Plasma Level Monitoring for Maintenance Neuroleptic Therapy

At Issue: Defining Treatment Refractoriness in Schizophrenia

“…If blood levels have not documented the bioavailability of the drug, depot long-acting neuroleptic drug administration should have been shown to offer no significant improvement. Just as inadequate dose and blood levels of antipsychotic drug must be excluded as a possible determinant of refractoriness, so must toxic and excessively high levels of drug (Van Putten et al 1988, 1989Marder et al 1989).…”

“…Several pharmacotherapy strategies have been employed to develop ways to overcome drug refractoriness in schizophrenia. Proponents of a “therapeutic window” for neuroleptic blood levels have generated data suggesting that large interindividual differences in absorption, transport, storage, and metabolism require a fine-grained analysis of steady-state plasma levels of drug and active metabolites (Bolwig-Hansen et al 1982; Smith et al 1984; Szukalski et al 1986; Sramek et al 1988; Van Putten et al 1988, 1989; Marder et al 1989). Other investigators have presented data suggesting that adding adjunctive drugs to conventional neuroleptics (e.g., lithium, propranolol, carbamazepine, benzodiazepines) may produce improved therapeutic outcomes in patients with poor response to neuroleptics alone (Csernansky et al 1985; Kane 1987; Osser 1988).…”