Promethazine

What is Promethazine?

• Promethazine (Phenergan; Promethegan Suppository; Remsed) is a competitive H1 receptor antagonist, which possesses antihistaminic, sedative, anti motion-sickness, antiemetic, and anticholinergic effects.

Promethazine

Promethazine molecule ball

Promethazine molecule spacefill

What are the uses of this medicine?

Promethazine (Phenergan; Promethegan Suppository; Remsed) is used for the treatment of:

• Perennial and seasonal allergic rhinitis.
• Vasomotor rhinitis.
• Allergic conjunctivitis due to inhalant allergens and foods.
• Mild, uncomplicated allergic skin manifestations of urticaria and angioedema.
• Amelioration of allergic reactions to blood or plasma.
• Dermographism.
• Anaphylactic reactions, as adjunctive therapy to epinephrine and other standard measures, after the acute manifestations have been controlled.
• Preoperative, postoperative or obstetric sedation.
• Prevention and control of nausea and vomiting associated with certain types of anesthesia and surgery.
• Therapy adjunctive to meperidine or other analgesics for control of postoperative pain.
• Sedation in both children and adults, as well as relief of apprehension and production of light sleep from which the patient can be easily aroused.
• Active and prophylactic treatment of motion sickness.
• Antiemetic therapy in postoperative patients.

How does this medicine work?

• Promethazine (proe meth' a zeen) is a first generation antihistamine that is used widely to treat and prevent nausea and to a lesser extent to treat allergy symptoms and as a mild sedative.
• Promethazine is a phenothiazine derivative which differs structurally from the antipsychotic phenothiazines by the presence of a branched side chain and no ring substitution.
• The hydrochloride salt form of promethazine, a phenothiazine derivative with antihistaminic, sedative and antiemetic properties.
• Promethazine hydrochloride selectively blocks peripheral H1 receptors thereby diminishing the effects of histamine on effector cells.
• Promethazine hydrochloride also blocks the central histaminergic receptors, thereby depressing the reticular system causing sedative and hypnotic effects.
• In addition, promethazine hydrochloride also has centrally acting anticholinergic properties and probably mediates nausea and vomiting by acting on the medullary chemoreceptive trigger zone.
• Promethazine is well absorbed from the gastrointestinal tract.
• Clinical effects are apparent within 20 minutes after oral administration and generally last 4 to 6 hours, although they may persist as long as 12 hours.

Who Should Not Use this medicine ?

This medicine cannot be used in patients:

• Children Less Than 2 Years of Age
• in comatose states
• who have demonstrated an idiosyncratic reaction or hypersensitivity to promethazine or other phenothiazines
• For the treatment of lower respiratory tract symptoms including asthma.

What drug interactions can this medicine cause?

• Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take.

Be sure to mention any of the following:

• antidepressants ('mood elevators') such as amitriptyline (Elavil), amoxapine (Asendin), clomipramine (Anafranil), desipramine (Norpramin), doxepin (Adapin, Sinequan), imipramine (Tofranil), nortriptyline (Aventyl, Pamelor), protriptyline (Vivactil), and trimipramine (Surmontil)
• antihistamines
• azathioprine (Imuran)
• barbiturates such as phenobarbital (Luminal)
• cancer chemotherapy
• epinephrine (Epipen)
• ipratropium (Atrovent)medications for anxiety, irritable bowel disease, mental illness, motion sickness, Parkinson's disease, seizures, ulcers, or urinary problems
• monoamine oxidase (MAO) inhibitors such as isocarboxazid (Marplan), phenelzine (Nardil), tranylcypromine (Parnate), and selegiline (Eldepryl, Emsam, Zelapar)
• narcotics and other pain medication
• sedatives
• sleeping pills
• tranquilizers

Is this medicine FDA approved?

• Promethazine was approved for use in the United States in 1957 and continues to be widely used with more than 10 million prescriptions filled yearly.

How should this medicine be used?

