Neosynephrine (phenylephrine)

Question 1

Class

Answer 1

Alpha agonist

Sympathomimetic

Decongestants

Question 2

Description

Answer 2

Stimulates alpha receptors in the blood vessels of the nasal mucosa which causes their constriction & thereby decreases the risk of nasal bleeding

Question 3

Onset & Duration

Answer 3

Onset: seconds

Peak effect: 30 minutes

Duration: 30 minutes - 4 hours

Question 4

Indications

Answer 4

Decongestant

Facilitation of nasotracheal intubation

Epistaxis & hemorrhoids

Hypotension/vasopressor

Priapism

Question 5

Contraindications

Answer 5

Hypersensitivity

Severe hypertension

Ventricular tachycardia

Use Precaution if:
Hypertensive
Diabetes
Thyroid disorder
Enlarged prostate/urinary issues

Question 6

Adverse Reactions

Answer 6

Headache or dizziness

Excitability/Nervousness

Restlessness & rarely arrhythmias

Trouble sleeping

Upset stomach or vomiting

Sweating

Question 7

Drug Interactions

Answer 7

Increase BP:
MAO inhibitors have been used in the past 14 days (dangerous interaction)

Tricyclic antidepressants

Hydrocortisone

Drugs that decrease effects:
Calcium channel blockers

ACE inhibitors

Benzos

phenylephrine + atropine = increased BP and tachycardia

phenylephrine + halogenated anaesthetics = increased cardiac irritability

phenylephrine + alpha blocking agents = blockade of vasopressor effect

phenylephrine + other sympathomimetics = increased risk of toxicity

Question 8

How supplied

Question 9

Dosage & Administration

Answer 9

Nasal congestion:

10mg orally every 4 hours

Question 10

Special Considerations

Answer 10

Pregnancy Category: C