Petasites root (Petasitidis rhizoma)

Published July 27, 1990.
List of German Commission E Monographs (Phytotherapy)


Name of Drug

Petasitidis rhizoma, petasites root.

Composition of Drug

Petasites root consists of the dried underground parts of Petasites hybridus (L.) Ph. Gartn., B. Mey. et Scherb. [Fam. Asteraceae], as well as its preparations in effective dosage.

The drug contains sesquiterpenes such as petasin.

Petasites root also contains pyrrolizidine alkaloids with 1,2-unsaturated necine structure and their N-oxides.


Supportive therapy for acute spastic pain in the urinary tract, particularly if stones exist.


Pregnancy, nursing.

Side Effects

None known.

Interactions with Other Drugs

None known.


Unless otherwise prescribed:

Daily dosage:

Preparations equivalent to 4.5 - 7 g drug. The daily dose must not exceed 1 µg (mcg) of pyrrolizidine alkaloids with 1,2-necine structure, including their N-oxides.

Mode of Administration

Extracts obtained with ethanol or lipophilic solvents and other galenical preparations for internal use.

Duration of Administration

Not longer than 4 - 6 weeks per year.