OBJECTIVES: Hydrochlorothiazide (HCTZ) is a frequently used diuretic. On 17/10/18, marketing authorization holders in agreement with the EMA issued a Dear Healthcare Professional Letter (DHCPL), informing on a dose-dependent association of HCTZ use and risk of non-melanoma skin cancer. We explored the potential impact on the prescribing of all antihypertensives (AHTs) and all low-ceiling diuretics in detail.

METHODS: We analyzed the DAPI database, which contains anonymous claims data of drugs dispensed at community pharmacies (CPs) at the expense of the Statutory Health Insurance (SHI) Funds. Nearly 88% of Germany's population is insured by the SHI system. This database covers all claims data from a representative sample of >80% of all CPs and were extrapolated to 100% of the SHI insured population. We analyzed the ATC codes C02, 03, 07–09. For HCTZ and other low-ceiling diuretics, we included all mono and fixed-dosed combination preparations available on the market. We calculated the average monthly dispensings in the periods 1–9/18 vs 1–6/19.

RESULTS: Overall prescribing of AHTs, on average 36.5 million packages/quarter, remained nearly unchanged throughout 1/18–6/19. HCTZ dispensings decreased from on average 1.78 million packs/month in 1–9/18 to 1.45 million/month in 1Q19 and 1.41 million/month in 2Q19. All low-ceiling diuretics’ dispensings decreased from 1.90 million packs/month before the DHCPL to 1.62 million/month in 2Q19, a minus of 0.28 million packs/month. Xipamide, indapamide, and chortalidone dispensings increased after 10/18, eg for chlortalidone to 50,700 packs in 11/18.

CONCLUSIONS: Monthly HCTZ dispensings in 1Q19 decreased by 326,000 packs compared to 1–9/18. Assuming one patient is receiving one pack/quarter, appr. 978,000 fewer patients received HCTZ. A minor increase in dispensings of alternative low-ceiling diuretics did not compensate for this decline, resulting in an overall minus of 0.28 million packs/month. These findings highlight the potential risks associated with safety warnings of chronic cardiovascular medications used by large populations.