Phenylephrine 10mg/ml Inj, 5ml
It is used to treat low blood pressure.
Drug Class
Vasopressor
Pharmacologic Class
Alpha-1 Adrenergic Agonist
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Phenylephrine is a medication given by injection, usually into a vein, to quickly raise your blood pressure. It works by tightening your blood vessels. It's often used in situations where your blood pressure drops too low, such as during surgery or certain medical conditions.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. It is essential to follow the instructions carefully. This medication is administered via injection into a vein, either as a single dose or continuously over a period of time.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on what to do next.
To use this medication correctly, follow your doctor's instructions and read all the information provided to you. It is essential to follow the instructions carefully. This medication is administered via injection into a vein, either as a single dose or continuously over a period of time.
Storing and Disposing of Your Medication
If you need to store this medication at home, consult with your doctor, nurse, or pharmacist to determine the proper storage procedure.
Missing a Dose
If you miss a dose, contact your doctor to receive guidance on what to do next.
Lifestyle & Tips
- This medication is administered in a controlled medical setting, so lifestyle modifications are not directly applicable during administration.
- Follow all instructions from your healthcare provider regarding your underlying condition.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
Hypotension (bolus): 50-200 mcg IV bolus, may repeat every 2-5 minutes as needed. Hypotension (infusion): Initial 0.5-1 mcg/min, titrate by 0.5 mcg/min increments every 10-15 minutes to desired blood pressure, usual range 0.5-6 mcg/min. Paroxysmal Supraventricular Tachycardia (PSVT): 100-500 mcg IV bolus, not to exceed 1 mg.
Dose Range:
0.05 - 6 mg
Condition-Specific Dosing:
hypotension_bolus_mcg:
50-200 mcg IV bolus, repeat as needed
hypotension_infusion_mcg_per_min:
0.5-6 mcg/min IV infusion, titrate to effect
psvt_mcg:
100-500 mcg IV bolus, max 1 mg
Pediatric Dosing
Neonatal:
Not established for routine use; use with extreme caution and expert consultation. Typical range for hypotension: 0.5-1 mcg/kg IV bolus, or 0.1-0.5 mcg/kg/min IV infusion, titrate to effect.
Infant:
Not established for routine use; use with extreme caution and expert consultation. Typical range for hypotension: 0.5-1 mcg/kg IV bolus, or 0.1-0.5 mcg/kg/min IV infusion, titrate to effect.
Child:
Not established for routine use; use with extreme caution and expert consultation. Typical range for hypotension: 0.5-1 mcg/kg IV bolus, or 0.1-0.5 mcg/kg/min IV infusion, titrate to effect.
Adolescent:
Dosing similar to adult, but start at lower end of range and titrate carefully.
Dose Adjustments
Renal Impairment:
Mild:
No specific dose adjustment recommended, monitor closely.
Moderate:
No specific dose adjustment recommended, monitor closely.
Severe:
No specific dose adjustment recommended, monitor closely.
Dialysis:
Not significantly dialyzable. No specific dose adjustment recommended, monitor closely.
Hepatic Impairment:
Mild:
No specific dose adjustment recommended, monitor closely.
Moderate:
No specific dose adjustment recommended, monitor closely.
Severe:
No specific dose adjustment recommended, monitor closely.
Pharmacology
Mechanism of Action
Phenylephrine is a direct-acting sympathomimetic amine that acts primarily as a selective alpha-1 adrenergic receptor agonist. It causes potent vasoconstriction, leading to an increase in systemic vascular resistance (SVR) and mean arterial pressure (MAP). This increase in blood pressure can lead to a reflex bradycardia.
