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Between July 2011 and June 2012, 8750 primary care registered patients in New Zealand started a course of isotretinoin.* For this report, we defined a course of treatment as any number of dispensings of isotretinoin with no breaks greater than three months. Patients in this report may also have had previous courses of treatment with isotretinoin.

Since 2009, isotretinoin has been available for General Practitioners to prescribe, fully subsidised with Special Authority criteria. Between July 2011 and June 2012, over half of all dispensings of isotretinoin were prescribed by General Practitioners.

Are patients taking isotretinoin being monitored as recommended?

The current recommendations state that patients prescribed isotretinoin should have a full blood count, fasting lipids and liver function tests performed at baseline (see Note) and at least once during a 16 to 30 week course of isotretinoin.1 Only 47% of patients had all three baseline tests as recommended, and only 13% of patients had all three tests both before and during their course of isotretinoin treatment.

National Data

47%

Percentage of patients with all three baseline tests before treatment with isotretinoin

Full Blood Count
63%
Fasting Lipids
55%
Liver Function Tests
66%

Percentage of patients who had each baseline test before starting a course of isotretinoin

Data for Sample Medical Centre †

Number of registered patients who started a course of isotretinoin:

20

Registered patients with baseline tests before commencing a course of isotretinoin:

All three tests
50%
Full Blood Count
60%
Fasting Lipids
50%
Liver Function Tests
50%

† Data for your practice includes prescribing by any health professional, including Dermatologists.

Note

Baseline tests should ideally occur within one month prior to prescription of isotretinoin. However, given that this medicine is predominantly prescribed to a younger population with generally stable health parameters, we extended the time frame for baseline tests, for the purpose of this report. A patient was counted as having a baseline test if they had the test within one year before and three weeks after receiving a prescription for isotretinoin. This also encompasses those patients who are given a prescription and test request form at the same time.

* Testing data for Nelson Marlborough DHB area is incomplete and patients in this area have been excluded from our analysis. Data sources: Ministry of Health PHO Enrolment, Pharmaceutical and Laboratory Claims Collections (accessed Feb, 2013).

References

  1. New Zealand Dermatological Society (NZDS). Isotretinoin. Available from: www.dermnetnz.org (accessed Feb, 2013).