Loratadine
Loratadine
Brand names:Claritin, Alavert
A second-generation H1 antihistamine with minimal sedation and once-daily dosing. Loratadine is one of three operational-grade non-sedating antihistamines (with cetirizine and fexofenadine) appropriate for allergic complaints in operators who must remain fully functional. Onset is slower than diphenhydramine; effect is sustained over 24 hours.
Pharmacology and Actions
Loratadine is a second-generation peripheral H1 antihistamine that selectively antagonizes H1 receptors without significant penetration of the blood-brain barrier, minimizing central sedative effects. Hepatic metabolism produces an active metabolite (desloratadine) which contributes substantially to the sustained 24-hour effect. Minimal anticholinergic activity at therapeutic doses.
Indications
- Seasonal and perennial allergic rhinitis
- Chronic urticaria
- Allergic conjunctivitis
- Mild to moderate allergic reactions in operational personnel who must remain functional
Absolute Contraindications
- Known hypersensitivity to loratadine or desloratadine
Precautions and Side Effects
Common (low frequency): headache, drowsiness (rare at standard doses), dry mouth, fatigue. Minimal anticholinergic effects compared with first-generation antihistamines. Cardiac: rare QT prolongation; no significant cardiac effects at recommended doses (unlike the older second-generation agents terfenadine and astemizole, which were withdrawn for QT issues). Drug interactions: minimal compared with first-generation antihistamines; CYP3A4 inhibitors (ketoconazole, erythromycin) may increase loratadine levels slightly without clinical significance for most patients. Half-life 8 hours (loratadine), 28 hours (desloratadine metabolite). Pregnancy Category B. Compatible with lactation (small amounts in breast milk; considered safer than first-generation alternatives). Pediatric use approved from 2 years. Hepatic impairment: reduce dose. Renal impairment: standard dosing.
Adult Dosing
Pediatric Dosing
Children 2 to 5 years: 5 mg PO once daily. Children 6 years and older: 10 mg PO once daily.
Pharmacokinetics
Peak Effect: 8 to 12 hours.
Duration: 24 hours.
Storage and Handling
Store at room temperature (15 to 30 degrees C). Protect from light and moisture. Tablets, ODT, and chewables all stable in standard aid bag and IFAK conditions.
Reconstitution:
Oral formulation only. No reconstitution required.
TCCC and TECC Role
Loratadine is not in the TCCC core formulary. It appears in tactical EMS supplemental formularies and deployment medical kits as the daily-use non-sedating antihistamine for operators with allergic complaints. Once-daily dosing, no significant sedation, no operational impact at standard dose. Not appropriate for acute anaphylaxis (epinephrine, diphenhydramine, and corticosteroids are required for anaphylactic reactions).
Loratadine, cetirizine, and fexofenadine are the three second-generation antihistamines most commonly carried in tactical and deployment medical kits. They are clinically similar but have small operational differences: loratadine has the lowest sedation incidence but the slowest onset (1 to 3 hours); cetirizine has the fastest onset but slight sedation in some operators; fexofenadine has the cleanest cognitive profile and is FAA-approved for aircrew. For a tactical operator who develops seasonal allergies during deployment, any of the three works. Loratadine's once-daily dosing and OTC availability make it the most accessible choice.
Using loratadine for acute allergic reactions where rapid onset is needed. The 1 to 3 hour onset means diphenhydramine or cetirizine (faster onset) are better choices for urticaria that has just developed or for moderate acute allergic symptoms. Loratadine's strength is sustained 24-hour control of established allergic complaints. The other mistake is using loratadine in true anaphylaxis - epinephrine is required for anaphylaxis; loratadine has no role in that setting.
This drug profile is provided as educational reference material for trained medical providers. It is not medical advice, not a substitute for formal training, and not a substitute for current published guidelines or medical direction.
Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances are subject to additional handling, accountability, and documentation requirements per DEA and state law. Always verify dosing, indications, contraindications, and route of administration against current published guidelines and your local protocols before administration.
If this content is being viewed during a medical emergency, call 911 immediately and follow the direction of your local emergency dispatch and medical control. Do not use this reference as a substitute for emergency medical services.
Drug information evolves. Last reviewed dates and source citations are provided for each entry. Confirm currency against the cited source before clinical use.
Penn Tactical Solutions publishes this reference for educational purposes. PTS does not provide medical direction and does not assume responsibility for clinical decisions made in the field. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Educational reference for trained medical providers. Not medical advice. Not a substitute for formal training, current published guidelines, or medical direction. Drug administration is governed by your scope of practice, agency standing orders, medical director protocols, and applicable state and federal regulations. Controlled substances require additional storage, accountability, and documentation per DEA and state law.
In a medical emergency, call 911. This reference is not a substitute for emergency medical services.
Verify dosing, indications, and contraindications against current published guidelines and your local protocols before administration. Confirm content currency against the source citation. Penn Tactical Solutions does not provide medical direction. Clinical responsibility rests with the administering provider, their medical director, and their agency.
Loratadine
| IV/IO | None (None) |
| IM | None (None) |
| IN | None (None) |
| PO | 10 mg PO once daily. Available as standard tablet, ODT (orally disintegrating tablet), and chewable tablet. ODT useful when water unavailable. (1 to 3 hours) |