The use of a Petasitesextract (and/or its fraction(s)) (A) for: (1) the production of a specific cyclooxygenase-2 (COX-2) inhibitor； (2) treatment and/or prophylaxis of diseases treatable by specific COX-2 inhibition； and/or (3) production of a spasmolytic and/or analgesic medicament. Independent claims are included for: (1) a Petasitesextract (and/or its fraction(s)) (A') which contains not more than 30 (preferably less than 0.001) wt. % petasine (I) (based on the solvent-free extract or extract fraction)； (2) a specific COX-2 inhibitor based on (A) (in (I)-containing, (I)-depleted or (I)-free form)； and (3) a composition based on (A) (in (I)-containing, (I)-depleted or (I)-free form), where (A) is a polar or apolar extract or is enriched with a polar and/or apolar extract. ACTIVITY : Analgesic； antiarthritic； osteopathic； antirheumatic； cytostatic； antiulcer； antiinflammatory； thrombolytic； cardiant； vasotropic； antianginal； cerebroprotective； neuroprotective； hypotensive； antimigraine； antiasthmatic； antiallergic； dermatological； nootropic； tuberculostatic； antipsoriatic； gynecological； tranquilizer； hypnotic； antidepressant； Gastrointestinal-Gen.； Cardiovascular-Gen.； Respiratory-Gen.； Uropathic. MECHANISM OF ACTION : COX-2 inhibitor.
