What's on this Page
What is Terfenadine
NOTE: This drug is discontinued in the U.S.
Terfenadine was a non-sedating antihistamine (H1-blocker) that is similar in structure to astemizole. Terfenadine, however, had a much shorter duration of action.
Both agents were structurally similar to haloperidol, a butyrophenone antipsychotic. Interestingly, all 3 agents have been associated with torsade de pointes (TdP).
Unlike other first-generation antihistamines, therapeutic doses of terfenadine produce insignificant anticholinergic activity or sedation, perhaps due to poor penetration of the drug into the CNS.
Terfenadine was originally approved by the FDA in May 1985 but was subsequently withdrawn in February 1998 due to its risk of causing cardiac arrhythmias.
Indications
- allergic rhinitis
For symptomatic relief of seasonal allergic rhinitis
Side Effects
- anxiety
- dizziness
- drowsiness
- headache
- hypotension
- insomnia
- nausea
- QT prolongation
- restlessness
- torsade de pointes
- ventricular tachycardia
- vomiting
- xerostomia
Monitoring Parameters
- ECG
- LFTs
Contraindications
- asthma
- breast-feeding
- cardiac disease
- children
- driving or operating machinery
- geriatric
- hepatic disease
- infants
- neonates
- pregnancy
- QT prolongation
- renal disease
- renal impairment
- torsade de pointes
Interactions
- Amitriptyline
- Amitriptyline; Chlordiazepoxide
- Amprenavir
- Atazanavir
- Atazanavir; Cobicistat
- Cisapride
- Clomipramine
- Darunavir
- Darunavir; Cobicistat
- Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide
- Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir
- Desipramine
- Dextromethorphan; Quinidine
- Disopyramide
- Doxepin
- Fosamprenavir
- Heparin
- Imipramine
- Indinavir
- Lanreotide
- Levomethadyl
- Lopinavir; Ritonavir
- Nelfinavir
- Nortriptyline
- Ombitasvir; Paritaprevir; Ritonavir
- Pentamidine
- Perphenazine; Amitriptyline
- Procainamide
- Protease inhibitors
- Protriptyline
- Quinidine
- Quinine
- Ritonavir
- Rufinamide
- Saquinavir
- Sparfloxacin
- Telaprevir
- Telithromycin
- Thioridazine
- Tipranavir
- Tricyclic antidepressants
- Trimipramine
- Voriconazole
- Zileuton
- Ziprasidone
