- 10 Common Allergy Triggers Slideshow Pictures
- Take the Quiz on Allergies
- Nasal Allergy Relief Products Slideshow
Does Phenergan (promethazine) cause side effects?
Phenergan (promethazine) is an antihistamine used to prevent and treat nausea and vomiting related to certain conditions (such as before/after surgery and motion sickness). It is also used to treat allergy symptoms such as
Phenergan may be used to help you feel sleepy/relaxed before and after surgery or to help certain narcotic pain relievers (such as meperidine) work better. It may also be used for a short time to treat a runny nose due to the common cold.
Phenergan works by blocking the histamines the body makes during an allergic reaction. Its other effects (such as anti-nausea, calming, pain relief) may work by affecting other natural substances (such as acetylcholine) and by acting directly on certain parts of the brain.
Common side effects of Phenergan include
Serious side effects of Phenergan include
- slow heartbeat,
- mental/mood changes (such as hallucinations, nervousness, irritability, restlessness, confusion),
- unusual/uncontrolled movements (such as fixed upward stare, neck twisting, tongue movements),
- shaking (tremor),
- difficulty urinating,
- easy bleeding/bruising,
- signs of infection (such as fever, persistent sore throat),
- severe stomach/abdominal pain,
- persistent nausea/vomiting,
- yellowing eyes/skin (jaundice),
- seizures, and
- neuroleptic malignant syndrome (high body temperature, severe extrapyramidal symptoms, changes in consciousness and mental status, and increased heart rate with low or high blood pressure).
Drug interactions of Phenergan include
- antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) and
The risk of serious side effects (such as slow/shallow breathing, severe drowsiness/dizziness) may be increased if Phenergan is taken with other products that may also affect breathing or cause drowsiness such as
During pregnancy, Phenergan should be used only when clearly needed.
What are the important side effects of Phenergan (promethazine)?
Promethazine causes side effects such as
- confusion, and
In children less than two it can depress respiration and lead to death. Therefore, it should not be used in children less than two years old. Dizziness may also occur.
Ironically, promethazine sometimes stimulates patients, particularly children. Such stimulation may be manifest by
Other side effects include anticholinergic side effects such as:
- blurred vision,
- dry mouth,
- dilated pupils,
- urinary retention (inability to urinate),
- impotence, and
Extrapyramidal symptoms (EPS) may occur. EPS are categorized as dystonic reactions (alterations in muscle tone), sharp, involuntary muscle movements (often limited to one muscle or muscle group), akathisia (subjective restlessness), and Parkinsonism.
Parkinsonian symptoms are more common in older persons whereas children more often develop involuntary muscle movement reactions. Dystonic reactions are most commonly seen during the first week of treatment. Restlessness and Parkinsonian symptoms usually develop days to weeks after starting therapy.
A serious complex called neuroleptic malignant syndrome (NMS) can occur in patients receiving phenothiazines. NMS consists of
- high body temperature,
- severe EPS,
- changes in consciousness and mental status, and
- increased heart rate with low or high blood pressure.
NMS occurs more frequently in young men and in persons who are dehydrated.
Rarely, blood cell disorders can occur; low white cell counts can lead to infections.
Phenothiazines such as promethazine can cause skin hyperpigmentation (darkening) but usually only after prolonged use. The effect usually is restricted to areas of the body exposed to sunlight. Thus, people who need long-term treatment with promethazine should either keep out of the sun or use effective sunscreens.
Phenothiazines can cause
- blurred vision,
- difficulty with nighttime vision, or
- changes in color vision.
Phenothiazines such as promethazine block dopamine receptors. This effect can lead to increases in blood levels of prolactin, a hormone involved in lactation (formation of breast milk). As a result, phenothiazines can cause the breast to produce fluid ("milk") even when a woman is not pregnant.
Additionally, phenothiazines can cause:
Phenergan (promethazine) side effects list for healthcare professionals
Central Nervous System
Drowsiness is the most prominent CNS effect of this drug. Sedation, somnolence, blurred vision, dizziness; confusion, disorientation, and extrapyramidal symptoms such as oculogyric crisis, torticollis, and tongue protrusion; lassitude, tinnitus, incoordination, fatigue, euphoria, nervousness, diplopia, insomnia, tremors, convulsive seizures, excitation, catatonic-like states, hysteria. Hallucinations have also been reported.
