Allergic rhinitis
First line
First-line allergic rhinitis treatment per ARIA. Efficacy is confirmed in numerous RCTs. Advantage over cetirizine: minimal drowsiness, which matters for drivers and precision workers. Adult dose is 10 mg once daily.
Second-generation antihistamines
ATC code: R06AX13 (Loratadine)
Long-acting peripheral H1-receptor antagonist. Virtually no CNS penetration, resulting in minimal sedation. Hepatic metabolism via CYP3A4 and CYP2D6 produces the active metabolite desloratadine. Onset of action 1-3 hours, duration exceeding 24 hours.
First line
First-line allergic rhinitis treatment per ARIA. Efficacy is confirmed in numerous RCTs. Advantage over cetirizine: minimal drowsiness, which matters for drivers and precision workers. Adult dose is 10 mg once daily.
First line
First-line treatment for chronic urticaria. As with cetirizine, up-dosing to 4-fold is permitted per /GA2LEN guidelines if the standard dose is insufficient. Higher doses are well tolerated without significant increase in sedation.
Not recommended
Loratadine does not work for the common cold. The 2015 Cochrane review «Antihistamines for the common cold» showed second-generation H1 antagonists do not improve cold symptoms. Only first-generation H1 drugs show a weak effect through their anticholinergic action, which loratadine largely lacks. , , and CDC do not include antihistamines in common cold recommendations. Widespread use in post-Soviet countries is inconsistent with the evidence base.
Not recommended
Systemic loratadine is not used in viral or bacterial conjunctivitis. The Preferred Practice Pattern distinguishes allergic conjunctivitis, where H1 blockers work, from infectious, where histamine is not involved in pathogenesis. Viral cases are treated symptomatically (cold compresses, artificial tears), bacterial with topical antibiotics.
Not recommended
Loratadine is not used in non-allergic rhinitis (vasomotor, idiopathic, infectious URI-related, medication-induced). ARIA 2020 and separate allergic and non-allergic rhinitis: systemic H1 blockers are not useful in the latter because the pathogenesis is not histamine-mediated. Topical azelastine and corticosteroids work for vasomotor rhinitis.
Not recommended
Routine loratadine before planned vaccination in healthy people without allergy history is not supported by international societies. CDC Pink Book, ACIP 2023, and : antihistamine premedication does not prevent anaphylaxis because the anaphylactic cascade outpaces H1 blockade. Selected RCTs show reduced vaccine immunogenicity of 10–25 % with antihistamine and antipyretic premedication (Prymula R et al. Lancet 2009). Patients with confirmed drug or vaccine allergy are managed individually by an allergist.
FDA category B. Considered a preferred antihistamine in pregnancy alongside cetirizine. Large cohort studies have not identified an increased risk of congenital malformations.
Passes into breast milk in negligible amounts. Compatible with breastfeeding per LactMed.
loratadine is evaluated for the following indications with varying evidence strength: Allergic rhinitis (evidence tier A), Chronic urticaria (evidence tier A), Non-allergic rhinitis (evidence tier F). See the full indication matrix with dosing and citations above on this page.
Common side effects of loratadine (≥ 1 in 100): Headache, Dry mouth, Fatigue (rare). See the Safety section for uncommon and serious reactions.
FDA category B. FDA category B. Considered a preferred antihistamine in pregnancy alongside cetirizine. Large cohort studies have not identified an increased risk of congenital malformations.
Passes into breast milk in negligible amounts. Compatible with breastfeeding per LactMed.
loratadine is contraindicated in: Hypersensitivity to loratadine or desloratadine. Full list in the Safety section.
second-generation H1 blockers do not work in URI. The 2015 Cochrane review confirmed the null effect on 5,099 participants. Short-course nasal decongestants and saline rinses help cold symptoms.
ARIA clearly separates allergic and non-allergic rhinitis. In vasomotor, idiopathic, infectious, and medication-induced rhinitis, systemic H1 blockers do not work – histamine is not the key mediator in pathogenesis.
CDC, ACIP, and WHO do not support this practice. Antihistamines do not prevent anaphylaxis. In selected RCTs, antihistamine and antipyretic premedication reduced vaccine immunogenicity by 10–25 %.
in viral or bacterial conjunctivitis, systemic antihistamines do not work. AAO recommends symptomatic treatment for viral and topical antibiotics for bacterial cases.