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Dextromethorphan

Dextromethorphan is a medicine used as a cough suppressant. It works on the signals in the brain that are responsible for triggering the cough reflex.
It is an over-the-counter medicine and is present in many prescription combination medications.

This medicine will not be effective in curing cough caused by asthma, emphysema, or smoking. Its mechanism targets the central nervous system, making it suitable for symptomatic relief of acute cough due to common cold or respiratory infections. For chronic respiratory conditions, alternative treatments are advised. Consultation with a healthcare professional is recommended, especially when considering its inclusion in combination medications, to ensure safe and appropriate use.

What are the uses of Dextromethorphan?

This medication is effective for temporary relief from cough without phlegm. It is useful for some infections in the air passage like: 

  • Sinusitis: Sinusitis is characterized by inflammation of the sinus passages, often accompanied by symptoms like nasal congestion, headache, and cough. Dextromethorphan helps alleviate the dry cough associated with sinusitis, providing individuals with relief from the persistent urge to cough, allowing for improved comfort during the recovery from this sinus infection.
  • Common Cold: The common cold frequently involves a dry, irritating cough as part of its symptom profile. Dextromethorphan is beneficial in managing this type of cough, offering temporary relief by suppressing the cough reflex. By easing cough symptoms, individuals with a common cold can experience improved rest and overall well-being during the course of the illness.

While Dextromethorphan is valuable for short-term relief from acute respiratory conditions, it is not typically recommended for managing long-term breathing issues such as emphysema or chronic bronchitis. These chronic conditions require a more comprehensive approach, often involving medications tailored to the specific nature of the respiratory ailment and long-term management strategies. It's crucial for individuals with chronic respiratory conditions to consult healthcare professionals for personalized advice on managing their symptoms effectively and maintaining respiratory health over the long term.

How and when to take Dextromethorphan?

  • The medicine is usually taken every 4-12 hours as prescribed by the doctor. The doctor might advise taking medicine with food or milk to avoid upsetting the stomach.
  • Use a proper measuring device to measure Dextromethorphan instead of kitchen spoons, as it can affect the amount of medicine you ingest.
  • If you have a tablet or a strip that disintegrates, let it dissolve well in the mouth. 
  • Keep dextromethorphan stored at room temperature, away from heat, light, and moisture.

What are the side effects of Dextromethorphan?

If you notice or experience signs of an allergic reaction like trouble breathing, hives, or swelling on the face, tongue, throat, or lips, seek medical help as soon as possible. 

The lesser severe and more likely side effect of taking Dextromethorphan can be an upset stomach. 

Some severe side effects can include: 

  • Severe anxiety, dizziness, nervousness, or restlessness
  • Seizures/ convulsions
  • Confusion
  • Hallucinations
  • Slow and shallow breathing. 

Common Side Effects:

  • Dizziness: Dextromethorphan can cause dizziness by disrupting normal neural activity in the brain, affecting balance and coordination.
  • Nausea: It can irritate the stomach lining, leading to feelings of nausea.
  • Drowsiness: As a central nervous system depressant, it can cause sedation and drowsiness.
  • Dry Mouth: The medication can reduce saliva production, leading to a dry mouth.
  • Constipation: It can slow down gastrointestinal motility, causing constipation.

Serious Side Effects:

  • Hallucinations: At higher doses, dextromethorphan can interfere with NMDA receptors in the brain, leading to sensory distortions and hallucinations.
  • Rapid Heartbeat: It can cause an increased heart rate, which may be problematic for individuals with heart conditions.
  • Seizures: In rare cases, it can lower the seizure threshold, leading to convulsions.
  • Breathing Problems: High doses can depress the respiratory system, causing difficulty in breathing.
  • Serotonin Syndrome: When taken with other medications that affect serotonin levels, such as certain antidepressants, it can lead to serotonin syndrome, characterized by agitation, confusion, rapid heart rate, and high blood pressure.

If you experience these side effects, you must immediately consult your doctor.   

What precautions should be taken?

  • Dextromethorphan is usually not recommended for children less than 4 years old. Always consult a doctor before giving cold and cough medication to children. 
  • Dextromethorphan is unsuitable if you have used MAO inhibitors like isocarboxazid, Marplan, phenelzine, rasagiline, selegiline, tranylcypromine, methylene blue injection two weeks before taking medicine. 
  • Before taking any cough, cold, or allergy medication, it is crucial to consult your doctor. If certain products are taken together, you may take too much of one or more drugs. 
  • Consult your doctor if you are pregnant, planning to become pregnant, or breastfeeding to discuss the safety of using dextromethorphan.
  • Before taking medicine, carefully read the instructions on the label and follow the doctor’s guidelines. 

