Symptomatic
Vestibular suppressants
The drugs that quiet an acute vertiginous storm. They buy comfort and function in the first few days — and then they get out of the way, because the same suppression that helps acutely slows recovery if it lingers.
What they do — and don’t
A vestibular suppressant dampens vestibular input to the central nervous system, easing vertigo, motion sensitivity and the autonomic storm of nausea and vomiting. It does not treat the underlying disorder. Use is normally restricted to the first 3–5 days of an episode, because prolonged administration impairs vestibular compensation and prolongs recovery.1,2
| Receptor | CNS site | Drug class | Effect |
|---|---|---|---|
| H1 (histaminergic) | Vestibular nuclei, chemoreceptor trigger zone | Antihistamines (meclizine, dimenhydrinate…) | Blocks abnormal afferent vestibular signalling and nausea |
| M1 (muscarinic) | Vestibular nuclei, reticular formation, CTZ | Anticholinergics (scopolamine); antihistamines (partial) | Suppresses sensory-mismatch transmission and motion sickness |
| GABA-A | Vestibular nuclei, reticular formation | Benzodiazepines (diazepam, lorazepam, clonazepam) | Hyperpolarises neurons → damps excessive vestibular firing |
| D2 (dopaminergic) | Chemoreceptor trigger zone | Dopamine antagonists (prochlorperazine, metoclopramide) | Antiemetic — reduces nausea and vomiting |
Antihistamines
The most commonly prescribed suppressants. They are H1 antagonists — usually with anticholinergic and sedative properties — that block histaminergic signalling in the vestibular nuclei and chemoreceptor trigger zone, and muscarinic transmission in the brainstem, interrupting the sensory-mismatch signals read as vertigo or motion sickness.1
- Meclizine (25–50 mg 2–3×/day) — long-acting, comparatively low sedation; preferred for ambulatory patients.
- Dimenhydrinate (50–100 mg every 4–6 h) — fast, reliable, but markedly sedating.
- Promethazine (12.5–25 mg PO/IM) — potent antiemetic for intractable nausea, at the cost of deep sedation and extrapyramidal risk.
- Diphenhydramine (25–50 mg) — effective but high anticholinergic load; avoid in older adults.
The evidence is for symptom control, not for accelerating recovery: trials show modest short-term reduction of vertigo and nausea in neuritis and labyrinthitis, with no benefit to compensation beyond the acute phase. Common side effects — drowsiness, dry mouth, blurred vision, urinary retention — can precipitate delirium and falls in the elderly.3
Anticholinergics
Scopolamine (hyoscine) blocks M1 muscarinicreceptors in the vestibular nuclei, reticular formation and CTZ. Delivered as a transdermal patch (1.5 mg / 72 h behind the ear), it is effective for motion-sickness prophylaxis but has little role in Ménière’s, neuritis or migraine. Its central antimuscarinic action causes confusion, delirium, hallucinations and memory impairment — pronounced in older or cognitively vulnerable patients — plus dry mouth, blurred vision and urinary retention. It is best reserved for short-term motion-sickness prophylaxis in younger, healthy individuals.1
Benzodiazepines
These calming, anti-anxiety medicines can settle severe vertigo and the fear that comes with it. They work fast but are habit-forming and very sedating, so they are used only briefly.
Benzodiazepines potentiate GABA-A transmission, hyperpolarising neurons and suppressing excess firing in the vestibular nuclei. Diazepam (2–10 mg BD), lorazepam (0.5–2 mg BD) and clonazepam (0.25–0.5 mg BD) reduce the intensity of acute attacks, and their anxiolytic effect helps when dizziness is amplified by panic.1
Use them judiciously and briefly. They are hazardous in the elderly — falls, cognitive impairment, delirium4 — carry tolerance and dependence, and like all suppressants they delay central compensation. They are therefore contraindicated as maintenance therapy for chronic vestibular disorders and should be avoided in patients undergoing vestibular physiotherapy.2
Dopamine antagonists
Prochlorperazine (5–10 mg PO/IM TID) and metoclopramide (10 mg TID) are effective antiemetics for vertigo-induced nausea, blocking D2 receptors in the chemoreceptor trigger zone. Their main hazard is extrapyramidal symptoms — dystonia and parkinsonism — especially with prolonged use or in children, so they are best reserved for short-term use during severe acute attacks.5
Key points
- Suppressants relieve acute symptoms only — they do not treat the cause.
- Four classes: antihistamines (H1), anticholinergics (M1), benzodiazepines (GABA-A), dopamine antagonists (D2).
- Meclizine is the workhorse antihistamine; scopolamine is for motion sickness; benzodiazepines for the severe acute attack.
- All can cause sedation and falls — be especially cautious in older adults.
- Limit to 3–5 days: prolonged use delays compensation and must not replace rehabilitation.