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Gua HC Side Effects

Generic Name: guaifenesin / hydrocodone

Note: This document contains side effect information about guaifenesin / hydrocodone. Some of the dosage forms listed on this page may not apply to the brand name Gua HC.

For the Consumer

Applies to guaifenesin / hydrocodone: oral capsule, oral liquid, oral solution, oral syrup, oral tablet, oral tablet extended release

Along with its needed effects, guaifenesin/hydrocodone may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking guaifenesin / hydrocodone:

Incidence not known
  • Difficult or troubled breathing
  • irregular, fast or slow, or shallow breathing
  • pale or blue lips, fingernails, or skin

Some side effects of guaifenesin / hydrocodone may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
  • Diarrhea
  • dizziness
  • feeling of warmth
  • headache
  • nausea
  • redness of the face, neck, arms, and occasionally, upper chest
  • sleepiness or unusual drowsiness
  • sudden sweating

For Healthcare Professionals

Applies to guaifenesin / hydrocodone: oral capsule, oral liquid, oral syrup, oral tablet, oral tablet extended release


The most commonly reported adverse effects have included headache, dizziness, sedation, nausea, diarrhea, decreased blood pressure, and flushing.[Ref]

Nervous system

Frequency not reported: Sedation (somnolence), headache, dizziness, decreased mental alertness with impaired mental and/or physical abilities

-Increased intracranial pressure[Ref]


Frequency not reported: Dose-related respiratory depression including fatal respiratory depression[Ref]


Frequency not reported: Nausea, diarrhea

Frequency not reported: Paralytic ileus[Ref]


Frequency not reported: Hot flush[Ref]


Frequency not reported: Decreased blood pressure[Ref]


Frequency not reported: Mental clouding, anxiety, fear, dysphoria, drug dependence, mood changes, sleeplessness


1. Covington TR, Lawson LC, Young LL, eds. "Handbook of Nonprescription Drugs. 10th ed." Washington, DC: American Pharmaceutical Association (1993):

2. "Product Information. Flowtuss (guaifenesin-hydrocodone)." Mission Pharmacal Company, San Antonio, TX.

3. Turturro MA, Paris PM, Yealy DM, Menegazzi JJ "Hydrocodone versus codeine in acute musculoskeletal pain." Ann Emerg Med 20 (1991): 1100-3

4. Morrow PL, Faris EC "Death associated with inadvertent hydrocodone overdose in a child with a respiratory tract infection." Am J Forensic Med Pathol 8 (1987): 60-3

5. Sackner MA "Effects of hydrocodone bitartrate on breathing pattern of patients with chronic obstructive pulmonary disease and restrictive lung disease." Mt Sinai J Med 51 (1984): 222-6

6. Fricke J, Halladay SC, Bynum L, Francisco CA "Pain relief after dental impaction surgery using ketorolac, hydrocodone plus acetaminophen, or placebo." Clin Ther 15 (1993): 500-9

7. "Product Information. Vicodin Tuss (guaifenesin-hydrocodone)" Knoll Pharmaceutical Company, Mount Olive, NJ.

8. "Product Information. Robitussin (guaifenesin)." Wyeth-Ayerst Laboratories, Philadelphia, PA.

9. Sorensen JL, Hargreaves WA, Weinberg JA "Heroin addict responses to six weeks of detoxification with LAAM." Drug Alcohol Depend 9 (1982): 79-87

Some side effects of Gua HC 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 Gua HC (guaifenesin / hydrocodone)

Consumer resources

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Professional resources

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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. 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.