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Detussin Expectorant Side Effects

Generic name: guaifenesin / hydrocodone / pseudoephedrine

Medically reviewed by Last updated on May 3, 2024.

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

Applies to guaifenesin / hydrocodone / pseudoephedrine: oral solution.


  • This drug may be habit-forming with long-term use.
  • This drug has an opioid drug in it. Opioid drugs can put you at risk for addiction, abuse, and misuse. Misuse or abuse of this drug can lead to overdose and death. If you have questions, talk with your doctor.
  • This drug has an opioid drug in it. Severe side effects have happened when opioid drugs were used with benzodiazepines or other drugs that may make you drowsy or slow your actions. This includes slow or troubled breathing and death. Benzodiazepines include drugs like alprazolam, diazepam, and lorazepam. Benzodiazepines may be used to treat many health problems like anxiety, trouble sleeping, or seizures. If you have questions, talk with your doctor.
  • Many drugs interact with this drug and can raise the chance of side effects like deadly breathing problems. Talk with your doctor and pharmacist to make sure it is safe to use this drug with all of your drugs.
  • Do not take with alcohol or products that have alcohol. Unsafe and sometimes deadly effects may happen.
  • Get medical help right away if you feel very sleepy, very dizzy, or if you pass out. Caregivers or others need to get medical help right away if the patient does not respond, does not answer or react like normal, or will not wake up.
  • Very bad and sometimes deadly breathing problems have happened with this drug. Talk with the doctor.
  • Get medical help right away if you have slow breathing, shallow breathing, or trouble breathing.
  • Even one dose of this drug may be deadly if it is taken by someone else or by accident, especially in children. If this drug is taken by someone else or by accident, get medical help right away.
  • Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
  • Do not take if you are pregnant.
  • Using this drug for a long time during pregnancy may lead to withdrawal in the newborn baby. This can be life-threatening. Talk with the doctor.
  • Be sure that you know your dose and how to take this drug. Dosing errors can lead to accidental overdose and death. If you have any questions, talk with your doctor or pharmacist.

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:

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:

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

For Healthcare Professionals

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


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]


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


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


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

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

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


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)


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


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


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.


Frequency not reported: Arthralgia, backache, muscle spasm


Frequency not reported: Miosis, visual disturbances


Frequency not reported: Decreased appetite

More about Detussin Expectorant (guaifenesin / hydrocodone / pseudoephedrine)

Patient resources

Other brands

Entex HC, Hycofenix, Su-Tuss HD Elixir

Related treatment guides


1. (2017) "Product Information. Hycofenix (guaifenesin / hydrocodone / pseudoephedrine)." Mission Pharmacal Company

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.