients. A review of the cardiovascular safety of the COX-2 inhibitors was begun in October 2004 after Vioxx (rofecoxib), one of six COX-2 inhibitors marketed in New Zealand, was withdrawn after international findings that its use was associated with an increased risk of heart attacks and strokes.
Pharmaceutical companies will also have to provide Medsafe with additional safety information as it becomes available. The Ministry is also seeking to extend, until further notice, the voluntary ban by pharmaceutical companies on promoting these products, some of which have been previously advertised on television. In February this year the Ministry warned against using COX-2 inhibitors in patients at high risk of heart attacks or strokes. High risk patients include those with a previous history of heart attack or stroke; those with diabetes, high blood pressure, high cholesterol levels or patients who smoke.
In early April a second COX-2 inhibitor, Bextra (valdecoxib), was voluntarily withdrawn by its manufacturer due to concerns about an increased risk of serious skin reactions. It is anticipated that a decision regarding the most appropriate strategy to manage the risk associated with Bextra (valdecoxib) will be made after the MARC meeting in June 2005.
"The advice which we are issuing today, based on the MARC recommendations, reflects our earlier view that an increased risk of heart attacks and strokes can occur with all COX-2 inhibitors," Ministry spokesman Dr Stewart Jessamine said. "However, we accept the very strong arguments from some patients and prescribers that for some people these medicines are the best treatment option. Therefore, we are allowing continued use but with restrictions to ensure that they are used mainly by those patients for whom they offer the most benefit and the least risk. This approach puts us in line with our European counterparts, the European Medicines Evaluation Agency, and pretty close to Australia," Dr Jessamin added.
Dr Jessamine, however, commented, "there are still a number of unanswered questions about the safety of the COX-2 inhibitors and Medsafe has asked companies to supply more information on the cardiovascular and gastrointestinal safety of these agents as it becomes available. Given this uncertainty, Medsafe and the University of Otago's Pharmacovigilance Centre will be keeping a close eye on these medicines for some time into the future. Knowing how many patients are taking these medicines is vital if we hope to make well informed decisions about risk to patients. "
"While the MARC has also recommended prohibiting Direct-to-Consumer advertising of COX-2 inhibitors, there has been a voluntary moratorium in place since Medsafe requested companies to stop professional and consumer advertising of these products in December 2004". Dr Jessamine said. " As this approach has been effective, Medsafe has requested that all pharmaceutical companies which market COX-2 inhibitors continue their voluntary moratorium on advertising to patients and prescribers, until further notice." New Zealand is the only other country, besides the United States, to allow direct to consumer advertising of prescription drugs. There have been calls for banning this form of advertising in the US too. (Related article: Impact of drug advertising and promotion on prescriptions)
"In summary, we believe we have a way forward which gives New Zealand patients and prescribers access to a class of medicines which we acknowledge are the best option for some people, while doing our best to ensure that they are selected only for those people and are used on the basis of informed decisions by both prescribers and consumers. We realise it's been a trying time for some, particularly arthritis patients. However, we trust the approach we have outlined today will reassure patients and prescribers that we have listened to what they have to say, and are acting in their best interests," Dr Jessamine said.
Which COX-2 inhibitors are available in New Zealand?
Celecoxib (brand name: Celebrex)
Etoricoxib (brand name: Arcoxia)
Meloxicam (brand name: Mobic)
Parecoxib (brand name: Dynastat)
Valdecoxib (brand name: Bextra) - voluntarily withdrawn April 2005
What alternative anti-inflammatory agents are available?
Alternative anti-inflammatory agents include:
Diclofenac (brand names: Apo-Diclofenac, Apo-Diclo SR, Voltaren)
Ibuprofen (brand names: I-Profen, Brufen, Brufen Retard)
Sulindac (brand names: Clinoril, Daclin)
Tiaprofenic acid (brand names: Surgam, Surgam SA)
Ketoprofen (brand names: Orudis, Oruvail)
Naproxen (brand names: Naxen, Naprosyn SR, Synflex)
Tenoxicam (brand names: Tilcotil)
Piroxicam (brand names: Piram D)