Ch 56

Question 1

effects of H1 stimulation

Answer 1

vasodilation
increased capillary permeability
bronchoconstriction
CNS - waking up

Question 2

H2 stim effects

Answer 2

secretion of gastric acid

Question 3

rhinitis, itching and local edema is caused by what

Answer 3

histamine

Question 4

The principal use of _____blockers is treatment of gastric and duodenal ulcers

Answer 4

H2

Question 5

what class?

Diphenhydramine (Benadryl) 
Promethazine (Phenergan) 
Chlorpheniramine  
Dexchlorpheniramine
Hydroxyzine

Answer 5

First Generation Histamine -1 Antagonists

Question 6

how do H1 blockers work

Answer 6

block the Histamine receptors. They do not reduce production

Question 7

what antihistamines work on motion sickness

Answer 7

promethazine (phenergan)

dimenhydrinate (Dramamine)

Question 8

infants and antihistamines

Answer 8

dose adjustment required. only for children older than 6 months

Question 9

Promethazine and children

Answer 9

not for children younger than 2 - deaths have occured

Question 10

Pregnancy and antihistamines

Answer 10

no

Question 11

breastfeeding and antihistamines

Answer 11

occasional small doses do not appear to cause sedation in infants but use caution

anticholinergic effects decrease breastmilk

Question 12

Antihistamines and older adults

Answer 12

on the Beers list

Question 13

what medical problems common in older adults can be made worse by antihistamines

Answer 13

glaucoma and BPH

Question 14

adverse effects H1 blockers

Answer 14

Sedation
nonsedative CNS effects- dizziness, incoordination, confusion, fatigue

paradoxical excitation - insomnia, nervousness, tremors, seizures - most common in children and after overdose

GI - n/v/loss of appetite, diarrhea, constipation -

Anticholinergic - drying of mucous membranes in mouth, nasal passages and throat, urinary hesitancy, constipation, palpitations (cant see, cant spit, cant pee, cant shit)

Question 15

how can you minimize GI effects of H1 blocker

Answer 15

give with food

Question 16

drug interactions - H1 blockers

Answer 16

alcohol and CNS depressants can further depress the CNS

alcohol
barbiturates
benzodiazepines
opioids

Question 17

Cetirizine (Zyrtec)

Levocetirizine (Xyzal)

Loratadine (Claritin)

Fexofenadine (Allegra)

Desloratadine

Answer 17

Second Generation Histamine-1 Antagonists

Question 18

diff between first and second gen H1 blockers

Answer 18

Same as first class, but little to no sedation or anticholinergic effects

CNS Stimulation

Question 19

uses for second gen H1 blockers

Answer 19

Mild allergies - conjunctivitis, rhinorrhea, transfusion reactions

Question 20

what second gen H1 blockers are used for local effects in nose

Answer 20

Azelastine (Astepro)

Olopatadine (Patanase)

Question 21

Fexofenadine and renal pt

Answer 21

renal dosing needed

Question 22

what food considerations need to be made for Fexofenadine

Answer 22

Certain fruit juices (apple juice, orange juice, grapefruit juice) can reduce fexofenadine absorption which reduces therapeutic effects

Question 23

how do you minimize adverse effects for antihistamines

Answer 23

take at night prior to sleep, take with meals for gi upset, frequent sips of liquid to reduce dry mouth

Question 24

-izine and -adine

Answer 24

second generation

Question 25

-amine and -zine

Answer 25

first gen

Question 26

least sedating antihistamine

Answer 26

fexofenadine (allegra)