Guaifenesin DM Syrup
It is used to thin mucus so it can be taken from the body by coughing.It is used to relieve coughing.
Drug Class
Antitussive, Expectorant
Pharmacologic Class
Expectorant (Guaifenesin); NMDA receptor antagonist, Sigma-1 receptor agonist (Dextromethorphan)
Pregnancy Category
Category C
FDA Approved
Jan 1970
DEA Schedule
Not Controlled
Overview
What is this medicine?
This medicine is used to help relieve coughs and chest congestion. Guaifenesin helps thin and loosen mucus in your lungs, making it easier to cough up. Dextromethorphan helps to reduce the urge to cough.
How to Use This Medicine
Taking Your Medication
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, take it with food to help minimize this side effect. It's essential to drink plenty of non-caffeinated fluids, unless your doctor advises you to limit your liquid intake.
When measuring liquid doses, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device to ensure accurate dosing.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your doctor or pharmacist. If you have questions about disposing of medications, consult your pharmacist, who may be aware of drug take-back programs in your area.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
To use this medication correctly, follow your doctor's instructions and read all the information provided. You can take this medication with or without food. If it causes stomach upset, take it with food to help minimize this side effect. It's essential to drink plenty of non-caffeinated fluids, unless your doctor advises you to limit your liquid intake.
When measuring liquid doses, use the measuring device that comes with the medication. If one is not provided, ask your pharmacist for a suitable measuring device to ensure accurate dosing.
Storing and Disposing of Your Medication
Store this medication at room temperature in a dry place, avoiding the bathroom. Keep all medications in a safe location, out of the reach of children and pets. Dispose of unused or expired medications properly. Do not flush them down the toilet or pour them down the drain unless instructed to do so by your doctor or pharmacist. If you have questions about disposing of medications, consult your pharmacist, who may be aware of drug take-back programs in your area.
Missing a Dose
If you take this medication regularly and miss a dose, take it as soon as you remember. However, if it's close to the time for your next scheduled dose, skip the missed dose and resume your regular dosing schedule. Do not take two doses at the same time or take extra doses. If you take this medication as needed, do not take it more frequently than directed by your doctor.
Lifestyle & Tips
- Drink plenty of fluids (water, juice) to help loosen mucus.
- Avoid irritants like smoke, dust, and pollutants.
- Use a humidifier to moisten the air.
- Do not exceed recommended dosage.
- Avoid alcohol while taking this medication as it can increase drowsiness.
Available Forms & Alternatives
Dosing & Administration
Adult Dosing
Standard Dose:
10-20 mL (Guaifenesin 200-400 mg, Dextromethorphan 10-20 mg) every 4 hours as needed
Dose Range:
10 - 20 mg
Condition-Specific Dosing:
maximumDailyDose:
Not to exceed 120 mg Dextromethorphan and 2400 mg Guaifenesin in 24 hours
Pediatric Dosing
Neonatal:
Not established
Infant:
Not established (generally not recommended for children under 4 years)
Child:
Children 6 to under 12 years: 5-10 mL (Guaifenesin 100-200 mg, Dextromethorphan 5-10 mg) every 4 hours as needed. Maximum 60 mg Dextromethorphan and 1200 mg Guaifenesin in 24 hours. Not for use in children under 4 years.
Adolescent:
Children 12 years and over: 10-20 mL (Guaifenesin 200-400 mg, Dextromethorphan 10-20 mg) every 4 hours as needed. Maximum 120 mg Dextromethorphan and 2400 mg Guaifenesin in 24 hours.
Dose Adjustments
Renal Impairment:
Mild:
No specific adjustment recommended for OTC use
Moderate:
Use with caution; consult healthcare provider
Severe:
Use with caution; consult healthcare provider
Dialysis:
Not well studied; consult healthcare provider
Hepatic Impairment:
Mild:
No specific adjustment recommended for OTC use
Moderate:
Use with caution; consult healthcare provider
Severe:
Use with caution; consult healthcare provider
Pharmacology
Mechanism of Action
Guaifenesin acts as an expectorant by increasing the volume and decreasing the viscosity of respiratory tract secretions, thereby facilitating their removal by ciliary action and coughing. Dextromethorphan is an antitussive that acts centrally on the cough center in the medulla to elevate the cough threshold.
Pharmacokinetics
Absorption:
Bioavailability:
Not precisely quantified for combination, but both components are well absorbed orally.
Tmax:
Guaifenesin: ~1 hour; Dextromethorphan: ~2-2.5 hours
FoodEffect:
Food may slightly delay absorption but does not significantly affect extent of absorption.