Pharmacokinetics
Absorption:
Bioavailability:
100% (IV)
Tmax:
Minutes (IV)
FoodEffect:
Not applicable (IV)
Distribution:
Vd:
Approximately 340 L
ProteinBinding:
Low (approximately 20%)
CnssPenetration:
Limited
Elimination:
HalfLife:
Approximately 2.5 hours (IV)
Clearance:
Approximately 2100 mL/min
ExcretionRoute:
Renal
Unchanged:
Approximately 16% (IV)
Pharmacodynamics
OnsetOfAction:
Immediate (IV)
PeakEffect:
5-10 minutes (IV bolus)
DurationOfAction:
15-20 minutes (IV bolus); continuous with infusion
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Help Right Away
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood pressure, including:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Chest pain or pressure
Shakiness
Signs of kidney problems, such as:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Abnormal heartbeat (fast, slow, or irregular)
Blurred vision
Shortness of breath
Sudden weight gain or swelling in the arms or legs
Numbness or tingling in the hands or feet
If you notice any signs of tissue damage at the injection site, such as redness, burning, pain, swelling, blisters, skin sores, or fluid leakage, inform your nurse immediately.
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor:
Dizziness or headache
Feeling nervous and excitable
Trouble sleeping
Restlessness
Upset stomach or vomiting
Excessive sweating
Stomach pain
Neck pain
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical attention immediately:
Signs of an allergic reaction, such as:
+ Rash
+ Hives
+ Itching
+ Red, swollen, blistered, or peeling skin with or without fever
+ Wheezing
+ Tightness in the chest or throat
+ Trouble breathing, swallowing, or talking
+ Unusual hoarseness
+ Swelling of the mouth, face, lips, tongue, or throat
Signs of high blood pressure, including:
+ Severe headache or dizziness
+ Passing out
+ Changes in eyesight
Chest pain or pressure
Shakiness
Signs of kidney problems, such as:
+ Inability to pass urine
+ Changes in urine output
+ Blood in the urine
+ Sudden weight gain
Abnormal heartbeat (fast, slow, or irregular)
Blurred vision
Shortness of breath
Sudden weight gain or swelling in the arms or legs
Numbness or tingling in the hands or feet
If you notice any signs of tissue damage at the injection site, such as redness, burning, pain, swelling, blisters, skin sores, or fluid leakage, inform your nurse immediately.
Other Possible Side Effects
Like all medications, this drug can cause side effects. While many people may not experience any side effects or only minor ones, it's essential to discuss any concerns with your doctor. If you experience any of the following side effects or any other unusual symptoms that bother you or persist, contact your doctor:
Dizziness or headache
Feeling nervous and excitable
Trouble sleeping
Restlessness
Upset stomach or vomiting
Excessive sweating
Stomach pain
Neck pain
This list is not exhaustive, and you may experience other side effects not mentioned here. If you have questions or concerns about side effects, consult your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Severe headache
- Chest pain or tightness
- Irregular or very slow heartbeat
- Difficulty breathing
- Dizziness or lightheadedness
- Numbness or tingling in hands or feet
- Pain or swelling at the injection site
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have high blood pressure, as this medication may affect your condition.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including:
+ Isocarboxazid
+ Phenelzine
+ Tranylcypromine
+ Selegiline
+ Rasagiline
Combining these medications with this drug may lead to severely high blood pressure.
If you are currently taking any of the following medications:
+ Linezolid
+ Methylene blue
Interactions with these medications can be significant, and your doctor needs to be aware of their use.
This list is not exhaustive, and it is crucial to disclose all your medications, including:
Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins
as well as any health problems you are experiencing. Your doctor and pharmacist need this information to ensure it is safe for you to take this medication with your other treatments. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
If you have high blood pressure, as this medication may affect your condition.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including:
+ Isocarboxazid
+ Phenelzine
+ Tranylcypromine
+ Selegiline
+ Rasagiline
Combining these medications with this drug may lead to severely high blood pressure.
If you are currently taking any of the following medications:
+ Linezolid
+ Methylene blue
Interactions with these medications can be significant, and your doctor needs to be aware of their use.
This list is not exhaustive, and it is crucial to disclose all your medications, including:
Prescription and over-the-counter (OTC) drugs
Natural products
* Vitamins
as well as any health problems you are experiencing. Your doctor and pharmacist need this information to ensure it is safe for you to take this medication with your other treatments. Never start, stop, or adjust the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication. If you have a known allergy to sulfites, consult with your doctor, as some formulations of this drug may contain sulfites. Regular blood tests will be necessary, as directed by your doctor, to monitor your condition. Additionally, if you are pregnant, planning to become pregnant, or are breastfeeding, discuss the potential benefits and risks of this medication with your doctor to determine the best course of treatment for you and your baby.
