Treatments for Irritable Bowel Syndrome (IBS) PHARMACIST’S LETTER / PRESCRIBER’S LETTER Background

Transcription

Detail-Document #250504
−This Detail-Document accompanies the related article published in−
PHARMACIST’S LETTER / PRESCRIBER’S LETTER
May 2009 ~ Volume 25 ~ Number 250504
Treatments for Irritable Bowel Syndrome (IBS)
Background
Irritable bowel syndrome (IBS) affects about
7% of individuals in North America. It’s defined
by abdominal pain and altered bowel habits for a
period of at least three months. Patients can
experience predominant constipation (IBS-C),
predominant diarrhea (IBS-D), or mixed
symptoms (IBS-M).
Unlike organic bowel
diseases (e.g., celiac sprue, colitis, inflammatory
bowel disease, etc), there are no structural or
biochemical abnormalities associated with IBS.1
A new systematic review of therapies for IBS was
recently published. This document discusses the
treatments for IBS and their evidence for
effectiveness. Recommendations for managing
IBS patients are also included.
Fiber and Laxatives
Increasing fiber is one of the most common
recommendations made to IBS patients, with the
intent of reducing pain and regulating bowel
function. However, studies show that insoluble
dietary fiber, like wheat bran, is unlikely to
improve symptoms.1
Patients may get improvement in overall IBS
symptoms with psyllium hydrophilic mucilloid
(Metamucil, etc). This is a soluble fiber, which
absorbs water and forms a gel that helps food
move smoothly through the GI tract. One study
also showed some benefit of using calcium
polycarbophil (FiberCon [U.S.], Prodiem Bulk
Fibre Therapy [Canada], etc) compared to
placebo. Like psyllium, calcium polycarbophil is
a hydrophilic bulk-forming laxative.1
The downside of adding fiber is the potential
for an increase in bloating, abdominal distension,
and flatulence. Gradually adding fiber might help
avoid this.1
One small study suggests that the osmotic
laxative polyethylene glycol (PEG) (Miralax
[U.S.], Lax-A-Day [Canada]) can double the
frequency of bowel movements in patients with
IBS-C. However, pain intensity is not reduced by
osmotic laxatives.1
Antidepressants
Pooled data from studies of both tricyclic
antidepressants (TCAs) and selective serotonin
reuptake inhibitors (SSRIs) (n=789) show that
these drugs are likely to improve overall
symptoms of IBS, regardless of IBS type. About
one in four patients treated will have some
benefit.1
The largest individual trial with a TCA
(n=216) looked at desipramine. The dose was
started low, and then titrated up to a dose
recommended for the treatment of depression.
(However, most trials used low doses of TCAs,
and using antidepressant doses don’t appear to be
necessary).2 The presence of depression did not
predict a response to treatment for IBS symptoms.
A high incidence of side effects resulted in a
dropout rate of almost one-third of subjects.1
SSRIs have a better side effect profile than
TCAs. Unlike TCAs, good evidence for efficacy
in improving IBS symptoms from individual trials
of SSRIs is lacking.1
The SSRIs have a prokinetic effect, so they
might work better in patients with IBS-C. Since
TCAs are more likely to cause anticholinergic
side effects like constipation, they might be better
for individuals with IBS-D.1 Experts say that
TCAs might be best for improving pain.
Antispasmodics
Antispasmodics (e.g., dicyclomine [BentylU.S., Bentylol-Canada], hyoscyamine [LevsinU.S. only], hyoscine butylbromide [BuscopanCanada only]) as a class can provide short-term
relief of symptoms like abdominal pain and
discomfort from IBS. The reason for this might
be that pain with IBS is caused by colonic smooth
muscle spasms.1
Systematic review (n=1,778) suggests that
about one patient will have symptom relief for
More. . .
