Allergic Rhinitis Treatments H1-Receptor Antagonists & Decongestants

Question 1

Histamine (H1)-Receptor Antagonists

MOA

Answer 1

competitive anatagonist of histamine
binds to H1 receptos without activation
prevents histamine binding and action

Question 2

Do Histamine (H1)-Receptor Antagonists do better at preventing or reversing histamine action?

Answer 2

preventing, much more effective, work best as prophylactic

Question 3

How do Histamine (H1)-Receptor Antagonists accomplish the reversal of symptoms

Answer 3

anticholinergic properties, causes drying of mucous membranes

Question 4

are 1st generation or 2nd generation Histamine (H1)-Receptor Antagonists more effective

Answer 4

1st generation

Question 5

Diphenhydramine

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 5

1st Generation H1-Receptor Antagonists
15 to 30 minutes until action 
6-8 hours duration 
\+++ sedative effect 
\+++ anticholinergic effect
B pregnancy category 

Common brand name Benadryl

Question 6

Chlorpheniramine

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 6

1st Generation H1-Receptor Antagonists
15 to 30 minutes until action 
4-6 hours duration 
\+ sedative effect 
\++ anticholinergic effect
B pregnancy category 

Best recommended out of 1st Generation H1-Receptor Antagonists for pregnancy

Question 7

Hydroxyzine

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 7

1st Generation H1-Receptor Antagonists
15 to 30 minutes until action 
4-6 hours duration 
\++ sedative effect 
\+ anticholinergic effect
C pregnancy category

Question 8

Promethazine

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 8

1st Generation H1-Receptor Antagonists
15 to 30 minutes until action 
4-6 hours duration 
\+++ sedative effect 
\+++ anticholinergic effect
C pregnancy category

Question 9

Loratadine (Claritin)

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 9

2nd Generation H1-Receptor Antagonists
1-3 hour until action 
>24 hours duration 
0 sedative effect 
0 anticholinergic effect
B pregnancy category

Question 10

Desloratadine

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 10

2nd Generation H1-Receptor Antagonists
<1 hour until action 
24 hours duration 
0 sedative effect 
0 anticholinergic effect
C pregnancy category

Question 11

Cetirizine (Zyrtec)

• generation
• onset
• duration
• relative sedative effect
• relative anticholinergic effect
• pregnancy category

Answer 11

2nd Generation H1-Receptor Antagonists
40 to 60 min until action 
greater or equal to 24 hours duration 
\+ sedative effect 
0 anticholinergic effect
B pregnancy category

Question 12

Histamine (H1)-Receptor Antagonists contraindications

Answer 12

hypersensitivity to formulation

Question 13

Histamine (H1)-Receptor Antagonists adverse reactions

Answer 13

anticholinergic effects (xersotomia, constipation, urinary retention), CNS depression (dizziness, sedation), paradoxial excitement

Question 14

Histamine (H1)-Receptor Antagonists drug interactions

Answer 14

anticholingeric agents – increase side effects

CNS depressants – increase side effect

Question 15

Histamine (H1)-Receptor Antagonists monitoring

Answer 15

monitor OTC use and side effects

Question 16

Histamine (H1)-Receptor Antagonists intranasal

Answer 16

Azelastine, Olopatadine

Question 17

Histamine (H1)-Receptor Antagonists topical

Answer 17

Diphenhydramine

Question 18

Histamine (H1)-Receptor Antagonists ophthalmic

Answer 18

Azelastine, Ketotifien, Olopatadine

Question 19

Decongestants MOA

Answer 19

stimulates alpha adrenergic receptors to produce vasoconstriction
also pseudoephedrine stimulates beta adrenergic receptors causes bronchial relaxation and increases heart rate and contractility

Question 20

Decongestants topical agents vs oral agents

Answer 20

topical decongestants are immediately effective, oral agents tend to last longer and have more systemic side effects

Question 21

overuse of topical decongestants can cause

Answer 21

rebound congestion

Question 22

Phenylephrine

Answer 22

intranasal decongestant spray requiring 2-3 sprays every 4 hours

oral decongestant every 4 hours

Question 23

Trahydrozoline

Answer 23

intranasal/ ophthalmic decongestant

Intranasal decongestant: 3-4 sprays every 3-4 hours
ophthalmic decongestant: 1-2 drops 2-4 times per day

Question 24

Naphazoline

Answer 24

intranasal/ ophthalmic decongestant

Intranasal decongestant: 1-2 sprays every 6 hours
ophthalmic decongestant: 1-2 drops every 6 hours

Question 25

Oxymetazoline

Answer 25

intranasal/ ophthalmic decongestant Intranasal decongestant: 2-3 sprays every 12 hours ophthalmic decongestant: 1-2 drops every 6 hours

Question 26

Pseudoephedrine

Answer 26

oral decongestant available in both immediate and extended release forms available

Question 27

what is a common drug used by amateur chemists to produce methamphetamine

Answer 27

Pseudoephedrine, an oral decongestant

Question 28

Decongestants contraindications

Answer 28

hypersensitivity | MAOI use within 14 days

Question 29

Why should those taking an MAOI (within the past 14 days) not use decongestants

Answer 29

use increases the risk of hypertension (associated with adverse effect decongestants)

Question 30

Decongestants Drug interactions

Answer 30

When used with sympathomimetics, adverse events of decongestants are enhances When used with SNRIs (venlafaxine), you may enhance tachycardic effects of decongestants

Question 31

Decongestant Adverse Events

Answer 31

Hypertension, tachycardia, rebound congestion

Question 32

Describe the rebound congestion experienced with decongestant use

Answer 32

after 3 to 5 days of nasal formula decongestant use patients can experience increased congestion that will not respond to decongestants for some time

Question 33

what should be monitored with decongestants use

Answer 33

heart rate and blood pressure | also monitor OTC use