Petasites /Asthma Original Research Petasites hybridus (Butterbur root) Extract in the Treatment of Asthma – An Open Trial Ulrich Danesch, PhD Abstract
eosinophils and neutrophils, to the airways where
The efficacy and tolerability of a butterbur root
they cause alterations in epithelial integrity,
extract (Petadolex®) for the treatment of
abnormalities in autonomic neural control of
asthma was analyzed in a prospective, non-
airway smooth vascular tone, increased vascular
randomized, open trial. Subjects included 64
permeability, mucus hypersecretion, change in
adults and 16 children/adolescents treated for
mucociliary function, increase in airway smooth
two months with the extract, followed by two
muscle responsiveness, and structural changes in
months during which the intake of the extract was optional. Concomitant asthma medication
Increased appreciation of the role of in-
was permitted. The number, duration, and
flammation in the pathophysiology of asthma has
severity of asthma attacks decreased, while
led to new treatment strategies. Studies have
peak flow, forced expiratory volume (FEV1), and
shown improvements in asthma symptoms caused
all measured symptoms improved during
by high doses of inhaled corticosteroids are asso-
therapy. In addition, more than 40 percent of
ciated with improvement in markers of airway
patients using asthma medications at baseline
inflammation.4,5 These observations confirm the
reduced intake of these medications by the end
strong link between airway inflammation, bron-
of the study. This study suggests the Petasites
chial hyperresponsiveness, and asthma symptoms
hybridus extract Petadolex is an effective and safe therapy for the treatment of asthma. (Altern Med Rev 2004;9(1)54-62)
consists of long-term therapy (control medication)and quick-relief therapy (relief medication). Introduction
Current management guidelines stress theimportance of first-line therapy with inhaled
corticosteroids (e.g., beclomethasone, budesonide,
disorder of the airways.1,2 In the past, the
fluticasone, triamcinolone) to suppress the
predominant pathophysiology of acute asthma was
inflammatory process.2 The main concern with
considered to be bronchospasm occurring in
inhaled corticosteroid treatment is the potential for
response to a variety of specific and nonspecific
dose-related systemic effects, including adrenal
stimuli such as allergens and irritants. However,
suppression, osteoporosis, growth inhibition, skin
the main pathophysiology of the attack is now
bruising, cataracts, and ocular hypertension.6
understood to be an inflammatory response, withinflammation leading to bronchospasm.3 Theinitial trigger in asthma may be the release of
Ulrich Danesch, PhD – Biology from the University of
inflammatory mediators from bronchial mast cells,
Heidelberg, Germany; past research position, Stanford,
macrophages, T-lymphocytes, and epithelial cells.
School of Medicine; currently in research and developmentfor Weber & Weber, the manufacturer of Petadolex.
Correspondence address: Muenchner Strasse 13, D-
activation of other inflammatory cells, such as
Page 54 Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004
Copyright2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
Original Research Petasites /Asthma
Cromolyn and nedocromil sodium have similar
since 1972 and licensed as a pharmaceutical un-
anti-inflammatory properties, but are less effective
der German regulations. This same extract has
in treating asthma than inhaled corticosteroids.
been available in the United States since 1997 as
The cysteinyl leukotrienes C4, D4, and E4
cause smooth muscle constriction and prolifera-
Historically, Petasites has been used thera-
tion and are important mediators in the pathophysi-
peutically for its analgesic effects and to reduce
ology of the inflammatory process. Based on this
spasms in the gastrointestinal tract and in asthma.
knowledge, a new class of anti-inflammatory
Recently, a multicenter, randomized, double-blind,
agents – the leukotriene antagonists – were de-
placebo-controlled clinical trial for migraine pro-
veloped.7 Leukotriene antagonists possess both
phylaxis was conducted on 229 evaluable patients
anti-inflammatory and bronchodilation activity.
with and without aura. The study found Petasites
Two types can be distinguished based on mecha-
extract safe and effective in reducing the frequency
nism of action: leukotriene-receptor-antagonists
of migraine attacks, the number of migraine days
(zafirlukast and montelukast) and leukotriene-syn-
per month, and headache intensity.12 The first clini-
thesis-inhibitors (zileuton). These medications
cal experiences with Petadolex in patients with
appear to improve lung function and reduce the
asthma were published by Gruia.13 In vitro exami-
use of inhaled and oral corticosteroids; however,
nations with smooth muscle cells of various ori-
they have the potential for side effects. Zileuton
gins14 and in guinea pig tracheal rings15 confirmed
requires liver function monitoring and systemic
the spasmolytic activity of Petasites. In addition
vasculitis has been associated with zafirlukast and
to spasmolytic action, Petasites exhibits anti-in-
flammatory activity. In mouse macrophages16 and
porcine leukocytes17 Petasites extract was shown
for acute and long-term asthma management, of-
to inhibit inflammatory leukotriene synthesis.
