What is the maximum recommended dose of meclizine (antihistamine)?

Maximum Dose of Meclizine

The maximum recommended dose of meclizine is 100 mg daily, administered orally in divided doses. 1

FDA-Approved Dosing

• The FDA label specifies that meclizine dosing ranges from 25 mg to 100 mg daily, taken orally in divided doses depending on clinical response 1
• The tablets must be swallowed whole 1

Clinical Context and Practical Considerations

Typical Dosing Patterns

• For motion sickness and vertigo, meclizine is commonly prescribed in 25 mg doses taken 1-2 times daily 2, 3
• The onset of action is approximately 1 hour after oral administration of standard tablet formulations 2
• Peak plasma concentrations occur at approximately 49-70 minutes after oral dosing in standard formulations 2, 4

Important Caveats

• While the FDA maximum is 100 mg daily, most clinical scenarios for motion sickness and vertigo are adequately managed with 25-50 mg daily 3
• Higher doses within the 100 mg maximum range should be reserved for patients with inadequate response to lower doses 1
• The medication should be dosed based on clinical response rather than automatically prescribing the maximum dose 1

Formulation Considerations

• Suspension formulations achieve more rapid plasma concentrations compared to tablets, though total bioavailability is similar 2
• This may be relevant when rapid onset is desired, though the maximum daily dose remains 100 mg regardless of formulation 1, 2