Meclizine

What is meclizine?

Meclizine is an antihistamine medication that belongs to the anticholinergic antiemetics drug class. This group of medications is used to treat motion sickness, nausea, and vomiting by blocking certain brain receptors and inhibiting the transmission of certain signals to the vomiting center in the brain. This stops the person from vomiting.

Meclizine is a generic drug. It is also sold under brand names, including Antivert, Bonine, Zentrip, and Dramamine Less Drowsy.

Some meclizine brands are available over the counter, such as Bonine and Dramamine Less Drowsy (these are mainly used for motion sickness). Others, such as Antivert, require a doctor’s prescription, as they are often prescribed for treating vertigo.¹

Warnings and precautions

• There is a risk of drowsiness when taking meclizine. This may impact your ability to think and stay alert when operating heavy machines or driving. Avoid engaging in such activities until you know how this drug affects you.

• Do not drink alcohol when taking meclizine.

What is meclizine used to treat?

Meclizine is used to treat and prevent vomiting, nausea, and dizziness caused by motion sickness.

The brand Antivert is prescribed to treat vertigo, which causes a spinning sensation or dizziness due to an issue in the inner ear or brain.²

How do you take meclizine?

Generic meclizine is available in tablet form. It comes in the following strengths:

• 12.5mg

• 25mg

• 50mg

Take meclizine exactly as prescribed by your doctor. Do not start or stop taking this medicine without first consulting your doctor. Do not take more than what you are prescribed to take.

Crush or chew meclizine chewable tablets. Don’t swallow chewy tablets whole.

Do not crush or chew meclizine non-chewable tablets. Swallow the tablet whole.

To prevent motion sickness symptoms, take meclizine around one hour before you do a sickness-inducing activity (i.e., traveling in a car). Adults and children over 12 years generally need to take 25–50mg by mouth once daily but follow the exact instructions provided by your doctor or pharmacist.³

If you are prescribed Antivert for vertigo, you’ll generally be told to take 25–100mg daily by mouth in divided doses. Your regimen will depend on how you respond to treatment.²

Please do not give this medication to children under 12 years old, as meclizine is not approved for use in this age group.

Seeing results

Meclizine works in as little as an hour to prevent the symptoms of motion sickness. The effects usually last for a day.³

Potential side effects of meclizine

Meclizine can cause some unwanted side effects. Some side effects are common and are not usually harmful, but others require immediate medical attention.

When taking meclizine, you may experience:²

• Dry mouth

• Drowsiness

• Urinary retention

• Fatigue

• Vomiting

• Headache

Blurry vision may occur in rare cases.

These side effects usually fade away in a few hours. However, speak to your doctor if these effects persist or worsen.

Seek emergency medical attention if you develop signs of an allergic reaction, including:

• Trouble breathing

• Skin rash

• Swollen face

Long-term use of meclizine

You may need to take meclizine over a long period to prevent motion sickness. Ask your doctor about the safety of long-term meclizine use.

Some recent large-scale studies have found a significant association between the long-term use of anticholinergic drugs and dementia, particularly in older groups and where high doses have been taken long-term. However, there was no statistically significant increase in risk associated with the use of antihistamines.⁴ ⁵

While no link has been established in currently available studies in terms of long-term meclizine use and dementia, caution is advised with long-term treatment with high doses.

If you experience any side effects or notice anything different, consult your doctor or pharmacist.

Missed doses

If you miss your dose, take it as soon as you remember. If the time is closer to your next scheduled dose than to your missed one, skip the dose you missed and resume your normal schedule.

Never take two doses of meclizine at once or close in time to each other just to catch up on the missed dose. Taking double doses can lead to dangerous side effects and increase the risk of overdose.

Overdoses

Taking too much meclizine may cause the following effects:

• Seizures

• Drowsiness

• Loss of consciousness

• Hallucinations

• Coma

Meclizine overdose may cause low blood pressure, but this is more likely in older people. In children, meclizine overdose can cause seizures, hallucinations, and/or trouble sleeping.³

Allergy information

Signs of an allergic reaction to meclizine include:

• Trouble breathing

• Skin rash

• Swollen throat, tongue, and/or face

If you experience an allergic reaction when using meclizine, stop taking it and seek immediate medical attention.

