Considerations for the safe prescribing and use of COX-2-specific inhibitors

Is Australia's national medicines policy failing? The case of COX-2 inhibitors

Australia has a National Medicines Policy with aims that include quality use of medicines, but policy stakeholders failed to protect Australia from the COX-2 (cyclo-oxygenase-2) inhibitor disaster. Drug regulators did not warn prescribers appropriately about potential cardiovascular risks. The Pharmaceutical Benefits Scheme did not limit unjustified drug expenditures on COX-2 inhibitors. Drug companies ran intense and misleading promotional campaigns on COX-2 inhibitors without adequate controls. Independent drug information was insufficient to counter the effects of the millions of dollars spent on advertising. Core elements of the National Medicines Policy--in particular the drug approval process, the post-marketing surveillance system, the control of drug promotion, and the quality of independent drug information--require major reappraisal if we want to avoid similar disasters in the future.

Impact of selective cyclooxygenase-2 inhibitors on anti-ulcer medication and non-steroidal anti-inflammatory drug use in patients with rheumatic disease

BACKGROUND

Anti-inflammatory medications are the most common treatment for rheumatic disease in Australia. Recent years have seen large increases in the use of selective cyclooxygenase-2 (COX-2) inhibitors. Predictors of use, costs and benefits of the new medications have not been evaluated.

AIMS

To determine trends in selective COX-2 inhibitor, non-steroidal anti-inflammatory drug (NSAID) and anti-ulcer medication (AUM) prescription following the introduction of selective COX-2 inhibitors; to determine predictors of selective COX-2 inhibitor, NSAID and AUM prescribing and to perform a limited evaluation of the costs and benefits associated with the introduction of selective COX-2 inhibitors.

METHODS

Groups of consecutive patients attending a hospital rheumatology clinic, private rooms of consulting rheumatologists and a dermatology outpatient clinic were surveyed by investigator-administered questionnaire on three separate occasions. Information was sought about AUM, NSAID and selective COX-2 use and about factors likely to influence selective COX-2 prescribing. Sampling was carried out at 3, 10 and 16 months after the release of COX-2 selective inhibitors in Australia. The final survey was 3 months after Pharmaceutical Benefits Scheme (PBS) listing of celecoxib in Australia. Costs of treatment were calculated from survey findings of frequency of drug use as well as published drug prices and hospitalisation costs.

RESULTS

Four-hundred and fifty-eight patients were surveyed. From the 3 months post-release to the 3 months post-PBS listing, a period of 13 months, COX-2 use in rheumatology patients increased from 18 to 57%. De novo prescription of selective COX-2 inhibitors increased from 42 to 61%. During the same period there was a fall in both NSAID (43-20%) and AUM use (41-27%). Neither selective COX-2 inhibitor nor NSAID prescription was related to risk factors for gastro-intestinal (GI) complications, but AUM use was found to correlate strongly to histories of gastroscopy, GI ulceration or GI bleed. The calculated increase in the cost of treatment was $1 033 002/10 000 patients per year. The net cost per serious GI event prevented was $71 736, compared with the normal cost of treatment of $2004.

CONCLUSIONS

Among rheumatology patients, selective COX-2 inhibitors have largely replaced NSAIDs and have resulted in a reduction in AUM consumption, but prescribing patterns for selective COX-2 inhibitors have not been related clearly to risk factors for GI complications. The introduction of selective COX-2 inhibitors has been associated with a significant increase in expenditure.

Medical management of osteoarthritis of the knee and hip joints

Osteoarthritis is a common, chronic condition which requires an individualised management plan involving multiple kinds of treatment. Exercise programs and the Arthritis Self-Management Program reduce pain and disability associated with osteoarthritis. Paracetamol is the most appropriate first-line analgesic. Non-steroidal anti-inflammatory drugs may be used as second-line analgesia on an as-needed basis (including continuous use), but must be used with caution. Cyclo-oxygenase-2-specific inhibitors are used if there are risk factors for upper-gastrointestinal complications, but only after considering cardiovascular risk. Glucosamine sulfate is a safe and effective over-the-counter treatment. Intra-articular therapies are used when others have failed.

Cyclooxygenase-2 inhibitors: Do they have a role in emergency department prescribing?

Cyclooxygenase-2 selective inhibitors (COXIB or CSI) have been released with a fanfare as efficacious and safer alternatives to traditional non-steroidal anti-inflammatory drugs. They purport to offer equivalent degrees of analgesia and an improved safety profile. COXIB currently available in Australasia are celecoxib (Celebrex), rofecoxib (Vioxx) and etoricoxib (Arcoxia). This review discusses the pharmacology of these agents and reviews recent literature regarding their effectiveness and safety. It endeavours to answer the question 'Should we be using COXIB in emergency departments in Australasia'?

