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Loratadine (Claritin)

Antihistamineoral · inferred

Second-generation antihistamine metabolized via CYP3A4 and CYP2D6 to active metabolite desloratadine. Non-sedating at recommended doses.

Projected serum levels — 10 mg, once daily

Loratadine (Claritin)
Loratadine (Claritin) modeled serum levels, 10 mg once daily over 15 days Population-based pharmacokinetic estimate. Steady state reached after approximately 1 days. 0 1.3 2.5 3.8 5 Day 0 Day 4 Day 8 Day 11 Day 15 Time on a regular schedule ≈ steady state · day 1

Maintenance schedule: 10 mg once daily (oral).

Modeled steady state after ~1 days: peak ≈ 4.1 mg, trough ≈ 0.66 mg body load. Population-based estimate over 15 days for a 10 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Antihistamine
Route modeled
Oral
Model confidence
inferred
Half-life
8.4 h
Common dose
10 mg
Suggested maximum
10 mg/day
Reference dose range
5–10 mg (single dose)
Suggested cadence
once daily
Validated against
10 mg oral — Cmax 0.006 mg/L at 1.5 h

Documented interactions

  • contraindicated
    Efavirenz (Sustiva) + Loratadine (Claritin) CYP induction

    Efavirenz (Sustiva) inducer of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~0.18x

  • contraindicated
    Rifampin + Loratadine (Claritin) CYP induction

    Rifampin inducer of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~0.18x

  • danger
    Carbamazepine (Tegretol) + Loratadine (Claritin) CYP induction

    Carbamazepine (Tegretol) inducer of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~0.28x

  • danger
    Clarithromycin (Biaxin) + Loratadine (Claritin) CYP inhibition

    Clarithromycin (Biaxin) mechanism_based of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~2.32x

  • danger
    Dasatinib (Sprycel) + Loratadine (Claritin) CYP inhibition

    Dasatinib (Sprycel) time_dependent_inhibitor of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~2.02x

  • danger
    Diltiazem + Loratadine (Claritin) CYP inhibition

    Diltiazem mechanism_based of CYP3A4 predicted to change Loratadine (Claritin) AUC by ~2.32x

Serum checks 222 modeled interaction pairings for loratadine (claritin) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Loratadine: a non-sedating antihistamine with once-daily dosing Haria M et al. · Drugs, 1994 DOI

    Review establishing loratadine as effective for allergic rhinitis and chronic urticaria, with minimal CNS penetration and no significant sedation at therapeutic doses.

  2. Comparative sedative effects of antihistamines Mann RD et al. · BMJ, 2000 DOI

    Large pharmacovigilance study confirmed loratadine had the lowest sedation rate among commonly prescribed antihistamines, comparable to placebo.

  3. Antihistamines for allergic rhinitis treatment from the viewpoint of nonsedative properties Yanai K et al. · Clinical and Experimental Allergy, 2012 DOI

    PET imaging study showed loratadine occupied less than 30% of brain H1 receptors at recommended doses, explaining its non-sedating profile compared to first-generation antihistamines.

3 published studies referenced in the app, each with a plain-language summary.