Bilastine Viatris
Second-generation antihistamine for allergic rhinitis and urticaria
Bilastine Viatris contains the active substance bilastine, a second-generation antihistamine that provides effective relief from allergic rhinitis (hay fever) and chronic spontaneous urticaria (hives) without causing significant drowsiness. It is taken once daily on an empty stomach and is approved for adults and adolescents aged 12 years and older.
Quick Facts
Key Takeaways
- Bilastine Viatris is a non-sedating, second-generation antihistamine used to treat allergic rhinitis and chronic spontaneous urticaria in adults and adolescents aged 12 years and older.
- The standard dose is one 20 mg tablet once daily, taken on an empty stomach (at least 1 hour before or 2 hours after food or fruit juice) for optimal absorption.
- Clinical studies show bilastine does not significantly impair cognitive or psychomotor function at the recommended 20 mg dose, making it suitable for patients who need to drive or operate machinery.
- Bilastine is minimally metabolised and excreted largely unchanged, resulting in a favourable drug interaction profile compared to many other antihistamines.
- Co-administration with P-glycoprotein inhibitors (such as ketoconazole, erythromycin, cyclosporine, ritonavir, or diltiazem) may increase bilastine plasma levels and should be approached with caution.
What Is Bilastine Viatris and What Is It Used For?
Bilastine Viatris belongs to the second-generation (non-sedating) antihistamine class of medications. It contains the active substance bilastine, which works by selectively and competitively blocking histamine H1 receptors. Histamine is a chemical naturally produced by the body during allergic reactions and is responsible for many of the uncomfortable symptoms associated with allergies, including sneezing, nasal itching, rhinorrhoea (runny nose), nasal congestion, and ocular symptoms such as watery and itchy eyes.
Unlike first-generation antihistamines such as diphenhydramine or chlorpheniramine, bilastine does not significantly cross the blood-brain barrier. This pharmacological property means that bilastine causes minimal central nervous system effects, including sedation, at the recommended therapeutic dose. The European Medicines Agency (EMA) has confirmed that bilastine at 20 mg demonstrates a safety and efficacy profile comparable to a placebo in psychomotor testing, a feature that distinguishes it from older antihistamine classes.
Bilastine Viatris is indicated for the symptomatic treatment of two main conditions. The first is allergic rhinoconjunctivitis (both seasonal and perennial), commonly known as hay fever when triggered by pollen. This condition affects an estimated 10-30% of the global adult population according to the World Health Organization (WHO) and the Allergic Rhinitis and its Impact on Asthma (ARIA) guidelines. Symptoms include repeated sneezing episodes, watery nasal discharge, nasal congestion, and itchy, red, watery eyes.
The second approved indication is chronic spontaneous urticaria (CSU), previously known as chronic idiopathic urticaria. CSU is characterised by the recurrent appearance of itchy wheals (hives) and/or angioedema for a duration exceeding six weeks, often without an identifiable external trigger. According to international guidelines published by the European Academy of Allergy and Clinical Immunology (EAACI), second-generation H1-antihistamines are recommended as the first-line treatment for CSU.
How Does Bilastine Work?
Bilastine exerts its therapeutic effects through selective, competitive antagonism of peripheral histamine H1 receptors. When allergens such as pollen, dust mites, or pet dander enter the body, they trigger mast cells and basophils to release histamine. This histamine then binds to H1 receptors on various cells throughout the body, causing the cascade of allergic symptoms. By occupying these receptors before histamine can bind, bilastine prevents the allergic response from developing fully.
Pharmacokinetic studies have demonstrated that bilastine achieves peak plasma concentrations approximately 1.0 to 1.5 hours after oral administration, with a terminal elimination half-life of approximately 14.5 hours. This pharmacokinetic profile supports once-daily dosing and provides symptom relief for a full 24-hour period. Notably, bilastine does not undergo significant hepatic metabolism via the cytochrome P450 enzyme system and is excreted largely unchanged in urine and faeces, contributing to its low potential for metabolic drug interactions.
What Should You Know Before Taking Bilastine Viatris?
Contraindications
Bilastine Viatris is contraindicated in patients with known hypersensitivity to bilastine or to any of the excipients listed in the product. While true allergic reactions to bilastine are rare, any signs of hypersensitivity such as rash, swelling of the face or throat, or difficulty breathing after taking the medication should prompt immediate discontinuation and medical attention.
