fen-il-EFF-rin
Therapeutic Classification: vasopressors
Pharmacologic Classification: adrenergics, alpha adrenergic agonists, vasopressors
High Alert
Absorption: Well absorbed from IM sites. IV administration results in complete bioavailability.
Distribution: Widely distributed to tissues.
Half-Life: 2.5 hr.
(vasopressor effects)
| ROUTE | ONSET | PEAK | DURATION |
|---|---|---|---|
| IV | immediate | unknown | 15–20 min |
| IM | 10–15 min | unknown | 0.5–2 hr |
| SUBQ | 10–15 min | unknown | 50–60 min |
Contraindicated in:
Use Cautiously in:
CV: ARRHYTHMIAS, bradycardia, chest pain, hypertension, ischemia, tachycardia
Derm: pruritus
GI: epigastric pain, nausea, vomiting
Local: phlebitis, sloughing at IV site
Neuro: blurred vision, headache, insomnia, nervousness, tremor
Resp: dyspnea
Drug-drug:
Hypotension
Hypotension During Anesthesia
Vasoconstrictor for Regional Anesthesia
Prolongation of Spinal Anesthesia
IV Administration:
IV phenylephrine is a vesicant. Central line administration is preferred; extravasation may cause severe ischemic necrosis. If central line is not available, may administer for <72 hr through a peripheral IV catheter placed in a large vein at a proximal site (e.g., in or proximal to antecubital fossa). May also administer through a midline catheter. If extravasation occurs, immediately stop infusion. Leave needle/cannula in place temporarily but do not flush the line. Gently aspirate extravasated solution; then remove needle/cannula. Elevate patient's extremity and apply dry warm compresses. Initiate phentolamine antidote for refractory cases in addition to supportive management. For phentolamine, dilute 5–10 mg in 10 mL of 0.9% NaCl and administer SUBQ into extravasation site as soon as possible after extravasation; if IV catheter remains in place, administer initial dose IV through the infiltrated catheter. May repeat in 60 min if patient remains symptomatic. Nitroglycerin 2% topical ointment (1-inch strip applied to site of ischemia to cover affected area; may repeat every 8 hr as necessary) may be used as alternative to phentolamine.