Phenylephrine
Phenylephrine hydrochloride
Brand names:Neo-Synephrine, Sudafed PE, Vazculep
A selective alpha-1 adrenergic agonist used in two distinct contexts: as a topical nasal decongestant and as an IV vasopressor for hypotension management. The oral OTC decongestant form is widely used but has minimal absorption and limited efficacy. The IV form is used in critical care for vasopressor support in anesthesia, sepsis, and select shock states.
Pharmacology and Actions
Phenylephrine is a direct-acting alpha-1 adrenergic agonist with minimal beta-receptor activity. The result is peripheral vasoconstriction, increased systemic vascular resistance, and increased blood pressure. Reflex bradycardia commonly accompanies the blood pressure rise. Topically applied to nasal mucosa, the vasoconstriction reduces mucosal swelling and nasal congestion. Topical hemostatic effects are also clinically relevant in select applications including epistaxis management.
Indications
- Nasal congestion (topical spray or oral)
- Hypotension during anesthesia (IV)
- Hypotension from vasodilatory shock when norepinephrine is unavailable (IV)
- Epistaxis management (topical hemostatic effect)
- Hemorrhoidal symptoms (topical preparations)
- Ophthalmic mydriasis for fundus examination
Absolute Contraindications
- Known phenylephrine or sympathomimetic allergy
- Severe hypertension or coronary artery disease (IV use)
- Ventricular tachycardia (IV use)
- Concurrent MAOI use within 14 days
- Closed-angle glaucoma (ophthalmic use)
Precautions and Side Effects
Reflex bradycardia is the most common cardiovascular effect with IV use; can be marked enough to require treatment. Hypertension and end-organ ischemia can occur with excessive dosing. Topical nasal use can cause rebound congestion (rhinitis medicamentosa) with use beyond 3 to 5 days. Headache, anxiety, and tremor are common with systemic absorption. Cardiac monitoring is required with IV use. Extravasation of IV solution can cause local tissue ischemia.
Adult Dosing
Pediatric Dosing
Pediatric IV hypotension: 5 to 20 mcg/kg IV bolus, titrate to BP. Infusion 0.1 to 0.5 mcg/kg/min. Topical nasal decongestant for pediatric patients age 6 and older follow product labeling. Avoid in children under 6 years for oral decongestant use.
Pharmacokinetics
Peak Effect: IV: 1 to 2 minutes. Topical nasal: 30 minutes.
Duration: IV: 15 to 20 minutes. Topical nasal: 4 hours. PO: 4 hours.
Storage and Handling
Store at controlled room temperature (15 to 30 degrees Celsius). Protect from light. IV ampules and vials should be inspected for discoloration before use.
Reconstitution:
IV preparation: typically supplied at 10 mg/mL ampules. For infusion, dilute 10 mg in 250 mL D5W or NSS for 40 mcg/mL concentration. Topical, oral, and ophthalmic preparations require no reconstitution.
TCCC and TECC Role
Phenylephrine has limited role in routine TCCC trauma care. The IV vasopressor use is generally reserved for critical care transport and hospital settings where norepinephrine is preferred for vasodilatory shock. The drug's primary tactical relevance is as a topical hemostatic adjunct in epistaxis management and as a deployment medicine staple for nasal congestion. The OTC oral form has minimal clinical effect; topical formulations are operationally superior for decongestion.
Phenylephrine is the drug carried in deployment medical kits primarily for nasal congestion management and epistaxis. The topical spray works well; the oral OTC form is largely placebo due to poor absorption. For tactical TEMS providers, phenylephrine's most clinically relevant use is topical application during epistaxis: soak a cotton pledget with phenylephrine and pack the affected nostril for mechanical and pharmacologic hemostasis. The IV vasopressor use is specialty care territory and rarely encountered in routine tactical EMS.
Prescribing or recommending OTC oral phenylephrine for nasal congestion when topical spray is significantly more effective. Oral phenylephrine has been shown in recent FDA review to have minimal efficacy at OTC doses due to poor bioavailability. Pseudoephedrine remains the more effective oral decongestant. The other common error is continuing topical nasal phenylephrine beyond 5 days, which produces rebound congestion that worsens the original problem.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Phenylephrine
| IV/IO | Hypotension bolus: 50 to 200 mcg IV slow push, titrate to BP. Infusion: 0.5 to 2 mcg/kg/min IV drip, titrated to MAP target (typically 65 mmHg or higher). Cardiac monitoring required. (Immediate (vasopressor effect within seconds to 1 minute)) |
| IM | Hypotension: 2 to 5 mg IM, may repeat in 1 to 2 hours. (10 to 15 minutes) |
| IN | Nasal congestion (topical spray): 1 to 2 sprays per nostril every 4 hours as needed. Maximum 3 to 5 days continuous use to avoid rebound congestion. (Topical decongestant: within minutes) |
| PO | Nasal congestion (OTC): 10 mg PO every 4 hours. Oral bioavailability is poor and clinical efficacy is questionable. (15 to 20 minutes (limited absorption)) |