Do not take meclizine again if you have already experienced an allergic reaction to it or any of its ingredients.

What to discuss with your doctor before you start taking meclizine

Before taking meclizine, tell your doctor if:

• You are allergic to meclizine or any other medication.

• You take other medications. Give your doctor a list of prescription and nonprescription medications, vitamins, and herbal remedies. Of particular importance are drugs that treat:

  • Anxiety

  • Muscle spasms

  • Psychotic disorders

  • Insomnia

  • Allergies

• Meclizine could worsen some medical conditions. Tell your doctor if you have:²

  • Asthma or other lung conditions — anticholinergic medications may make mucus more viscous and difficult to clear, potentially worsening symptoms.⁶

  • Enlarged prostate — people with an enlarged prostate may have difficulty urinating. Meclizine can also cause urinary retention,⁷ so taking this drug could worsen symptoms.

  • Glaucoma — anticholinergic medications may increase intraocular pressure, particularly acute narrow-angle glaucoma.⁸

  • Kidney problems — since meclizine is excreted via the kidneys, kidney problems could potentially cause the drug to build up in your body.³

  • Liver problems — meclizine is metabolized by the liver, so you might have increased exposure if your liver can’t process it effectively.³

• You are pregnant, planning a pregnancy, or breastfeeding.

Stopping meclizine

Stopping this medication may cause your symptoms to return. Don’t stop taking meclizine without consulting your doctor first.

Meclizine and pregnancy

Meclizine is an FDA category B medication. Human studies have not shown that meclizine harms a fetus, but one animal study on rats found meclizine use could be harmful (the dose given was much higher than a human dose).²

Meclizine and breastfeeding

It is not known if meclizine passes into breast milk or harms a nursing baby. If it does, it could have some adverse effects on the baby.

Ask your doctor for their advice concerning meclizine use while breastfeeding. They can evaluate whether the benefits of using meclizine outweigh any potential risk.

Interactions with other drugs

Meclizine interacts with the following medications:⁹

• Other antihistamines, including diphenhydramine (Benadryl, Nytol, and others), chlorpheniramine (Aller-Chlor, Chlor Trimeton, and others), and hydroxyzine (Vistaril)

• Sleep medications, including zolpidem (Ambien), doxepin (Silenor), eszopiclone (Lunesta), and ramelteon (Rozerem)

• Benzodiazepines, including diazepam (Valium), alprazolam (Xanax), clonazepam (Klonopin), and temazepam (Restoril)

• Opioids, including morphine (Kadian, MS Contin, and others), oxycodone (Oxaydo, Xtampza, Oxycontin, and others), methadone (Dolophine or Methadose), and hydrocodone (Hysingla or Zohydro ER)

• Anticholinergic drugs, including scopolamine (Transderm Scop), dicyclomine (Bentyl), and oxybutynin (Ditropan XL)

• Dronabinol (Marinol)

• Phenobarbital

Other drugs listed as causing major interactions with meclizine are:¹⁰

• Esketamine nasal spray (Spravato)

• Ketamine

• Potassium chloride (Kal Potassium 99, Klor-Con, or K-Tab)

• Potassium citrate (Urocit K)

• Sodium oxybate (Xyrem)

• Topiramate (Eprontia, Qudexy XR, Trokendi XR, and Topamax) 

• Zonisamide (Zonegran)

Drug approval history

Meclizine was first approved by the FDA to be sold under the brand name Antivert in 1957.²

Tips and advice for taking meclizine

The following tips can help you take meclizine safely and effectively:

• This medication can cause drowsiness. Wait until you know how this medication affects you before engaging in activities that require focus, such as sports, heavy lifting, and driving.

• Elderly people are also more sensitive to the side effects that this drug can cause. Be careful, as drowsiness can increase the risk of falling.

• It is recommended to refrain from drinking alcohol when taking this medication as alcohol can increase the sedative effects.

• This medication should be stored in a safe place at room temperature. Do not expose it to moisture, sunlight, or heat.