Purpose: To characterize real-world concomitant use of beta-blockers (BB) and mineralocorticoid receptor antagonists (MRA) in s/v patients, and to describe the use of oral diuretics with different s/v titration patterns.
Methods: Patients with a first s/v prescription (Rx) between Jan 2016 and Dec 2016, and a minimum of 12months of pre-index data (first s/v Rx = index date), and at least one additional s/v Rx following index, were identified in the longitudinal pharmacy database (IMS LRx), covering approximately 60% of all dispensed Rx from public health insured patients. Prescriber specialty, s/v dose at index, and patient-level s/v titration patterns were analysed. The dose of the four most frequently prescribed oral diuretics (furosemide, torasemide, hydrochlorothiazide, and xipamide) was calculated and normalized per substance to the defined daily dose (DDD, WHO definition). The DDD per patient was calculated as dispensed DDD divided by the time until the next dispensation. Pre- and post-index doses were compared in patients with recorded pre-index diuretics. For calculations purposes, no post-index diuretic dispensation was defined as a dose of zero. For interpretation, DDD was transformed to the furosemide equivalent dose.
Results: A total of 10,556 adult patients (=18 years old) fulfilled the inclusion criteria. Post-index use of BB was similar between general practitioner (GP) and cardiologist patients (84% vs 86%); while MRA use was lower in GP versus cardiologist patients (54% vs 63%).
Oral diuretics were dispensed in 77% of all s/v patients during the 6 months pre-index period compared to 73% in the 6months post-index (p<0.001); 64% of all s/v patients had diuretics dispensed in both pre- and post-index, while 12% discontinued and 9% started diuretics after index. Post-index daily diuretic dose was 47% higher in GP patients compared to cardiologist patients (p<0.001).
In the entire s/v cohort, the mean furosemide equivalent dose was 218mg during the 6 months pre-index and 163mg in the 6 months after index. Daily diuretic dose decreased from pre to post-index by 48mg (-26%) in patients up-titrated on s/v (p<0.001), decreased by 67mg (-28%) in patients with no s/v titration (p<0.001) and decreased by 35mg (-14%) in those who were down-titrated on s/v (p=0.003)-Figure.
Conclusions: Concomitant use of BB and MRA remained high following s/v index. GPs generally prescribed less MRA and higher doses of oral diuretics than cardiologists. Lower diuretic doses and more frequent down-titration of diuretics after s/v index was observed in patients who were up-titrated on s/v compared with those who had s/v down-titrated. This suggests that an adjustment of oral diuretic doses may need to be considered during s/v initiation and titration.