ten in conjunction with oral corticosteroids and/
A clinical trial of Petasites root powder in
or leukotriene antagonists. Long-acting beta-ago-
patients with chronic asthma and chronic bron-
nists like salmeterol and formoterol act as
chitis demonstrated improved lung function in all
bronchodilators by relaxing the smooth muscle
groups treated with Petasites powder.18 The ben-
cells of the airways. In contrast, short-acting beta-
efit was probably at least in part due to the inhibi-
agonists like salbutamol, fenoterol, terbutaline,
tion of leukotrienes. Trials using synthetic
albuterol, pirbuterol, and reproterol are used for
leukotriene antagonists have shown superiority
quick relief on demand rather than as control medi-
compared to placebo in respect to various lung
function parameters, such as FEV1, peak expira-
The Petasites extract used in this study –
tory flow, use of relief medication, and number of
Petadolex®, softgel capsules (manufactured by
Weber & Weber International GmbH & Co. KG,
Germany) contain 50 mg of a standardized lipo-
and rhinitis is recognized as a risk factor for sub-
philic extract of the rhizome of Petasites hybridus,
sequent asthma. A Petasites leaf extract (CO2-ex-
the butterbur plant. The extract is obtained by high
tract Ze339 – not identical to Petadolex) was
pressure, liquid carbon dioxide extraction in a stan-
shown to be equally effective as cetirizine in the
dardized and patented procedure, and contains a
treatment of seasonal allergic rhinitis in a random-
minimum of 15 percent petasins. Petasins are a
ized controlled trial.20 In another trial, levels of
group of sesquiterpene compounds mainly thought
inflammatory mediators (including histamine and
to be responsible for the pharmacological actions
leukotrienes) in the nasal fluid of individuals with
of the butterbur extract.8,9,10 The manufacturing
allergic rhinitis were significantly reduced after
process removes pyrrolizidine alkaloids that are
taking a Petasites extract for five days.21 In an-
potentially hepatotoxic and carcinogenic.11 The
other randomized, controlled trial with 20 patients
finished product has been available in Germany
with seasonal allergic rhinitis, CO2-extract Ze339
Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004 Page 55
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Petasites /Asthma Original Research Table 1. Demographic and Baseline Characteristics Subjects
ber 2000 to March2002; 77.5 percenthad mild asthma,
of the disease. In ad-dition to Petadolex,all other available
Study Design
Additonal asthma medication, percent of patients
phase and a treat-ment phase lasting2-4 months. Duringthe run-in phase, pa-
protected against AMP-induced nasal responsive-
tients recorded asthma symptoms, dosage of
ness. This observation is in keeping with an inhi-
asthma medication, and number, duration, and
bition of leukotriene synthesis by Petasites, since
severity of asthma attacks. Patients then received
leukotriene receptor antagonists also attenuate
the trial medication and a diary. Adults took 50
mg Petadolex three times daily, while children
were given 50-150 mg daily, depending on age.
examine the efficacy and safety of an extract of
Patients were examined by their physician four
Petasites hybridus in the treatment of asthma.
and eight weeks after issue of trial medication. FEV1 was measured each time. After two monthsof treatment, patients were free to continue withthe trial medication for another two months; hencethe maximum duration of treatment was fourmonths, the minimum two months.
Page 56 Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004
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Original Research Petasites /Asthma Efficacy Measurements
by the following parameters: number, duration, andseverity of asthma attacks; asthma symptoms (cough-ing, difficulty breathing, chest tightness, difficultyexhaling, wheezing, expectoration) using a four-point
weeks 13-16
scale; FEV1; peak flow; asthma medication usage;
and evaluation by patient and physician. Statistical Analysis weeks 9-12
statistics (mean, standard deviation, median, mini-mum, maximum, and quartiles). Changes in asthmamedication, FEV1, and peak flow were calculatedintra-individually and expressed as percentage
weeks 5-8 Asthma Attacks
Seventeen of the study’s 80 subjects reported
an asthma attack during the study (21.3%), eight of
whom had attacks during the retrospective (baseline)
weeks 1-4
period. The number of asthma attacks was calculatedper week and per patient. Asthma attacks decreasedby 48.1 percent from baseline to week 8 of the treat-ment period. In the first four weeks of the follow-upphase, during which intake of Petadolex was optional,
baseline
asthma attacks decreased further (by a total of 70.4%)
but increased during the last four weeks, mainly due
to one child who had an exceptionally high number
of asthma attacks (n=34) while attending school campduring hay fever season (Table 2).