There are no absolute contraindications based on specific medical conditions beyond hypersensitivity. However, bilastine should be used with particular caution in patients with moderate to severe renal impairment, as the drug is primarily excreted renally. In patients with severe kidney disease (creatinine clearance below 30 mL/min), bilastine plasma concentrations may be elevated, potentially increasing the risk of adverse effects. Clinical data in this population is limited, and dose adjustment guidance from prescribers is recommended.
Warnings and Precautions
Bilastine must be taken on an empty stomach — at least 1 hour before or 2 hours after food or fruit juice. Food and fruit juice (especially grapefruit juice) significantly reduce the absorption of bilastine, potentially rendering it ineffective. This is because bilastine absorption depends on intestinal organic anion-transporting polypeptide (OATP) transporters, which are inhibited by certain food components and fruit juice constituents.
Patients should be aware of several precautions when taking bilastine. Although bilastine is classified as non-sedating, individual responses to any antihistamine may vary. Rare cases of somnolence and fatigue have been reported. Patients should exercise caution when performing activities requiring alertness until they have established how they respond to the medication.
Elderly patients may be more susceptible to the effects of antihistamines due to age-related changes in drug metabolism and renal function. While no dose adjustment is specifically recommended based on age alone, monitoring for side effects in older adults is advisable. Limited clinical data exists for the use of bilastine in patients over 65 years of age.
Bilastine does not prolong the QTc interval at therapeutic doses according to thorough QT studies. However, as with any medication, patients with pre-existing cardiac conduction disorders or those taking other QT-prolonging drugs should discuss the use of bilastine with their physician. Co-administration of bilastine with ketoconazole or erythromycin did not result in clinically relevant changes to the electrocardiogram in controlled studies.
Pregnancy and Breastfeeding
The safety of bilastine during pregnancy has not been established in adequate, well-controlled human studies. Animal reproductive toxicity studies have not demonstrated teratogenic effects or adverse effects on fertility, embryo-foetal development, or postnatal development. However, the absence of harm in animal studies does not guarantee safety in humans. As a precautionary measure, bilastine should be avoided during pregnancy unless the treating physician considers the potential benefit to the mother to clearly outweigh the potential risk to the foetus.
Bilastine has been detected in the milk of lactating animals, and therefore a risk to breastfed infants cannot be excluded. A decision must be made by the healthcare provider whether to discontinue breastfeeding or to discontinue bilastine therapy, taking into account the benefit of breastfeeding for the child and the benefit of therapy for the mother. Women who are pregnant, planning to become pregnant, or breastfeeding should consult their doctor before starting bilastine.
Always inform your doctor or pharmacist if you are pregnant, think you may be pregnant, are planning to have a baby, or are breastfeeding before taking any medication, including Bilastine Viatris.
How Does Bilastine Viatris Interact with Other Drugs?
Bilastine is not significantly metabolised by the cytochrome P450 (CYP) enzyme system, which is responsible for metabolising many drugs. This characteristic gives bilastine a notable advantage in terms of drug-drug interaction potential compared to some older antihistamines. However, bilastine is a substrate of the efflux transporter P-glycoprotein (P-gp) and the uptake transporter OATP1A2, which are relevant to its intestinal absorption and overall bioavailability.
Clinical interaction studies have demonstrated that drugs which inhibit P-glycoprotein or OATP transporters can increase bilastine plasma concentrations. This increase in exposure may potentially enhance both therapeutic effects and adverse effects. The following table summarises the most clinically relevant drug interactions with bilastine based on published pharmacokinetic studies and regulatory assessments.
Major Interactions
| Interacting Drug | Mechanism | Effect | Recommendation |
|---|---|---|---|
| Ketoconazole | P-gp and CYP3A4 inhibitor | Increases bilastine AUC by approximately 2-fold | Use with caution; monitor for increased side effects |
| Erythromycin | P-gp inhibitor | Increases bilastine AUC by approximately 2-fold | Use with caution; consider alternative antibiotics |
| Cyclosporine | P-gp inhibitor | May significantly increase bilastine plasma levels | Avoid co-administration or use under close medical supervision |
| Ritonavir | P-gp and CYP3A4 inhibitor | Expected significant increase in bilastine exposure | Avoid co-administration; consider alternative antihistamine |
| Grapefruit juice | OATP1A2 inhibitor | Reduces bilastine bioavailability by approximately 30% | Do not take bilastine with grapefruit juice or other fruit juices |
Minor Interactions
Diltiazem: This calcium channel blocker is a moderate inhibitor of P-glycoprotein. Co-administration with bilastine has been shown to increase bilastine plasma concentrations by approximately 50%. While this increase is generally well tolerated, patients taking both medications should be monitored for any signs of increased antihistamine effects.