Copyright © 2009 by Therapeutic Research Center
Pharmacist’s Letter / Prescriber’s Letter ~ P.O. Box 8190, Stockton, CA 95208 ~ Phone: 209-472-2240 ~ Fax: 209-472-2249
www.pharmacistsletter.com ~ www.prescribersletter.com
(Detail-Document #250504: Page 2 of 4)
every five patients treated with an antispasmodic.
However, most of the antispasmodics that have
been studied for IBS are not available in the U.S.
or Canada. In addition, studies typically have not
specified the type of IBS treated.1
The most common side effects with
antispasmodics are anticholinergic in nature.
These include dry mouth, dizziness, and blurred
vision. About one in 18 patients treated will
experience a side effect, according to available
data.1
Limited data suggest that peppermint oil,
thought to relax smooth muscle in the GI tract,
might improve symptoms of IBS in about one out
of three patients treated. Side effects reported in
studies were rare.1
The usual dose of peppermint oil for adults
with IBS is 0.2 to 0.4 mL given three times daily,
in enteric-coated liquid-filled capsules.2
Antispasmodics
should
be
considered
especially when IBS symptoms are exacerbated
by meals.3 In this case, they can be taken about
30 minutes before a meal, on an as-needed basis.4
Antidiarrheals
Since patients with IBS-D have a faster colonic
transit than healthy patients, drugs that slow
colonic transit might be beneficial. There is some
data on loperamide. Loperamide (Imodium, etc)
doesn’t help for IBS symptoms like pain, but it
does reduce frequency and improve stool
consistency in almost all patients who are treated.1
Alosetron (Lotronex)
There’s good evidence that alosetron
(Lotronex, available in U.S. only), a serotonin
5HT-3 antagonist, is better than placebo at
improving IBS symptoms in patients with IBSD.1,5
The majority of the body’s serotonin is found
in the GI tract. Serotonin plays a major role in GI
motor and secretory function and visceral
sensation. Antagonism at the 5HT-3 receptor
specifically delays GI transit, reduces colonic
tone, decreases the gastrocolic reflex, and
decreases visceral sensation.1
Data from eight placebo-controlled trials
(n=5,000) show that about eight patients will need
to be treated with alosetron for one patient to
experience adequate relief from discomfort and
urgency. However, alosetron has serious side
effects that include constipation and colon
ischemia. The number needed to harm (NNH) for
one adverse event with alosetron is ten. About
one patient for every 1,000 patient-years of
alosetron treatment will have ischemic colitis.1
The benefit vs. risk is most favorable in
women who have not responded to other
therapies. Several years ago, alosetron was pulled
from the market for a period of time. However, it
was subsequently returned to the U.S. market, and
has since been available through a special
prescribing program for women with chronic,
severe IBS-D who have failed other therapies.5
A 30-day supply of 1 mg twice daily of
Lotronex costs over $1,000.
Tegaserod (Zelnorm)
Tegaserod (Zelnorm) is better than placebo at
relieving IBS symptoms in women with IBS-C
and IBS-M. However, cardiovascular events like
stroke and heart attack are more common with
tegaserod compared to placebo. It was withdrawn
from the U.S. market in 2007.1
For a period of time, tegaserod was available
through FDA under a treatment investigational
new drug application (T-IND) protocol.
However, it is no longer available under the TIND, and is only available for emergency use in
life-threatening situations.
Tegaserod is no longer available in Canada.
Lubiprostone (Amitiza)
Lubiprostone (Amitiza), available in the U.S.
but not Canada, is more effective than placebo at
relieving IBS symptoms in women with IBS-C.
Its efficacy in men has not been conclusively
demonstrated.6
Lubiprostone is derived from prostaglandin.
It’s a C-2 chloride channel activator.
Lubiprostone works topically from the luminal
surface of the GI tract to promote chloride
secretion into the intestine. Sodium then enters
the lumen as a result of the negative charge of the
chloride ions, and water follows passively.6
The most common side effects with
lubiprostone are nausea, diarrhea, and abdominal
pain. Lubiprostone is contraindicated in patients
with mechanical bowel obstruction.6
Lubiprostone was first approved for the
treatment of chronic constipation.