What are the dosages of Dextromethorphan?

The dosages of dextromethorphan can vary depending on the specific formulation of the medication, the intended use, and the age of the individual. It's important to follow the recommended dosage instructions provided by the healthcare professional or as indicated on the product packaging. Dosages are typically specified in terms of milligrams (mg) of dextromethorphan per dose. Here are some general guidelines:

  • For Adults and Children over 12 years old:
    • Typical oral dose: 10-20 mg every 4-6 hours as needed.
    • Maximum daily dose: 120 mg in a 24-hour period.
  • For Children 6-12 years old:
    • Dosage may vary, but it is usually around 5-10 mg every 4-6 hours as needed.
    • Maximum daily dose: 60 mg in a 24-hour period.
  • For Children 4-6 years old:
    • Dosage is generally lower, typically around 2.5-5 mg every 4-6 hours as needed.
    • Maximum daily dose: 30 mg in a 24-hour period.

It's crucial to use the correct measuring device, such as a provided dosing cup or syringe, when administering liquid formulations to ensure accurate dosing. Additionally, individuals should not exceed the recommended dosage, as exceeding the recommended dose can lead to adverse effects.

What if I missed the dose of Dextromethorphan?

Cough medicine is usually taken as needed. Your doctor may not have provided a schedule. However, if you forget a particular dose, quickly take the missed dose when you remember.

If it is time for your next dose, skip the previous one and take the next dose. Do not try to take two doses of Dextromethorphan to make up for the missed dose. 

What if there is an overdose of Dextromethorphan?

If you have ingested more than the recommended dosage, avail emergency medical attention. Some symptoms that can tell if you have overdosed can be vomiting, drowsiness, nausea, dizziness, vomiting, problem breathing, seizures, and a fast heartbeat. 

What are the storage conditions for Dextromethorphan?

  • Keep the medicine safe and out of the reach of children. 
  • Keep the drug at room temperature between 20 to 25C (68 to 77F). 
  • Keep the medicine away from direct contact with heat, light, and moisture. 
  • Do not try to freeze the medication.
  • Keep it in a closed container. 

Disposal of the medicine

Unneeded medications should be disposed of carefully to prevent pets, children, and others from consuming them. Flushing them down the toilet is not recommended. The safest and most effective way to dispose of these medications is by using a medicine take-back program, which ensures that the drugs are handled and discarded safely and responsibly, protecting both people and the environment.

Caution with other medicine

Using Dextromethorphan with the following medications can be harmful. Therefore, inform your doctor before taking the medicine if you are using the following medication:

  • Celecoxib 
  • Cinacalcet 
  • Darifenacin
  • Imatinib
  • Quinidine
  • Ranolazine
  • Ritonavir
  • Sibutramine
  • Terbinafine

Also, inform your doctor if you are on medication for high blood pressure or depression.

How quickly does Dextromethorphan show results?

The medicine will start showing effect around 30-60 minutes after injecting the medication. It can reach peak effect between 2-4 hours. 

While taking medication like Dextromethorphan, it is crucial to follow the guidelines provided by the healthcare professional. Consult the doctor immediately if you experience side effects. Accurately inform the medical staff about the medication you are already taking or have taken in the past few months to avoid complications. 

When should I contact the doctor for the side effects?

If you have mild side effects from dextromethorphan, like nausea, drowsiness, or dizziness, you can usually handle these at home. However, if you feel very drowsy or dizzy, contact your doctor. You might need a lower dose or a different medicine.

Serious side effects like agitation, high fever, or trouble breathing, need immediate medical attention.

Dextromethorphan Vs Pholcodine

 

Dextromethorphan

Pholcodine

Composition

Levorphanol is a chemical related to codeine and a non-opioid derivative of morphine. Dextromethorphan is a synthetic, methylated dextrorotary counterpart of levorphanol.

Pholcodine is a morphinane alkaloid that is a morphine derivative with a 3-morpholinoethyl group. 

Uses

When you have the flu, a cold, or another ailment, Dextromethorphan is used to treat your cough temporarily.

Pholcodine, an opioid medication, treats non-productive (dry) cough in adults and children.

