PharmacoEconomics & Outcomes News 324 - 4 Aug 2001

High cost of discontinuingantihypertensive therapy in ItalyAntihypertensive drugs are frequently discontinued,

which causes considerable cost to the health system,say researchers from Italy.

The researchers used data for 4614 residents ofRavenna, Italy, who received a prescription foramlodipine, atenolol, fosinopril, indapamide or losartanfor the first time during 1997.* The most frequentlyprescribed initial therapy was atenolol (44% of patients),followed by amlodipine (23%), fosinopril (19%), losartan(8%) and indapamide (7%).

65% discontinuedThe researchers found that 3000 patients (65%)

discontinued antihypertensive treatment.** Only 1192(26%) continued treatment, of whom 219 received aprescription for an additional agent. 422 patients (9%)switched to other antihypertensive agents. Among thosewho discontinued treatment, 2499 discontinuedtreatment after having received a single prescription.Compliance was significantly better with losartan,compared with the other 4 agents. The analysis alsoshowed that the mean daily dosage for all 5 agents wasbelow the therapeutic range in many patients; meandaily dosages above the therapeutic range ‘occurredonly in the occasional patient’.

The total cost of antihypertensive treatment over thestudy period was estimated at L717 million.† The costassociated with treatment discontinuation wasestimated at about L222.6 million, which represented31% of the total cost. Treatment continuation accountedfor 48% of the total cost and switching for 21% (L345.4million and L148.9 million, respectively). The costanalysis also showed that, among those who continuedtreatment, the average annual cost of treatment wassignificantly lower in patients taking atenolol orindapamide, compared with amlodipine, fosinopril andlosartan. Costs (1998 values) were based on Italianmarket prices.* The study received funding from Merck Sharp & Dohme Italia SpA.** Patients who discontinued treatment were those who received only1 prescription or those who received ≥ 2 prescriptions for a treatmentduration < 273 days. Patients who continued treatment were thosewho received ≥ 2 prescriptions for a treatment duration ≥ 273 days.Patients who switched treatment were those who receivedprescriptions for a treatment duration ≥ 273 days with ≥ 2 drugs insequence.† Italian lire

Degli Esposti E, et al. Pharmacoutilization of antihypertensive drugs: a model ofanalysis. International Journal of Clinical Pharmacology and Therapeutics 39:251-258, Jun 2001 800869802

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PharmacoEconomics & Outcomes News 4 Aug 2001 No. 3241173-5503/10/0324-0001/$14.95 Adis © 2010 Springer International Publishing AG. All rights reserved