gms | German Medical Science

Background: Long-acting nitrates are recommended as second-line treatment of stable coronary artery disease, they relief symptoms but do not prevent the occurrence of cardiovascular events. Therefore the potential need for long term therapy should be assessed regularly. Pentaerythritol tetranitrate (PETN), a very popular long-acting nitrate in the former East Germany, is not reimbursed by the statutory health insurance since the end of 2011. This decision was based on the lack of studies providing sufficient evidence for safety and efficacy. However private prescriptions for PETN are still possible.

The aim of the study was to assess whether the discontinuation of a treatment with PETN resulted in alternative prescriptions or reduced polypharmacy.

Materials and Methods: This is an observational study. We used prescription data from different German statutory health insurances to follow up patients in a federal state of former East Germany from 2011–2012. Patients receiving PETN within the last 6 months 2011 (2nd half 2011) but not in the last 6 months 2012 (2nd half 2012) were divided into two groups: 1) patients starting an anti-anginal therapy with an alternative agent after discontinuation of PETN and 2) patients without an alternative treatment after discontinuation of PETN. Alternative agents were defined as other long-acting nitrates, molsidomine, ivabradine and ranolazine. In addition the prescription of short-acting nitrates for acute angina and of beta-blockers or calcium channel blockers which are also approved for anti-anginal treatment was observed.

Results: A total of 12,062 patients received PETN prescriptions in 2nd half 2011 but not 2nd half 2012. In 51% of these patients the therapy was switched to an alternative agent; 42% did not get an alternative treatment. Another 7% of patients had already an alternative agent before PETN was ended and will not be considered in this analysis. While patients received 2.2 mio defined daily doses (DDDs) PETN in the 2nd half 2011 (and none in 2nd half 2012) the increase of the alternative agents was only 1.0 Mio DDDs, mainly for other long-acting nitrates (0.8 Mio DDDs). There were no changes in the rate and frequency of prescriptions for beta-blockers or for calcium channel blockers.

The total number of different drugs prescribed per patient did not change between 2nd half 2011 and 2nd half 2012 for patients switched to an alternative agent (9.26 vs. 9.38 drugs on average), but it decreased for patients whose PETN was withdrawn without initiation of an alternative treatment from 9.21 to 8.27, respectively. The rate of patients with a need of short-acting nitrates for angina did not change in the former group – 11.1% under therapy with PETN in 2nd half 2011 in comparison to 10.8% under an alternative treatment in 2nd half 2012. However, the rate even dropped from 9.2% to 6.5% for those where PETN was not replaced.

Conclusion: A considerable rate of patients — up to 40% — treated with PETN did not receive an alternative treatment after discontinuation of PETN, even if we cannot rule out that few patients continue to receive PETN on private prescription. We have no evidence that discontinuation without any alternative prescription caused any harm to patients. Moreover the prescription rate for short acting nitrates decreased after discontinuation of PETN without replacement indicating even less acute anginal symptoms in this group. Our data indicate that physicians used the opportunity for assessing the need for long-acting nitrates and discontinued therapy and thereby reduced polypharmacy.