Terfenadine

Terfenadine is a non-sedative antihistamine.

Dosage in adults is 60 mg twice daily.

It has the potential to induce ventricular arrhythmias so it is essential to check the contraindications and to take a careful drug history.

Terfenadine should not be used if a patient has heart or liver problems; a patient should not take terfenadine with grapefruit juice; and the recommended dose should never be exceeded.

Terfenadine interacts with some other medications e.g. erythromycin and clarithromycin. Possible interactions with terfenadine should be checked before prescribing terfenadine.

Terfenadine is now only available on prescription.

The summary of product characteristics must be consulted before prescribing terfenadine.

Notes:

• terfenadine is only available in the UK on a named-patient basis through specialist importers. There are no longer any licensed preparations containing terfenadine available in the UK (November 2005)

Reference:

1. Committee on Safety of Medicines (21/4/1997). Terfenadine: proposed change to prescription use, letter from Professor M D Rawlins.
2. Current Issues in Pharmacovigilance (1997), 23, 9.