Distribution:
Vd:
Guaifenesin: Not well established; Dextromethorphan: Large (suggests extensive tissue distribution)
ProteinBinding:
Guaifenesin: Not significant; Dextromethorphan: Not significant
CnssPenetration:
Dextromethorphan: Yes (central action); Guaifenesin: Limited
Elimination:
HalfLife:
Guaifenesin: ~1 hour; Dextromethorphan: ~1.4-3.9 hours (parent drug), 10-26 hours (dextrorphan)
Clearance:
Not precisely quantified for combination
ExcretionRoute:
Guaifenesin: Renal (as metabolites); Dextromethorphan: Renal (as parent drug and metabolites)
Unchanged:
Guaifenesin: <1% unchanged; Dextromethorphan: Small amount unchanged
Pharmacodynamics
OnsetOfAction:
Guaifenesin: ~30 minutes; Dextromethorphan: ~15-30 minutes
PeakEffect:
Guaifenesin: ~1 hour; Dextromethorphan: ~2.5 hours
DurationOfAction:
Guaifenesin: ~4-6 hours; Dextromethorphan: ~5-6 hours
Confidence:
Medium
Safety & Warnings
Side Effects
Serious Side Effects: Seek Medical Attention Immediately
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
* Signs of an allergic reaction, such as:
+ 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
+ Swelling of the mouth, face, lips, tongue, or throat
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you have side effects that bother you or do not go away, contact your doctor for advice.
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Although rare, this medication can cause severe and potentially life-threatening side effects. If you experience any of the following symptoms, contact your doctor or seek medical help right away:
* Signs of an allergic reaction, such as:
+ 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
+ Swelling of the mouth, face, lips, tongue, or throat
Other Possible Side Effects
Like all medications, this drug can cause side effects. However, many people do not experience any side effects or only have mild ones. If you have side effects that bother you or do not go away, contact your doctor for advice.
Reporting Side Effects
This list does not include all possible side effects. If you have questions or concerns about side effects, contact your doctor. You can also report side effects to the FDA at 1-800-332-1088 or online at https://www.fda.gov/medwatch.
Seek Immediate Medical Attention If You Experience:
- Cough lasting more than 7 days or recurring
- Cough accompanied by fever, rash, or persistent headache
- Worsening symptoms
- Signs of allergic reaction (rash, itching, swelling, severe dizziness, trouble breathing)
- Signs of serotonin syndrome (agitation, confusion, rapid heart rate, sweating, muscle stiffness, twitching, nausea, vomiting, diarrhea)
Before Using This Medicine
Before Taking This Medication: Important Information to Share with Your Doctor
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Respiratory issues, such as a cough that produces a significant amount of mucus, a persistent cough caused by smoking or exposure to smoke, or lung conditions like asthma or emphysema.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
To ensure your safety, it is crucial to provide your doctor and pharmacist with a comprehensive list of all your medications, including:
Prescription and over-the-counter (OTC) medications
Natural products
* Vitamins
Additionally, inform them about any existing health problems. This information will help your doctor determine whether it is safe for you to take this medication with your other medications and health conditions. Never start, stop, or change the dosage of any medication without first consulting your doctor.
It is essential to inform your doctor about the following:
Any allergies you have, including allergies to this medication, its components, or other substances, such as foods or drugs. Be sure to describe the allergic reaction you experienced, including any symptoms that occurred.
Respiratory issues, such as a cough that produces a significant amount of mucus, a persistent cough caused by smoking or exposure to smoke, or lung conditions like asthma or emphysema.
If you have taken certain medications for depression or Parkinson's disease within the last 14 days, including isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline, as this may increase the risk of severely high blood pressure.
If you are currently taking linezolid or methylene blue, as these medications can interact with this drug.
To ensure your safety, it is crucial to provide your doctor and pharmacist with a comprehensive list of all your medications, including:
Prescription and over-the-counter (OTC) medications
Natural products
* Vitamins
Additionally, inform them about any existing health problems. This information will help your doctor determine whether it is safe for you to take this medication with your other medications and health conditions. Never start, stop, or change the dosage of any medication without first consulting your doctor.
Precautions & Cautions
It is essential to inform all your healthcare providers, including doctors, nurses, pharmacists, and dentists, that you are taking this medication.
To minimize the risk of severe side effects, do not exceed the dosage prescribed by your doctor. Taking more than the recommended amount can increase your chance of experiencing serious adverse effects.
Adhere to the prescribed treatment duration and do not take this medication for longer than specified by your doctor.
If you are following a low-sodium or sodium-free diet, consult with your doctor before taking this medication, as some products may contain sodium.
Individuals with phenylketonuria (PKU) should discuss their condition with their doctor, as certain products may contain phenylalanine.
Note that some formulations of this medication may not be suitable for children of all ages. If you have any questions or concerns, consult with your doctor.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor. It is crucial to discuss the potential benefits and risks of this medication to both you and your baby to make an informed decision.
To minimize the risk of severe side effects, do not exceed the dosage prescribed by your doctor. Taking more than the recommended amount can increase your chance of experiencing serious adverse effects.
Adhere to the prescribed treatment duration and do not take this medication for longer than specified by your doctor.
If you are following a low-sodium or sodium-free diet, consult with your doctor before taking this medication, as some products may contain sodium.