Duration of asthma attacks was calculated
per week, per attack, and per patient. The duration
of asthma attacks was documented for 74 of 103 at-
tacks. The mean duration of asthma attacks during
le 2.
weeks 1-4 was strongly affected by one patient who
b
reported an attack that lasted nine hours, leading to
Ta Petadolex (number of valid cases in brackets)Asthma attac
an increase in the mean duration. Apart from thatperiod (i.e., weeks 1-4) the duration of asthma at-tacks was reduced by 90.5 percent (Table 2).
and per patient. Severity decreased continuously
point scale (0=no attack, 1=mild, 2=moderate, 3=se-
during treatment up to week 8 (by 68.5%) and dur-
vere). Severity was calculated per week, per attack,
ing the follow-up phase during which intake ofPetasites extract was optional (total decrease versusbaseline by 83.3%) (Table 2). Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004 Page 57
Copyright2004 Thorne Research, Inc. All Rights Reserved. No Reprint Without Written Permission
Petasites /Asthma Original Research Figure 1. Lung Function: Change in FEV1 Asthma Symptoms during Treatment with Petadolex (n=65)
(coughing, difficulty breathing, chesttightness, difficulty exhaling, wheezing,expectoration) were recorded in each
patient’s diary using a four-point verbalscale over the duration of the study. After
ing on the type of symptom. Followingthe initial treatment phase slightly more
than half of the patients (n=39) continuedon the extract, while the remainder (n=31)
ing time, patients discontinued the volun-tary phase, with 64 percent of subjects
symptoms increased in severity at the end
of the observation period (week 16) com-pared to week 8 in the group that had dis-
Figured as percentage change from baseline (week 0); data points represent mean values with standard
continued Petadolex. In contrast, mostsymptoms improved further (weeks 8-16)in the group on Petadolex. Figures 2a and2b illustrate the course of asthma symp-toms during the study, using the symptom
Pulmonary Function
For the efficacy evaluation, patients were
only included if they had lung function (FEV1,
Asthma Medication
peak flow) measured at each of the three visits
(baseline, after four weeks, and after eight weeks).
treated with inhaled corticosteroids at the begin-
Not every patient had lung function measured and
ning of the study. At the end of the study (weeks
documented in this trial, thus resulting in variable
9-16) 42.9 percent of the evaluable patients (n=14)
valid cases. Since lung function is dependent on
had reduced the amount of inhaled steroids dur-
age, sex, weight, and the type of test instrument
ing therapy with Petadolex; and one patient in-
used, the percentage change from baseline was
creased dosage. The reduction in the amount of
calculated intra-individually. The mean improve-
inhaled steroids was calculated intra-individually
ment for FEV1 (Figure 1) was 11.3 percent (n=65),
as percentage change from baseline, which cor-
for peak flow 28.5 percent (n=50). Comparing
rects for the different brands and potencies of in-
baseline with the treatment effect after eight
haled medications. Values for all four treatment
weeks, 70.6 percent of the evaluable patients
phases must have been available for inclusion in
(n=68) had an improved FEV1 and 83.9 percent
the analysis. After 9-16 weeks (n=14) there was a
of patients (n=56) had an improved peak flow.
16.1-percent reduction in the amount of inhaledsteroids used (Figure 3).
Page 58 Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004
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Original Research Petasites /Asthma Figure 2a. Wheezing: Change of the
acting beta-agonists; 48.3 percent of these patients
reduced the amount of short-acting beta-agonistsduring weeks 9-16. The daily dosage was reduced
by a mean of 13.4 percent, calculated as percent-age change from baseline (n=29).
Except for four patients, all subjects with
evaluable corticosteroid or short-acting beta-ago-
nists data had taken the Petasites extract duringthe follow-up phase. Evaluation of Efficacy by Patient and Physician
investigator at the week 8 visit to offer an assess-
ment of the efficacy of their treatment. Improve-ments were rated as very good, good, moderate,or poor. Ninety-five percent (n=72) reported
Data points represent mean values with standard
Figure 2b. Wheezing: Change of the Mean Score Starting at Week 8
Petadolex was effective in treating their
in Patients Treated with (n=39) or
asthma, with 83 percent (n=63) rating theirimprovement as very good or good (Figure
4). The physician evaluation was comparable,with an efficacy rating of very good or good
Safety and Tolerability
good by 67 of 76 patients (88.2%). None ofthe 76 patients or physicians rated the
tolerability as “poor.” During the study, 11
subjects. Adverse events reported by children
were abdominal pain/flatulence, sneezing,
allergic conjunctivitis, allergic rhinitis, andhalitosis. Adults reported hair loss, coughing,
depression. Two patients required treatment
of adverse events. One patient was treated for
allergic rhinitis and the other patient was
Data points represent mean values with standard
Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004 Page 59
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Petasites /Asthma Original Research
daily asthma attacks was reduced by nearly half. Figure 3. Asthma Medication: Change in
Attacks decreased further in the follow-up phase,
Inhaled Corticosteroid Usage during
only to increase at the very end due to the afore-mentioned patient with an extraordinary number
of attacks. Asthma duration and severity decreasedeven more effectively – by 80-90 percent – at the
end of the follow-up phase. In this subgroup ofpatients with asthma attacks, 66.7 percent had an
improved FEV1 and 91.7 percent had improved
sess and monitor airflow obstruction. IncreasedFEV1 and peak flow are indicative of an improved
airflow. More than a 10-percent increase in FEV1
in this study should be considered clinically rele-
vant. With 70.6 percent of the patients having anincreased FEV1 and 83.9 percent having increased
peak flow, it can not be concluded the mean im-
provement in lung function was due to dramaticchanges in only a few patients.
