Clinically relevant drug interactions in anxiety disorders

OBJECTIVE: Certain drugs used in the treatment of patients with anxiety disorders can interact with other psychotropic drugs and with pharmacological treatments for physical illnesses. There is a need for an updated comparative review of clinically relevant drug interactions in this area. DESIGN: Relevant literature on drug interactions with medications used in the treatment of anxiety disorders was identified through a search in MEDLINE and EMBASE. RESULTS: Drug interactions involving medications used to treat anxiety disorders may be pharmacokinetic, such as enzyme inhibition or induction in the cytochrome P450 system and transporter-mediated drug interactions, or pharmacodynamic, such as additive effects in causing drowsiness or additive effects at neurotransmitter receptors. Certain selective serotonin reuptake inhibitors (fluoxetine, fluvoxamine, and paroxetine) are particularly liable to be potentially involved in untoward pharmacokinetic interactions. CONCLUSIONS: The potential for drug interactions with medications used in anxiety disorders should be the cause of clinical concern, particularly in elderly individuals. However, the liability for harmful drug interactions may be anticipated, and the risk reduced. Although not all interactions are clinically relevant, careful monitoring of clinical response and possible interactions is essential.