Terfenadine

H1 antagonist.

4–6 h

Rhinitis allergica, allergic skin reactions.

Bronchial asthma, hypokalemia (previous compensation), known QT time reduction, combination with macrolides or azole antifungals, psoriasis vulgaris (worsening possible).

• Adults/teenagers: 2 times/day 60-120 mg p.o.
• Children 9-12 years: 2 times/day 30-60 mg p.o.
• Children 6-9 years: 2 times/day 30 mg p.o.

Gastrointestinal disturbances, hyperhidrosis, headache, pruritus, flushing, urticaria, depression, reaction limitation, seizures, fatigue, dizziness, visual disturbances, extrasystoles, cardiac arrhythmias, galactorrhea, bronchospasm, dry mouth, transaminase increase, dysmenorrhea, myalgias, alopecia, photosensitization.

Notice. Discontinue preparation if syncope occurs!

See Table 1.

Hypersensitivity to the active substance, pregnancy, lactation, children < 6 years (Tbl.), children < 12 months (Tbl., suspension), severe liver dysfunction.

Hisfedin, Terfenadine ratiopharm

In the meantime, terfenadine has been withdrawn from the market in various countries due to cardiac side effects. The successor of terfenadine (fexofenadine) is the metabolite of terfenadine responsible for the histamine H1 receptor antagonism. The unfavourable effects on the electrophysiology of the heart are due to the terfenadine mother substance, not to the antihistaminically active metabolite.

1. del Cuvillo A et al (2006) Comparative pharmacology of the H1 antihistamines. J Investig Allergol Clin Immunol 16: 3-12
2. Borchard U (2003) New H1 antihistamines in comparison. Allergology 1: 23-32

Essential interactions of terfenadine