The pollen season in Romania begins in March with birch and beech, continues in May-June with grasses, and closes in August-September with ragweed (Ambrosia artemisiifolia), which aggressively colonises the fields around Bucharest, Călărași and Ialomița. For around 20% of Romanians this means allergic rhinitis, conjunctivitis and sometimes asthma. H1 antihistamines are the first line of treatment — but not all of them are alike.
A short history: two generations, two profiles
H1 antihistamines block the receptors for histamine, the main mediator of the allergic reaction. The first generation (chlorphenamine, diphenhydramine, hydroxyzine, promethazine) easily crosses the blood-brain barrier — hence the marked sedative effect. The second generation (loratadine, desloratadine, cetirizine, levocetirizine, fexofenadine, bilastine, rupatadine) penetrates the brain minimally, so they are practically non-sedating at therapeutic doses.
Practically all modern guidelines (ARIA — Allergic Rhinitis and its Impact on Asthma, EAACI, BNF) recommend the second generation as first line for allergic rhinitis and chronic urticaria. The first generation keeps its role in a few niches: occasional insomnia (diphenhydramine, doxylamine OTC), motion sickness (promethazine), premedication in acute reactions.
Comparison of common active substances in Romania
| Active substance | Generation | Sedation | Adult dose | Commercial examples |
|---|---|---|---|---|
| Loratadine | II | Minimal | 10 mg/day | Claritine, Symphoral, Loratadină EG |
| Desloratadine | II | Minimal | 5 mg/day | Aerius, Dezacor, Desloratadină Teva |
| Cetirizine | II | Mild (~10%) | 10 mg/day | Zyrtec, Alerid, Cetirizină Atb |
| Levocetirizine | II | Mild | 5 mg/day | Xyzal, L-Cet |
| Fexofenadine | II | Practically absent | 120-180 mg/day | Telfast, Allegra |
| Bilastine | II | Minimal | 20 mg/day | Bilaxten, Borenar |
| Chlorphenamine | I | Marked | 4 mg every 6h | component of Coldrex Junior, Theraflu Combo |
| Hydroxyzine | I | Marked | 25 mg every 8h | Atarax |
Driving: this is the trap
The differences matter. Driving-simulator studies and PET imaging show that cetirizine and levocetirizine have brain H1 occupancy between 10-26%, while fexofenadine and bilastine stay below 10%. Loratadine is somewhere in between.
The ANMDMR recommendation (per the SmPCs) and the manufacturers': with the second generation, avoid alcohol and monitor drowsiness individually. The first generation (chlorphenamine, hydroxyzine, diphenhydramine) is incompatible with driving or activities requiring vigilance, especially in the first 4-6 hours after taking it.
Typical cases: what to take for what
- Seasonal allergic rhinitis (pollens): loratadine 10 mg or desloratadine 5 mg or bilastine 20 mg, once a day, in the morning. It can be combined with a nasal corticosteroid spray (mometasone, fluticasone).
- Chronic spontaneous urticaria: second generation at the standard dose, escalated to x2 or x4 (off-label but standard ARIA/EAACI), under medical supervision.
- Allergic conjunctivitis: eye drops with olopatadine, ketotifen or azelastine — fast, local effect.
- Itching in chickenpox, insect bites: loratadine or desloratadine.
- Occasional insomnia (in adults): doxylamine 12.5-25 mg or diphenhydramine — but not chronically; it tolerates quickly and has a morning hangover effect.
CNAS reimbursement and OTC status
Loratadine, cetirizine and desloratadine are OTC in standard doses and forms. The combined versions (with pseudoephedrine, e.g. Aerinaze) are P-RF — prescription only. Prices between chains vary: a box of loratadine 10 mg/30 tablets can differ by 30-40% between Catena, Tei and Dr.Max — check on HartaFarmacii before buying. CNAS reimbursement applies to the Rx versions for chronic indications (chronic spontaneous urticaria on List C2, certain generics).
In pregnancy and in children
Loratadine and cetirizine are the most studied in pregnancy — FDA category B, recommended by the EAACI guidelines if the clinical need justifies it. In children: cetirizine is approved from 6 months, desloratadine syrup from 1 year, loratadine syrup from 2 years. Diphenhydramine in young children — only on medical advice, risk of paradoxical excitation.
Frequently asked questions
- Which is the strongest antihistamine?
- The question is a trap. All second-generation ones have comparable efficacy for rhinitis; the major differences are in the safety profile (sedation, QT, liver).
- Can I drive if I take loratadine?
- Most people, yes. But test it the first time with a dose on a free evening — rarely, some people are sensitive.
- Are antihistamines addictive?
- Not in the classic sense. The first generation can produce tolerance to the sedative effect, but not addiction.
