Concomitant use of two or more antipsychotic drugs is common in Sweden.

OBJECTIVES

To assess the prevalence of concomitant use of two or more antipsychotic drugs and other psychotropic drugs in the Swedish population.

METHODS

Data for this observational cohort study were collected from the Swedish Prescribed Drug Register including all dispensed drugs to the entire Swedish population (9.4 million inhabitants). We identified all individuals with at least one dispensed prescription of antipsychotic drug during January to June 2008. After 12 months, a second exposure period was chosen. Individuals who were dispensed two or more antipsychotic drugs in both periods were considered long-time users of antipsychotic polypharmacy.

RESULTS

In 2008, 1.5% of the Swedish population was dispensed antipsychotic drugs, the majority (75%) using only one antipsychotic drug. Out of individuals who were dispensed 2 or more antipsychotic drugs during the first period, 62% also was also dispensed at least 2 antipsychotic drugs during the second period. A total of 665 different unique combinations were used in 2008. Individuals prescribed two or more antipsychotic drugs during both periods were more often dispensed anxiolytics and sedatives than those who were dispensed only one antipsychotic drug. Elderly were dispensed antipsychotic drugs much more often than younger persons.

CONCLUSIONS

In Sweden, 25% of patients dispensed antipsychotic drugs receive a combination of two or more antipsychotic drugs. Individuals who are dispensed antipsychotic polypharmacy are more often dispensed anxiolytics and sedatives than those prescribed only one antipsychotic drug. Long-term observational studies are needed to assess the efficacy and safety of such combinations.