Note: This document contains side effect information about dextromethorphan. Some dosage forms listed on this page may not apply to the brand name Buckley's Mixture Cough Suppressant.
Applies to dextromethorphan: mouth/throat lozenge, oral capsule, oral gel, oral liquid, oral strip, oral suspension extended release, oral syrup, oral tablet chewable.
Serious side effects
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, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
Other side effects
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 you have any side effects that bother you or do not go away.
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 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
For Healthcare Professionals
Applies to dextromethorphan: compounding powder, oral capsule, oral disintegrating strip, oral drops, oral liquid, oral lozenge, oral solution, oral suspension extended release, oral syrup, oral tablet chewable.
General
Adverse effects have included gastrointestinal disturbances such as stomach upset and diarrhea.[Ref]
Nervous system
Frequency not reported: Drowsiness, dizziness, convulsions[Ref]
Respiratory
Frequency not reported: Respiratory depression[Ref]
Gastrointestinal
Frequency not reported: Vomiting, nausea, diarrhea, abdominal pain, gastrointestinal disturbance[Ref]
Hypersensitivity
Rare (less than 0.1%): Fixed-drug eruptions[Ref]
Psychiatric
Cases of abuse have been reported.[Ref]
Frequency not reported: Mental confusion, excitation, insomnia, abuse[Ref]
Dermatologic
Frequency not reported: Rash, angioedema, pruritus, urticaria[Ref]
