The use of phenylephrine
with crystalloid co-loading or colloid preloading has not been associated with neonatal acidosis or differences in Apgar scores (14).
Ngan Kee et al  studied the combination of phenylephrine
and ephedrine in different ratios given as infusion to minimise the cardiac effects of vasopressors.
Recent research has shown that phenylephrine
is as effective as ephedrine in prevention of maternal hypotension, nausea and vomiting and it is associated with higher umbilical blood pH with no difference in APGAR scores or neonatal outcome4-6.
It is now well accepted that the best approach to spinal hypotension is by means of a combination of intravenous crystalloid co-load and phenylephrine
. This is the most effective method of ensuring maternal safety and comfort and preventing neonatal acidosis.
The results of the present study indicated that the prophylactic infusion of low doses of ephedrine (10 mg) and phenylephrine
(125 [micro]g) before spinal anesthesia for cesarean section, caused a significant decrease in the frequency and severity of maternal hypotension, need for vasoactive drugs, nausea, vomiting, need for antiemetic drug, and an increase in the Apgar score of neonates.
The addition of phenylephrine
to endothelium-intact and endothelium-denuded rat aortic rings produced a sustained contraction.
Many guidelines offer the choice of ephedrine or phenylephrine
as the vasopressor, including the National Institute for Health and Care Excellence (NICE)  and SA guidelines.
TABLA 1 EFECTS OF PENTHOBARBFPAL (PB), PHENYLEPHRINE
(PE) AND TACRINE (TA) ON HEART RATE PB BPM BPM CG 351 [+ o -] 5.17 (a) 273 [+ o -] 4.63 CP 348 [+ o -] 6.78 (a) 276 [+ o -] 6.33 TC 348 [+ o -] 6.24 (a) 294 [+ o -] 4.08 * TCCP 338 [+ o -] 7.70 (a) 280 [+ o -] 10.73 PE % PB BPM CG 77.9 [+ o -] 1.12 260 [+ o -] 4.98 CP 79.4 [+ o -] 1.65 265 [+ o -] 8.18 TC 85.0 [+ o -] 1.56 * 300 [+ o -] 6.93 * TCCP 81.9 [+ o -] 2.30 282 [+ o -] 12.10 TA % PB % PE CG 74.2 [+ o -] 1.45 95.6 [+ o -] 1.75 CP 77.3 [+ o -] 2.66 97.6 [+ o -] 2.20 TC 86.6 [+ o -] 2.46 * 101.9 [+ o -] 2.04 TCCP 84.3 [+ o -] 2.42 * 102.9 [+ o -] 2.58 * Data are presented as heart rate absolute numbers (BPM) or as percentage respect to PB (% PB) or to PE (% PE).
New York State guidelines on the topical use of phenylephrine
in the operating room.
tension with phenylephrine
(SIGMA[R]) was carried out added to the organ bath in a cumulative way (10 [micron]M to 100).
Standard dosing of pseudoephedrine and phenylephrine
Dose Frequency Maximum daily dose Pseudoephedrine HCI 60mg (2 x 30mg tablets) * Every 4 to 6 hours 240mg Phenylephrine
HCI 10mg Every 4 hours 60mg (1 tablet) * also available in extended-release formulations; 120mg twice daily
Supporters of the bill said there are alternative products on the market-including those that contain phenylephrine
, a version of pseudoephedrine that cannot be converted to methamphetamime.