The
recommended oral dose for constipation is 24 mcg
More. . .
twice daily. Note that the dose of lubiprostone for
IBS is lower, at 8 mcg twice daily.6
A 30-day supply of lubiprostone will cost
cash-paying patients around $220.
Antibiotics
Short courses of non-absorbable antibiotics are
better than placebo for improving overall
symptoms of IBS, and for reducing bloating
specifically. There’s data for rifaximin (Xifaxan,
available in U.S. only), with three RCTs (n=545)
supporting its superiority over placebo. Duration
of effect is variable. Symptom improvement can
last after the antibiotic is stopped, for ten weeks or
more in some cases. Most of the patients studied
had IBS-D.1
Studies of rifaximin for IBS used higher doses
than the FDA-approved dose for treatment of
traveler’s diarrhea, which is 200 mg three times
daily for three days. The dose of rifaximin
studied for IBS was 1,100 to 1,200 mg divided
two to three times daily for ten to 14 days.1
No severe adverse events were seen with these
high doses of rifaximin. Two of the rifaximin
studies reported individual side effects, and there
was no significant difference between the
rifaximin and placebo groups.1
Probiotics
Nineteen trials evaluating the use of probiotics
in IBS patients (n=1,668) were included in a
systematic review.
Eleven of these studies
(n=936) looked at improvement in IBS symptoms
as a dichotomous (benefit vs. no benefit) type of
outcome. About one in four patients treated had
symptom improvement. All of the different
probiotics,
including
Lactobacillus,
Bifidobacteria, Streptococcus, and combinations,
showed a trend toward benefit.1
However, when the degree of improvement in
IBS symptoms was considered as reported in
fourteen trials (n=1,351), Lactobacillus did not
have an effect on IBS symptoms. Probiotics with
Bifidobacteria (e.g., Align, Activia, VSL #3 [all
U.S. only]; Bifidox [Canada]) appear to be more
effective.1 For more information about probiotics
and their uses see our, “Comparison of Probiotic
Products."
Nondrug Therapies
Pooled data (n=1,278) show that psychological
therapies (e.g., cognitive behavioral therapy,
interpersonal psychotherapy, hypnotherapy) can
improve overall symptoms of IBS. However,
relaxation therapy alone does not offer any
benefit. The mechanism for improvement of IBS
symptoms might be stress reduction, empathic
attitude of the provider, etc.1
There isn’t good evidence to support avoiding
specific foods to help improve symptoms of IBS.
However, the majority of patients relate
symptoms to consumption of certain foods and as
a result, avoid those foods. If this is the case,
don’t discourage the patient unless exclusion of
the particular food could lead to dietary
deficiencies.1
Conclusion
There are a wide variety of treatments for IBS,
with varying degrees of effectiveness. Treatment
decisions are often based on the severity of
disease, and on the predominant IBS symptom of
either constipation or diarrhea.3
For all patients with IBS, insoluble fiber like
psyllium can be tried for regulating bowel
movements and reducing pain.1 Be aware of the
potential for gas and bloating. Introduce fiber
gradually to minimize these side effects.1
Recommend antispasmodics or peppermint oil
to reduce abdominal discomfort.1,2 Consider this
especially for patients whose symptoms are
worsened by meals.3 Antidepressants might also
help with abdominal pain.1
Probiotics containing Bifidobacteria might
help improve bloating and flatulence associated
with IBS.1 SSRIs or TCAs can be tried for overall
symptom improvement as well.1 Consider SSRIs
for IBS-C, and TCAs for IBS-D.
