All About Dextromethorphan Oral Forms

What are dextromethorphan’s side effects?

Like most drugs, dextromethorphan may cause mild to serious side effects. This section describes some of the more common side effects dextromethorphan may cause. It doesn’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

• your age
• other health conditions you have
• other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of dextromethorphan. They can also suggest ways to help reduce side effects.

Mild side effects

Here’s a list of some of the mild side effects dextromethorphan can cause. To learn about other mild side effects, talk with your doctor or pharmacist. Or read the drug’s labeling information for the capsules and the suspension.

Mild side effects of dextromethorphan that have been reported include:

• nausea
• discomfort in the abdomen
• drowsiness
• dizziness
• fatigue (low energy)

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Dextromethorphan is available as an over-the-counter (OTC) drug. Serious side effects from dextromethorphan are possible. But when taking it according to the instructions on the product label, side effects rarely occur.

Allergic reaction

For some people, dextromethorphan can cause an allergic reaction.

In general, symptoms of allergic reaction can be mild or serious. You can learn more about possible symptoms in this article.

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms and can determine whether you should keep taking dextromethorphan.

But if you have symptoms of a severe allergic reaction, such as swelling or difficulty breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to dextromethorphan, they may have you switch to a different treatment.

What should be considered before taking dextromethorphan?

Below is important information you should consider before taking dextromethorphan.

Interactions

Taking a medication with certain vaccines, foods, and other things can affect how the medication works. These effects are called interactions.

Dextromethorphan can interact with other medications. It can also interact with certain supplements and foods.

Before taking dextromethorphan, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any herbs, vitamins, and supplements you use. Sharing this information can help you avoid potential interactions.

Drug interactions

Monoamine oxidase inhibitors (MAOIs) can interact with dextromethorphan. Examples of these drugs are:

• isocarboxazid (Marplan)
• phenelzine (Nardil)
• rasagiline (Azilect)

This list does not contain all drugs that may interact with dextromethorphan. If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Dextromethorphan and alcohol

If you drink alcohol, it’s best to skip or limit it while taking dextromethorphan. The combination can increase the risk of side effects or their severity. These side effects include:

• sleepiness
• dizziness
• nausea

Also, serious toxicity has been reported with the misuse of dextromethorphan and alcohol. (For more information about dextromethorphan misuse, see the “FAQ” section below.)

Talk with your doctor or pharmacist if you have questions about drinking alcohol while taking dextromethorphan. They can tell you how much, if any, is safe to drink while taking dextromethorphan.

Other interactions

Dextromethorphan can interact with other substances, such as:

• Vitamins or supplements: Dextromethorphan may interact with the herb St. John’s wort. You may want to avoid taking this supplement while taking dextromethorphan.
• Foods: Dextromethorphan may interact with grapefruit and grapefruit juice. Ask your doctor whether you should avoid consuming grapefruit products while taking dextromethorphan.

Pregnancy and breastfeeding

It’s not known whether it’s safe to take dextromethorphan during pregnancy or while breastfeeding. If you’re pregnant, breastfeeding, or planning either, talk with your doctor before taking dextromethorphan.

Warnings

Dextromethorphan can sometimes cause harmful effects in people who have certain conditions. This is known as a drug-condition interaction. Other factors may also affect whether dextromethorphan is a good option for you.

If any of the following factors apply to you, talk with your doctor or pharmacist. They can help you determine whether dextromethorphan is a safe option for you. These factors include:

• cough that includes lots of mucus in your throat
• cough that lasts longer than a week or occurs along with other symptoms, such as fever or rash
• chronic (long-term) cough that occurs due to smoking or breathing problems, such as chronic obstructive pulmonary disease (COPD) or asthma
• problems urinating that are related to an enlarged prostate
• previous allergic reaction to dextromethorphan or other ingredients in its forms
• pregnancy
• breastfeeding

What is dextromethorphan’s dosage?

Dextromethorphan is available as an over-the-counter (OTC) drug. The information below is from the instructions on the product labels.

Forms and strengths

Dextromethorphan comes in the following forms and strengths:

• oral capsule filled with liquid (also known as a softgel) in a strength of 15 milligrams (mg)
• extended-release oral suspension in a strength of 30 mg per 5 milliliters (mL)

A suspension is a type of liquid mixture. “Extended release” means the drug is released into your body slowly over a long period of time.

Recommended dosages

This section describes dosages of dextromethorphan, an OTC medication. Be sure to follow the instructions on the product labels when taking it. And see the “Questions about taking dextromethorphan” section below for information on how to take dextromethorphan.

Dosage for cough

Dextromethorphan helps relieve a dry cough. Its dosage varies depending on your age and the form you’re taking.

Oral capsule

Dextromethorphan oral capsule is approved for use in adults and children ages 12 years and older. The recommended dosage is 30 mg every 6–8 hours as needed for cough. That means a dose is two 15-mg capsules.

