Antipsychotic combinations: Blind step or logical?

Tardive dyskinesia (TD). SGAs are associated with a lower incidence of TD compared with FGAs, but adding an FGA to an SGA may increase the patient’s TD risk.³⁰ Also assess patients regularly (as often as weekly during acute treatment and every 6 to 12 months during maintenance treatment)³¹ for extrapyramidal symptoms, including akathisia. Administer appropriate rating scales (such as the Abnormal Involuntary Movements Scale [AIMS], Barnes Akathisia Rating Scale [BARS], or Simpson-Angus Rating Scale [SARS]), and treat these adverse events as clinically indicated.

QTc effects. Because antipsychotics can increase QTc intervals, follow patients closely with cardiac monitoring and electrocardiography. Monitoring is especially important if you use ziprasidone in combination therapy, as it may increase the QTc interval more than other SGAs.²⁸

Other adverse effects. The concurrent use of 2 antipsychotics may amplify side effects that are generally considered mild, such as sedation. For example, risperidone and ziprasidone are considered to cause low to moderate sedation. This combination may result in an additive sedative effect that could negatively impact the patient’s psychosocial functioning.

Anticholinergic effects may also be potentiated, especially if a particular combination of antipsychotics warrants anticholinergic medication use for extrapyramidal symptoms.

Related resources

• Texas Medication Algorithm Project (TMAP). Schizophrenia antipsychotic treatment algorithm. www.dshs.state.tx.us/mhprograms/TIMA.shtm.
  
• Lehman AF, Lieberman JA, Dixon LB, et al. Practice guideline for the treatment of patients with schizophrenia, 2nd ed. Am J Psychiatry 2004;161(suppl):1-56.
  

Drug brand names

• Aripiprazole • Abilify
  
• Clozapine • Clozaril
  
• Haloperidol • Haldol
  
• Lamotrigine • Lamictal
  
• Loxapine • Loxitane
  
• Olanzapine • Zyprexa
  
• Quetiapine • Seroquel
  
• Risperidone • Risperdal
  
• Valproic acid • Depakene
  
• Ziprasidone • Geodon
  

Disclosures

Dr. Gibson reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products. He receives research support from the PhRMA Foundation.

Dr. Patel receives grant support from Takeda Pharmaceuticals and is a consultant for Eli Lilly and Company and Shire Pharmaceuticals.

Dr. Lauriello receives grant support from Eli Lilly and Company and serves as a consultant to Eli Lilly and Company and Vanda Pharmaceuticals.

Dr. Buckley receives grant support from AstraZeneca, National Institute of Mental Health, Pfizer Inc., Solvay, and Wyeth and is a consultant for AstraZeneca, Bristol-Myers Squibb, Eli Lilly and Company, Janssen Pharmaceutica, Lundbeck, Pfizer Inc., Solvay, and Wyeth. He receives honoraria from Bristol Myers-Squibb, Janssen Pharmaceutica, Lundbeck, and Pfizer Inc.