Loratadine Tablet

Therapeutic Class

Systemic Antihistamines

Dosage Form, Composition & NAFDAC Registration Number (NRN)

Tablet (NRN: A4-7347): Loratadine 10 mg.

Pack size: Blister packs of 2 x 10 and 10 x 10.

Syrup (NRN: A4-7551): Loratadine 5 mg

Pack size: 60 ml Plastic bottle.

Pharmacology

Mechanism of action: Competitively antagonizes histamine at the H 1 -receptor site.

Pharmacokinetics: Rapidly absorbed following oral administration. T_max is 1.3hrs for loratadine and 2.5hrs for its metabolite. Food increases bioavailability (AUC) approximately 40% however, T_max is delayed by 1hr. Steady state is reached by approximately the fifth dosing day.

Distribution: 97% protein bound.

Metabolism: Metabolite is descarboethoxyloratadine. Metabolized by CYP-450 3A4 and P450 2D6 and it undergoes extensive first-pass metabolism.

Elimination: Approximately 80% equally distributed between urine and feces in the form of metabolic products within 10 days. The t½ for loratadine is 8.4hrs (3 -20hrs). The t½ for descarboethoxyloratadine is 28 hrs (8.8 to 92 hrs).

Indications

Loratadine is used for the symptomatic relief of allergic conditions such as sneezing, rhinorrhea, itching, ocular itching and burning. It is also indicated for the relief of chronic urticaria and other allergic dermatological disorders.

Contra-indications

Risk-benefit ratio should be considered when the following medical problems exist; bladder neck obstruction, prostatic hypertrophy, urinary retention, glaucoma, or sensitivity to loratadine.

Precautions/Warnings

Precaution should be exercised when administering loratadine to patients with severe hepatic impairment as reduced clearance of loratadine may occur

• Patients sensitive to one of the antihistamines may be sensitive to others
• Safe use of loratadine in pregnancy has not been established

Interactions

No drug-drug interaction that is considered serious. However, it should not be taken with alcohol.

Adverse Effects

Sedative and anticholinergic effects are not likely. Headache, nausea and fatigue have been reported. Those reported rarely include; hair loss, changes in liver function and severe allergic reactions.

Dosage & Administration

Adult and children over 6 years: 10 mg daily.

Children 2 – 5 years: One teaspoonful (5 mg) daily.

Patients with severe liver impairment should take one tablet every other day or as directed by the Physician.

Storage/Handling Recommendations

Store protected from light.

Keep in a cool dry place and away from children.