Doxylamine And Phenylephrine

Doxylamine And Phenylephrine Uses, Dosage, Side Effects, Food Interaction and all others data.

Doxylamine is a first-generation antihistamine. It can be used by itself as a short-term sedative and in combination with other drugs to provide night-time allergy and cold relief. Doxylamine is also used in combination with the analgesics paracetamol (acetaminophen) and codeine as an analgesic/calmative preparation, and is prescribed in combination with vitamin B6 (pyridoxine) to prevent morning sickness in pregnant women.

Doxylamine is an antihistamine derived from monoethanolamine possessing antimuscarinic and pronounced sedative effects.

Doxylamine is an antihistamine commonly used as a sleep aid. This drug is also used to relieve symptoms of hay fever (allergic rhinitis), hives (rash or itching), and other allergic reactions. Doxylamine is a member of the ethanolamine class of antihistamines and has anti-allergy power far superior to virtually every other antihistamine on the market, with the exception of diphenhydramine (Benadryl). It is also the most powerful over-the-counter sedative available in the United States, and more sedating than many prescription hypnotics. In a study, it was found to be superior to even the barbiturate, phenobarbital for use as a sedative. Doxylamine is also a potent anticholinergic.

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.

Doxylamine And Phenylephrine
Uses
Dosage
Side Effect
Precautions
Interactions
Uses during Pregnancy
Uses during Breastfeeding
Accute Overdose
Food Interaction
Half Life
Volume of Distribution
Clearance
Interaction With other Medicine
Contradiction
Storage

Trade Name	Doxylamine And Phenylephrine
Generic	Doxylamine + phenylephrine
Weight	10.5mg + 10mg, 7.5mg + 10mg
Type	Oral tablet
Therapeutic Class
Manufacturer
Available Country	United States
Last Updated:	September 19, 2023 at 7:00 am

Uses

Doxylamine is used for Hypersensitivity reactions, Insomnia

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.

Doxylamine And Phenylephrine is also used to associated treatment for these conditions: Common Cold, Flu Symptoms, Insomnia, Mild Allergic Rhinitis, Nausea, VomitingAllergic 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 Doxylamine And Phenylephrine works

Like other antihistamines, doxylamine acts by competitively inhibiting histamine at H1 receptors. It also has substantial sedative and anticholinergic effects.

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.

Dosage

Doxylamine And Phenylephrine dosage

Hypersensitivity reactionn: 25 mg every 4-6 hr. Max: 150 mg daily.

Insomnia: 25 mg given 30 minutes before retiring at night.

Should be taken with food. Take with food or milk.

Side Effects

Acute dystonic reactions and long-lasting impaired consciousness in child. CNS depression including slight drowsiness to deep sleep, lassitude, dizziness, incoordination. Headache, psychomotor impairment and antimuscarinic effects. Rarely rashes and hypersensitivity reactions, blood disorders, convulsions, sweating, myalgia, extrapyramidal effects, tremor, confusion, tinnitus, hypotension, hair loss.

Toxicity

Signs of overdose include wheezing, tightness in the chest, fever, itching, bad cough, blue skin color, fits, swelling of face, lips, tongue, or throat.

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.

Precaution

May impair ability to drive and operate machinery. Angle-closure galucoma, urinary retention, prostatic hypertrophy or pyloroduodenal obstruction; epilepsy; hepatic impairment. Elderly. Lactation.

Interaction

Enhance effects of CNS depressants eg alcohol, barbiturates, hypnotics, opioid analgesics, anxiolytic sedatives and antipsychotics. Atropine, TCAs, MAOIs. Can mask signs of ototoxicity caused by aminoglycosides.

Volume of Distribution

The volume of distribution of phenylephrine is 340L.

Elimination Route

Readily absorbed via the gastrointestinal tract.

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

10 hours

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.

Pregnancy & Breastfeeding use

Category A: Controlled studies in women fail to demonstrate a risk to the fetus in the 1st trimester (and there is no evidence of a risk in later trimesters), and the possibility of fetal harm remains remote.