Alcohol: In controlled clinical studies, bilastine at the 20 mg therapeutic dose did not potentiate the effects of alcohol on psychomotor performance. However, as with all antihistamines, patients are generally advised to exercise caution when consuming alcohol, as individual responses may vary and the combination may theoretically increase the risk of sedation in susceptible individuals.
Other antihistamines or CNS depressants: Co-administration with other antihistamines, sedatives, anxiolytics, or opioid analgesics has not been formally studied but may theoretically increase the risk of central nervous system depression. Patients should inform their physician of all medications and supplements they are taking to enable an appropriate risk assessment.
Food significantly reduces the oral bioavailability of bilastine. Always take Bilastine Viatris on an empty stomach, at least 1 hour before or 2 hours after a meal. Avoid taking with any fruit juice, especially grapefruit juice, as this also impairs absorption via OATP1A2 transporter inhibition.
What Is the Correct Dosage of Bilastine Viatris?
Adults
Adults (18 years and older)
Standard dose: 20 mg (one tablet) once daily, taken orally on an empty stomach.
Timing: Take at least 1 hour before or 2 hours after food or fruit juice. The tablet should be swallowed whole with water.
Duration: For seasonal allergic rhinitis, treatment should continue for as long as exposure to allergens persists. For chronic spontaneous urticaria, the duration of treatment should be determined by the physician based on the clinical course. Long-term studies have demonstrated efficacy and safety for treatment durations of up to 12 months.
Children
Adolescents (12–17 years)
Standard dose: 20 mg (one tablet) once daily, taken on an empty stomach. The same dose as adults applies.
Children under 12 years
Not recommended: Bilastine Viatris 20 mg tablets are not recommended for children under 12 years of age due to insufficient data on safety and efficacy. Other formulations (e.g., oral solution) may be available for younger children — consult a healthcare professional for advice on suitable alternatives.
Elderly
Patients 65 years and older
Standard dose: No dose adjustment is required based on age alone. However, limited clinical data is available for patients over 65 years. As renal function may decline with age, monitoring for adverse effects is advisable in elderly patients, particularly those with concurrent renal impairment.
Special Populations
| Population | Dose | Notes |
|---|---|---|
| Mild renal impairment | 20 mg once daily | No dose adjustment necessary |
| Moderate renal impairment | 20 mg once daily | Use with caution; monitor for adverse effects |
| Severe renal impairment | Use with caution | Limited data; increased plasma levels expected. Consult prescriber |
| Hepatic impairment | 20 mg once daily | No dose adjustment; bilastine is not extensively hepatically metabolised |
Missed Dose
If you forget to take a dose of Bilastine Viatris, take it as soon as you remember, provided it is still on an empty stomach. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a forgotten one. If you have any further questions about the use of this medicine, ask your doctor or pharmacist.
Overdose
In clinical studies, bilastine has been administered at doses up to 220 mg (11 times the recommended dose) without clinically significant adverse effects in healthy volunteers. The most common symptoms expected in overdose are those related to the known pharmacological profile of antihistamines, potentially including increased somnolence, headache, and dizziness.
There is no specific antidote for bilastine overdose. Treatment should be symptomatic and supportive. If a significant overdose is suspected, contact a poison control centre or seek medical attention immediately. Due to bilastine's low protein binding, haemodialysis is not expected to be effective in removing the drug from the systemic circulation.
What Are the Side Effects of Bilastine Viatris?
Like all medicines, Bilastine Viatris can cause side effects, although not everybody experiences them. The side effect profile of bilastine has been extensively evaluated in multiple randomised, double-blind, placebo-controlled clinical trials involving thousands of patients with allergic rhinoconjunctivitis and chronic spontaneous urticaria. Overall, bilastine 20 mg demonstrated a tolerability profile similar to placebo across these studies.
