Histamine Receptor Antagonists

Question 1

What is Histamine?

Answer 1

is another wake-promoting system in the posterior and ventral hypothalamus (i.e., tuberomamillary nucleus, TMN) that innervates many brain regions via histamine receptors (cortex, spinal cord).

Question 2

What is the Only commercially available Histamine RECEPTOR ANTAGONIST/Antidepressant:?

Answer 2

Doxepin

Question 3

What is the MOA of Histamine Receptor Antagonists?

Answer 3

Selectively blocks type 1 histamine receptors (H1) at LOW

DOSES (3-6 mg) vs. 10-fold higher doses (Antidepressant)

Question 4

What is the use of Doxepin?

Answer 4

SLEEP MAINTENANCE INSOMNIA; t1/2 = 15 h

Question 5

What is the adverse effects of Dopexin?

Answer 5

Day-time sleepiness, dry mouth, dry eyes