Is there any difference between over-the-counter meclizine and prescription meclizine?

For the non-prescription versions, there is only one standard recommended dosage for Meclizine. For the prescription versions, the recommended dosage will vary, depending on the medical condition being treated.

Dosing for Non-Prescription Meclizine
The recommended non-prescription meclizine dosage for preventing and treating motion sickness in individuals 12 years old and older is one or two tablets (25 to 50 mg) once daily or as directed by the doc. Meclizine usually works best if you take it before motion sickness symptoms begin, although you can expect some relief even if you wait until symptoms develop.

Dosing for Prescription Meclizine
Prescription meclizine is approved for both motion sickness and vertigo in people ages 12 and older. For treating vertigo, the standard dosing is 25 to 100 mg total per day, given as two (or more) smaller doses per day.

For preventing and treating motion sickness, the standard prescription meclizine dosage is 25 to 50 mg taken one hour before embarkation, repeated every 24 hours if necessary.

There is no difference between Meclizine and Meclizine HCL.

Take care, best wishes!