SAN ANTONIO – Simultaneous prescription of psychotropic drugs likely to cause problematic interactions increased in children over a 10-year period, according to findings from a review of Medicaid data presented at the annual meeting of the American Academy of Child and Adolescent Psychiatry.
Another study presented at AACAP, also using Medicaid data, found that children in areas underserved by child psychiatrists are likelier to be prescribed atypical antipsychotic drugs for nonpsychotic conditions than in areas where more child psychiatrists practice.
The polypharmacy study, presented by Dr. Regina Bussing of the University of Florida in Gainesville, looked at Medicaid records from 29 states to identify 45-day overlaps in concurrently prescribed psychiatric medications in children. The researchers used three commercially available interaction checkers to identify combinations classed as contraindicated.
Dr. Bussing and her colleagues found that the prevalence of scripts of two or more medications in different drug classes rose from 1999 through 2007 and plateaued afterward, meaning that anywhere from 18.3% to 27.7% children were prescribed at least one psychotropic drug. About 1.5% of children treated with two or more drugs received two atypical antipsychotics, and 0.6% were prescribed two stimulant classes.
The researchers looked at prescription data for cohorts of between 485,874 and 966,613 patients for each 2-year bracket studied. Throughout the study period, the overall prevalence of psychotropic drug combinations rated as “contraindicated” or having “major” interaction risks was 0.21% for children 5 years and under, 1.12% for children 6-9 years, 2.06% for ages 10-14 years, and 2.83% for children 15-17.
In Florida, the prevalence of potentially risky prescriptions was considerably higher, at 0.46% of the youngest children and 3.92% of the oldest. The state of Florida “is No. 49 in funding for mental health; that might be one of the factors” promoting the polypharmacy trend, Dr. Bussing commented.
More common patterns classified as potentially risky that were seen in the study included combining a selective serotonin reuptake inhibitor with trazodone. This likely represents efforts by clinicians to target mood and insomnia symptoms simultaneously, suggested Dr. Bussing. However, adding trazodone can increase the risk of serotonin syndrome or cardiac conduction problems. As for other drug combinations seen in the study, “I don’t understand it at all. I’d love to know what people are trying to do,” she noted.
Dr. Bussing said further research was needed to better understand the clinical, rather than just theoretical, interaction risks of polypharmacy in this patient group. Electronic health records are increasingly programmed to alert to potential interactions, but clinicians routinely override them, she said, likely feeling the true risk to be lower than conveyed by interaction-checking databases.
Findings from a separate study showed that the use of atypical antipsychotic drugs varied widely by county in Maryland, and that children aged 4-17 years who lived in counties with more practicing child psychiatrists were less likely to be prescribed an atypical antipsychotic drug for a nonpsychotic condition, according to Dinci Pennap of the University of Maryland School of Pharmacy in Baltimore.
Ms. Pennap and colleagues reviewed Medicaid data for 133,247 children aged 4-17 years. Of these, 48,087 (36%) had one or more nonpsychotic diagnoses, and 9.6% of these received at least one prescription for an atypical antipsychotic drug between 2010 and 2012.
The investigators also determined from registries how many child psychiatrists practiced in the counties where subjects resided. Adequate coverage was calculated at one child psychiatrist per approximately 7,000 youth. Of the 24 counties in Maryland, 7 had no child psychiatrists, 10 had too few, and 7 had sufficient numbers.
Non-Hispanic black children in counties without any child psychiatrists were significantly more likely to receive an atypical antipsychotic drug, compared with other racial and ethnic groups (12.1% vs. 6.6%; P less than .0001). County variations accounted for 2.7% of atypical antipsychotic drug use in this population. The use of atypical antipsychotic drugs was also higher in children with multiple diagnoses.
“A major limitation here was that we couldn’t account for who was prescribing what because we are using county level data,” Ms. Pennap said. “However, the underlying statement is that someone besides child psychiatrists has to be doing [the prescribing]”; in some counties there were none practicing at all, Ms. Pennap said.
Moreover, “there is no indication in the Maryland Medicaid data that children on [atypical antipsychotic drugs] are being followed for metabolic or cardiovascular disorders” that might result from treatment, Ms. Pennap said.
Dr. Bussing’s study was funded by the University of Florida. She disclosed prior research support from Pfizer and Otsuka. Ms. Pennap’s study had no outside funding. She disclosed no conflicts of interest.