Phenergan with Dextromethorphan Side Effects
Generic Name: dextromethorphan / promethazine
Note: This document contains side effect information about dextromethorphan / promethazine. Some of the dosage forms listed on this page may not apply to the brand name Phenergan with Dextromethorphan.
For the Consumer
Applies to dextromethorphan / promethazine: oral syrup
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of high or low blood pressure like very bad headache or dizziness, passing out, change in eyesight.
- Fast or slow heartbeat.
- Trouble passing urine.
- Feeling very tired or weak.
- Trouble controlling body movements, twitching, change in balance, trouble swallowing or speaking.
- Hallucinations (seeing or hearing things that are not there).
- Mood changes.
- Ringing in ears.
- Any unexplained bruising or bleeding.
- Change in eyesight.
- Feeling nervous and excitable.
- Not able to sleep.
- Yellow skin or eyes.
- A very bad and sometimes deadly health problem called neuroleptic malignant syndrome (NMS) may happen. Call your doctor right away if you have any fever, muscle cramps or stiffness, dizziness, very bad headache, confusion, change in thinking, fast heartbeat, heartbeat that does not feel normal, or are sweating a lot.
- This drug may cause very bad and sometimes deadly breathing problems. Call your doctor right away if you have slow, shallow, or trouble breathing.
- Low white blood cell counts have rarely happened with this drug. This may lead to a higher chance of getting an infection. Tell your doctor if you have ever had a low white blood cell count. Call your doctor right away if you have signs of infection like fever, chills, or sore throat.
What are some other side effects of this drug?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Feeling sleepy.
- Dry mouth.
- Upset stomach or throwing up.
- Feeling tired or weak.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to dextromethorphan / promethazine: oral syrup
Nervous system side effects have included tinnitus, drowsiness, dizziness, sedation, somnolence, confusion, disorientation, lassitude, incoordination, fatigue, euphoria, nervousness, insomnia, tremors, convulsive seizures, excitation, catatonic-like states, hysteria, hallucinations, and extrapyramidal symptoms such as oculogyric crisis, torticollis, and tongue protrusion[Ref]
Gastrointestinal side effects have included dry mouth, nausea, vomiting, and gastrointestinal disturbances.[Ref]
Cardiovascular side effect have included increased or decreased blood pressure, tachycardia, bradycardia, and faintness.[Ref]
Hepatic side effects have included jaundice.[Ref]
Hematologic side effects have included leukopenia, thrombocytopenia, thrombocytopenic purpura, and agranulocytosis.[Ref]
Dermatologic side effects have included dermatitis, photosensitivity, and urticaria.[Ref]
Respiratory side effects have included asthma, nasal stuffiness, respiratory depression (potentially fatal) and apnea (potentially fatal).[Ref]
Hypersensitivity side effects ave included angioneurotic edema.[Ref]
Other side effects have included neuroleptic malignant syndrome (potentially fatal).[Ref]
A potentially fatal symptom complex sometimes referred to as Neuroleptic Malignant Syndrome (NMS) has been reported in association with promethazine alone or in combination with antipsychotic drugs. Clinical manifestations of NMS are hyperpyrexia, muscle rigidity, altered mental status and evidence of autonomic instability (irregular pulse or blood pressure, tachycardia, diaphoresis and cardiac dysrhythmias). The diagnostic evaluation of patients with this syndrome is complicated. In arriving at a diagnosis, it is important to identify cases where the clinical presentation includes both serious medical illness (e.g., pneumonia, systemic infection, etc.) and untreated or inadequately treated extrapyramidal signs and symptoms (EPS). Other important considerations in the differential diagnosis include central anticholinergic toxicity, heat stroke, drug fever and primary central nervous system (CNS) pathology.
The management of NMS should include 1) immediate discontinuation of promethazine, 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. Since recurrences of NMS have been reported with phenothiazines, the reintroduction of promethazine should be carefully considered.[Ref]
Other side effects have included paradoxical reactions. Hyperexcitability and abnormal movements have been reported in patients following a single administration of promethazine. Consideration should be given to the discontinuation of promethazine 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.[Ref]
Ocular side effects have included blurred vision and diplopia.[Ref]
1. "Product Information. Promethazine DM (dextromethorphan-promethazine)." Vintage Pharmaceuticals Inc, Hunstville, AL.
Some side effects of Phenergan with Dextromethorphan may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
More about Phenergan with Dextromethorphan (dextromethorphan / promethazine)
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- Dosage Information
- Drug Interactions
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