The polypharmacy is a very controversial subject; it brings together problems of interaction between drugs, side effects, and rationality of co-prescriptions, pharmaco-economic aspects. The long acting is useful to solve adherence to treatment but they are often prescribed in polytherapy.

The aim of this studies is to compare long-acting haloperidol, fluphenazine, risperidone and paliperidone regard to prescribing associations and pharmaco-economy. Also we want to consider for each long-acting which and how many drugs are associated and the implications in terms of pharmaco-economics. We examined all prescriptions (126 patients) over a period of 12 months in a mental health center, identifying which long acting had the best pharmaco-economic profile.

Despite being the less prescribed and not being associated with other psychiatric drugs, paliperidone palmitate shows the best pharmaco-economic profile.

The costs of a drug are in relationship not only with unit price but also with the question of safety in order to oppose the overmedication.

The authors have not supplied their declaration of competing interest.