Cardiovascular – Increased or decreased blood pressure, tachycardia, bradycardia, faintness.
Hematologic – Leukopenia, thrombocytopenia, thrombocytopenic purpura, agranulocytosis.
Gastrointestinal – Dry mouth, nausea, vomiting, jaundice.
Other – Angioneurotic edema. Neuroleptic malignant syndrome (potentially fatal) has also been reported.
Hyperexcitability and abnormal movements have been reported in patients following a single administration of promethazine HCl.
Consideration should be given to the discontinuation of promethazine HCl and to the use of other drugs if these reactions occur. Respiratory depression, nightmares, delirium, and agitated behavior have also been reported in some of these patients.
To report suspected adverse reactions, contact Renaissance Pharma, Inc. at 1-866-897-5002 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
What drugs interact with Phenergan (promethazine)?
CNS Depressants – Phenergan (Promethazine HCl) Suppositories may increase, prolong, or intensify the sedative action of other central-nervous-system depressants, such as
- sedatives/hypnotics (including barbiturates),
- narcotic analgesics,
- general anesthetics,
- tricyclic antidepressants, and
Therefore, such agents should be avoided or administered in reduced dosage to patients receiving promethazine HCl. When given concomitantly with Phenergan (Promethazine HCl) Suppositories, the dose of barbiturates should be reduced by at least one-half, and the dose of narcotics should be reduced by one-quarter to one-half.
Dosage must be individualized. Excessive amounts of promethazine HCl relative to a narcotic may lead to restlessness and motor hyperactivity in the patient with pain; these symptoms usually disappear with adequate control of the pain.
Epinephrine – Because of the potential for promethazine HCl to reverse epinephrine's vasopressor effect, epinephrine should NOT be used to treat hypotension associated with Promethazine HCl Suppositories overdose.
Anticholinergics – Concomitant use of other agents with anticholinergic properties should be undertaken with caution.
Monoamine Oxidase Inhibitors (MAOI) – Drug interactions, including an increased incidence of extrapyramidal effects, have been reported when some MAOI and phenothiazines are used concomitantly. This possibility should be considered with Phenergan (Promethazine HCl) Suppositories.
Drug/Laboratory Test Interactions
The following laboratory tests may be affected in patients who are receiving therapy with promethazine HCl:
Diagnostic pregnancy tests based on immunological reactions between HCG and anti-HCG may result in false-negative or false-positive interpretations.
Glucose Tolerance Test
An increase in blood glucose has been reported in patients receiving promethazine HCl.
Phenergan (promethazine) is an antihistamine used to prevent and treat nausea and vomiting related to certain conditions (such as before/after surgery and motion sickness). It is also used to treat allergy symptoms such as rash, itching, and runny nose. Common side effects of Phenergan include drowsiness, dizziness, constipation, blurred vision, and dry mouth. During pregnancy, Phenergan should be used only when clearly needed. It is unknown if Phenergan passes into breast milk.
Multimedia: Slideshows, Images & Quizzes
How to Get Rid of Nausea and Vomiting
What is nausea? Do you want to know how to get rid of nausea and how to stop vomiting? Learn home remedies for nausea,...
The Most Common Food Allergies for Kids and Adults
What common food allergens cause the most problems for adults and children? See this list of common food allergies and learn to...
Allergies Quiz: Symptoms & Home Remedies
What are the causes of allergies? This online quiz challenges your knowledge of common food and household allergens,...
Stomach Pain Quiz: Nausea & Other Causes
Tummy Troubles? Get a better idea of what's causing the nausea, vomiting, bloating, gas, constipation, diarrhea, pain, and other...
Picture of Eye Allergies
Severe allergic eye symptoms can be very distressing and are a common reason for visits to the allergist or ophthalmologist. See...
10 Worst Cities for Spring Allergies With Pictures
See pictures of the top 10 "spring allergy capitals", according to the Asthma and Allergy Foundation of America (AAFA). From...
Allergies: 10 Ways to Reduce Mold Allergies
WebMD shows you 10 ways to fight the fungus and reduce mold allergy symptoms from dust masks to bottles of bleach.
Out-of-Control Allergy Symptoms: Treatment Relief in Pictures
Learn 10 signs your allergies are out of control. See these surprising allergy symptoms and find out how to get relief for...
