A study comparing hyoscine hydrobromide and glycopyrrolate in the treatment of death rattle

Abstract

This study looked at the efficacy of drug treatment in managing death rattle in a 30-bedded specialist palliative care unit. The study was conducted in two phases. In the first, patients received hyoscine hydrobromide as the antimuscarinic; glycopyrrolate was used in the second phase. The patients in the two phases were well matched for diagnosis, age, sex and duration of death rattle. A noise score scale of 0-3 was used, which was separately validated using a verbal rating scale and noise-meter readings. Noise scores were taken at the start; 30 min after an antimuscarinic drug was administered; an hour after the initial injection if a repeat dose was given at 30 min; and 4-hourly thereafter. Drug charts of all patients with death rattle were analysed to ascertain the amount of each drug given and the cost. The incidence of death rattle was 44% in phase I, and 36% in phase II. The percentage of patients with reduced noise scores 30 min after one injection of hyoscine was significantly greater than after one dose of glycopyrrolate (56% vs 27%, P = 0.002). The need for a second injection after 30 min was less using hyoscine (33% vs 50%, P = 0.03). There was no statistically significant difference in improvement at 1 h, or at the last recorded score before death. A comparison of the cost of drug treatment using hyoscine or glycopyrrolate was made, and the potential reduction in cost per patient in the glycopyrrolate group was largely offset by increased expenditure on other drugs, especially diamorphine, midazolam and levomepromazine. The results of this study suggest that: (1) glycopyrrolate 0.2 mg is less effective at reducing death rattle than hyoscine hydrobromide 0.4 mg when assessed at 30 min, (2) the use of glycopyrrolate may lead to an increased need for other sedative or anti-emetic medication such as diamorphine, midazolam or levomepromazine, and (3) the cost benefit of using glycopyrrolate over hyoscine hydrobromide is a small part of the total drug budget, and may be less than anticipated due to the increased need of these other drugs.