Recommend loperamide to reduce the
frequency of bowel movements for patients with
IBS-D, but don’t expect it to help with abdominal
cramping.1 Reserve alosetron (Lotronex) for
women with severe IBS-D refractory to other
therapies. It’s available through a restricted
prescribing program because of the increased risk
for ischemic colitis.1
Try osmotic laxatives like PEG for increasing
stool frequency in patients with IBS-C.1 Reserve
lubiprostone (Amitiza) for women with IBS-C
who haven’t responded to other therapies. It’s
prescription only and quite expensive.1
Psychotherapy can help improve symptoms of
IBS, possibly by reducing stress.1 But relaxation
More. . .
therapy alone doesn’t offer any advantage over
usual care.1
Users of this document are cautioned to use their own
professional judgment and consult any other necessary
or appropriate sources prior to making clinical
judgments based on the content of this document. Our
editors have researched the information with input
from experts, government agencies, and national
organizations. Information and Internet links in this
article were current as of the date of publication.
Project Leader in preparation of this DetailDocument:
Stacy A. Hester, R.Ph., BCPS,
Assistant Editor
References
1.
2.
3.
4.
5.
6.
Brandt LJ, Chey WD, Foxx-Orenstein AE, et al. An
evidence-based systematic review on the
management of irritable bowel syndrome. Am J
Gastroenterol 2009;104:S1-S35.
Jellin JM, Gregory PJ, et al.
Pharmacist's
Letter/Prescriber's Letter Natural Medicines
Comprehensive
Database.
http://www.naturaldatabase.com. (Accessed April
15, 2009).
American
Gastroenterological
Association.
American Gastroenterological Association medical
position statement: irritable bowel syndrome.
Gastroenterology 2002;123:2105-7.
Mertz HR. Irritable bowel syndrome. N Engl J Med
2003;349:2136-46.
Product information for Lotronex. Prometheus.
San Diego, CA 92121. April 2008.
Product information for Amitiza.
Takeda.
Deerfield, IL 60015. April 2008.
Cite this Detail-Document as follows: Treatments for irritable bowel syndrome (IBS).
Letter/Prescriber’s Letter 2009;25(5):250504.
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Managing Irritable Bowel Syndrome (IBS)
Irritable bowel syndrome (IBS) affects more than one in ten people. Little is
known about the causes of IBS. It can be worsened by stress or emotional upsets.
There may be differences in the symptoms of IBS between patients. This means
that, of the many different treatment approaches available, you and your healthcare
provider will need to select those that are most likely to help your individual
symptoms.
What nondrug measures can I use?
Many people say that changing their diet is helpful. Some common culprits
thought to make IBS worse are caffeine; alcohol; sorbitol (the artificial sweetener);
fried or fatty foods; and gas-forming foods like cabbage, broccoli, or beans. Make
sure that, if you do exclude something from your diet, you aren’t risking any type
of deficiency (calcium, for example, from eliminating dairy products).
Adding fiber might be helpful for reducing the symptoms of IBS. Soluble fiber
is best (supplements like Metamucil and dietary sources like applesauce, oatmeal,
potatoes, and rice). Insoluble fiber, like wheat bran, doesn’t seem to work. The
downside of fiber is that it can increase your chances of having gas and bloating.
Add fiber gradually to reduce these effects.
You may also benefit from eating smaller, more frequent meals. Large meals
can sometimes worsen IBS symptoms.
While stress does not appear to cause IBS, it may make the symptoms worse.
Some patients have found that techniques to reduce stress or a good exercise
program are helpful. There’s no harm in trying, so do what works best for you.
Are there medications I can take?
Over the years a number of different medications have been tried for IBS. You
should always consult with your healthcare provider before trying any medication,
especially nonprescription ones. Listed below are the most commonly used
medications for IBS. Some of these medications require a prescription.
Antidiarrheal agents. Loperamide (Imodium) can be used for diarrhea, but it
doesn’t help with stomach pain and bloating.
(Please continue to the next page for more treatment options)
Prepared for the subscribers of
Pharmacist’s Letter / Prescriber’s Letter to give to their patients.
