Vasoconstrictor sympathomimetics
Mechanism Of Action:
Stimulation of peripheral α- adrenoceptors within the vasculature, leading to vasoconstriction and increased systolic and diastolic blood pressure.
Indications:
- Acute Hypotension
- Cardiac arrest.
Cautions and Contraindications:
- Severe Hypertension
- Hypersensitivity
- Ventricular tachycardia
Side – Effects:
- Hypertension
- Headache
- Arrhythmias
- Bradycardia/ tachycardia
| Norepinephrine |
| Availability : Injection Solution: 1 mg/mL. |
| Administration/handling: IV Reconstitution • Add 4 mL (4 mg) to 250 mL D5W (16 mcg/mL). Maximum concentration: 32 mL (32 mg) to 250 mL (128 mcg/mL). |
| Rate of administration: Closely monitor IV infusion flow rate (use infusion pump). • Monitor B/P q2min during IV infusion until desired therapeutic response is achieved, then q5min during remaining IV infusion. • Never leave pt unattended. • Maintain B/P at 90–100 mm Hg in previously normotensive pts, and 30–40 mm Hg below preexisting B/P in previously hypertensive pts. • Reduce IV infusion gradually. Avoid abrupt withdrawal. • If using peripherally inserted catheter, it is imperative to check the IV site frequently for free flow and infused vein for blanching, hardness to vein, coldness, pallor to extremity. • If extravasation occurs, area should be infiltrated with 10–15 mL sterile saline containing 5–10 mg phentolamine (does not alter pressor effects of norepinephrine). |
| Storage : Do not use if solution is brown or contains precipitate. • Store at room temperature. Diluted solution stable for 24 hrs at room temperature. |
| Acute Hypotension Unresponsive to Fluid Volume Replacement IV infusion: Adults, elderly: Initially, administer at 8–12 mcg/min. Adjust rate of flow to desired response. Average maintenance range: 2–4 mcg/min (varies greatly based on clinical situation). Children: Initially, 0.05–0.1 mcg/kg/min; titrate to desired effect. Maximum: 2 mcg/kg/min |
| Ephedrine |
| Availability: Tablets: 12.5 mg, 25 mg injectable solution, as sulfate 50mg/mL •50mg/10mL (5mg/mL) vial; 25mg/5mL, 50mg/10mL single-dose prefilled syringe; equivalent to ephedrine base 3.8mg/mL injectable solution, as hydrochloride •47mg/mL; equivalent to ephedrine base 38mg/mL •47mg/5mL (9.4mg/mL); equivalent to ephedrine base 7.7mg/mL •23.5mg/5mL (4.7mg/mL); equivalent to ephedrine base 3.8mg/mL |
| IV Preparation Visually inspect parenteral drug products for particulate matter and discoloration before preparation and administration. Products vary regarding requirement for dilution IV Administration Administer prepared diluted solutions or undiluted drug as IV bolus Formulations for direct IV bolus administration •Emerphed (ephedrine sulfate 5 mg/mL) •Rezipres (ephedrine HCl 4.7 mg/mL and 9.7 mg/mL) Administer by IV injection. Also has been administered by SC or IM injection. |
| •Ephedrine sulfate injection, 50 mg/mL, must be diluted before administration as an intravenous bolus dose. •Bolus intravenous injection: 5 mg to 10 mg as needed, not to exceed 50 mg. Hypotension During Anesthesia IV Ephedrine sulfate: Initially, 5–10 mg by IV bolus injection; administer additional bolus doses as needed (up to a total dose of 50 mg) to achieve desired BP response. Other IV dosage regimens have been recommended. IM or SC Ephedrine sulfate: Usual dose of 25–50 mg has been administered. Bronchospasm Oral Ephedrine hydrochloride or sulfate self-medication: 12.5–25 mg every 4 hours as needed for treatment of mild symptoms of intermittent asthma; administer in fixed combination with guaifenesin. Parenteral Ephedrine sulfate: Parenteral doses of 12.5–25 mg have been given. |
| Phenylephrine |
| Availability: Injection, Solution: 10 mg/mL. Solution, Nasal Drops (Neo-Synephrine): 0.125%, 0.25%. Solution, Nasal Spray (Neo-Synephrine): 0.25%, 0.5%. Solution, Oral: 2.5 mg/5 mL. Tablets (Sudafed PE): 10 mg. |