Side Effects

 

  • Fainting
  • Lightheadedness
  • Nervousness
  • Nausea
  • Vomiting
  • Stomach pain.



 
  • Occasional drowsiness
  • Excitation
  • Confusion
  • Sputum retention
  • Vomiting
  • Gastrointestinal disturbances.
     

 

Faqs

1. Can you take dextromethorphan with other medications?

It's important to check with a healthcare professional or pharmacist before combining dextromethorphan with other medications. Certain drug interactions may occur, and they can vary depending on the specific medications involved. Always inform your healthcare provider about all the medications, including prescription and over-the-counter drugs, as well as supplements, that you are taking.

2. Is dextromethorphan safe for children?

Dextromethorphan is generally considered safe for children when used as directed. However, it's crucial to follow the recommended dosage guidelines based on the child's age and weight. Caregivers should avoid giving multiple medications with similar ingredients to prevent accidental overdose. Always consult with a pediatrician or healthcare professional before administering any medication to children.

3. Is dextromethorphan for chesty or dry cough?

Dextromethorphan is typically used for dry, non-productive coughs. It works by suppressing the cough reflex in the brain, providing temporary relief from the urge to cough. It may not be as effective for chesty or productive coughs where the goal is often to help loosen and expel mucus. In cases of chesty coughs, an expectorant may be recommended instead.

4. Does dextromethorphan cause drowsiness?

Drowsiness is not a common side effect of dextromethorphan. Dextromethorphan is designed to specifically target the cough reflex in the brain and does not typically have sedative effects. However, individual reactions to medications can vary, and some people may experience drowsiness. It's advisable to assess your response to the medication before engaging in activities that require alertness, and if drowsiness occurs, it's recommended to avoid driving or operating heavy machinery.

5. What is the main use for dextromethorphan? 

Dextromethorphan is primarily used as a cough suppressant. It helps reduce the urge to cough by acting on the brain's cough center.

6. Who should not take dextromethorphan? 

People who should avoid dextromethorphan include:

  • Those taking MAO inhibitors (a type of antidepressant)
  • Individuals with a history of certain mental health conditions
  • People with chronic coughs due to smoking, asthma, or emphysema 

7. What food should I avoid while taking dextromethorphan?

Avoid alcohol and grapefruit or grapefruit juice, as they can increase the risk of side effects.

8. Is dextromethorphan good for the heart? 

Dextromethorphan does not specifically benefit the heart and should be used with caution in individuals with heart conditions. Consult a healthcare provider for advice.

9. Can I take dextromethorphan at night? 

Yes, you can take dextromethorphan at night. It may help suppress nighttime coughing and improve sleep.

10. What happens if you have too much dextromethorphan? 

Taking too much dextromethorphan can cause serious side effects such as dizziness, confusion, hallucinations, high blood pressure, and in severe cases, it can be life-threatening. Seek medical help immediately if overdose is suspected.

11. What is the warning for dextromethorphan? 

Warnings include avoiding use with MAO inhibitors, not exceeding recommended doses, and using caution if you have certain medical conditions such as high blood pressure or heart disease. It can also cause drowsiness, so avoid driving or operating heavy machinery if affected.

12. Will dextromethorphan make you sleepy?

Dextromethorphan can cause drowsiness in some people, though this is not a universal side effect. Be cautious when first taking it to see how it affects you.

13. How much dextromethorphan is safe in a day?

The safe dosage of dextromethorphan varies by product and individual. Generally, adults should not exceed 120 mg per day. Always follow the dosage instructions on the product label or as prescribed by a healthcare provider.

14. Does dextromethorphan cause high BP?

Dextromethorphan can potentially raise blood pressure, especially if taken in high doses or combined with other substances that have similar effects. People with high blood pressure should use it with caution and consult a healthcare provider.

References:

https://www.drugs.com/Dextromethorphan.html https://www.webmd.com/drugs/2/drug-363/Dextromethorphan-hbr-oral/details
https://www.mayoclinic.org/drugs-supplements/Dextromethorphan-oral-route/proper-use/drg-20068661

Disclaimer: The information provided here is not meant to substitute an advice from a healthcare professional. The information is not intended to cover all the possible uses, side-effects, precautions, and drug interactions. This information is not intended to suggest that using a specific drug is suitable, safe, or efficient for you or anyone else. The absence of any information or warning regarding the drug should not be interpreted as an implicit guarantee from the organisation. We strongly advise you to consult a doctor if you have any concerns about the drug and never use the medication without a doctor’s prescription.