Antispasmodics. Hyoscyamine (Levsin [U.S.]), dicyclomine (Bentyl [U.S.],
Bentylol [Canada]), and hyoscine butylbromide (Buscopan [Canada]) can reduce
pain and cramping by decreasing muscle spasms in your intestinal tract. They’re
especially helpful if your IBS symptoms are worsened by meals. However,
antispasmodics may have some unpleasant side effects such as dry mouth,
sedation, and constipation.
Laxatives. Osmotic laxatives, like polyethylene glycol or PEG (Miralax [U.S.],
Lax-A-Day [Canada]) and milk of magnesia (MOM), can be tried for constipation.
Antidepressants. Antidepressants can reduce IBS symptoms as well as relieve
depression and anxiety.
Herbal products. Several products have been tried that are available without a
prescription. For example, peppermint oil is an antispasmodic that may help. You
should consult with your healthcare provider before trying any alternative
medications as these are active compounds and may have other physical effects
and drug interactions that need to be considered.
Probiotics. Some probiotics might help with the symptoms of IBS, like
bloating and gas. Look for products that contain Bifidobacteria, as this probiotic
seems to be the most beneficial. Some products that contain Bifidobacteria include
Align (U.S.), Activia (U.S.), Bifidox (Canada), or VSL #3.
Other therapies. Lubiprostone (Amitiza [U.S.]) is a prescription drug that’s
helpful for women with IBS who have constipation. Alosetron (Lotronex [U.S.]) is
another prescription drug that’s sometimes used in women with severe IBS with
diarrhea. These drugs are expensive and have some important side effects, so they
are generally used when other treatments have failed.
Where can I go for information?
There are some very good places on the internet where patients with IBS can go
to keep up with current information about this disorder. A listing of these sites is
given for your reference. Remember to talk with your healthcare provider about
any information you find so you can discuss which treatments are best for you.
Source
International Foundation for Functional
GI Disorders
The UNC Center for Functional GI and
Motility Disorders
The IBS Page
IBS Resource Center
Canadian Society of Intestinal Research
Web Address
www.iamibs.org
www.med.unc.edu/medicine/fgidc
www.panix.com/~ibs/
www.healingwell.com/ibs/
www.badgut.com/
(May 2009)
Controlando el síndrome del intestino irritable (SII)
El síndrome del intestino irritable (SII) afecta a más de una de cada diez personas. Poco se sabe
sobre las causas del SII. Puede ser agravada por el estrés o por los trastornos emocionales.
Puede haber diferencias en los síntomas de SII entre los pacientes. Esto significa que, de los
diversos métodos de tratamiento disponibles, usted y su proveedor de atención médica tendrá que
seleccionar aquellos que tienen más probabilidades de ayudarle con sus síntomas individuales.
¿Qué medidas no farmacológicas se pueden utilizar
Mucha gente dice que los cambios en su dieta son útiles. Algunos agentes responsables del
empeoramiento del IBS son la cafeína; el alcohol; el sorbitol (edulcorante artificial); la comida
frita; y los alimentos que producen gases como la col, el brócoli, o los frijoles. Asegúrese de que
si usted elimina algo de su dieta no esté arriesgando el tener algún tipo de deficiencia
(deficiencia de calcio, por ejemplo, si elimina los productos lácteos).
La adición de fibra puede ser útil para reducir los síntomas de SII. Lo mejor es la fibra soluble
(suplementos como Metamucil y alimentos como el puré de manzana, la avena, las papas y el
arroz). La fibra insoluble, como el salvado de trigo, no parece funcionar. La desventaja de la
fibra es que puede aumentar sus posibilidades de tener gas e hinchazón. Agregue fibra
gradualmente para reducir estos efectos.
El comer comidas más pequeñas y más frecuentes puede ofrecerle algunos beneficios. Las
comidas abundantes a veces pueden empeorar los síntomas del SII.
