Unfaithful neurotransmitter transporters: focus on serotonin uptake and implications for antidepressant efficacy.
Level 5 - mechanism / opinion, no new human data
Narrative review synthesizing mechanistic literature without systematic search or meta-analysis
PubMed 19022290 · doi:10.1016/j.pharmthera.2008.10.004
What was done
This narrative review synthesizes published literature on the roles of biogenic amine transporters (serotonin transporter [SERT], norepinephrine transporter [NET], and dopamine transporter [DAT]), cross-substrate promiscuity among these transporters, the role of low-affinity non-traditional transporters (organic cation transporters [OCT] and plasma membrane monoamine transporter [PMAT]), and genetic variants such as 5-HTTLPR in modulating antidepressant response.
What was found
No quantitative data, sample sizes, or effect estimates are reported in the abstract. The review qualitatively describes that dual- and triple-uptake inhibitors often show higher clinical efficacy than single-target agents, which may be explained by transporter promiscuity. It also reports that non-traditional transporters (OCT and PMAT) take up biogenic amines and may buffer the therapeutic effects of uptake inhibitors, and that transporter polymorphisms and compensatory adaptations can modify treatment outcomes.
Why it matters
This review outlines a mechanistic framework integrating secondary clearance mechanisms, non-traditional transporters, and genetic polymorphisms to explain antidepressant resistance and guide future drug development.
Limits
The abstract reports no empirical data, sample sizes, or systematic review methodology. The conclusions reflect mechanistic hypotheses and narrative synthesis rather than direct clinical trial evidence.
Cited by
- supports Dopamine transporters can bind to extracellular serotonin and clear it into dopamine terminals when SSRIs block serotonin reuptake.