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Histamine H3 receptor antagonists in ADHD.


Histamine H3 receptor antagonists in ADHD.

MK-0249 is a histamine H3 receptor antagonist.1

The H3 receptor is mainly localized in the central nervous system. The H3 receptor acts as:2

  • presynaptic autoreceptor
    • modulates histamine release
  • presynaptic heteroreceptor
    • regulates the release of other neurotransmitters such as monoamines and amino acids

Histamine H3 receptor antagonists showed positive cognitive effects3 as a result of dopamine release in PFC and ACC.4

A randomized, double-blind, placebo-controlled crossover study found no short-term efficacy of MK-0249 on ADHD symptoms in adults. As a side effect, 32% reported increased insomnia, compared with 11% for placebo. The remaining side effect rate was identical to placebo5