Phenylephrine
Phenylephrine Uses, Dosage, Side Effects, Food Interaction and all others data.
Phenylephrine is an alpha-1 adrenergic receptor agonist used to treat hypotension, dilate the pupil, and induce local vasoconstriction. The action of phenylephrine, or neo-synephrine, was first described in literature in the 1930s.
Phenylephrine was granted FDA approval in 1939.
Phenylephrine is an alpha-1 adrenergic agonist that raises blood pressure, dilates the pupils, and causes local vasoconstriction. Ophthalmic formulations of phenylephrine act for 3-8 hours while intravenous solutions have an effective half life of 5 minutes and an elimination half life of 2.5 hours. Patients taking ophthalmic formulations of phenylephrine should be counselled about the risk of arrhythmia, hypertension, and rebound miosis. Patients taking an intravenous formulation should be counselled regarding the risk of bradycardia, allergic reactions, extravasation causing necrosis or tissue sloughing, and the concomitant use of oxytocic drugs.
| Trade Name | Phenylephrine |
| Availability | Rx and/or OTC |
| Generic | Phenylephrine |
| Phenylephrine Other Names | Fenilefrina, Phenylephrine, Phenylephrinum |
| Related Drugs | metoprolol, atenolol, diltiazem, dexamethasone, amiodarone, methylprednisolone, hydrocortisone, bisoprolol, epinephrine topical, epinephrine |
| Weight | 2.5mg/5ml, 10mg, tannate10mg, , 0.25% + 3%, 0.25%, 0.25% + 11%, 0.125%, 1%, 0.5%, 10%, 2.5%, 650mg + 20mg + 10mg + 2.5mg/20ml, +, 12.5mg + 5mg + 12.5mg/5ml, 2.5mg + 5mg + 7.5mg/5ml, 4mg + 20mg + 40mg, 10mg + 5mg + 6.25mg/5ml, 10mg + 10mg + 2.5mg/5ml, 14.4% + 15% + 0.25% + 1% |
| Type | Injection, Oral Liquid, Oral Tablet, Chewable, Extended Release, Disintegrating, Intravenous, Ophthalmic Solution, Rectal Cream, Rectal Gel, Rectal Ointment, Rectal Suppository, Rectal, Nasal Drops, Nasal Solution, Nasal Spray, Oral Kit, Oral Suspension, Oral Syrup |
| Formula | C9H13NO2 |
| Weight | Average: 167.205 Monoisotopic: 167.094628665 |
| Protein binding | Data regarding the protein binding of phenylephrine in serum is not readily available. |
| Groups | Approved |
| Therapeutic Class | |
| Manufacturer | Martindale Pharma, An Ethypharm Group Company, Bausch &, Lomb Swiss |
| Available Country | United Kingdom, United States, Switzerland |
| Last Updated: | September 19, 2023 at 7:00 am |
Uses
Phenylephrine is an alpha-1 adrenergic agonist used in the management of hypotension, generally in the surgical setting associated with the use of anesthetics.
Phenylephrine injections are indicated to treat hypotension caused by shock or anesthesia, an ophthalmic formulation is indicated to dilate pupils and induce vasoconstriction, an intranasal formulation is used to treat congestion, and a topical formulation is used to treat hemorrhoids. Off-label uses include situations that require local blood flow restriction such as the treatment of priapism.
Phenylephrine is also used to associated treatment for these conditions: Allergic Rhinitis (AR), Anorectal discomfort, Cold, Common Cold, Common Cold/Flu, Congestion of the Conjunctivas, Conjunctivitis allergic, Cough, Cough caused by Common Cold, Eye allergy, Eye redness, Fever, Flu caused by Influenza, Headache, Headache caused by Allergies, Headache caused by Common Cold, Headache caused by Pollen Allergy, Hemorrhoids, Hypotension, Irritative cough, Itching of the nose, Itching of the throat, Laryngotracheitis, Nasal Congestion, Nose discomfort, Ocular Inflammation, Ocular Irritation, Paroxysmal Supraventricular Tachycardia, Pollen Allergy, Respiratory tract congestion, Respiratory tract irritation, Rhinopharyngitis, Rhinorrhoea, Seasonal Allergies, Shock, Cardiogenic, Sinus Congestion, Sinus pressure, Sinusitis, Sneezing, Sore Throat, Tracheobronchitis, Upper respiratory tract hypersensitivity reaction, site unspecified, Vasomotor Rhinitis, Aching caused by Flu caused by Influenza, Bronchial congestion, Itchy throat, Minor aches and pains, Watery itchy eyes, Airway secretion clearance therapy, Antihistamine, Dilatation of the pupil, Vasoconstrictor in regional analgesia therapy
How Phenylephrine works
Phenylephrine is an alpha-1 adrenergic agonist that mediates vasoconstriction and mydriasis depending on the route and location of administration. Systemic exposure to phenylephrine also leads to agonism of alpha-1 adrenergic receptors, raising systolic and diastolic pressure as well as peripheral vascular resistance. Increased blood pressure stimulates the vagus nerve, causing reflex bradycardia.