The following side effect frequency categories are based on pooled data from clinical trials and post-marketing surveillance, classified according to the Medical Dictionary for Regulatory Activities (MedDRA) system organ classification and standard frequency conventions:
Common
Affects 1 to 10 in every 100 patients
- Headache
- Somnolence (drowsiness)
Uncommon
Affects 1 to 10 in every 1,000 patients
- Dizziness
- Fatigue
- Dry mouth
- Abdominal pain
- Nausea
- Upper abdominal pain
- Dyspnoea (shortness of breath)
- Nasal dryness
- Pharyngeal discomfort
- Increased appetite
- Anxiety
- Insomnia
- ECG abnormalities (QTc prolongation, bundle branch block)
- Vertigo
- Tinnitus (ringing in the ears)
- Pruritus (itching)
- Herpes simplex reactivation
Rare / Very Rare
Affects fewer than 1 in 1,000 patients
- Tachycardia (fast heart rate)
- Extrasystoles (extra heartbeats)
- Gastroenteritis
- Thirst
- Weight gain
- Abnormal liver function tests
Clinical trial data consistently demonstrate that bilastine at the 20 mg dose does not cause statistically significant sedation compared to placebo. Notably, in a large meta-analysis of bilastine clinical trials published in Clinical and Translational Allergy, the incidence of somnolence with bilastine 20 mg was not significantly different from placebo (3.1% vs 2.7%). This distinguishes bilastine from many other second-generation antihistamines, including cetirizine, which shows a higher somnolence rate in comparative studies.
Post-marketing pharmacovigilance has not identified any new safety signals beyond those reported in clinical trials. Long-term safety data from studies extending up to 12 months have confirmed that bilastine maintains a consistent safety profile with no evidence of tolerance development, tachyphylaxis, or withdrawal effects upon discontinuation.
While rare, seek immediate medical attention if you experience signs of an allergic reaction to bilastine, including skin rash, swelling of the face, lips, tongue, or throat, difficulty breathing, or severe dizziness. Discontinue the medication and consult your doctor if you experience persistent or troublesome side effects.
How Should You Store Bilastine Viatris?
Store Bilastine Viatris tablets at room temperature, not exceeding 30°C (86°F). The tablets should be kept in the original blister packaging until ready for use to protect them from moisture and light degradation. Do not store in the bathroom or other humid environments, as moisture can affect the stability of the active ingredient.
Keep all medicines out of the sight and reach of children. Do not use Bilastine Viatris after the expiry date which is stated on the blister and carton after “EXP”. The expiry date refers to the last day of that month. Do not throw away any medicines via wastewater or household waste. Ask your pharmacist how to throw away medicines you no longer use. These measures will help protect the environment.
If you notice any visible changes to the tablets, such as discolouration, crumbling, or unusual odour, do not use them and consult your pharmacist for a replacement. Properly stored bilastine tablets remain stable for the duration indicated by the manufacturer, typically 2 to 3 years from the date of manufacture.
What Does Bilastine Viatris Contain?
The active substance in Bilastine Viatris is bilastine. Each tablet contains 20 mg of bilastine. Bilastine is a piperidine derivative with the chemical formula C28H37N3O3 and a molecular weight of 463.6 g/mol. It is a white to off-white crystalline powder that is practically insoluble in water.
Excipients (Inactive Ingredients)
The other ingredients in Bilastine Viatris 20 mg tablets are:
- Microcrystalline cellulose — used as a filler and binder to give the tablet its form
- Croscarmellose sodium — a disintegrant that helps the tablet break apart in the gastrointestinal tract for absorption
- Colloidal anhydrous silica — a flow agent that ensures uniform distribution of the active ingredient
- Magnesium stearate — a lubricant used during the manufacturing process to prevent the tablet from sticking to equipment
Bilastine Viatris tablets are white to off-white, round, biconvex tablets. They are typically available in blister packs of 10, 20, 30, 50, or 100 tablets, although not all pack sizes may be marketed in every country. The tablets do not contain lactose, gluten, or sucrose, making them suitable for patients with common dietary intolerances to these substances.
If you have known allergies to any of the excipients listed above, consult your pharmacist or doctor before taking Bilastine Viatris. Although excipient allergies are rare, patients with a history of hypersensitivity reactions should review the full list of ingredients with their healthcare provider.
Frequently Asked Questions About Bilastine Viatris
Bilastine Viatris is a second-generation antihistamine used to relieve symptoms of allergic rhinoconjunctivitis (hay fever, including sneezing, runny nose, itchy and watery eyes) and urticaria (hives, including itching and wheals) in adults and adolescents aged 12 years and older. It works by blocking the effects of histamine, the substance released by the body during an allergic reaction.
