Can oxycarbamazepine cause vertigo, and what is the recommended evaluation and management for a patient who develops vertigo while taking it?

Oxcarbazepine and Vertigo

Yes, oxcarbazepine commonly causes dizziness and vertigo as a known adverse effect, occurring in approximately 14-40% of patients, and management involves dose adjustment, timing modification, or switching to alternative medications if symptoms are intolerable. 1

Can Oxcarbazepine Cause Vertigo?

Oxcarbazepine is well-documented to cause vertigo and dizziness as frequent adverse effects. The FDA label explicitly lists vertigo (3% incidence) and dizziness (occurring in a substantial proportion of patients) among common adverse reactions. 1 In clinical trials, dizziness was one of the most common reasons for treatment discontinuation (6.4% of patients), and approximately 23% of adult patients discontinued oxcarbazepine due to adverse reactions including dizziness-related symptoms. 1

• Dizziness and vertigo are among the most frequently reported adverse effects in all age groups treated with oxcarbazepine, occurring in both monotherapy and adjunctive therapy settings. 1
• The mechanism relates to oxcarbazepine's effects on sodium channels in the central nervous system, which can affect vestibular processing and balance. 2
• These symptoms typically emerge early in treatment and may be dose-dependent. 1

Evaluation of Vertigo in Patients Taking Oxcarbazepine

Determine if Vertigo is Drug-Related vs. Other Causes

First, establish the temporal relationship between oxcarbazepine initiation/dose escalation and vertigo onset. Drug-induced vertigo typically begins within days to weeks of starting the medication or increasing the dose. 1

Differentiate between peripheral and central causes of vertigo:

• Assess for true rotational vertigo (spinning sensation) versus lightheadedness or presyncope. 3
• Perform Dix-Hallpike maneuver and supine roll test to rule out benign paroxysmal positional vertigo (BPPV), which can coexist with medication-related dizziness. 3
• Look for nystagmus characteristics: gaze-evoked nystagmus suggests central pathology, while fatigable nystagmus with position changes suggests BPPV. 3
• Evaluate for additional neurological signs (ataxia, diplopia, abnormal gait) that may indicate central nervous system involvement beyond simple medication side effects. 1

Check for hyponatremia, which occurs in 2.7% of oxcarbazepine-treated patients and can cause or worsen dizziness and vertigo. 2 Obtain serum sodium levels, as symptomatic hyponatremia was a reason for discontinuation in 1% of patients. 1

Review medication list for other contributing factors:

• Multiple medications can cause dizziness/vertigo including antihypertensives, cardiovascular medications, and other anticonvulsants. 3
• Assess for polypharmacy and potential drug-drug interactions. 4

Management Strategies

Initial Management Approach

Modify oxcarbazepine dosing schedule first before discontinuing:

• Administer oxcarbazepine at bedtime to minimize daytime dizziness impact on daily activities. 3 This strategy is specifically recommended in expert consensus guidelines for managing dizziness caused by carbamazepine/oxcarbazepine. 3
• Consider temporary dose reduction if symptoms are severe, then slower titration back to therapeutic levels. 1

If hyponatremia is present:

• Address the hyponatremia with fluid restriction or sodium supplementation as clinically indicated. 2
• Consider dose reduction or medication change if hyponatremia is symptomatic or severe. 1

When to Switch Medications

Switch to alternative anticonvulsants if:

• Dizziness/vertigo persists despite bedtime dosing and dose optimization. 3
• Patient cannot tolerate the symptoms affecting quality of life and daily function. 3
• Hyponatremia is recurrent or difficult to manage. 2

Alternative second-line sodium channel blockers include:

• Lamotrigine, topiramate, or phenytoin sodium for patients who cannot tolerate oxcarbazepine-related dizziness. 3
• These alternatives have different side effect profiles and may be better tolerated. 3

Avoid Vestibular Suppressants

Do not add vestibular suppressant medications (meclizine, benzodiazepines, prochlorperazine) for oxcarbazepine-induced vertigo. 4

• Vestibular suppressants should only be used for acute peripheral vestibular disorders, not medication-induced dizziness. 4
• These medications interfere with central vestibular compensation and increase fall risk, especially in elderly patients. 4, 5
• Adding vestibular suppressants to oxcarbazepine increases polypharmacy burden and potential for drug-drug interactions without addressing the underlying cause. 4

Special Considerations

For patients requiring oxcarbazepine for vestibular paroxysmia (a paradoxical situation):

• Oxcarbazepine is actually the treatment of choice for vestibular paroxysmia, significantly reducing attack frequency (relative risk 0.67 compared to placebo). 6, 7
• In this context, the therapeutic benefit outweighs the dizziness side effect, and bedtime dosing should be emphasized. 3, 8, 9
• Consider adding betahistine mesilate (18 mg twice daily) as augmentation, which has been shown to enhance efficacy and may help with vestibular symptoms. 8, 9

Monitor for concurrent conditions:

• Patients may have multiple vestibular disorders simultaneously (e.g., BPPV plus medication side effects). 3
• Failure to improve with medication adjustment should prompt comprehensive vestibular evaluation. 3

Fall risk assessment is critical:

• Oxcarbazepine-related dizziness increases fall risk, particularly in elderly patients or those with mobility impairments. 4
• Educate patients about postural changes and fall prevention strategies. 4
• Consider deprescribing other medications that contribute to fall risk. 4