Alternate Routes of Administration of Antidepressant and Antipsychotic Medications

To review the administration of antidepressant and antipsychotic medications via inhaled, intranasal, buccal, sublingual, transdermal, and rectal routes.

A PubMed search was conducted for all data through March 31, 2015 to identify pertinent literature. Search terms included the generic name of each antidepressant and antipsychotic medication in combination with the following terms: alternate routes of administration, inhaled, intranasal, buccal, sublingual, transdermal, and rectal.

English-language case reports, studies, and reviews describing medication administration in human subjects were included.

Commercially available products that use an alternative route of administration include loxapine for inhalation, asenapine for sublingual administration, and selegiline for transdermal administration. Case reports and studies describe intranasal, sublingual, and transdermal routes of administration of antipsychotic medications as well as buccal, sublingual, transdermal, and rectal administration of antidepressant medications. The concordance between the physicochemical properties possessed by some antipsychotic and antidepressant agents and the physicochemical properties required for nontraditional routes of administration suggest that administration via alternative routes may be feasible for some of these drugs. Further exploration of drug absorption via alternative routes in addition to consideration of patient and formulation factors may yield improvements in medication therapy for patients with psychiatric illnesses.

For patients unable to tolerate oral or injectable therapy, administration of psychotropic medications via nontraditional routes may be feasible. The development of alternative routes of drug delivery could prevent discontinuation of needed medication therapy.