Recommended dosage: For Allergy:

• The average oral dose is 25 mg taken before retiring; however, 12.5 mg may be taken before meals and on retiring, if necessary. Single 25 mg doses at bedtime or 6.25 mg to 12.5 mg taken 3 times daily will usually suffice.

For Motion Sickness:

• The average adult dose is 25 mg taken twice daily. The initial dose should be taken one-half to one hour before anticipated travel and be repeated 8 to 12 hours later, if necessary.

For Nausea and Vomiting:

• The average effective dose of promethazine hydrochloride for the active therapy of nausea and vomiting in children or adults is 25 mg. When oral medication cannot be tolerated, the dose should be given parenterally (promethazine injection) or by rectal suppository. 12.5 mg to 25 mg doses may be repeated, as necessary, at 4 to 6 hour intervals.
• For nausea and vomiting in children, the usual dose is 0.5 mg per pound of body weight.
• For prophylaxis of nausea and vomiting, as during surgery and the postoperative period, the average dose is 25 mg repeated at 4 to 6 hour intervals, as necessary.

For Sedation:

• Administration of 12.5 mg to 25 mg promethazine hydrochloride by the oral route or by rectal suppository at bedtime will provide sedation in children.
• Adults usually require 25 mg to 50 mg for nighttime, presurgical, or obstetrical sedation.

For Pre- and Postoperative Use:

• Promethazine hydrochloride in 12.5 mg to 25 mg doses for children and 50 mg doses for adults the night before surgery relieves apprehension and produces a quiet sleep.
• For preoperative medication, children require doses of 0.5 mg per pound of body weight in combination with an appropriately reduced dose of narcotic or barbiturate and the appropriate dose of an atropine-like drug.
• Postoperative sedation and adjunctive use with analgesics may be obtained by the administration of 12.5 mg to 25 mg in children and 25 mg to 50 mg doses in adults.
• Promethazine hydrochloride is contraindicated for children under 2 years of age.

Administration:

• Promethazine comes as a tablet and syrup to take by mouth and as a suppository to use rectally.
• When promethazine is used to treat allergies, it is usually taken one to four times daily, before meals and/or at bedtime. When promethazine is used to relieve cold symptoms, it is usually taken every 4 to 6 hours as needed.
• When promethazine is used to treat motion sickness, it is taken 30 to 60 minutes before travel and again after 8 to 12 hours if needed. On longer trips, promethazine is usually taken in the morning and before the evening meal on each day of travel.
• When promethazine is used to treat or prevent nausea and vomiting it is usually taken every 4 to 6 hours as needed.
• Promethazine may also be taken at bedtime the night before surgery to relieve anxiety and produce quiet sleep.
• Promethazine suppositories are for rectal use only.
• Do not try to swallow the suppositories or insert in any other part of your body.
• If you are taking promethazine liquid, do not use a household spoon to measure your dose.
• Use the measuring spoon or cup that came with the medication or use a spoon made especially for measuring medication.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As a tablet and syrup and as a suppository

This medicine is available in fallowing brand namesː

• Phenergan; Promethegan Suppository; Remsed

What side effects can this medication cause?

The most common side effects of this medicine may include: Central Nervous System:

• Drowsiness
• Sedation
• somnolence
• blurred vision
• dizziness
• confusion
• disorientation
• extrapyramidal symptoms
• Hallucinations

Cardiovascular:

• Increased or decreased blood pressure, tachycardia, bradycardia, faintness.

Dermatologic:

• Dermatitis, photosensitivity, urticaria.

Hematologic:

• Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis.

Gastrointestinal:

• Dry mouth, nausea, vomiting, jaundice.

Respiratory:

• Asthma, nasal stuffiness, respiratory depression (potentially fatal) and apnea (potentially fatal).

• Respiratory depression, nightmares, delirium, and agitated behavior have also been reported in some of these patients.

Less common, but serious side effects may include:

• Angioneurotic edema
• Neuroleptic malignant syndrome
• Hyperexcitability

What special precautions should I follow?