Extended-release oral suspension

Dextromethorphan extended-release oral suspension is approved for use in adults and children ages 4 years and older. The following table shows the recommended dosages.

Questions about taking dextromethorphan

Below are some common questions about taking dextromethorphan.

• Can dextromethorphan be chewed, crushed, or split? No, you should not chew, crush, or split dextromethorphan oral capsule. You should swallow it whole. If you have difficulty swallowing pills, consider taking dextromethorphan extended-release oral suspension. You can also find tips for taking pills in this article.
• Should I take dextromethorphan with food? You can take dextromethorphan with or without food.
• Is there a best time of day to take dextromethorphan? You can take dextromethorphan any time of day. Take it according to the instructions on the product label.
• Will I need to take dextromethorphan long term? No, you shouldn’t. Dextromethorphan is approved to help relieve coughing from a short-term cause, such as the common cold. If your cough lasts longer than 1 week, talk with your doctor. They can help determine the cause of your symptoms and recommend appropriate ways to treat or manage them.

Overdose

Do not take more dextromethorphan than recommended on the product label, as this can lead to harmful effects.

Symptoms of overdose

Symptoms caused by an overdose can include:

• euphoria (feeling high)
• nausea and vomiting
• visual hallucinations (seeing things that aren’t real)
• nystagmus (repeating eyeball movements that you can’t stop)
• serotonin syndrome (too much serotonin in your body), which may cause:
  • agitation
  • confusion
  • dilated pupils
  • headache
  • rapid or irregular heartbeat
  • low blood pressure
  • fever
  • seizure
  • loss of consciousness

Without prompt medical care, severe cases of serotonin syndrome can lead to death. In extreme cases or if untreated, overdose can lead to coma or death.

What to do in case you take too much dextromethorphan

Call your doctor if you think you’ve taken too much dextromethorphan. You can also call 800-222-1222 to reach America’s Poison Centers or use its online resource. But if you have severe symptoms, immediately call 911 or your local emergency number. Or go to the nearest emergency room.

What are some frequently asked questions about dextromethorphan?

Find answers to some commonly asked questions about dextromethorphan.

Can dextromethorphan be taken for depression?

No, it’s not taken for depression. Dextromethorphan is an over-the-counter (OTC) drug that helps relieve a dry cough from a short-term cause. It contains the same active ingredient as the brand-name medications Delsym and Robitussin Long-Acting CoughGels. These brand-name medications are also used to help relieve a cough.

Some prescription medications contain dextromethorphan as an active ingredient. One example is Auvelity, which contains dextromethorphan and bupropion. Auvelity is approved to treat depression.

But dextromethorphan by itself isn’t taken for depression.

Talk with your doctor or pharmacist if you have questions about other medications that contain dextromethorphan.

Is it safe to use dextromethorphan in dogs?

It might be, but only if your veterinarian recommends it specifically and tells you how much to give your dog. Dextromethorphan is not approved for use in animals.

Talk with your veterinarian to learn more. Do not give dextromethorphan or any other medications to a pet unless your veterinarian recommends it.

Does dextromethorphan have a risk of misuse or dependence?

Yes, dextromethorphan has a risk of misuse. Misuse refers to taking a drug in a way that differs from the product label or your doctor’s prescribed instructions.

Some people misuse dextromethorphan by taking it in amounts higher than the recommended dosage to try to get high or hallucinate. People sometimes also misuse dextromethorphan by combining it with alcohol or other substances.

Dextromethorphan misuse is dangerous, and there have been reports of fatal overdoses.

Long-term misuse of dextromethorphan may lead to psychological dependence. This means you feel like you need the drug to function as usual.

Because of these risks, many states have restrictions on OTC dextromethorphan. Some limit the amount of dextromethorphan products that can be sold. And some allow sales only to people ages 18 years and older.

If you’re concerned about misuse or dependence while taking dextromethorphan, talk with your doctor.

What is dextromethorphan taken for?

Dextromethorphan is available as an over-the-counter medication. The FDA approves dextromethorphan to help relieve coughing due to a short-term cause. This includes the common cold.

The oral capsule is approved for use in adults and children ages 12 years and older. The extended-release oral suspension is approved for use in adults and children ages 4 years and older.

Dextromethorphan is taken to ease a dry cough. A dry cough is a common symptom of respiratory infections, such as the common cold. It typically occurs along with other symptoms, like throat pain or irritation. When you have irritation in your throat or airway, your body naturally gets the urge to cough.

Dextromethorphan helps to suppress a cough. It works in the brain by reducing the urge to cough.

Dextromethorphan cost

Whether or not you have health insurance, cost may be a factor when you’re considering dextromethorphan. Most insurance plans do not cover over-the-counter medications like dextromethorphan.

What you’ll pay for dextromethorphan may depend on your location, the form you choose, and other factors.

If you have questions about how to pay for dextromethorphan, talk with your doctor or pharmacist.