Anticholinergic use in children and adolescents after initiation of antipsychotic therapy.

BACKGROUND

Second-generation antipsychotics (SGAs) are thought to have a lower likelihood of inducing extrapyramidal symptoms (EPS) than are first-generation antipsychotics (FGAs). Clinical observations suggest that younger patients may be more sensitive to SGA-associated EPS than are adults and require therapy with anticholinergic agents.

OBJECTIVE

To determine the proportion of patients 5-18 years of age who received anticholinergic therapy during the initial stages of antipsychotic treatment, as well as to compare anticholinergic utilization across patients receiving aripiprazole, risperidone, and quetiapine, SGAs previously identified as the most commonly prescribed at the academic institution studied.

METHODS

Patients 5-18 years of age who were initiating a course of an antipsychotic between January 1, 2005, and September 1, 2008, were identified in a retrospective review of prescription and medical records. Data on demographic characteristics, antipsychotic and anticholinergic utilization, indications, diagnoses, and concomitant medications were collected from the medical record. Only the first therapeutic course of an antipsychotic identified was analyzed. Anticholinergic utilization at antipsychotic initiation and after 30 days was assessed.

RESULTS

A total of 235 antipsychotic treatment courses were identified. Of these, 152 patients met our inclusion criteria. Anticholinergic utilization at any time during the first 30 days of treatment was identified in 32 patients (21%), while EPS was documented for 12 patients (8%). FGA or polypharmacy (simultaneous use of >or=2 scheduled antipsychotic) use versus SGA use (OR 18.98; 95% CI 4.74 to 75.95) was the primary characteristic significantly associated with anticholinergic utilization within 30 days after initiation. Of the most commonly used SGAs, risperidone was the drug with which anticholinergics were most frequently prescribed (p = 0.03).

CONCLUSIONS

Anticholinergic prescribing exceeded the incidence of EPS, as documented in the medical record (21% vs 8%), and differed across individual medications and antipsychotic class. Utilization of FGAs or polypharmacy was a key predictor of anticholinergic use.