Lessons from early large-scale adoption of celecoxib and rofecoxib by Australian general practitioners

OBJECTIVE

To assess trends in the first two years of prescribing of COX-2-selective non-steroidal anti-inflammatory drugs (C2SNs) by Australian general practitioners.

DESIGN

Retrospective analysis of deidentified electronic patient records from GPs enrolled in the General Practice Research Network (GPRN).

SETTING AND PARTICIPANTS

Overall prescription rates for C2SNs and NSAIDs were assessed for all GPRN participants (437 GPs) between 1 September 1999 and 30 September 2002. Also, three cohorts of patients, with at least 12 months of prescription data, who received their first prescription for celecoxib between August and October 2000 (Cohort 1, 2366 patients), celecoxib between February and April 2001 (Cohort 2, 640 patients), and rofecoxib between February and April 2001 (Cohort 3, 608 patients) were selected for further analysis.

MAIN OUTCOME MEASURES

Age and sex of patients; reason for prescription; previously prescribed pain medications and concomitant use of medications that could predispose to an adverse renal or bleeding event.

RESULTS

Prescriptions for C2SNs increased dramatically after they were listed on the Pharmaceutical Benefits Scheme (PBS). C2SN prescriptions for patients aged less than 65 years accounted for 52.6%, 59.5% and 50.7% of those in Cohorts 1, 2 and 3, respectively; large numbers of patients in the study cohort had reasons recorded for prescription that did not comply with PBS restrictions, and between 36.7% and 61.3% of patients in the three cohorts had not received a prescription for any pain medication in the year before being prescribed a C2SN. Between 4.7% and 7.9% were coprescribed drugs that could cause renal complications.

CONCLUSIONS

Rapid, early adoption of C2SNs by Australian GPs has resulted in prescribing and drug use patterns that were not in accord with quality use of medicine (QUM) principles.

Potential cardiovascular effects of COX-2 selective nonsteroidal antiinflammatory drugs

The newly developed nonsteroidal antiinflammatory drugs (NSAIDs) that selectively inhibit cyclooxygenase-2 (COX-2), are effective against pain and inflammation and appear to have less gastrointestinal toxicity than conventional NSAIDs. Their COX-2 selectivity, however, has raised concerns regarding their cardiovascular safety, since they do not inhibit COX-1, the isoform of the enzyme that is active in thrombosis and vasoconstriction. At this point there is no conclusive evidence that COX-2 inhibitors cause ischemic vascular events, because retrospective post hoc analyses conflict one another, and no specific randomized trials have yet been done. Renal effects, edema and hypertension appear to be similar between conventional NSAIDs and COX-2-selective inhibitors. Aspirin is still required for patients with cardiovascular risk who are prescribed a COX-2-selective inhibitor.

A clinical audit of the prescribing of celecoxib and rofecoxib in Australian rural general practice

AIMS

The new cyclooxygenase-2 (COX-2) selective inhibitors, celecoxib (Celebrex) and rofecoxib (Vioxx), have been widely prescribed since their launch. No reviews currently appear in the literature of prescribing patterns in Australia. This paper describes a self-audit of the clinical use of selective COX-2 inhibitor therapy undertaken with rural general practitioners (GPs) in Australia.

METHODS

A structured audit form was developed and distributed to interested GPs. The form was self-administered and focused on issues about COX-2 inhibitors and the types of patients who were receiving them, e.g. indications, patient demographics, risk factors and drug interactions.

RESULTS

A total of 627 patients were recruited (569 celecoxib and 58 rofecoxib). A range of doses was prescribed. Osteoarthritis was the most common indication (68.1%). Risk factors known for the nonselective nonsteroidal anti-inflammatory drugs were identified in 65.1% of patients, with the most common being advanced age, hypertension and previous peptic ulcer disease. Potential drug interactions were common. A variety of reasons for initiation of therapy was identified; these included perceived increased efficacy, safety and failure of other treatment.

CONCLUSIONS

These results show that COX-2 inhibitors are being prescribed for patients with multiple risk factors that may place the patient at increased risk of adverse drug reactions to a COX-2 inhibitor. The perception of improved safety and efficacy was common and is of concern. Limitations of the study include the reliance on self-reporting.

The road to consensus: considerations for the safe use and prescribing of COX-2-specific inhibitors

We describe a process which aimed to achieve consensus on evidence-based considerations for the safe prescribing and use of the COX-2-specific inhibitors available in Australia among a group of 31 clinicians and other health professionals, drawn from practice, academia and industry. Difficulties were encountered at several points: the composition of the working group was contentious; the evidence, drawn from large clinical studies, was criticised by some for problems of study design, data analysis and reporting; interpretation of study results was influenced by the interpreter's knowledge, skills and biases; and the formulation of the "Considerations" became more controversial as summary statements were contracted and simplified. Agreement on the final draft was achieved among 23 of 31 participants. Evidence-based practice guidelines are a welcome development in modern medicine, but the consensus required to produce them can mask important diversity of opinion.