Antihistamines Flashcards
There are three (3) prototype medications, generations, can you name them?
1st generationH2 antagonist 2nd generation H₁ antagonist & Intranasal antihistamines
Name 3- 1st generationH2 antagonist?
Diphenhydramine- Benadryl Promethazine,-(Phenergan) Dimenhydrinate, Hydroxine- Vistaril
Name some second generation antihistamines
Loratadine-(Claritin), Cetirzine (Zrytect), Fexofenadine (Allegra), Desloratadine (Clarinex)
What is the action of an antihistamine?
Block histamine, hence histamine is a chemical released during inflammation that increases secretions and narrows airways
When or what is the use of an antihistamine?
Mild seasonal allergies, Anaphylaxis, Motion sickness, Insomnia & often used in combination with sympathomimetics to provide a nasal decongestant effect
What are adverse effects or complications of taking an antihistamine?
Sedation, Anticholinergic effects (dry mouth, constipation) GI upset , Acute toxicity, Resp depression & tissue injury at IV site
How does a client present in acute toxicity of an antihistamine?
Flushes face, high fever, tachy, dry mouth, urine retention, pupil dilatation
What is the antidote for antihistamine toxicity?
Activate charcoal & a cathartic to decrease the absorption, administer acetaminophen for fever & ice packs or sponge baths
Promethazine ( Phenergan) can cause what adverse effects?
Resp depression & tissue injury at IV site, - IM is the preferred route if unavailable, administer through a large-bore IV in concentration of 25 mg/mL or less-monitor & instruct the client to report manifestations of extravasation- burning or pain at site.
What are complications /precautions with an antihistamine?
Use with caution who have asthma, seizure disorder, cardiac & renal disease, urinary retention, open-angle glaucoma, & prostate hypertrophy, Pregnancy, & contraindicated during the third trimester, & Promethazine is contraindicated in children< 2 years, Use with caution in older adults dues to resp depression
What are drug interactions with antihistamines?
ETOH, and meds causing CNS depression-opioids, barbiturates, & benzos
What does an expectorant do ?
Liquefy the lower resp tract secretions
Why are expectorants used?
For the relief of resp conditions characterized by a nonproductive cough
What is a common expectorant?
Guaifenesin (Mucinex)
What are contraindications of an expectorant?
Do not use with persistent coughs, which could indicate an underlying medical problem.
What are adverse effects of an expectorant?
GI N& V, CNS- H/A dizziness, Resp. Bronchospasm, Rhinorrhea
A nurse is teaching a client who has a new prescription for dextromethorphan to suppress a cough. The nurse should instruct the client to monitor for which of the following manifestations as an adverse effect of this medication?
1. Diarrhea
2. Anxiety
3. Sedation
4. Palpitations
- Sedation (it also causes nausea)
A nurse is caring for a client who has been taking phenylephrine nasal drops for the past 10 days for sinusitis. The nurse should assess the client for which of the following symptoms as an adverse effect of this med?
1. Sedation
2. Nasal congestion
3. Productive cough
Constipation
- *** Remember when used for over 5 days, rebound nasal congestion can occur when taking nasal sypathomimetic medication (phenylephrine)
What is an adverse effect for 1st generation antihistamine?
Constipation
A nurse is teaching a client who has a new Rx for diphenhydramine for allergic rhinitis. The nurse should instruct the client to monitor for which of the following symptoms or manifestations as an adverse effect of this drug? Select all that apply
1. Dry mouth
2. Nonproductive cough
3. Skin rash
4. Drowsiness
5. Urinary hesitation
- Dry mouth, 4. Drowsiness
- Urinary hesitation
A nurse is teaching a client about the use of fluticasone, (a corticosteroid) to treat perennial rhinitis. Which of the following patient statements indicates an understanding of the drug teaching?
1. I should use the spray every 4 hours while I am awake.
2. It can take as long as three weeks before the medication takes a maximum effect.
3. The medication can also be used to treat motion sickness.
4. I can use this medication when my nasal passages are blocked.
- the benefits can be seen within a few hours, but the maximum benefits can take up to three weeks.
