Reference

Glossary

The working vocabulary of vertigo pharmacology. Inline dotted terms throughout the chapter link here.

Anticholinergic burden: The cumulative effect of all anticholinergic medications a patient takes. A high burden raises the risk of confusion, delirium, falls and cognitive decline, especially in older adults.
Beers Criteria: The American Geriatrics Society list of potentially inappropriate medications in older adults. It flags first-generation antihistamines and benzodiazepines — both common vestibular suppressants.
Betahistine: A histamine analogue (weak H1 agonist, potent H3 antagonist) used as first-line maintenance prophylaxis in Ménière's disease; reduces vertigo frequency with an uncertain effect on hearing.
Blood–labyrinth barrier: The barrier limiting systemic drug entry into the cochlear and vestibular end organs — the rationale for intratympanic and nanoparticle-based local delivery.
Chemoreceptor trigger zone (CTZ) · area postrema: A medullary centre that detects emetic stimuli and drives nausea and vomiting. Its H1, M1 and D2 receptors are the targets of antiemetic vestibular suppressants.
Endolymphatic hydrops: Abnormal accumulation of endolymph distending the membranous labyrinth — the leading pathophysiological hypothesis for Ménière's disease and the target of betahistine, diuretics and intratympanic therapy.
Extrapyramidal symptoms (EPS): Movement side effects — acute dystonia, parkinsonism, akathisia — from dopamine-antagonist antiemetics such as prochlorperazine and metoclopramide, especially with prolonged use or in children.
Flunarizine: A calcium-channel blocker that stabilises vestibular neurons; an RCT-supported prophylactic for vestibular migraine. Side effects include weight gain, sedation and parkinsonism.
GABA-A receptor: The main inhibitory neurotransmitter receptor in the CNS. Benzodiazepines potentiate it, hyperpolarising neurons and damping excessive vestibular-nucleus firing.
H1 histamine receptor: A histamine receptor in the vestibular nuclei and CTZ. Antihistamines block it to reduce vestibular signalling and nausea; betahistine, by contrast, is a weak H1 agonist.
H3 histamine receptor: A presynaptic autoreceptor regulating histamine release. Betahistine antagonises it, increasing inner-ear blood flow and endolymph resorption in Ménière's disease.
Intratympanic gentamicin: An aminoglycoside instilled into the middle ear to chemically ablate vestibular hair cells in refractory Ménière's vertigo (> 85% control), carrying a risk of hearing loss and persistent imbalance.
Intratympanic therapy: Delivery of a drug across the round-window membrane directly into the inner ear, minimising systemic exposure. Used in refractory Ménière's disease — corticosteroid (hearing-sparing) or gentamicin (chemical ablation).
Muscarinic (M1) receptor: An acetylcholine receptor in the vestibular nuclei, reticular formation and CTZ. Anticholinergics such as scopolamine block it to reduce motion sickness — at the cost of central anticholinergic side effects.
Persistent postural-perceptual dizziness (PPPD) · PPPD: A chronic functional vestibular disorder of non-spinning dizziness and motion/visual hypersensitivity, often following an acute vestibular insult. SSRIs/SNRIs plus rehabilitation and CBT are first-line.
SSRI / SNRI: Selective serotonin (and noradrenaline) reuptake inhibitors. First-line pharmacotherapy for PPPD, reducing vestibulo-visual hypersensitivity and motion-triggered anxiety; benefit takes 4–6 weeks.
Vestibular compensation: The neuroplastic process by which the brain recalibrates balance after asymmetric or lost vestibular input. It is the engine of recovery — and it is blunted by prolonged vestibular suppressants, which is why they must be stopped early.
Vestibular migraine · VM: A common cause of episodic vertigo, diagnosed by Bárány Society criteria, managed with acute abortive agents (triptans/NSAIDs) and prophylaxis (β-blockers, flunarizine, tricyclics, topiramate).
Vestibular neuritis: Acute unilateral vestibulopathy, probably from viral (HSV-1) reactivation in the vestibular nerve. Treated with early corticosteroids and rehabilitation; antivirals are not supported.
Vestibular suppressant: A drug that gives short-term symptomatic relief in acute vertigo by dampening vestibular input to the CNS, without treating the cause. Antihistamines, anticholinergics, benzodiazepines and dopamine antagonists are the main classes; use is normally limited to 3–5 days.