Phenylephrine 10mg Tablets
It is used to treat nose stuffiness.
Drug Class
Nasal decongestant
Pharmacologic Class
Alpha-1 adrenergic agonist
Pregnancy Category
C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
Phenylephrine is a medication used to relieve nasal congestion, often found in cold and allergy medicines. It works by shrinking the blood vessels in your nose, which helps to open up your nasal passages and make breathing easier. It's important to know that recent scientific reviews have questioned how well oral phenylephrine works for nasal congestion.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, taking it with food may help.
Storing and Disposing of Your Medication
Store your medication at room temperature in a dry location, avoiding the bathroom. Keep all medications in a safe place, out of the reach of children and pets. When disposing of unused or expired medication, do not flush it down the toilet or pour it down the drain unless instructed to do so. Instead, consult your pharmacist for guidance on proper disposal. You may also have access to local drug take-back programs.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next dose, skip the missed dose and resume your regular schedule. Do not take two doses at the same time or extra doses. If you take this medication as needed, follow your doctor's instructions and do not take it more frequently than recommended.
Lifestyle & Tips
- Stay hydrated by drinking plenty of fluids.
- Avoid irritants like smoke or allergens that can worsen congestion.
- Use saline nasal sprays for additional moisture and relief.
- Get adequate rest.
Available Forms & Alternatives
Available Strengths:
Dosing & Administration
Adult Dosing
Standard Dose:
10 mg every 4 hours as needed
Dose Range:
10 - 10 mg
Condition-Specific Dosing:
maximum_daily_dose:
60 mg in 24 hours
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established (generally not recommended for children under 4 years)
Child:
4-5 years: 2.5 mg every 4 hours (max 15 mg/24h); 6-11 years: 5 mg every 4 hours (max 30 mg/24h)
Adolescent:
12 years and older: 10 mg every 4 hours (max 60 mg/24h)
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended
Moderate:
Use with caution; consider lower doses or extended intervals
Severe:
Use with caution; consider lower doses or extended intervals due to potential for increased systemic exposure
Dialysis:
Not well studied; use with caution
Hepatic Impairment:
Mild:
No specific adjustment recommended
Moderate:
Use with caution; consider lower doses or extended intervals due to extensive first-pass metabolism
Severe:
Use with caution; consider lower doses or extended intervals due to extensive first-pass metabolism
Confidence:
Medium
Pharmacology
Mechanism of Action
Phenylephrine is a direct-acting sympathomimetic amine that acts predominantly on alpha-1 adrenergic receptors. It causes vasoconstriction of arterioles in the nasal mucosa, leading to a reduction in swelling and congestion. It has minimal beta-adrenergic activity.
Pharmacokinetics
Absorption:
Bioavailability:
Highly variable, generally low (reported as <1% to 38%) due to extensive first-pass metabolism
Tmax:
0.75 - 2 hours
FoodEffect:
Food may slightly delay absorption but does not significantly alter overall exposure.
