Guaifenesin / hydrocodone / pseudoephedrine Side Effects

Medically reviewed by Drugs.com. Last updated on Nov 10, 2023.

Applies to guaifenesin / hydrocodone / pseudoephedrine: oral solution.

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.
• Signs of high or low blood pressure like very bad headache or dizziness, passing out, or change in eyesight.
• Chest pain or pressure or a fast heartbeat.
• Trouble breathing, slow breathing, or shallow breathing.
• 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.
• Trouble passing urine.
• Shakiness.
• Change in eyesight.
• Very upset stomach or throwing up.
• Very bad constipation.
• Feeling very tired or weak.
• Feeling very sleepy.
• Anxiety.
• Taking an opioid drug like this drug may lead to a rare but very bad adrenal gland problem. Call your doctor right away if you have very bad dizziness or passing out, very bad upset stomach or throwing up, or if you feel less hungry, very tired, or very weak.
• A severe and sometimes deadly problem called serotonin syndrome may happen if you take this drug with certain other drugs. Call your doctor right away if you have agitation; change in balance; confusion; hallucinations; fever; fast or abnormal heartbeat; flushing; muscle twitching or stiffness; seizures; shivering or shaking; sweating a lot; severe diarrhea, upset stomach, or throwing up; or severe headache.

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 any of these side effects or any other side effects bother you or do not go away:

• Dizziness.
• Feeling nervous and excitable.
• Not able to sleep.
• Headache.
• Constipation.
• Feeling sleepy.
• Upset stomach or throwing up.
• Sweating a lot.
• Feeling tired or weak.
• Dry mouth.
• Restlessness.

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 guaifenesin/hydrocodone/pseudoephedrine: oral liquid, oral tablet.

General

The most common adverse events were sedation (somnolence, mental clouding, lethargy), impaired mental and physical performance, lightheadedness, dizziness, headache, dry mouth, nausea, vomiting, constipation, tachycardia, arrhythmias including premature ventricular contractions, CNS stimulation including anxiety, restlessness, nervousness, tremor, and irritability.^[Ref]

Respiratory

Frequency not reported: Bronchitis, cough, dyspnea, nasal congestion, nasopharyngitis, respiratory depression including fatal respiratory depression, sinusitis, upper respiratory tract infection

Cardiovascular

Frequency not reported: Increased blood pressure, decreased blood pressure, tachycardia, chest pain, orthostatic hypotension, palpitations, syncope, prolonged QT interval, hot flush, atrial fibrillation, myocardial infarction, arrhythmias including premature ventricular contractions, flushing

Psychiatric

Frequency not reported: Confusion, anxiety, dysphoria, agitation, addiction, abuse, misuse, fear, depression, hyperactivity, ataxia, hallucinations, hyperexcitability, opioid withdrawal syndrome, drug abuse, drug dependence

Nervous system

Serotonin syndrome has been reported with concomitant opioids and serotonergic drugs.

Frequency not reported: Coma, ataxia, somnolence, facial dyskinesia, tremor, insomnia, migraine, increased intracranial pressure, seizure, dizziness, impaired mental and physical performance, serotonin syndrome

Gastrointestinal

Frequency not reported: Abdominal pain, bowel obstruction, diarrhea, difficulty swallowing, GERD, indigestion, pancreatitis, paralytic ileus, dysgeusia, ischemic colitis, increase of serum amylase, dry mouth, biliary tract spasm (spasm of the sphincter of Oddi)

Dermatologic

Frequency not reported: Hyperhidrosis, rash, pruritus, erythema, severe reactions such as acute generalized exanthematous pustulosis (AGEP)

Genitourinary

Frequency not reported: Ureteral spasm, spasm of vesicle sphincters, urinary retention, urinary tract infection, hypogonadism, infertility

Endocrine

Frequency not reported: Adrenal insufficiency, androgen deficiency

Adrenal insufficiency has been reported with opioid use, most often following greater than one month of use. Androgen deficiency has been reported with chronic opioid use.

Musculoskeletal

Frequency not reported: Arthralgia, backache, muscle spasm

Ocular

Frequency not reported: Miosis, visual disturbances

Metabolic

Frequency not reported: Decreased appetite

Further information

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