To study persistence and adherence with the use of common antihypertensive (AHT) medications.

Longitudinal assessment of Pharmaceutical Benefit Scheme claim records covering the period January 2004 to December 2006. We analysed a 10% random sample of all Australian long-term health concession card holders who had been commenced on an angiotensin II receptor antagonist (A2RA), an angiotensin-converting enzyme inhibitor (ACEI) and/or a calcium channel blocker (CCB), but for whom no AHT medication had been dispensed in the previous 6 months.

Proportion of patients failing to fill a second prescription; median persistence time with medication (ie, non-cessation of therapy); persistence with medication over 33 months; median medication possession ratio (MPR, defined as the proportion of prescribed medication actually consumed by patients persisting with treatment).

The database yielded information relating to 48 690 patients prescribed AHT medication. Nineteen per cent of patients failed to collect a second prescription. The median persistence time was 20 months. The data were little different from the population average with respect to A2RAs or ACEIs, but persistence was 57% poorer with respect to CCBs (log-rank P < 0.001) (28% of patients prescribed CCBs failed to collect a second prescription; median persistence time, 7 months). There were differences in persistence between individual drugs in the respective classes, the best outcomes being with candesartan and telmisartan (A2RAs; 10%–20% better), perindopril (ACEI; 25% better) and lercanidipine (CCB; 25% better). Median MPRs were generally around 100%, indicating that most patients who collected prescriptions also showed good adherence to treatment regimens.

There is an ongoing problem of poor persistence with commonly used AHT medications. This may represent a diminished opportunity for cardiovascular disease prevention.