Distribution:
Vd:
Not well established for oral formulation, but generally considered low
ProteinBinding:
Low (approximately 16-20%)
CnssPenetration:
Limited
Elimination:
HalfLife:
2-3 hours
Clearance:
High systemic clearance due to extensive metabolism
ExcretionRoute:
Renal (primarily as inactive metabolites)
Unchanged:
<1% (oral dose)
Pharmacodynamics
OnsetOfAction:
15-30 minutes
PeakEffect:
1-2 hours
DurationOfAction:
Up to 4 hours
Safety & Warnings
Side Effects
Urgent Side Effects: Seek Medical Help Right Away
Although rare, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
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
+ Dizziness or fainting
+ Changes in eyesight
Chest pain or pressure
Rapid heartbeat
Shakiness
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 symptoms that bother you or do not go away, contact your doctor:
Dizziness
Headache
Feeling nervous and excitable
Trouble sleeping
Restlessness
* Upset stomach or vomiting
Reporting Side Effects
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, some people may experience severe and potentially life-threatening side effects while taking this medication. If you notice any of the following symptoms, contact your doctor immediately or seek emergency medical attention:
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
+ Dizziness or fainting
+ Changes in eyesight
Chest pain or pressure
Rapid heartbeat
Shakiness
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 symptoms that bother you or do not go away, contact your doctor:
Dizziness
Headache
Feeling nervous and excitable
Trouble sleeping
Restlessness
* Upset stomach or vomiting
Reporting Side Effects
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
- Dizziness or lightheadedness
- Palpitations or rapid heart rate
- Chest pain
- Difficulty breathing
- Severe nervousness or anxiety
- Trouble sleeping
- Difficulty urinating
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, or rasagiline. Combining these medications can lead to severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
This list is not exhaustive, and it is crucial to disclose all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems you have. Your doctor and pharmacist need this information to ensure it is safe for you to take this medication. 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, or rasagiline. Combining these medications can lead to severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
This list is not exhaustive, and it is crucial to disclose all your medications, including prescription and over-the-counter drugs, natural products, and vitamins, as well as any health problems you have. Your doctor and pharmacist need this information to ensure it is safe for you to take this medication. 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. To minimize the risk of severe side effects, do not exceed the dosage prescribed by your doctor. Adhering to the recommended treatment duration is also crucial; do not take this drug for longer than the period specified by your doctor.
When considering administration to children, note that different brands of this medication may be approved for use in various age groups. Therefore, it is crucial to consult with your doctor before giving this drug to a child to ensure the appropriate brand and dosage are used.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is vital to discuss your situation with your doctor. This conversation will help weigh the benefits and risks of taking this medication to both you and your baby, allowing for an informed decision about your treatment.
When considering administration to children, note that different brands of this medication may be approved for use in various age groups. Therefore, it is crucial to consult with your doctor before giving this drug to a child to ensure the appropriate brand and dosage are used.
If you are pregnant, planning to become pregnant, or are breastfeeding, it is vital to discuss your situation with your doctor. This conversation will help weigh the benefits and risks of taking this medication to both you and your baby, allowing for an informed decision about your treatment.
Overdose Information
Overdose Symptoms:
- Hypertensive crisis (severely high blood pressure)
- Tachycardia (rapid heart rate)
- Palpitations
- Arrhythmias
- Headache
- Nervousness
- Tremor
- Seizures
- Cerebral hemorrhage
- Myocardial infarction
What to Do:
Call 1-800-222-1222 (Poison Control Center) immediately or seek emergency medical attention. Treatment is supportive and symptomatic, focusing on managing blood pressure and cardiovascular effects.
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) (concurrent use or within 14 days of MAOI discontinuation) - risk of hypertensive crisis
Major Interactions
- Tricyclic Antidepressants (TCAs) - enhanced pressor effect
- Beta-blockers (non-selective) - increased risk of hypertension and reflex bradycardia
- Other sympathomimetics (e.g., pseudoephedrine, ephedrine, amphetamines) - additive pressor effects, increased risk of cardiovascular events
- Ergot alkaloids (e.g., ergotamine, methysergide) - increased risk of peripheral ischemia
Moderate Interactions
- Alpha-adrenergic blockers (e.g., prazosin, tamsulosin) - may reduce phenylephrine's effect
- Cardiac glycosides (e.g., digoxin) - increased risk of arrhythmias
- Linezolid - potential for hypertensive reaction (weak MAOI activity)
- Thyroid hormones - increased risk of cardiovascular effects
Minor Interactions
- Not available
Monitoring
Baseline Monitoring
Blood Pressure (BP)
Rationale: To establish baseline and identify pre-existing hypertension, which is a contraindication or requires caution.
Timing: Prior to initiation
Heart Rate (HR)
Rationale: To establish baseline and identify pre-existing arrhythmias or tachycardia.
