Polyfarmacy is frequent in patients with dual diagnosis.

To quantify the number and describe the treatments prescribed in a cohort of outpatients with dual diagnosis.

A descriptive and transversal study was performed. Patients with dual diagnosis treated at an Outpatient Drug Treatment Center from January 2005 to December 2009 were included. Data from demographic, clinical and therapeutical variables were gathered once. The instruments used for the diagnosis were EuropASI y SCID-I. The number and type of prescript drugs were related with protocol variables.

The study sample included 80 patients (71,6% men, average age 37,2 ± 9). Psychotic disorders (46.8%) and cocaine dependence/abuse (34.6%) were the most frequent comorbid psychiatric illnesses found. 40.8% of patients were polydrug users. The mean of prescript drugs was 3,06 ± 1,4 and only 14% of patients were on monotherapy. The frequency of drugs prescribed was: 68,4% antidepressant, 63,3% antipsychotic, 55,7% antiepileptic and 36,7% anxiolytic drugs. Older patients ( > 45years) took a major number of prescripted drugs (3,88 ± 1,1). Patients with psychotic disorders took the 43.9% of drugs prescripted (p = 0,042). Patients with benzodiazepine abuse took higher number of prescription drugs (5 ± 1,4;p = 0,003) compared with patients with other dependence or abuse.

Patients with dual diagnosis take high quantity of drugs. Older patients, diagnosis of psychosis and benzodiacepine abuse were related with polydrug prescription. Quantification of medication is recommended for treatment optimisation and avoiding yatrogenic.