Chlorpheniramine (Allergy) Side Effects
Generic Name: chlorpheniramine
Note: This page contains information about the side effects of chlorpheniramine. Some of the dosage forms included on this document may not apply to the brand name Chlorpheniramine (Allergy).
Not all side effects for Chlorpheniramine (Allergy) may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.
For the Consumer
Applies to chlorpheniramine: capsules, controlled-release capsules, suspension drops, sustained-release capsules, syrup, tablets
Other dosage forms:
Check with your doctor if any of these most COMMON side effects persist or become bothersome:
Seek medical attention right away if any of these SEVERE side effects occur while taking chlorpheniramine (the active ingredient contained in Chlorpheniramine (Allergy))
Constipation; diarrhea; dizziness; drowsiness; dry mouth, nose, or throat; excitability; headache; loss of appetite; nausea; nervousness or anxiety; trouble sleeping; upset stomach; vomiting; weakness.
Severe allergic reactions (rash; hives; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); difficulty urinating or inability to urinate; fast or irregular heartbeat; hallucinations; seizures; severe dizziness, lightheadedness, or headache; tremor; trouble sleeping; vision changes.
For Healthcare Professionals
Applies to chlorpheniramine: compounding powder, injectable solution, oral capsule extended release, oral liquid, oral suspension extended release, oral syrup, oral tablet, oral tablet chewable, oral tablet extended release
Central nervous system side effects have included depression resulting in drowsiness in 75% or more of treated patients. Dyskinesias have rarely been reported following chronic use of chlorpheniramine (the active ingredient contained in Chlorpheniramine (Allergy))
Nearly all patients treated with chlorpheniramine experience drowsiness. This drowsiness may subside in some patients with extended use.
Few cases of dyskinesias and tremors, often of the face, have been reported in patients whose chronic use of chlorpheniramine extended over a period of 3 to 10 years. Some of these cases were only partially relieved by discontinuation of the drug. Haloperidol was successful in relieving symptoms.
Gastrointestinal side effects have included dry mouth and constipation in up to one-third of treated patients.
Cardiovascular side effects have included hypotension, tachycardia, and palpitations.
Ocular side effects of chlorpheniramine (the active ingredient contained in Chlorpheniramine (Allergy)) may include blurred vision, diplopia, and dry eyes due to anticholinergic effects.
Genitourinary side effects have included dysuria, urinary hesitancy, and a decreased urine flow. In rare cases, the anticholinergic effect of chlorpheniramine (the active ingredient contained in Chlorpheniramine (Allergy)) has precipitated acute urinary retention.
Hematologic side effects have included bone marrow suppression, thrombocytopenia, and aplastic anemia.
A fatal case of agranulocytosis has been reported in a patient taking chlorpheniramine, pseudoephedrine, acetaminophen, dextromethorphan, phenylpropanolamine, and aspirin. Chlorpheniramine was felt to be the cause.
More about Chlorpheniramine (Allergy) (chlorpheniramine)
Related treatment guides
Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.