Timing: Prior to initiation
Routine Monitoring
Blood Pressure (BP)
Frequency: Periodically, especially in patients with cardiovascular risk factors or during initial therapy
Target: Within patient's normal range
Action Threshold: Significant increase (e.g., >20 mmHg systolic or >10 mmHg diastolic above baseline) or sustained elevation
Heart Rate (HR)
Frequency: Periodically, especially in patients with cardiovascular risk factors
Target: Within patient's normal range
Action Threshold: Significant increase (e.g., >20 bpm above baseline) or onset of palpitations/arrhythmias
Symptom assessment for decongestion
Frequency: As needed by patient
Target: Improved nasal breathing
Action Threshold: Lack of efficacy after several doses or worsening symptoms
Symptom Monitoring
- Nervousness
- Dizziness
- Insomnia
- Headache
- Palpitations
- Tremor
- Difficulty urinating (especially in men with BPH)
- Chest pain
Special Patient Groups
Pregnancy
Category C. Use during pregnancy should be avoided unless the potential benefit outweighs the potential risk to the fetus. Limited human data suggest possible association with minor malformations or increased risk of gastroschisis, especially with first-trimester exposure. Consult a healthcare provider.
Trimester-Specific Risks:
First Trimester:
Potential for increased risk of gastroschisis (a birth defect involving the abdominal wall) and other minor malformations, though data are conflicting and limited.
Second Trimester:
Generally considered safer than first trimester, but still use with caution and only if clearly needed.
Third Trimester:
May cause vasoconstriction in the placenta, potentially reducing uterine blood flow. Avoid close to term due to risk of maternal hypertension and fetal distress.
Lactation
L3 (Moderately safe). Phenylephrine is excreted into breast milk in small amounts. While generally considered low risk for the infant, it may cause irritability, sleep disturbances, or tachycardia in some infants. It may also reduce milk supply due to its vasoconstrictive effects. Use with caution, especially in newborns or premature infants.
Infant Risk:
Low to moderate; potential for irritability, sleep disturbances, tachycardia, or reduced milk supply.
Pediatric Use
Not recommended for children under 4 years of age. Dosing for children 4-11 years should be carefully weighed against the questionable efficacy and potential side effects. Always use pediatric-specific formulations and dosing guidelines. Overdose risk is higher in young children.
Geriatric Use
Use with caution in elderly patients due to increased sensitivity to sympathomimetic effects and higher prevalence of underlying cardiovascular conditions (e.g., hypertension, ischemic heart disease), benign prostatic hyperplasia (BPH), and glaucoma. Start with lower doses and monitor closely for adverse effects.
Clinical Information
Clinical Pearls
- Oral phenylephrine's efficacy as a nasal decongestant has been widely questioned due to its very low oral bioavailability and extensive first-pass metabolism. In September 2023, an FDA advisory committee concluded that oral phenylephrine is not effective as a nasal decongestant at recommended doses.
- Patients with hypertension, heart disease, thyroid disease, diabetes, or benign prostatic hyperplasia (BPH) should use phenylephrine with extreme caution or avoid it.
- Advise patients that pseudoephedrine (available behind the counter) is generally considered more effective for oral nasal decongestion.
- Educate patients on the importance of not exceeding recommended doses to avoid serious cardiovascular side effects.
- Phenylephrine is often combined with antihistamines, cough suppressants, or analgesics in multi-symptom cold and flu preparations. Patients should be aware of all active ingredients to avoid accidental overdose.
Alternative Therapies
- Pseudoephedrine (oral decongestant, available behind the counter)
- Saline nasal sprays (non-pharmacological)
- Nasal corticosteroids (e.g., fluticasone, mometasone - for allergic rhinitis)
- Topical decongestant nasal sprays (e.g., oxymetazoline, xylometazoline - for short-term use only due to risk of rhinitis medicamentosa)
- Antihistamines (for allergic rhinitis symptoms)
Cost & Coverage
Average Cost:
$5 - $20 per 30 tablets
Generic Available:
Yes
Insurance Coverage:
Often not covered by insurance as it is an over-the-counter (OTC) medication, unless prescribed.
General Drug Facts
If your symptoms or health issues persist or worsen, it is essential to contact your doctor promptly. To ensure safe and effective treatment, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so it's a good idea to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek emergency medical attention. When reporting the incident, be prepared to provide details about the medication taken, the amount, and the time it occurred.