Terfenadine


Concise Prescribing Info
Indications/Uses
Allergic conditions.
Dosage/Direction for Use
Adult : PO >12 yr and >50 kg: 60-120 mg/day in the morning or 60 mg twice daily. Max: 120 mg/day.
Dosage Details
Oral
Allergic conditions
Adult: >12 yr and >50 kg: 60-120 mg in the morning or 60 mg bid. Max: 120 mg daily.
Renal Impairment
CrClDosage
<40Half the usual daily dose
Contraindications
Porphyria.
Special Precautions
Child and elderly. Avoid in patients with cardiac or significant hepatic disease, electrolyte imbalance, or known or suspected prolongation of the QT interval. Lactation, pregnancy.
Adverse Reactions
Anxiety, palpitations, insomnia, mild GI distubances, erythema multiforme and galactorrhoea.
Potentially Fatal: Ventricular arrhythmias including torsades de pointes. Palpitations, dizziness, syncope or convulsions may indicate arrhythmias. Hepatitis.
Drug Interactions
Potentially Fatal: Increased risk of ventricular arrhythmia with triazole and imidazole antifungals, macrolide antibacterials, streptogramin antibacterials, SSRI, HIV-protease inhibitors and non-nucleoside reverse transcriptase inhibitors, arrhythmogenic drugs, diuretics, astemizole and zileutron.
Food Interaction
Grapefruit juice may inhibit the metabolism of terfenadine.
Action
Description: Terfenadine, a piperidine derivative, is a non-sedating H1 receptor antagonist antihistamine.
Pharmacokinetics:
Absorption: Rapidly absorbed from GI tract. Peak plasma concentrations: within 2 hr.
Distribution: Protein binding: 97% (terfenadine). Does not appear to cross the blood-brain barrier to significant extent. Limited amounts of fexofenadine, but not terfenadine detected in breast milk. Elimination half-life: 16-23 hr (terfenadine).
Metabolism: Prodrug and undergoes extensive first-pass metabolism in the liver to active (carboxylic acid derivative fexofenadine) and inactive metabolites.
Excretion: Excreted in the urine and faeces (traces of unchanged drug and metabolites)
Disclaimer: This information is independently developed by MIMS based on Terfenadine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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