Overdose Information
Overdose Symptoms:
- Severe hypertension (very high blood pressure)
- Headache
- Vomiting
- Bradycardia (very slow heart rate)
- Palpitations
- Ventricular arrhythmias
- Cerebral hemorrhage
- Pulmonary edema
What to Do:
Overdose requires immediate medical attention. Treatment is symptomatic and supportive. Hypertension can be treated with an alpha-adrenergic blocking agent (e.g., phentolamine). Bradycardia may require atropine. Call 1-800-222-1222 (Poison Control).
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) - concurrent use or within 14 days of MAOI discontinuation due to risk of severe, prolonged hypertensive crisis.
Major Interactions
- Tricyclic Antidepressants (TCAs) - may potentiate pressor effect.
- Atropine - may potentiate pressor effect.
- Oxytocic Drugs (e.g., oxytocin, methylergonovine) - risk of severe persistent hypertension and stroke.
- Beta-blockers (non-selective) - may result in unopposed alpha-adrenergic stimulation leading to severe hypertension and reflex bradycardia.
- Alpha-adrenergic blocking agents (e.g., phentolamine) - may antagonize the pressor effect of phenylephrine.
- General Anesthetics (e.g., halothane, cyclopropane) - may sensitize the myocardium to the effects of sympathomimetics, increasing risk of arrhythmias.
Moderate Interactions
- Digoxin - increased risk of arrhythmias.
- Ergot alkaloids - increased risk of vasoconstriction and hypertension.
- Other sympathomimetics - additive pressor effects.
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Blood Pressure (BP)
Rationale: To establish baseline and guide initial dosing.
Timing: Prior to initiation of therapy.
Heart Rate (HR)
Rationale: To establish baseline and monitor for reflex bradycardia.
Timing: Prior to initiation of therapy.
Electrocardiogram (ECG)
Rationale: To assess cardiac rhythm and identify pre-existing abnormalities.
Timing: Prior to initiation, especially in patients with cardiac history.
Routine Monitoring
Blood Pressure (BP)
Frequency: Continuously (arterial line preferred) or every 1-5 minutes during titration, then every 5-15 minutes once stable.
Target: Individualized, typically MAP >65 mmHg or SBP >90 mmHg, or as clinically indicated.
Action Threshold: Hypotension (below target) or hypertension (above target); adjust infusion rate accordingly.
Heart Rate (HR)
Frequency: Continuously
Target: Individualized, typically 60-100 bpm, but reflex bradycardia is common.
Action Threshold: Significant bradycardia (<50 bpm) or tachycardia (>120 bpm); assess for underlying cause or need for intervention.
Cardiac Rhythm (ECG)
Frequency: Continuously
Target: Normal sinus rhythm
Action Threshold: Development of arrhythmias (e.g., PVCs, VT, SVT); assess for underlying cause or need for intervention.
Urine Output
Frequency: Hourly
Target: >0.5 mL/kg/hr
Action Threshold: Oliguria (<0.5 mL/kg/hr) or anuria; may indicate inadequate renal perfusion.
Peripheral Perfusion (skin color, temperature, capillary refill)
Frequency: Every 1-4 hours
Target: Warm, dry, good capillary refill
Action Threshold: Cool, clammy, mottled skin, prolonged capillary refill; may indicate inadequate tissue perfusion.
Injection Site
Frequency: Regularly (e.g., every 1-2 hours)
Target: No redness, swelling, or pain
Action Threshold: Signs of extravasation (swelling, pallor, pain); stop infusion immediately and consider phentolamine.
Symptom Monitoring
- Headache
- Palpitations
- Chest pain or discomfort
- Dizziness
- Nausea
- Vomiting
- Anxiety
- Tremor
- Shortness of breath
- Changes in mental status
Special Patient Groups
Pregnancy
Category C. Use only if the potential benefit justifies the potential risk to the fetus. Phenylephrine can cause uterine vasoconstriction and reduced placental perfusion, potentially leading to fetal hypoxia and bradycardia.
Trimester-Specific Risks:
First Trimester:
Potential for fetal harm, but data are limited. Avoid if possible.
Second Trimester:
Risk of uterine vasoconstriction and reduced placental perfusion.