In the one-third of the study’s patients who
treated asthma only with Petadolex capsules, no
Figured as percentage change from baseline (week
impairment of lung function was observed at the
0); data points represent mean values with standard
end of the study, and 80 percent of those patientshad an improved FEV1 or peak flow. This sug-gests Petadolex may be effective in the treatment
depression. The adverse events were not rated by
of asthma not only in combination with additional
the treating physician to be causally related to the
asthma medication but also as a stand-alone medi-
intake of Petadolex and did not lead to withdrawal
Subjects who took Petadolex capsules also
noted a mean 50-percent, self-reported improve-
Discussion
ment in documented asthma symptoms after two
months of treatment. Although in the final two
study was to analyze the efficacy and tolerability
months the use of Petasites extract capsules was
of Petadolex capsules in patients with mild-to-
optional, one-half of the patients continued tak-
moderate asthma. Eighty patients completed the
ing the extract. Compared to week 8, the severity
study – none was excluded from the analysis.
of symptoms decreased further in the group re-
However, due to missing data, not all variables
maining on Petadolex, whereas symptoms in-
could be analyzed for the complete patient popu-
creased in severity in the group that discontinued
Petadolex. Coughing was an exception, probably
influenced by two acute cases of bronchitis. The
from Petasites hybridus taken for 8-16 weeks may
results of the follow-up phase support the obser-
be effective in reducing the severity of various
vation suggesting improvement was due to treat-
In the course of the study, 21.3 percent of
In vitro, the same extract used in this study
the study population reported asthma attacks. Af-
has demonstrated spasmolytic as well as anti-in-
ter two months of treatment the mean number of
flammatory activities. Beta-agonists and cortico-steroids are standard therapies for asthma, which,
Page 60 Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004
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Original Research Petasites /Asthma Figure 4. Assessment of Efficacy by the Patient (n=76)
age 6-9 age 10-12 age 13-17 age >=18 all patients
Very good=very good improvement, good=good improvement, moderate=moderate improvement, poor=unchanged or worse condition
as noted, is characterized by bronchoconstriction
and inflammation of airway cells. In this study,
treatment with Petadolex led to a reduction in the
dropouts due to adverse events. The low number
use of beta-agonists and corticosteroids by a mean
of adverse events and the conclusion that the ad-
of 15 percent. In the follow-up phase, the usage
verse events were not rated to be causally related
of corticosteroids was further reduced, with 43-
to intake of the extract demonstrates Petadolex was
and 48-percent of evaluable patients able to re-
safe and well tolerated in this trial.
duce corticosteroids and beta-agonists, respec-
The study results suggest the Petasites
tively. The circumstance of patients reducing the
hybridus extract Petadolex is an efficacious and
amount of asthma medication of their own accord
well-tolerated therapy for the treatment of asthma
and without being instructed to do so by the in-
Disclosure
medications at the end of the study suggests the
improvements in lung function were due to therapy
was funded by Weber&Weber, Inning, Germany,
with Petadolex and not to increased asthma co-
medication. Of evaluable patients with an im-proved FEV1, 87.5 percent had also reduced theamount of corticosteroids. Only one patient in-creased steroid usage. A similar result was ob-
Alternative Medicine Review ◆ Volume 9, Number 1 ◆ 2004 Page 61
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Petasites /Asthma Original Research References
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Outdoor Action Guide to High Altitude: Acclimatization and Illnesses There are inherent risks in traveling at high altitude. The information provided here is designedfor educational use only and is not a substitute for specific training or experience. PrincetonUniversity and the author assume no liability for any individual’s use of or reliance upon anymaterial contained or referenced her
Dr. Smith will present a review of two important areas of dental pharmacotherapeutics, analgesics and seda-tives. Besides discussing the basic pharmacology of the most commonly used drugs in these two therapeutic groups, he will also address the clinical considerations dental practitioners should weigh before treating pa-tients with these agents, including drug/drug interactions, drug/disease