Toxicity
Patients experiencing and overdose may present with headache, hypertension, reflex bradycardia, tingling limbs, cardiac arrhythmias, and a feeling of fullness in the head. Overdose may be treated by supportive care and discontinuing phenylephrine, chronotropic medications, and vasodilators. Subcutaneous phentolamine may be used to treat tissue extravasation.
Food Interaction
No interactions found.Phenylephrine Drug Interaction
Moderate: duloxetineUnknown: fexofenadine, diphenhydramine, loratadine, ubiquinone, dextromethorphan, omega-3 polyunsaturated fatty acids, cyclobenzaprine, fluticasone nasal, pregabalin, guaifenesin, acetaminophen, montelukast, acetaminophen, cyanocobalamin, ascorbic acid, cholecalciferol, alprazolam, ondansetron, cetirizine
Phenylephrine Disease Interaction
Major: cardiovascular diseaseModerate: BPH, diabetes, glaucoma
Volume of Distribution
The volume of distribution of phenylephrine is 340L.
Elimination Route
Phenylephrine is 38% orally bioavailable. Clinically significant systemic absorption of ophthalmic formulations is possible, especially at higher strengths and when the cornea is damaged.
Half Life
Intravenous phenylephrine has an effective half life of 5 minutes and an elimination half life of 2.5 hours.
Clearance
Phenylephrine has an average clearance of 2100mL/min.
Elimination Route
86% of a dose of phenylephrine is recovered in the urine with 16% as the unmetabolized drug, 57% as the inactive meta-hydroxymendelic acid, and 8% as inactive sulfate conjugates.
Innovators Monograph
You find simplified version here Phenylephrine
FAQ
What is Phenylephrine used for?
Phenylephrine is a medication primarily used as a decongestant, to dilate the pupil, to increase blood pressure, and to relieve hemorrhoids. When taken orally as a decongestant, it relieves nasal congestion due to colds and hay fever.
How safe is Phenylephrine?
Phenylephrine is approved by the U.S. Food and Drug Administration (FDA) and is safe and effective when used according to the Drug Facts label.
How does Phenylephrine work?
Phenylephrine works by directly stimulating alpha-1 adrenergic receptors in the arteries causing vasoconstriction.
What are the common side effects of Phenylephrine?
Mild upset stomach, trouble sleeping, dizziness, lightheadedness, headache, nervousness, shaking, or fast heartbeat may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. This product may reduce blood flow to your hands or feet, causing them to feel cold.
Is Phenylephrine safe during pregnancy?
Phenylephrine that's taken by mouth is not safe for pregnant women. Phenylephrine are generally not recommended during the first 13 weeks of pregnancy.
Is Phenylephrine safe during breastfeeding?
Phenylephrine an ingredient in pediatric cough and cold preparations, is considered safe. While excretion into breast milk is unknown, it is unlikely to be excreted into breast milk in large quantities due to its poor bioavailability.
Can I drink alcohol with Phenylephrine?
Do not drink alcohol while taking this medication. Drinking alcohol while taking this medication can cause confusion, dizziness, lightheadedness, and increased risk of falling
Can I drink alcohol with Phenylephrine?
This Phenylephrine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. Drinking alcohol can increase certain side effects of chlorpheniramine and Phenylephrine.
How often can I take Phenylephrine?
Phenylephrine is usually taken every 4 hours as needed.
Can I take Phenylephrine on an empty stomach?
Take this Phenylephrine by mouth with or without food or as directed by your doctor. Taking it with food may decrease stomach upset.
How long does Phenylephrine take to work?
The decongestant effect of Phenylephrine in cold or flu remedies should be noticeable within 15 to 30 minutes, and the effects last less than 4 hours. A rapid increase in blood pressure is usually seen following an intravenous dose that persists for up to 20 minutes.
How long does Phenylephrine stay in my system?
The elimination half life of Phenylephrine is about 2.5 to 3.0 hours. The clinical effects of a single intravenous bolus dose of Phenylephrine are short lived and needs to be repeated every 10–15 minutes.
How long can I take Phenylephrine?
This Phenylephrine is for temporary use only. Do not use for more than 7 days in a row without first consulting your doctor. Phenylephrine nasal is usually used every 4 hours.
When should I stop taking Phenylephrine?
Stop using Phenylephrine and call your doctor at once if you have: fast, pounding, or irregular heartbeat; severe dizziness or nervousness; sleep problems (insomnia).
Who should not take Phenylephrine?
Do not use Phenylephrine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
What happens if I miss a dose?
Since cold medicine is used when needed, you may not be on a dosing schedule. Skip any missed dose if it's almost time for your next dose. Do not use two doses at one time.
What happen if I take too much Phenylephrine?
Taking too much Phenylephrine can be dangerous. It can make you restless or your heartbeat fast, and make you feel sick or vomit. You may also have difficulty peeing.
Will Phenylephrine affect my fertility?
Phenylephrine or pseudophedrine have any impact on fertility.
Does Phenylephrine cause heart palpitations?
Phenylephrine can cause heart palpitations or raise your blood pressure.
Can Phenylephrine affect my kidneys?
Phenylephrine can increase blood pressure and cause your heart and kidneys to work too hard.