• Promethazine may cause breathing to slow or stop, and may cause death in children. Promethazine should not be given to babies or children who are younger than 2 years old and should be given with caution to children who are 2 years of age or older.
• Promethazine hydrochloride may cause marked drowsiness or impair the mental and/or physical abilities required for the performance of potentially hazardous tasks, such as driving a vehicle or operating machinery.
• The use of alcohol or other central nervous system depressants such as sedatives/hypnotics (including barbiturates), narcotics, narcotic analgesics, general anesthetics, tricyclic antidepressants, and tranquilizers, may enhance impairment.
• Promethazine hydrochloride may lead to potentially fatal respiratory depression. Use of promethazine hydrochloride in patients with compromised respiratory function (e.g., COPD, sleep apnea) should be avoided.
• Promethazine hydrochloride may lower seizure threshold. It should be used with caution in persons with seizure disorders or in persons who are using concomitant medications, such as narcotics or local anesthetics, which may also affect seizure threshold.
• Promethazine hydrochloride should be used with caution in patients with bone-marrow depression.
• A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with promethazine hydrochloride alone or in combination with antipsychotic drugs.
• The management of NMS should include 1) immediate discontinuation of promethazine hydrochloride, antipsychotic drugs, if any, and other drugs not essential to concurrent therapy, 2) intensive symptomatic treatment and medical monitoring, and 3) treatment of any concomitant serious medical problems for which specific treatments are available. There is no general agreement about specific pharmacological treatment regimens for uncomplicated NMS.
• Despite its phenothiazine structure, promethazine has not been linked to instances of clinically apparent acute liver injury. Administration of promethazine hydrochloride has been associated with reported cholestatic jaundice.
• It is not known whether promethazine hydrochloride is excreted in human milk.

What to do in case of emergency/overdose?

Symptoms of overdosage may include:

• mild depression of the central nervous system and cardiovascular system to profound hypotension, respiratory depression, unconsciousness, and sudden death. Other reported reactions include hyperreflexia, hypertonia, ataxia, athetosis, and extensor-plantar reflexes (Babinski reflex).
• Convulsions may rarely occur.
• Atropine-like signs and symptoms-dry mouth, fixed, dilated pupils, flushing, as well as gastrointestinal symptoms-may occur.

Management of overdosage:

• In case of overdose, call the poison control helpline of your country. In the United States, call 1-800-222-1222.

• Overdose related information is also available online at poisonhelp.org/help.
• In the event that the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services. In the United States, call 911.

Can this medicine be used in pregnancy?

• Pregnancy Category C.
• There are no adequate and well-controlled studies of promethazine hydrochloride in pregnant women.
• Promethazine hydrochloride should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Can this medicine be used in children?

• Promethazine should not be given to babies or children who are younger than 2 years old and should be given with caution to children who are 2 years of age or older.

What are the active and inactive ingredients in this medicine?

Active ingredient:

• PROMETHAZINE HYDROCHLORIDE

Inactive ingredients:

• LACTOSE MONOHYDRATE
• MICROCRYSTALLINE CELLULOSE
• MAGNESIUM STEARATE

Who manufactures and distributes this medicine?

Manufactured by:

• Sandoz Inc.
• Princeton, NJ

What should I know about storage and disposal of this medication?

• Store at 20° to 25°C (68° to 77°F).
• Dispense contents in a tight, light-resistant container as defined in the USP with a child-resistant closure.

First Generation Antihistamines

• Brompheniramine
• Carbinoxamine
• Chlorcyclizine
• Chlorpheniramine
• Clemastine
• Cyclizine
• Cyproheptadine
• Dexbrompheniramine
• Dexchlorpheniramine
• Dimenhydrinate
• Diphenhydramine
• Doxylamine
• Hydroxyzine
• Meclizine
• Phenyltoloxamine
• Promethazine
• Triprolidine

Second Generation Antihistamines

• Acrivastine
• Cetirizine
• Fexofenadine
• Levocetirizine
• Loratadine
• Desloratadine

• Dailymed label info on Promethazine
• FDA Promethazine

Promethazine Resources
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