Chapter 9 anti inflammatory and immunomodulating agents - antihistamine actions

Question 1

diphenhydramine (Benadryl)
ciesmastine (Tavist)
carbinoxamine

ethanolamines

Answer 1

**H1 receptor antagonist **
* H1 receptor fx’s
1) lung - constrict bronchial smooth muscle
2) adrenal medulla - release catecholamine
3) veins - constrict
4) capillaries - inc permeability
5) GI muscle - contract
6) 6) cyclic GMP

indication
* type 1 allergies - allergic rhinitis
* conjunctivits (inflammation of eyeball)
* including simple urticaria (hives)
* puritus
* angioedema (swelling of the deeper layers of the skin, caused by a build-up of fluid. The symptoms of angioedema can affect any part of the body, but swelling usually affects the: eyes. lips.)
* induce sleep..

effects
* sedative -variable
* anticholinergic - HIGH
* GI upset- low

contraindication
* may aggrevate bronchial asthma
* urinary retention
* glaucoma

SLOW onset not for prophylaxis

Question 1

cromolyn sodium (nasalcrom)

release inhibitor

Answer 1

• inhibits release of histamine from mast cells

indication
* prophylaxis of bronchial astham + seasonal allergic conjunctivitis

effects
* well tolerated
* local irritation

nasal spray, oral

require 4-6 doses per day to prevent rxn

Question 2

chlorpheniramine
brompheniramine (dimetane)
dexclorpheniramine

alkylamines

Answer 2

**H1 receptor antagonist **
* H1 receptor fx’s
1) lung - constrict bronchial smooth muscle
2) adrenal medulla - release catecholamine
3) veins - constrict
4) capillaries - inc permeability
5) GI muscle - contract
6) 6) cyclic GMP

indication
* type 1 allergies - allergic rhinitis
* conjunctivits (inflammation of eyeball)
* including simple urticaria (hives)
* puritus
* angioedema (swelling of the deeper layers of the skin, caused by a build-up of fluid. The symptoms of angioedema can affect any part of the body, but swelling usually affects the: eyes. lips.)
* induce sleep..

effect
* sedative - low to mod
* anitcholinergic - moderate
* gi upset - low

contraindication
* may aggrevate bronchial asthma
* urinary retention
* glaucoma

duration 4-25 hrs

Question 3

promethazine (phenergan)

phenthiazine

Answer 3

**H1 receptor antagonist **
* H1 receptor fx’s
1) lung - constrict bronchial smooth muscle
2) adrenal medulla - release catecholamine
3) veins - constrict
4) capillaries - inc permeability
5) GI muscle - contract
6) 6) cyclic GMP

effect
* sedative high
* anticholinergic: high

indication
* type 1 allergies - allergic rhinitis
* conjunctivits (inflammation of eyeball)
* including simple urticaria (hives)
* puritus
* angioedema (swelling of the deeper layers of the skin, caused by a build-up of fluid. The symptoms of angioedema can affect any part of the body, but swelling usually affects the: eyes. lips.)
* induce sleep..

contraindication
* may aggrevate bronchial asthma
* urinary retention
* glaucoma

duration 4-25 hrs

Question 4

cyprophetadine
desloratadine (clarniex)
hydroxyzine (atarax)
meclinzine (antivert)

piperidines + piperazines

Answer 4

**H1 receptor antagonist **
* H1 receptor fx’s
1) lung - constrict bronchial smooth muscle
2) adrenal medulla - release catecholamine
3) veins - constrict
4) capillaries - inc permeability
5) GI muscle - contract
6) 6) cyclic GMP

indication
* type 1 allergies
* hydroxyzine – anxiety and pruitus
* meclizine – motion sickness and vertigo

effects
* sedative - low moderate
* anitcholinergic - moderate

contra
* anitcholinergic effect - aggravate bronchial asthma, urinary retention, glaucoma

Question 5

loratdine (Claritin)
fexofenadine (allegra)
cetirizine (zyrtec)
azelastine (astelin)

nonsedating anithistamines

Answer 5

H1 receptor antagonist
* H1 receptor fx’s
1) lung - constrict bronchial smooth muscle
2) adrenal medulla - release catecholamine
3) veins - constrict
4) capillaries - inc permeability
5) GI muscle - contract
6) cyclic GMP

indications:
seasonal allergic rhinitis

effects
* little to no sedation

contraindication
* fatal arrhythmias w/ following
1) erthromycin
2) ketoconazole (antifungal)
3) itraconazole (antifungal)

Question 6

cimetidine (tagamet)
ranitidine (zantac)
famotidine (pepcid)
nizatidine (Axid)
levocetirizine (xyzal)

h2 receptor antagonists

Answer 6

h2 receptor antagonist
* fx of h2 (inc HR and inc HCL (breaks down the food and the digestive enzymes split up the proteins) and pepsin (helps break down proteins) secretion
* stimulate cyclic AMP

indication
* dudodenal and gastric ulcer
* hypersecretion of acid

effects
* diarrhea
* dizziness

contraindications
* caution with cimetidine since it inc levels of many drugs

Question 7

Histamine actions additional…

Answer 7

H1 + H2
1) capillaries and arterioles - dilate
2) Heart - inc contracitlity
3) biochemcial – stimulat na+ and ca++ permeability of membrane

H3 (histamine releasing cells)
* inhibit histamine release