| Administration/handling: IV Reconstitution • For IV push, dilute with NS to a concentration of 0.1–1 mg/mL. For IV infusion: dilute 10–100 mg with 500 mL 0.9% NaCl or D5W. Rate of administration • For IV push, give over 20–30 sec. • For IV infusion, titrate dose to maintain systolic B/P greater than 90 mm Hg. Storage: Store vials at room temperature. |
| Nasal: Instruct pt to blow nose prior to administering medication. • With head tilted back, apply drops in 1 nostril. Wait 5 min before applying drops in another nostril. • Sprays should be administered into each nostril with head erect. • Pt should sniff briskly while squeezing container, then wait 3–5 min before blowing nose gently. • Rinse tip of spray bottle |
| Nasal Decongestant: Do not use for more than 3 days. Intranasal: Adults, elderly, children 12 yrs and older: 2–3 drops or 2–3 sprays of 0.25%–0.5% solution into each nostril q4h as needed. Children 6–11 yrs: 2–3 drops or 2–3 sprays of 0.25% solution into each nostril q4h as needed. Children 2–5 yrs: 1 drop of 0.125% solution (dilute 0.5% solution with 0.9% NaCl to achieve 0.125%) in each nostril. Repeat q2–4h as needed |
| PO: Adults, elderly, children 13 yrs and older: 10 mg q4h as needed for up to 7 days. Maximum: 60 mg/day. Children 6–11 yrs: 5 mg q4h as needed for up to 7 days. Maximum: 30 mg/day. Children 4–5 yrs: 2.5 mg q4h as needed for up to 7 days. Maximum: 15 mg/day |
| Hypotension, Shock: IV infusion: Adults, elderly: 0.5–6 mcg/kg/min. Titrate to desired response. Children: Initially, 0.1–0.5 mcg/kg/min. Titrate to desired effect. |
Metabolism and Half- life:
Metabolized in the liver and other tissues by MAO and COMT.
Monitoring:
- Continuous cardiac monitoring in a high- dependency area is required.
- Monitoring of oxygen saturation, urine output and renal function is also necessary.
Drug Interactions:
Severe , prolonged hypertension when given in combination with MAOIs.
Important Points:
Ephedrine can be used to treat hypotension resulting from spinal/epidural anesthesia.
NURSING CONSIDERATIONS
Baseline assessment
- Obtain baseline symptomology, vital signs.
- Question history of hypertension, cardiac disease, asthma, recent use of MAOI therapy.
- Assess ECG, B/P continuously (be alert to precipitous B/P drop).
- Be alert to pt complaint of headache.
Intervention/evaluation
- Monitor B/P, heart rate. For severe hypotension or shock states, monitor central venous pressure non-invasive hemodynamic monitoring systems.
- Monitor IV flow rate diligently.
- Assess for extravasation characterized by blanching of skin over vein, coolness (results from local vasoconstriction); color, temperature of IV site extremity (pallor, cyanosis, mottling).
- Assess nailbed capillary refill.
- Monitor I&O; measure output hourly, report urine output less than 30 mL/hr.
- Once B/P parameter has been reached, IV infusion should not be restarted unless needed.
Patient/family teaching
- Discontinue drug if adverse reactions occur.
- Do not use for nasal decongestion for longer than 3 days (rebound congestion).
- Discontinue drug if insomnia, dizziness, weakness, tremor, palpitations occur.
- Nasal: Stinging/burning of nasal mucosa may occur.
- Ophthalmic: Blurring of vision with eye instillation generally subsides with continued therapy.
- Discontinue medication if redness/swelling of eyelids, itching occurs
REFERENCES
- Robert Kizior, Keith Hodgson, Saunders Nursing Drug handbook,1st edition 2024, Elsevier Publications. ISBN-9780443116070
- McGraw Hill- Drug Handbook, Seventh Edition, 2013, McGraw Hill Education Publications,9780071799430.
- April Hazard, Cynthia Sanoski, Davi’s Drug Guide for Nurses -Sixteenth Edition 2019, FA Davis Company Publications,9780803669451.
- Jones and Bartlet, Pharmacology for Nurses, Second Edition, 2020, Jones and Bartlet Learning Publications, ISBN 9781284141986.
- Nursebro.com, Search – Nursebro
Stories are the threads that bind us; through them, we understand each other, grow, and heal.
JOHN NOORD
Connect with “Nurses Lab Editorial Team”
I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.
