MECLIZINE 

What is meclizine?

Meclizine is a first-generation antihistamine and antiemetic commonly used for motion sickness or vertigo (a sensation that you or your surroundings are spinning). It can be taken in 12.5 to 25 mg doses every six to eight hours as needed. If motion sickness is anticipated for a certain activity, taking meclizine 30-60 minutes prior is best. The maximum dose is 100 mg per day.

How can meclizine help alleviate certain long COVID symptoms? 

While rare, there have been reports of new-onset vertigo associated with a COVID infection as well as other neurological symptoms such as persistent dizziness.¹ It is known that the SARS-CoV-2 virus can infiltrate the central nervous system and directly invade the brain. The mechanism of its association with vertigo is still unclear. Still, it is thought to be due to the effect of the virus on neural networks impacting our hearing and balance or cytokine storm that occurs when immune cells become hyperactivated and trigger an excess release of inflammatory mediators.² Dizziness can also be due to multiple factors such as dehydration, headache, and lightheadedness due to stress from the infection.

Meclizine blocks certain receptors in the vomiting center and chemoreceptor trigger zone in our brain, which are responsible for causing feelings of nausea and dizziness. This allows for relief of vertigo and dizziness from neurological long-term COVID symptoms.

What evidence supports meclizine’s use for long COVID?

There are currently no studies exploring the use of meclizine specifically for new-onset vertigo or dizziness after a COVID infection. However, there have been multiple case reports of patients with post-COVID vertigo using meclizine for management.

In a patient with vertigo attacks lasting two weeks following the resolution of his COVID symptoms, he was given meclizine 25 mg tablets in addition to prescription medications (ondansetron and diazepam intravenously). While his nausea resolved, his vertigo was ongoing.³

In another patient’s case of acute vertigo associated with nausea and vomiting following a COVID infection, the patient was given meclizine 25 mg three times a day and ondansetron (a prescription anti-nausea medication) as needed after use of an anti-nausea medication betahistine which is currently not available in the US.¹ The patient experienced complete resolution of vertigo and nausea after seven days.

While the data for the use of meclizine for post-COVID vertigo is mixed, it is a reasonable option to improve dizziness. It can be trialed with other prescription medications to improve vertigo, nausea, and vomiting.

What are some things to watch out for with meclizine?

Meclizine should not be used chronically as it can cause side effects such as urinary retention, dry mouth, and blurry vision. It can also cause drowsiness and memory impairment; therefore, it should not be taken before driving or operating heavy machinery. These side effects can worsen with older age and higher doses of the medication. If you are taking this medication more frequently, let your doctor know, as it can contribute to the side effects of other medicines as well.

References:

1)      Devaragudi S, Gupta M. Vertigo in the Setting of COVID-19 Infection: A Case Report. Cureus. 2023 Feb 6;15(2):e34708. doi: 10.7759/cureus.34708

2)      Korres G, Kitsos DK, Kaski D, Tsogka A, Giannopoulos S, Giannopapas V, Sideris G, Tyrellis G, Voumvourakis K. The Prevalence of Dizziness and Vertigo in COVID-19 Patients: A Systematic Review. Brain Sci. 2022 Jul 20;12(7):948. doi: 10.3390/brainsci12070948

3)      Motawea KR, Monib FA, Shaheen N. Acute Vertigo in a Patient Following COVID-19 Infection: A Case Report and Literature Review. Indian J Otolaryngol Head Neck Surg. 2023 Apr 20;75(3):1-5. doi: 10.1007/s12070-023-03745-x