Guaitussin AC Side Effects

Generic name: codeine / guaifenesin

Medically reviewed by Drugs.com. Last updated on Feb 27, 2024.

Note: This document provides detailed information about Guaitussin AC.

Applies to codeine / guaifenesin: oral liquid, oral solution, oral syrup Side Effects associated with codeine / guaifenesin. Some dosage forms listed on this page may not apply specifically to the brand name Guaitussin AC.

Applies to codeine / guaifenesin: oral liquid, oral solution, oral syrup.

Serious side effects of Guaitussin AC

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.
• Very bad dizziness or passing out.
• Chest pain or pressure or a fast heartbeat.
• Trouble breathing, slow breathing, or shallow breathing.
• Noisy breathing.
• Feeling very sleepy.
• Feeling confused.
• A heartbeat that does not feel normal.
• Hallucinations (seeing or hearing things that are not there).
• Mood changes.
• Seizures.
• Very bad belly pain.
• Very bad headache.
• Trouble passing urine.
• Shakiness.
• Change in eyesight.
• Very upset stomach or throwing up.
• Very bad constipation.
• Feeling very tired or weak.

Other side effects of Guaitussin AC

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:

• Constipation.
• Dizziness.
• Feeling sleepy.
• Upset stomach or throwing up.
• Sweating a lot.
• 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 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

For healthcare professionals

Applies to codeine/guaifenesin: oral capsule, oral liquid, oral syrup, oral tablet.

General

The more commonly reported adverse effects of codeine include nausea, vomiting, and diarrhea. Guaifenesin is generally well tolerated.

Nervous system

• Frequency not reported: CNS depression, lightheadedness, dizziness, sedation, headache, convulsions, weakness^[Ref]

Codeine

Cardiovascular

• Frequency not reported: Tachycardia, bradycardia, palpitation, faintness, syncope, orthostatic hypotension, circulatory depression

Codeine

Gastrointestinal

• Frequency not reported: Nausea, vomiting, constipation, biliary tract spasm, increased colonic motility, toxic dilation

Guaifenesin:

• Frequency not reported: Abdominal pain (upper), diarrhea, nausea, vomiting^[Ref]

Codeine

Genitourinary

• Frequency not reported: Oliguria, urinary retention, antidiuretic effect^[Ref]

Codeine

Dermatologic

Codeine:

• Frequency not reported: Rash

Guaifenesin:

• Frequency not reported: Rash^[Ref]

Codeine-induced rash may be related to direct stimulation of histamine release.^[Ref]

Hypersensitivity

• Frequency not reported: Pruritus, giant urticaria, angioneurotic edema, laryngeal edema

Guaifenesin:

• Frequency not reported: Hypersensitivity reactions (pruritus, urticaria)

Codeine

Ocular

• Frequency not reported: Visual disturbances

Codeine

Psychiatric

• Frequency not reported: Euphoria, dysphoria, transient hallucination, disorientation

Codeine

Respiratory

Codeine:

• Frequency not reported: Respiratory depression^[Ref]

Respiratory depression and death have occurred in children who received codeine in the postoperative period following tonsillectomy and/or adenoidectomy. Further investigation has shown these patients to be ultra-rapid metabolizers of codeine. Children with obstructive sleep apnea who are treated with codeine appear to be particularly sensitive to the respiratory depressant effects of codeine.^[Ref]

Further information

Guaitussin AC side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer