|
Phenylephrine: |
Pure a-agonist
(Synthetic) |
|
|
|
IVP DOSING |
| 0.1-0.5 mg |
Give over 30 seconds. Repeat Q 10-15 minutes to maintain BP. 0.5 mg IVP is also the dose given to treat PSVT. |
|
INFUSION DOSING |
| This is the starting rate... | 100-180 mcg/min |
|
Something in this range should be about right for a maintainance infusion... |
40-60 mcg/min |
| This is the MAXIMUM infusion rate! | 300 mcg/min |
Used
for severe hypotension, especially during surgery, shock (including drug induced
shock), and in PSVT (hardly a first choice). Can be combined with regional anesthesia to prolong local
effects. Also used in OTC products as a decongestant.
Half
Life: Effects persist up to
20 minutes after IV, 60 minutes after SQ.
Side
Effects: HTN, CVA, Sz,
arrhythmias, bradycardia, dyspnea, worsening of asthma, anaphylaxis, decreased
organ perfusion, HA, anxiety.
Contraindicated:
in severe HTN, VT, bradycardia, mesenteric or peripheral ischemia, severe
arteriosclerosis, hyperthyroidism, and heart block.
Phenylephrine
is potentiated by MAOIs, TCAs, atropine, oxytocics.
Phenylephrine
is antagonized by a
and b-blockers,
diuretics, and phenothiazines.
Extravasation
causes tissue necrosis.
If
Extravasation occurs inject phentolamine 5-10mg SQ mixed with 10-15cc of NS.
 |