Third Trimester:
Increased risk of uterine vasoconstriction, reduced placental perfusion, and fetal hypoxia/bradycardia, especially during labor and delivery.
Lactation
L3 (Moderately safe). Phenylephrine is excreted into breast milk. While oral absorption by the infant is poor, caution is advised. Monitor the infant for signs of agitation, irritability, or changes in feeding/sleep patterns. Consider alternative agents or temporary interruption of breastfeeding if clinically necessary.
Infant Risk:
Low risk of adverse effects due to poor oral absorption, but potential for irritability or cardiovascular effects in sensitive infants.
Pediatric Use
Use with extreme caution. Dosing is weight-based and requires careful titration. Neonates and infants may be more sensitive to the effects and more prone to adverse events. Continuous monitoring of vital signs is essential.
Geriatric Use
Geriatric patients may be more sensitive to the pressor effects of phenylephrine and more prone to adverse cardiovascular events (e.g., hypertension, arrhythmias). Start with lower doses and titrate slowly, monitoring closely for adverse effects.
Clinical Information
Clinical Pearls
- Phenylephrine is a pure alpha-1 agonist, primarily causing vasoconstriction and increasing SVR, which can lead to reflex bradycardia. This distinguishes it from other vasopressors like norepinephrine (alpha and beta effects).
- Always administer phenylephrine injection via IV route. Avoid extravasation, as it can cause tissue necrosis. If extravasation occurs, infiltrate the area with phentolamine.
- Titrate the dose carefully to achieve the desired blood pressure target, as individual responses can vary widely.
- Monitor blood pressure and heart rate continuously, ideally with an arterial line for critically ill patients.
- Be aware of potential drug interactions, especially with MAOIs, which can lead to severe hypertensive crisis.
- Phenylephrine is often preferred in patients with tachycardia or arrhythmias where a pure vasoconstrictor effect is desired without significant chronotropic or inotropic effects.
Alternative Therapies
- Norepinephrine (Levophed) - mixed alpha and beta agonist, often first-line for septic shock.
- Dopamine - dose-dependent effects (dopaminergic, beta, alpha).
- Epinephrine (Adrenalin) - mixed alpha and beta agonist, potent vasopressor and inotrope.
- Vasopressin (Pitressin) - non-adrenergic vasopressor, often used as an adjunct in refractory shock.
Cost & Coverage
Average Cost:
Price varies widely by supplier and contract per 5ml vial
Generic Available:
Yes
Insurance Coverage:
Typically covered by most insurance plans as a generic injectable in hospital/clinic settings.
General Drug Facts
If your symptoms or health problems persist or worsen, it is essential to contact your doctor for further evaluation and guidance. To ensure safe and effective treatment, never share your medication with others, and do not take medication prescribed for someone else.
Store all medications in a secure location, out of the reach of children and pets, to prevent accidental ingestion. Properly dispose of unused or expired medications by checking with your pharmacist for guidance on the best disposal method. Unless instructed to do so, avoid flushing medications down the toilet or pouring them down the drain, as this can harm the environment. Many communities have drug take-back programs, which your pharmacist can help you locate.
Some medications may come with an additional patient information leaflet, so it is a good idea to check with your pharmacist for more information. If you have any questions or concerns about your medication, consult with your doctor, nurse, pharmacist, or other healthcare provider.
In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide detailed information about the medication, including the amount taken, the time it was taken, and any other relevant details.
Store all medications in a secure location, out of the reach of children and pets, to prevent accidental ingestion. Properly dispose of unused or expired medications by checking with your pharmacist for guidance on the best disposal method. Unless instructed to do so, avoid flushing medications down the toilet or pouring them down the drain, as this can harm the environment. Many communities have drug take-back programs, which your pharmacist can help you locate.
Some medications may come with an additional patient information leaflet, so it is a good idea to check with your pharmacist for more information. If you have any questions or concerns about your medication, consult with your doctor, nurse, pharmacist, or other healthcare provider.
In the event of a suspected overdose, immediately contact your local poison control center or seek emergency medical attention. Be prepared to provide detailed information about the medication, including the amount taken, the time it was taken, and any other relevant details.