title: Lithium-drug interactions altering the intracellular lithium level: an in vitro study.
abstract: An in vitro incubation system utilizing a bicarbonate-CO2 buffer system accurately predicts the in vivo red cell:plasma lithium ratio (LR). Piperazine phenothiazines produced the most marked elevations of intracellular lithium, doubling the LR when added to the system at 3 X 10(-5) M. The aminoalkyl phenothiazines and thioxanthenes were somewhat less active, while the non-phenothiazine antipsychotics, such as loxapine, haloperidol and molindone, produced only minor increases in the LR. Tricyclic antidepressants produced a 20-30% increase, while other types of antidepressants, the major neurotransmitters and their metabolites, hormones, benzodiazepines and diuretics did not show any activity. Of the antihypertensives studied, only hydralazine had an effect on the LR. The effect of fluphenazine on the intracellular lithium level was paralleled by an increase in intracellular sodium and was blocked by dipyridamole. Several important lithium-drug interactions may contribute to an increased LR and suggest caution in the interpretation of studies of the relationship between the LR and clinical aspects of the affective disorders.
mesh_terms: D014150:Antipsychotic Agents / Q000097:blood; D001826:Body Fluids / Q000378:metabolism*; D004347:Drug Interactions; D004573:Electrolytes / Q000097:blood; D004912:Erythrocytes / Q000378:metabolism; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism*; D007473:Ion Channels / Q000378:metabolism; D008094:Lithium / Q000097:blood*; D011619:Psychotropic Drugs / Q000097:blood
chemical_list: D014150:Antipsychotic Agents; D004573:Electrolytes; D007473:Ion Channels; D011619:Psychotropic Drugs; D008094:Lithium