Pharma 1 Flashcards
From where is histamine produced and where is it stored
mast cells
from what amino acid is histamine produced from and from what enzyme
histidine
histidine decarboxylase enzyme
when histamine binds to H1 receptor what does it do
bronchoconstriction vascular dilation and increased permeability increased in nasal and bronchial mucus positive inotropic , cramps and diarrhea itching
when histamine binds to H2 receptor what does it do
on parietal cells
HCL production
positive inotropic and chronotropic
ant histamines are more effective in preventing symptoms than reversing them
true
main effect of antihistamine
decrease allergic rxn
decrease pruritis, sneezing and rhinorrhea
decrease neurotransmission in CNS (sedation and impaired cognitive )
what are the other effects of antihistamine unrelated to H1 block
anti cholinergic / antimuscarinic
anti serotenergic
anti alpha adrenergic
antichollinergic like and effect
diphenhydramine and promethazine
cant see cant pee cant shit cant spit and tachycardia
antiserotenergic like and effect
cyproheptadine
weight gain and increased appetite
anti alpha adrenergic like and effect
promethazine
reflex tachycardia and hypotension
what are the indications for the use of antihistamines
relief common cold symptoms
motion sickness
insomnia
allergic conditions
what is DOC for motion sickness
scopalamine ( antimuscarinic)
what can be used for motion sickness other than DOC
H1 blockers
Diphenhydramine
Dimenhydrinate
Cycloxine , meclizine and promethazine
are motion sickness drugs effective if symptoms already present
no
H1 blocker inhibits nausea and vomiting mediated by
chemoreceptor and vestibular pathway
what does an antiemetic block
H1 and M1
Meclizine indications
motion sickness and vertigo associated with vestibular disorders
only first generation anti histamines can be used for insomnia ( 2nd generation cant be used)
true cuz they have sedative property
what does diphenhydramine do in children
paradoxical hyperactivity
are H1 blockers medication of choice for insomnia
no
characteristics and examples of first generation anti histamine
cheap OTC Dirty drugs Cross bbb leading to sedation Chlorpheniramine and diphenhydramine
characteristics and examples of second generation anti histamine
carboxylated so became polar and cannot cross BBB
improved speciificity
s/e headache
Fexofenadine , loratadine and desloratadine
what are the drug interactions of anti histamine
cant be used with other CNS depressants or alcohol
cant be used with MAOI
cant be used with choline esterase inhibitors
do oral anti histamine have a fast onset of action
yes
are oral anti histamine useful in management of allergic rhinitis symp
yes
which generation is used for allergic rhinitis
second generation
are ophthalmic and nasal antihistamine delivery devices available
yes
what is a topical intranasal anti histamine
olopatadine and azelastine
when is the combination of anti histamine and decongestant useful
congestion feature of rhinitis
patients have no response
incomplete control of symptoms
what are alternatives for oral anti histamine
intranasal corticosteriod short acting alpha adrenergic agonist intranasal cromolyn leukotriene receptor antagonist intranasal ipratropium
example of intranasal corticosteriod
fluticasone
what is the most effective drug to treat allergic rhinitis
fluticasone ( intranasal corticosteriod)
onset of action of intranasal corticosteriod and what is smth it improves that anti histamine alone cant
3-36 hours
nasal congestion
example of short acting alpha adrenergic agonist ( nasal decongestant) and what does it do
phenylephrine
constrict arteriole in nasal mucosa and reduce airway resistance ( bronchodilation)
example of longer acting alpha adrenergic agonist
oxymetazoline
what are the formulations of adrenergic agonists available
intranasal and oral
why rhinitis medicamentosa happens and to which drug
intranasal formulation of short acting alpha adrenergic agonist used for more than 3 days leading to rebound nasal congestion
how does intranasal cromolyn work
mast cell stabilizer
to optimize therapeutic effect of intranasal cromyln dosing should begin before how many weeks prior to allergen exposure
1-2 weeks
what is rebound congestion called
rhinitis medicamentosa
what is the inferior to other treatments
leukotriene receptor antagonist
is leukotriene receptor antagonist a reasonable option to be used with patients that have asthma
yes
what drug relieves rhinorrhea but not sneezing or nasal congestion
intranasal ipratropium
before treating cough the identification of the cause is important so treat underlying cause
true
management of cough includes
treat underlying cause
cough suppressant
what are the antitussive drugs
codeine
dextromethorphan
guaifenesin
benzonatate
characteristic of codeine
naturally occuring opiate
decreases cough center sensitivity in CNS
cause constipation
decrease mucousal secretion
characteristics of dextromethorphan
synthetic of morphine
decrease cough center sensitivity in CNS
OTC
when is dextromethorphan not effective
cough due to asthma , smoking and emphysema
why do we prefer dextromethorphan over codeine
its equally effective but less S/E and less addictive potential
what drug is a recreational drug and what does it mean
dextromethorphan
hallucinations and euphoria
dont give dextromethorphan to child less than
4
serious life threatening s/e could happen when taking dextromethorphan if
MAOI didnt clear out of body ( 14 days to clear)
what drug is an expectorant
guaifenesin
guaifenesin has two formulations single ingredient or in combination with codeine or dextromethrophan
true
what does guaifenesin does
thins mucus and lubricates RS tract
what does benzonatate suppress
cough reflex in peripheral
what is MOA of benzonatate
anesthetizes stretch receptors
what are adverse effects of benzonatate
numbness of tongue mouth throat
dizziness
chocking
when benzonatate s/e appear should you eat
no
benzonatate should be taken at specific doses not need of basis and dont double missed doses
true
benzonatate shouldnt be given for child less than
10
what is the age of child benzonatate and dextromethorphan shouldnt be given to
10
4