- How long can I take an antihistamine non-stop?
- Second generation — for months during the allergy season. First generation — only occasionally.
- Can I combine two antihistamines?
- Two second-generation ones — no. A seasonal second-generation course + an antihistamine eye drop — yes. Second generation in the day + first generation at night (insomnia) — in principle possible, but ask the doctor.
- Why am I advised to take it in the morning?
- Because the allergens (pollens) concentrate in the morning, and the pharmacokinetic coverage is at its maximum in the first half of the day.
Treatment schemes in allergic rhinitis
The ARIA guideline (Allergic Rhinitis and its Impact on Asthma) classifies rhinitis along two axes — duration (intermittent vs. persistent) and severity (mild vs. moderate-severe). The treatment recommendations rise in steps:
- Step 1: oral second-generation antihistamine as needed; saline nasal washes (Sinomarin, Marimer); avoidance of the identified allergen.
- Step 2: oral second-generation antihistamine daily + nasal corticosteroid spray (mometasone, fluticasone, beclometasone) — the most effective combination for moderate rhinitis.
- Step 3: adding an intranasal antihistamine (azelastine) or a fixed combination (Dymista — azelastine + fluticasone); montelukast if asthma is associated.
- Step 4: allergen-specific immunotherapy (sublingual or subcutaneous) for patients with well-defined allergies who do not respond to conventional therapy. Available in Romania at specialised centres (Acarizax for dust mites, Grazax for grasses).
The first generation: when it still makes sense
Although the newer generations have replaced them in rhinitis and urticaria, the first generation keeps a few legitimate niches:
- Premedication in acute allergic reactions — diphenhydramine i.m./i.v. in severe acute urticaria, alongside a corticosteroid and adrenaline.
- Occasional sedation — doxylamine (a component in Sanval Forte) or diphenhydramine (Benadryl) in short-term insomnia.
- Motion sickness — promethazine, dimenhydrinate (Aviomarin) — effective, but watch for sedation and dry mucous membranes.
- Hydroxyzine (Atarax) — a non-benzodiazepine anxiolytic useful in patients in whom benzodiazepines are contraindicated; also a useful antipruritic in chronic nocturnal urticaria.
- Antiemetic in pregnancy — meclozine, doxylamine (in combination with pyridoxine — Diclectin in other markets) have a good profile.
The general warning is the same: anticholinergic effects (dry mucous membranes, urinary retention, narrow-angle glaucoma, constipation, confusion in the elderly). Beers Criteria 2023 — first-generation antihistamines are categorised as "to be avoided" in patients over 65 because of the cognitive and fall risk.
Combinations with decongestants and "flu remedies"
Many OTC cold products combine an antihistamine + a decongestant ± an analgesic — Coldrex MaxGrip, Theraflu, Fervex, Aspirin Complex. The advantage: convenience. The disadvantage: fixed doses that do not suit everyone and a cumulation of side effects.
The typical components:
- Pseudoephedrine — an α-adrenergic decongestant, watch for hypertension, glaucoma, enlarged prostate; restricted to prescription in many cases, including in Romania.
- Phenylephrine — a weaker alternative, whose oral efficacy was recently questioned by the FDA.
- Chlorphenamine — a sedating first-generation antihistamine.
- Paracetamol — an analgesic-antipyretic.
- Caffeine — mild vasoconstriction, analgesic synergy.
Practical recommendation: buy separately when the symptoms are targeted (an antihistamine for sneezing, a decongestant for a blocked nose, paracetamol for fever); avoid the combinations if you only have one of the symptoms.
Practical cases — what to choose
- Adult under 35, professional driver, allergic rhinitis: fexofenadine 180 mg in the morning — practically zero sedation.
- Breastfeeding mother, acute urticaria: loratadine 10 mg/day — compatible with breastfeeding per LactMed.
- 75-year-old, nocturnal itching from dermatitis: loratadine in the day + an emollient topical application; avoid hydroxyzine because of the anticholinergic risk.
- Adolescent, ragweed allergy: bilastine 20 mg in the morning + nasal spray with mometasone (Nasonex).
- Acute allergic reaction to a sting: cetirizine 10 mg ± a short corticosteroid course; with signs of anaphylaxis — an auto-injectable adrenaline (EpiPen) and call 112.
Sources
- ARIA — Allergic Rhinitis and its Impact on Asthma 2020 update
- EAACI — urticaria guidelines 2022
- ANMDMR — SmPCs for loratadine, cetirizine, bilastine (anm.ro)
- EMA — second-generation antihistamines safety reviews
- BNF — antihistamines chapter
- Beers Criteria 2023 — American Geriatrics Society
- LactMed — National Library of Medicine, breastfeeding profiles
- CNAS — reimbursement lists (cnas.ro)