From the Guidelines
Meclizine is effective for motion sickness, as evidenced by its use as an antihistamine medication to prevent and treat nausea, vomiting, and dizziness associated with motion sickness. The most recent and highest quality study 1 provides guidance on the dosage of meclizine, which is 12.5–25 mg tid. Meclizine works by blocking signals to the brain's vomiting center and reducing sensitivity in the inner ear's balance system.
Key Points to Consider
- Meclizine is an antihistamine medication that helps prevent and treat nausea, vomiting, and dizziness associated with motion sickness.
- The typical dose is 12.5–25 mg tid, as recommended in the most recent study 1.
- Meclizine works by blocking signals to the brain's vomiting center and reducing sensitivity in the inner ear's balance system.
- Common side effects include drowsiness and dry mouth, so it is essential to avoid alcohol and activities requiring alertness while taking it.
- Non-drowsy formulations are available but may be less effective.
- For best results, take meclizine before symptoms begin, as it is more effective as a preventive measure than as treatment after motion sickness has already developed.
Comparison with Other Medications
- Other medications used for motion sickness include ondansetron, promethazine, and scopolamine, as mentioned in the study 1.
- However, meclizine is a commonly used antihistamine for motion sickness, and its effectiveness is supported by the most recent study 1.
- It is essential to note that the study 1 does not recommend vestibular suppressant medications, including meclizine, for the treatment of BPPV, except for short-term management of vegetative symptoms such as nausea or vomiting in severely symptomatic patients.
From the FDA Drug Label
Meclizine hydrochloride tablets are indicated for the treatment of vertigo associated with diseases affecting the vestibular system in adults (1). The FDA drug label does not answer the question.
From the Research
Efficacy of Meclizine in Motion Sickness
- Meclizine has been studied as a potential treatment for motion sickness in several studies 2, 3, 4, 5.
- A 1984 study compared the efficacy of transdermal scopolamine, oral meclizine, and placebo in protecting against motion sickness, and found that transdermal scopolamine provided better protection than placebo or meclizine 2.
- A 2014 study investigated the effects of meclizine on the semicircular canals and otoliths, and found that meclizine decreased the vestibulo-ocular reflex gain 3.
- A 2020 study found that meclizine led to a relative increase in torsional velocity compared to placebo during vestibular stimulation, and had an inhibitory effect on eye movement reflexes for low accelerations during visual-vestibular trials 4.
- Meclizine was also compared to other agents for prophylaxis of seasickness in a 1994 study, and was found to be effective, although not significantly different from other medications 5.
Comparison to Other Treatments
- Meclizine was found to be less effective than transdermal scopolamine in a 1984 study 2.
- Meclizine was compared to dimenhydrinate with cinnarizine and promethazine with d-amphetamine in a 2014 study, and was found to have different effects on the vestibulo-ocular reflex gain and saccadic eye response 3.
- Meclizine was found to be effective in preventing seasickness, although not significantly different from other medications, in a 1994 study 5.
Side Effects and Limitations
- Meclizine was found to have negligible side effects in a 1984 study, although dryness of mouth was reported more frequently with transdermal scopolamine 2.
- Meclizine was found to have an inhibitory effect on eye movement reflexes for low accelerations during visual-vestibular trials, but may be counterproductive in high-acceleration environments 4.