Phenylephrine

Description

Phenylephrine is a nasal decongestant. It is used to relieve nasal congestion c

aused by colds, allergies, or sinus infections. Its ability to constrict blood vessels makes it useful in reducing swelling and improving blood flow. It works by narrowing the blood vessels in the nasal passages and other areas of the body. This helps reduce swelling and congestion, making breathing easier. This medication is usually taken by mouth, nasal spray, or injection, depending on the form. For oral tablets, follow your doctor's instructions, typically every 4–6 hours as needed, without exceeding the maximum daily dose. Nasal sprays are usually used 2–3 times per day for short-term relief. Always follow your healthcare provider’s guidance for the correct form, dose, and timing.

Uses

Contraindications

Side effects

Precautions and Warnings

Uses

Nasal Congestion Relief, usually available in oral and intranasal forms, often in combination with other ingredients (such as Chlorpheniramine), to relieve nasal congestion associated with the common ...
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Pupil Dilation (Mydriasis): Used in ophthalmic (eye drop) formulations to intentionally dilate the pupils for comprehensive eye examinations or before and after eye surgery.

Contraindications

When should one not use Phenylephrine

If you are pregnant or breastfeeding, consult your doctor before use. If you are taking medications for high blood pressure or heart disease, especially MAO inhibitors, check with your healthcare pro...

Side effects

Common side effects of this drug are:

Headache
Dizziness
Nausea
Nervousness or restlessness
Mild increase in blood pressure

Precautions and Warnings

Pregnancy

Can I take Phenylephrine during pregnancy?

Phenylephrine should only be used during pregnancy if clearly needed and prescribed by your doctor. It may affect blood pressure and circulation, so consult your healthcare provider before taking it.

Breast Feeding

Can I take Phenylephrine while breastfeeding?

Phenylephrine may pass into breast milk in small amounts. Speak with your doctor before use to ensure it is safe for your baby, and monitor your child for any unusual symptoms.

Driving

Can I drive if I have consumed Phenylephrine?

Phenylephrine may cause dizziness or drowsiness in some people. Avoid driving or operating heavy machinery until you know how the medication affects you.

Alcohol

Can I consume alcohol with Phenylephrine?

Alcohol can increase the risk of dizziness, drowsiness, or lightheadedness while taking phenylephrine. It is best to avoid alcohol during treatment to stay safe.

Other General Warnings

Talk to your doctor if

You have high blood pressure or heart problems, as phenylephrine can increase blood pressure.
You have thyroid disorders, since it may worsen symptoms like rapid heartbeat or anxiety.
You have diabetes, as phenylephrine can sometimes affect blood sugar levels.
You have glaucoma, especially narrow-angle glaucoma, before using this medicine.
You are taking other medications, including MAO inhibitors, antidepressants, or decongestants.
You have kidney or liver problems, since dosage adjustments may be needed.
You experience persistent headache, dizziness, or palpitations while taking phenylephrine.

Mode of Action

How Does It Work?

It works by narrowing the blood vessels in the nasal passages and other areas of the body. This helps reduce swelling and congestion, making breathing easier.

Dosage

Overdose

Signs of overdose may include high blood pressure, severe headache, chest pain, rapid heartbeat, dizziness, nausea, or fainting. If you suspect an overdose, seek emergency medical help immediately.

Missed a Dose

If you miss a dose of phenylephrine, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed dose; do not take extra to catch up. Taking too much can increa...

Content Details

WRITTEN BY

Ravindra Ghongade

B. Pharm

REVIEWED BY

Dr. Nikita Toshi

BDS (Bachelor of Dental Surgery), WHO FIDES member

Frequently Asked Questions (FAQs)

Q: What is phenylephrine used for?

A: Phenylephrine is mainly used to relieve nasal congestion caused by colds, allergies, or sinus infections.

Q: How should I take phenylephrine?

Follow your doctor’s instructions. Oral tablets are usually taken every 4–6 hours as advised by your doctor, and nasal sprays are used 2–3 times a day. Do not exceed the recommended dose or use nasal ...
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Q: What are the common side effects of phenylephrine?

A: You may experience headache, dizziness, nausea, nervousness, or mild increase in blood pressure. Most side effects are temporary, but consult your doctor if they persist or worsen.

Q: What should I do if I miss a dose or overdose?

If you miss a dose, take it as soon as you remember, or skip it if it’s almost time for your next dose. Do not double the dose. In case of overdose, seek emergency medical help immediately, as it can ...
Read more

References

Last Updated on: 08 Dec 2025 | 11:25 PM (IST)

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Disclaimer

The information provided herein is supplied to the best of our abilities to make it accurate and reliable as it is published after a review by a team of professionals. This information is solely intended to provide a general overview on the product and must be used for informational purposes only. You should not use the information provided herein to diagnose, prevent, or cure a health problem. Nothing contained on this page is intended to create a doctor-patient relationship, replace or be a substitute for a registered medical practitioner's medical treatment/advice or consultation. The absence of any information or warning to any medicine shall not be considered and assumed as an implied assurance. We highly recommend that you consult your registered medical practitioner for all queries or doubts related to your medical condition. You hereby agree that you shall not make any health or medical-related decision based in whole or in part on anything contained in the Site. Please click here for detailed T&C.