Phenylephrine: Difference between revisions
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Neil.m.young (talk | contribs) (Text replacement - "α1" to "α<sub>1</sub>") |
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*Metabolism: | *Metabolism: | ||
*Excretion: | *Excretion: | ||
*Mechanism of Action: selective | *Mechanism of Action: selective α<sub>1</sub> agonist causes vasoconstriction | ||
===Primary Receptor=== | ===Primary Receptor=== | ||
* | *α<sub>1</sub> | ||
===Relative Effects=== | ===Relative Effects=== | ||
*↑SVR | *↑SVR | ||
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*Use with caution in patients with spinal cord injury-related bradycardia | *Use with caution in patients with spinal cord injury-related bradycardia | ||
*Useful for treatment of vasodilatory shock when norepinephrine or [[dopamine]] have precipitated tachyarrhythmias | *Useful for treatment of vasodilatory shock when norepinephrine or [[dopamine]] have precipitated tachyarrhythmias | ||
*In patients with ↓LV function, unopposed | *In patients with ↓LV function, unopposed α<sub>1</sub> may lead to decreased CO or myocardial ischemia | ||
**However clinical trials do not support these effects when used in clinically appropriate dose range | **However clinical trials do not support these effects when used in clinically appropriate dose range | ||
Revision as of 12:33, 29 July 2017
General
- Type: Vasopressors
- Dosage Forms:
- Common Trade Names: Neosynephrine
Adult Dosing
Hypotension
- Start 100-200 mcg/min then taper down
- 40-60 mcg/min works for most
Low Flow Priapism
- Dilute phenylephrine 1mg in 9mL NS for final concentration of 100mcg/mL
- For 500 mcg/ml, take 0.5 ml of 10mg/ml phenylephrine, and dilute in 9.5 cc NS
- Inject base of penis with 29-Ga needle (after blood aspiration to confirm position)
- 100-500 mcg every 3-5min (max 1000 mcg) until resolution or 1 hour
Pediatric Dosing
Special Populations
- Pregnancy Rating: C
- Lactation: infant risk cannot be ruled out
- Renal Dosing
- Adult
- Pediatric
- Hepatic Dosing
- Adult
- Pediatric
Contraindications
- Allergy to class/drug
Adverse Reactions
- Baroreceptor-mediated reflex bradycardia
- If extravasates use phentolamine
Serious
Common
Pharmacology
- Half-life:
- Metabolism:
- Excretion:
- Mechanism of Action: selective α1 agonist causes vasoconstriction
Primary Receptor
- α1
Relative Effects
- ↑SVR
- ↓HR (reflex bradycardia)
Notes
- Use with caution in patients with spinal cord injury-related bradycardia
- Useful for treatment of vasodilatory shock when norepinephrine or dopamine have precipitated tachyarrhythmias
- In patients with ↓LV function, unopposed α1 may lead to decreased CO or myocardial ischemia
- However clinical trials do not support these effects when used in clinically appropriate dose range
Indication
- Neurogenic Shock
- Second line agent for septic shock