Individuals with phenylketonuria (PKU) should discuss their condition with their doctor, as certain products may contain phenylalanine.
Note that some formulations of this medication may not be suitable for children of all ages. If you have any questions or concerns, consult with your doctor.
If you are pregnant, planning to become pregnant, or are breastfeeding, inform your doctor. It is crucial to discuss the potential benefits and risks of this medication to both you and your baby to make an informed decision.
Overdose Information
Overdose Symptoms:
- Nausea
- Vomiting
- Dizziness
- Drowsiness
- Blurred vision
- Nystagmus (involuntary eye movements)
- Ataxia (loss of coordination)
- Respiratory depression (slow, shallow breathing)
- Excitation
- Confusion
- Hallucinations
- Seizures
- Coma
What to Do:
Seek immediate medical attention. Call 911 or Poison Control at 1-800-222-1222. Treatment is supportive and symptomatic.
Drug Interactions
Contraindicated Interactions
- Monoamine Oxidase Inhibitors (MAOIs) (concurrent use or within 14 days of stopping MAOIs due to risk of serotonin syndrome with Dextromethorphan)
Major Interactions
- Serotonergic drugs (e.g., SSRIs, SNRIs, TCAs, triptans, mirtazapine, tramadol, linezolid, St. John's Wort) - increased risk of serotonin syndrome with Dextromethorphan
- CYP2D6 inhibitors (e.g., fluoxetine, paroxetine, quinidine, amiodarone, bupropion) - may increase Dextromethorphan levels and adverse effects
Moderate Interactions
Minor Interactions
- None specifically noted for this combination at typical OTC doses
Monitoring
Symptom Monitoring
- Effectiveness of cough suppression and mucus thinning
- Resolution of cough and congestion
- Development of adverse effects (e.g., dizziness, nausea, drowsiness, rash)
- Signs of serotonin syndrome (agitation, hallucinations, rapid heart beat, fever, overactive reflexes, nausea, vomiting, diarrhea)
Special Patient Groups
Pregnancy
Category C. Use only if the potential benefit justifies the potential risk to the fetus. Consult a healthcare provider before use.
Trimester-Specific Risks:
First Trimester:
Limited data, generally avoid unless clearly needed.
Second Trimester:
Generally considered safer than first trimester, but still use with caution.
Third Trimester:
Generally considered safer than first trimester, but still use with caution. Dextromethorphan has been used in late pregnancy without clear adverse effects, but caution is advised.
Lactation
L3 (Moderately Safe). Both Guaifenesin and Dextromethorphan are excreted into breast milk. Use with caution and observe infant for drowsiness or irritability. Consult a healthcare provider.
Infant Risk:
Low to moderate risk. Potential for drowsiness or irritability in the infant, especially with higher doses or in poor metabolizers of Dextromethorphan.
Pediatric Use
Not recommended for children under 4 years of age. For children 4-12 years, use only age-appropriate formulations and follow specific dosing instructions carefully. Overdosing can be serious.
Geriatric Use
Use with caution. Elderly patients may be more sensitive to the sedative effects of Dextromethorphan and may have underlying medical conditions or be on other medications that could interact. Start with lower doses if appropriate and monitor for adverse effects.
Clinical Information
Clinical Pearls
- This is an OTC product; emphasize proper dosing and not exceeding the maximum daily dose.
- Advise patients to stay well-hydrated to maximize the expectorant effect of guaifenesin.
- Warn about the potential for abuse of dextromethorphan, especially in adolescents, due to its dissociative properties at high doses.
- Counsel patients to avoid concurrent use with MAOIs or other serotonergic drugs due to the risk of serotonin syndrome.
- If cough persists for more than 7 days, worsens, or is accompanied by fever, rash, or persistent headache, advise patients to consult a doctor.
Alternative Therapies
- Single-ingredient Guaifenesin (for chest congestion without cough suppression)
- Single-ingredient Dextromethorphan (for cough suppression without expectorant)
- Honey (for cough relief)
- Saline nasal sprays/washes (for congestion)
- Humidifiers
- Other antitussives (e.g., benzonatate, codeine - prescription only)
- Other expectorants (e.g., N-acetylcysteine - prescription/supplement)
Cost & Coverage
Average Cost:
Low cost (typically $5-$15) per 4 oz (120 mL) bottle
Generic Available:
Yes
Insurance Coverage:
Often not covered by insurance as an OTC product, but may be eligible for FSA/HSA.
General Drug Facts
If your symptoms or health issues persist or worsen, it's essential to contact your doctor for further guidance. To ensure your safety, never share your medication with others or take someone else's medication. Some medications may come with an additional patient information leaflet, so be sure to check with your pharmacist for more information. If you have any questions or concerns about your medication, don't hesitate to reach out to your doctor, nurse, pharmacist, or other healthcare provider. In the event of a suspected overdose, immediately call your local poison control center or seek medical attention. When seeking help, be prepared to provide details about the medication taken, including the amount and time of ingestion.