Exam 4; Biogenic Amines Flashcards
What is used to convert histamine to histamine
histadine decarboxylase
What are four functions of histamine
growth and regeneration
neurotransmission
regulator of microcirculation
defense mechanisms
Histamine is released following a tissue injury, and has what four effects
inflammatory response
mechanical, thermal, chemical, or radiant injury
warning system via stimulation of sensory neurons
enhancer of the immune system
What is the mechanism of action of histamine
it binds to specific histamine receptor
What are four physiologic effects involving histamine and the vascular system
constricts larger vessels
dilate smaller vessels
cause pooling of the blood at the injury site
cause endothelial cell leakage; “wheal”
What is the “triple response” to injected histamine
central red spot; due to vasodilation
flare
wheal
What are the two neuronal physiologic effects of histamine
stimulation of sensory neuron; itching/pain
CNS effects increasing alertness
What are two physiologic effects of histamine regarding the smooth muscle
constricts bronchioles; bronchoconstriction
constricts metastmeal muscle; diarrhea
What is the physiologic effect of histamine regarding exocrine secretion
stimulates bronchial, salivary, and digestive secretions
What is the mechanism behind anti-histamine actions
blocks the histamine receptor
What are the CNS effects of H1 blockers
sedative (can be excitatory in children and the elderly)
anti-emetic
anti-nausea
H1 blockers cause the drying of this
mucous membranes
histamine stimulates the secretion
How does H1 blockers affect the peripheral nervous system
acts as a local anesthetic
Hows does H1 blockers affect the smooth muscle
it is a dilator; bronchial smooth muscle dilator
H1 blockers inhibit the secretion of what
interleukins, which are stimulators of the immune system and other inflammatory mediators
H2 blockers affect gastric secretion how
histamine is required to stimulate gastric secretion from parietal cells, an H2 blockade leads to a decrease in acid secretion
What three things under the category of “dermatoses” are the first generation classes H1 anti-histamines used for
urticarias (itching)
insect stings/bites
allergic rhinitis and allergic conjunctivitis
What are H1 antihistamines NOT of value in treating
asthma or the common cold
H1 anti-histamines are used for these two things besides dermatoses
motion sickness (anti-emetic, anti-nauseant) sedative
This first generation h1 blocker has sedative effects and is used for motion sickness
diphenyhydramine
This first generation h1 blocker is used for motion sickness
clemastine
This first generation h1 blocker is not used for motion sickness
chlopheniramine
This first generation h1 blocker is used as a sedative and anti-itch
hydroxyzine
This first generation h1 blocker was a precursor of the first anti-psychotic drugs and is a strong sedative/anti-emetic
promethazine
This first generation h1 blocker is a sedative and has local anesthetic effects
tripelennamine
True or False
The first generation h1 blockers can ever the CNS
True; because they are not ionized
All of the first generation h1 blockers can act on what
the peripheral and central histamine receptors
What are the four second generation h1 blockers
the "-ines" lortadine fexofenadine desloratadine cetirizine
The second generation H1 blockers have less this than compared to the first generation
CNS effects; all are ionized in the blood
What are the three toxicities and contraindications for ALL h1 blockers
high therapeutic index
first generations can react with other CNS depressants
anti-mucarinic effects
What are the four H2 blockers
(-tidine's) cimetidine rantidine famotidine nazitidine
What is the side effects of cimetidine
H2 blocker anti-androgen effects breast growth in males lactation in women low sperm count
The -tidine drugs do not cross what
the blood brain barrier
H2 blockers
What is serotonin synthesized from
tryptophan
What are the four physiologic effects of serotonin
smooth muscle constriction
itching and pain
central neurotransmission (important neurotransmitter)
can cause nausea
What is carcinoid syndrome
tumor of enterochromaffin cells (where serotonin is found)
What are the five effects of an increase in serotonin
diarrhea bronchospasm sin flushing fibrosis of heart valves no CNS effects; produced peripherally
How is the role of serotonin in migraines inferred
by the effect of certain drugs useful in treating migraines
How do the agents that affect migraines alter the serotonin system
agonists or partial agonists of serotonin receptor
The serotonin agonists that act on migraines all cause what
vasoconstriction
What are the agents that act on serotonin receptors
the “-triptan’s”
sumatriptan
The triptan drugs should never be given with these drugs, would lead to a synergistic effect
SSRIs or MAO inhibitors
What is serotonin syndrome
hyperthermia and muscle twitching
What are the two ergot alkaloids
ergotamine
dihydrogotamine
How do the ergot alkaloids affect serotonin
partial serotonin agonists; can also affect adrenergic and dopaminergic receptors
What are the for side effects of ergot alkaloids
ergotism; excess of ergot alkaloids "St. Anthony's fire" hallucinations uterine contractions severe vasospasms; gangrene
What is the pregnancy category of ergot alkaloids (ergotamine and dihydrogotamine)
X
