allergic reactions this product contains sodium metabisulfite, a sulfite that may cause allergic-type reactions, including anaphylactic symptoms and life-threatening or less severe asthmatic episodes in certain susceptible people. the overall prevalence of sulfite sensitivity in the general population is unknown and probably low. sulfite sensitivity is seen more frequently in asthmatic than in nonasthmatic people. 5.7 peripheral and visceral ischemia phenylephrine hydrochloride can cause excessive peripheral and visceral vasoconstriction and ischemia to vital organs, particularly in patients with extensive peripheral vascular disease. 5.8 renal toxicity phenylephrine hydrochloride can increase the need for renal replacement therapy in patients with septic shock. monitor renal function.

lution prior to bolus intravenous administration. 2.3 preparing a solution for continuous intravenous infusion for continuous intravenous infusion, withdraw 10 mg (1 ml of 10 mg/ml concentration) of phenylephrine hydrochloride injection and add to 500 ml of 5% dextrose injection, usp or 0.9% sodium chloride injection, usp (providing a final concentration of 20 mcg/ml). 2.4 dosing for perioperative setting in adult patients undergoing surgical procedures with either neuraxial anesthesia or general anesthesia: 50 mcg to 250 mcg by intravenous bolus administration. the most frequently reported initial bolus dose is 50 mcg or 100 mcg. 0.5 mcg/kg/min to 1.4 mcg/kg/min by intravenous continuous infusion, titrated to blood pressure goal. 2.5 dosing for septic or other vasodilatory shock in adult patients with septic or other vasodilatory shock: no bolus. 0.5 mcg/kg/min to 6 mcg/kg/min by intravenous continuous infusion, titrated to blood pressure goal. doses above 6 mcg/kg/min do not show significant incremental increase in blood pressure.

eriatric use clinical studies of phenylephrine did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. other reported clinical experience has not identified differences in responses between the elderly and younger patients. in general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. 8.6 hepatic impairment in patients with liver cirrhosis [child pugh class a (n=3), class b (n=5) and class c (n=1)], dose-response data indicate decreased responsiveness to phenylephrine. consider using larger doses than usual in hepatic impaired subjects. 8.7 renal impairment in patients with end stage renal disease (esrd) undergoing hemodialysis, dose-response data indicates increased responsiveness to phenylephrine. consider using lower doses of phenylephrine hydrochloride in esrd patients.

ate volume of distribution (340 l) exceeded the body volume by a factor of 5, suggesting a high distribution into certain organ compartments. the average total serum clearance (2095 ml/min) was close to one-third of the cardiac output. a mass balance study showed that phenylephrine is extensively metabolized by the liver with only 12% of the dose excreted unchanged in the urine. deamination by monoamino oxidase is the primary metabolic pathway resulting in the formation of the major metabolite (m-hydroxymandelic acid) which accounts for 57% of the total administered dose.