Aunque el estrés no parece causar el SII, puede empeorar los síntomas. Algunos pacientes han
encontrado que las técnicas para reducir el estrés o un buen programa de ejercicios son útiles. El
intentarlo no produce daño, por lo tanto haga lo que funcione mejor para usted.
¿Hay medicamentos que puedo tomar?
A través de los años se han probado una serie de diferentes medicamentos para el tratamiento del
SII. Consulte siempre con su médico antes de probar cualquier medicamento, sobre todo los de
venta libre. A continuación se enumeran los medicamentos más comúnmente usados para el SII.
Algunos de estos medicamentos requieren receta médica.
Agentes anti diarreicos. La loperamida (Imodium) se puede utilizar para la diarrea, pero no
ayuda con el dolor de estómago y la hinchazón.
Antiespasmódicos. La hiosciamina (Levsin [EE.UU.]), la diciclomina (Bentyl [EE.UU.],
Bentylol [Canadá]) y el butilbromuro de hioscina (Buscapina [Canadá]) pueden reducir el dolor y
los calambres al disminuir los espasmos musculares en el tracto intestinal. Son especialmente
útiles si los síntomas del SII se agravan con las comidas. Sin embargo, los antiespasmódicos
pueden tener algunos efectos secundarios desagradables, tales como sequedad de la boca,
sedación y estreñimiento.
Laxantes. Los laxantes osmóticos, como el polietilén glicol o PEG (Miralax [EE.UU.], el LaxA-Day [Canadá]) y la leche de magnesia (MOM) pueden ser utilizados para el estreñimiento.
Antidepresivos. Los antidepresivos pueden reducir los síntomas del SII, así como aliviar la
depresión y la ansiedad.
Productos herbales. Varios productos, de venta sin receta médica, han sido probados. El aceite
de menta por ejemplo, es un antiespasmódico que puede ayudar. Usted debe consultar con su
médico antes de probar cualquier medicina alternativa ya que estos son compuestos activos y
pueden tener otros efectos físicos e interactuar con otros medicamentos.
Probióticos. Algunos probióticos podrían ayudar con los síntomas del SII, como la hinchazón y
el gas. Busque productos que contienen Bifidobacterias, ya que este probiótico parece ser el que
ofrece más beneficios. Algunos de los productos que contienen Bifidobacterias son Alinear
(EE.UU.), Activia (EE.UU.), Bifidox (Canadá) y VSL # 3.
Otras terapias. La lubiprostona (Amitiza [EE.UU.]) es un medicamento útil para las mujeres
con SII que tienen estreñimiento. El alosetrón (Lotronex [EE.UU.]) es otro medicamento de
venta con receta médica que se utiliza a veces en las mujeres con SII grave y con diarrea. Estos
medicamentos son caros y tienen algunos efectos secundarios importantes, por lo que
generalmente se usan cuando otros tratamientos han fracasado.
¿Dónde puedo acudir para obtener información?
Hay algunos sitios muy buenos en la Internet adonde los pacientes con SII pueden ir para
mantenerse al día con información actualizada acerca de este trastorno. A continuación le damos
una lista de estos sitios para que usted pueda usar como referencia. Recuerde de hablar con su
médico acerca de cualquier información que encuentre para que pueda discutir cuales
tratamientos son los mejores para usted.
Fuente
Dirección de la Web
Fundación Internacional para los
Trastornos Funcionales Gastrointestinales
www.iamibs.org
El Centro UNC para los Trastornos
Funcionales Gastrointestinales y de
Motilidad
www.med.unc.edu/medicine/fgidc
La pagina de SII
www.panix.com/~ibs/
El Centro de Recursos de SII
www.healingwell.com/ibs/
La Sociedad Canadiense de Investigación
Intestinal
www.badgut.com/
[Mayo de 2009]

Treatments for Irritable Bowel Syndrome (IBS) PHARMACIST’S LETTER / PRESCRIBER’S LETTER Background

Transcription

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