Bilastine is classified as a non-sedating antihistamine. At the recommended 20 mg dose, clinical studies have shown that bilastine does not significantly impair psychomotor performance or cause drowsiness compared to placebo. However, somnolence has been reported uncommonly. If you do experience drowsiness, you should avoid driving or operating heavy machinery until you know how the medication affects you.
Bilastine must be taken on an empty stomach because food significantly reduces its oral bioavailability by approximately 30%. This occurs because bilastine relies on OATP (organic anion-transporting polypeptide) transporters in the intestine for absorption. Components in food and fruit juices (especially grapefruit juice) inhibit these transporters, reducing the amount of bilastine that enters the bloodstream. For best results, take bilastine at least 1 hour before or 2 hours after eating.
Bilastine has a limited drug interaction profile because it is not significantly metabolised by the liver's cytochrome P450 enzymes. However, caution is required with P-glycoprotein inhibitors such as ketoconazole, erythromycin, cyclosporine, ritonavir, and diltiazem, as these may increase bilastine plasma levels. Always inform your doctor and pharmacist about all medications, supplements, and herbal products you are taking.
There are limited data on the use of bilastine during pregnancy. Animal studies have not shown direct harmful effects, but as a precaution, bilastine should be avoided during pregnancy unless clearly necessary and prescribed by a doctor. Bilastine is also excreted in animal milk, so the risk to breastfed infants cannot be excluded. Consult your healthcare provider for advice on managing allergy symptoms during pregnancy.
Bilastine can be taken for as long as allergy symptoms persist. For seasonal allergies (hay fever), it is typically taken during the relevant pollen season. For chronic spontaneous urticaria, longer-term treatment may be necessary. Clinical studies have demonstrated safety and efficacy for treatment periods up to 12 months. The duration of treatment should be decided by your doctor based on your individual condition.
References
- European Medicines Agency (EMA). Bilastine – Summary of Product Characteristics (SmPC). EMA Product Database. Available at: www.ema.europa.eu.
- Bachert C, et al. Bilastine in allergic rhinoconjunctivitis and urticaria. Clinical and Translational Allergy. 2012;2:1. doi:10.1186/2045-7022-2-1.
- Zuberbier T, et al. The international EAACI/GA2LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022;77(3):734-766. doi:10.1111/all.15090.
- Bousquet J, et al. Allergic Rhinitis and its Impact on Asthma (ARIA) 2019 update. Allergy. 2020;75(5):1042-1057. doi:10.1111/all.14049.
- Jauregui I, et al. Bilastine: a new antihistamine with an optimal benefit-to-risk ratio for safety during driving. Expert Opinion on Drug Safety. 2016;15(1):89-98. doi:10.1517/14740338.2016.1112785.
- World Health Organization (WHO). Model List of Essential Medicines – 23rd edition. Geneva: WHO; 2023.
- British National Formulary (BNF). Bilastine. NICE. Available at: bnf.nice.org.uk.
- Lasseter KC, et al. Pharmacokinetics of bilastine in subjects with various degrees of renal insufficiency. Clinical Drug Investigation. 2013;33(10):665-673. doi:10.1007/s40261-013-0118-0.
- Sadaba B, et al. Pharmacokinetic drug–drug interaction study of bilastine with cyclosporine and ketoconazole. European Journal of Drug Metabolism and Pharmacokinetics. 2013;38:73-82.
Medical Editorial Team
This article has been written and reviewed by the iMedic Medical Editorial Team, consisting of licensed physicians specialising in clinical pharmacology, allergy, and internal medicine. All content follows international guidelines from the European Medicines Agency (EMA), EAACI, ARIA, and the World Health Organization (WHO). Our editorial process adheres to the GRADE evidence framework, ensuring that all medical claims are supported by the highest available level of evidence.
iMedic Medical Editorial Team — Clinical Pharmacology and Allergy Specialists
iMedic Medical Review Board — Independent expert panel following EMA, EAACI, and WHO standards
Evidence Level: 1A — Based on systematic reviews, meta-analyses of randomised controlled trials, and regulatory authority assessments (EMA, FDA). All recommendations align with current EAACI/ARIA guidelines for the management of allergic rhinitis and urticaria.