Allergies: Common Plants and Trees That Trigger Allergies
Find out more about which plants and trees might be producing pollen that is causing your itchy eyes and a runny nose.
When Animal (Allergies) Attack: Pet Allergy Symptoms, Treatment
How do you control and relieve pet allergies? How do you prevent pet allergies? Learn dog and cat allergy symptoms, the cause of...
Allergies: Myths and Facts About Seasonal Allergies
Seasonal allergy symptoms are hard. Do deserts prevent allergies? What can allergies do to your body? What is an allergen? Adult...
Itchy Eyes? Top 13 Ways to Tame Eye Allergies
Do you need eye drops? Eye allergies, or allergic conjunctivitis, cause itchy eyes and other allergic symptoms. Avoiding...
Preparing for Severe Allergies at School
Help your child manage and prepare for severe allergies at school. Protect your child from food allergies, insect stings, and...
Related Disease Conditions
An allergy refers to a misguided reaction by our immune system in response to bodily contact with certain foreign substances. When these allergens come in contact with the body, it causes the immune system to develop an allergic reaction in people who are allergic to it. It is estimated that 50 million North Americans are affected by allergic conditions. The parts of the body that are prone to react to allergies include the eyes, nose, lungs, skin, and stomach. Common allergic disorders include hay fever, asthma, allergic eyes, allergic eczema, hives, and allergic shock.
Nausea and Vomiting
Nausea and vomiting are symptoms of many conditions including motion sickness, pregnancy, emotional stress, gallbladder disease, and other illnesses. Learn about causes, treatment, and when to be concerned.
Digestive Diseases: Nausea and Vomiting
Second Source WebMD Medical Reference
Drug Allergy (Medication Allergy)
Drug or medication allergies are caused when the immune system mistakenly creates an immune response to a medication. Symptoms of a drug allergic reaction include hives, rash, itchy skin or eyes, dizziness, nausea, diarrhea, fainting, and anxiety. The most common drugs that people are allergic to include penicillins and penicillin type drugs, sulfa drugs, insulin, and iodine. Treatment may involve antihistamines or corticosteroids. An EpiPen may be used for life-threatening anaphylactic symptoms.
Sinus Infection vs. Allergies
Both sinus infections and allergies (allergic rhinitis) cause symptoms such as runny or stuffy nose and fatigue. Sinus infection (known as sinusitis) is inflammation of the sinuses, caused by infection from bacteria, viruses, and/or fungi (molds). Allergic rhinitis occurs when certain allergies cause nasal symptoms. When a person with allergies breathes in an allergen, such as pollen, dust, or animal dander, symptoms such as runny or stuffy nose, itching, sneezing, and fatigue occur.
COVID-19 vs. Allergies
Though there is some overlap in allergy and COVID-19 signs and symptoms there are also significant differences. Symptoms that they have in common include headache, fatigue, tiredness, shortness of breath, wheezing, and sore throat. Fever does not occur with allergies but is one of the defining symptoms of COVID-19 infections.
Treatment & Diagnosis
- Allergies- Easing Sneezing: House Cleaning Tips
- Allergy: Taking the Sting Out of Insect Allergies
- Allergies: Mold and More:Battling Indoor Allergens
- Allergies, Control Your Spring
- Allergy: Winning the War Against Allergies
- Asthma and Allergies and Your Child
- Allergies: Spring Allergies -- Gailen D. Marshall Jr., MD, PhD -- 04/03/03
- Allergies FAQs
- Tummy Trouble FAQs
- Air Pollution and Allergies: A Connection?
- Allergies: Don't Sneeze at Allergy Relief
- Food Allergies vs. Food Intolerance
- What Are Strategies to Deal With Mite Allergies ?
- Do Anti-Mite Carpet Cleaners Help Mite Allergies?
- When to Call the Doctor for Fever, Nausea, Diarrhea, Colds, and Coughs
Medications & Supplements
- promethazine suppository - rectal, Phenergan, Promethegan
- promethazine - injection, Phenergan
- promethazine - oral, Phenergan
- promethazine/codeine syrup - oral, Phenergan w/ codeine
- Ondansetron (Zofran) vs. promethazine (Phenergan)
- promethazine, Phenergan, Phenadoz, Promethegan
- promethazine and codeine, Phenergan with Codeine
- Types of Migraine Headache Medications
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Professional side effects and drug interactions sections courtesy of the U.S. Food and Drug Administration.