How to time bilastine away from food and fruit juice, judge your own drowsiness before driving, and tell ordinary allergy symptoms from an emergency.
Bilastine is an antihistamine tablet for allergic rhinoconjunctivitis or
urticaria. It works best taken consistently away from food, and while it
is less sedating for many people than older antihistamines, it can still
cause drowsiness — so learning your own response matters before you drive
or use machinery.
Two rules govern this tablet, and they apply together rather than in sequence.
Take 20 mg once daily on an empty stomach
Take one tablet with water, one hour before or two hours after food or
fruit juice. Food and fruit juice reduce absorption, so keep the same
interval every day.
Check your own alertness
Bilastine can still cause drowsiness or dizziness. Learn your response
before driving or using machinery, and avoid taking an extra
antihistamine unless advised.
Daily dose 20 mg bilastine — one tablet, taken on an empty stomach.
Use the same fasting interval each day for the prescribed period. If a
dose is missed, take the next dose at the normal time rather than
doubling. Track nasal, eye or skin symptoms, triggers, and drowsiness —
persistent symptoms may need a diagnosis review or additional local
treatment, not a higher bilastine dose without advice.
People with rhythm risk, low electrolytes, significant bradycardia, or
QT-prolonging medicines need an individual review before taking bilastine.
Report new palpitations or fainting to your doctor.
Keep in the original package, away from moisture and direct heat, and out
of children’s reach. Follow the temperature limit on your pack and do not
use it after the expiry date.
Bilastine is a non-sedating, second-generation antihistamine that acts as an
H1 receptor inverse agonist — it stabilises the inactive conformation of the
H1 receptor, suppressing basal receptor activity in addition to blocking
histamine binding. This inverse-agonist property distinguishes it from pure
antagonists and may contribute to the down-regulation of H1 receptor gene
expression in nasal mucosa with regular prophylactic use [PMID 32521742,
PMCID PMC7355758].Bilastine is not metabolised by the cytochrome P450 enzyme system and does
not act as an inhibitor or inducer of CYP enzymes, which means it has a low
potential for pharmacokinetic drug–drug interactions via that pathway.
However, its bioavailability is reduced by approximately 30% when taken with
a high-fat meal and by 25% with a standard meal, and fruit juice can further
reduce absorption — hence the recommendation to take it on an empty stomach.
Bilastine is a substrate of P-glycoprotein, an efflux transporter at the
blood–brain barrier, which limits central nervous system penetration and
contributes to its low sedation profile [PMID 32521742, PMCID PMC7355758].The caution about QT prolongation arises because bilastine, while showing
minimal effect on the QT interval at therapeutic and even supratherapeutic
doses in dedicated studies, may have an additive effect when co-administered
with other medicines that prolong the QT interval or in the presence of
electrolyte disturbances (particularly hypokalaemia and hypomagnesaemia).
It is not contraindicated by age or renal impairment, and no dose adjustment
is needed in those populations [PMID 32521742, PMCID PMC7355758].
Bilastine blocks histamine H1 receptors and can reduce symptoms of
allergic rhinoconjunctivitis or urticaria while exposure continues. It
does not remove the trigger and is not a treatment for anaphylaxis.
Persistent or atypical symptoms should be reviewed rather than treated by
escalating the dose yourself.
A licensed EU doctor reviews your case and, if appropriate, issues a
prescription. See how a consultation works and
how eligibility and safety checks work across every consultation in
safety.
This page is reference information, not medical advice and not a prescription.
Whether a medicine is appropriate for you is decided by a registered doctor
after reviewing your consultation.
