Download Antihistamines

Antihistamines
Some patients report a decrease in interstitial cystitis
(IC) symptoms using antihistamines or medicines with
antihistamine properties. Though the most widely
used antihistamine to treat IC is hydroxyzine, some
people with IC find relieve from Claritin, Benadryl or
Singulair.
Ideally, within one month the dosage is increased
to 75 mg, 50 mg taken at night and 25 mg taken
during the day. Benefits of hydroxyzine may be
seen within a few weeks to two months after
initiating therapy.
To decrease the sedating side effects, some
patients start hydroxyzine therapy at a 10 mg
dosage, available in the liquid form, and work their
way up, gradually, to a maximum dosage of 50 to
75 mg. After one year, some patients are able to
decrease their dosage by one-half. Others report
that upon reducing their dosage, symptoms will
return within a few days.
Potential Side Effects
Side effects include sedation, dry mouth, nose, and
throat, vaginal dryness, erectile dysfunction, and
increased depression in patients diagnosed with
concurrent depression.
Hydroxyzine
A mild anti-anxiety drug, hydroxyzine is available in
two oral forms:
 Hydroxyzine pamoate (Vistaril)
 Hydroxyzine hydrochloride (Atarax)
According to the American Urological Association
(AUA) clinical guidelines for IC, hydroxyzine is a
second-line treatment. It affects mast cell
degranulation, which is thought to play a part in
some IC patients’ symptoms, especially those who
have a history of allergies, migraines and irritable
bowel syndrome. Hydroxyzine has been shown to
improve these conditions, as well as IC.
Hydroxyzine has been found to decrease:
 Nocturia (night time voiding)
 Daytime frequency
 Pain (burning, pressure, painful intercourse)
Hydroxyzine pamoate has a slightly higher
absorption rate. Hydroxyzine-HCL is a liquid form
available for patients allergic to fillers or dyes used
in the capsules or pills.
Dosage & Treatment Plan
Most patients start with a 10 to 25 milligram
(mg) dosage of Atarax, Vistaril or their generic
equivalent at bedtime every night for 1 week, and
progress to 50 mg every night the second week.
Interstitial Cystitis Association © 2012
www.ichelp.org
RFZ/ Updated Dec 2012
Printed Dec 2012
Take this medicine early in the evening initially to
avoid excessive morning drowsiness. Most patients
report that daytime drowsiness disappears within
four to five days after beginning hydroxyzine
therapy. Some patients report that with each
dosage increase, the drowsiness period is shorter
and not as intense.
Pregnancy & Warnings
Animal studies have found that fetal abnormalities
occur at doses ten times higher than given to
humans. It is not recommended that hydroxyzine
be used if pregnant or nursing. Hydroxyzine is
contraindicated for use in epileptic patients.
Anti-Seizure Medicines
Originally developed as an anti-seizure medicine,
gabapentin (neurontin) is also used to treat nerverelated pain. Some types of IC pain may to be
generated by nerve endings and the central
nervous system. Studies show gabapentin
improves symptoms in some IC patients, especially
in combination with other IC medications.
Histamine Blockers
Most antihistamines prescribed for allergy and IC
are called "H1" blockers. When histamine binds to
its’ H1 receptor on cells, it produces an allergic
reaction. The H1 receptors aren’t the only ones
that histamines go to, however. They can also bind
to H2 receptors, and drugs that block these
receptors can also be helpful in calming allergic
reactions. H2 blockers include:
 Cimetidine (Tagamet)
 Ranitidine (Zantac)
 Nizatidine (Axid)
 Famotidine (Pepcid)
By blocking H2 receptors in the gut, these
medicines reduce stomach acid secretions and,
thus, stomach pain. Studies on the H2 blocker,
cimetidine, showed it reduced bladder pain as
well, maybe because of the histamine-blocking
action. But why it works in IC really isn’t so clear.
In two small studies (one with 9 and one with 14
patients), Tagamet reduced bladder pain for 40
to 60 percent of the IC patients.
In Japan, Suplatast tosilate, also known as IPD1151T, is indicated for IC, as well as asthma and
allergies. This medicine acts somewhat earlier in
the allergic process than histamine or leukotriene
blockers do by affecting IgE, an antibody that
plays a role in allergic reactions. Suplatast tosilate
helps suppress the production of IgE. It also helps
to block production of cytokines (allergy signaling
chemicals) and suppresses allergy-related
eosinophils. This medicine remains under
investigation in the US.
Mycophenolate mofetil is approved by the US
Food and Drug Administration (FDA) for use in
patients who have had an organ transplant.
However, a large national study sponsored by the
National Institutes of Health (NIH) did not find
mycophenolate mofetil to be effective for IC and
the study was ultimately canceled.
Leukotriene Inhibitors
Leukotrienes, which are substances produced by
some immune system cells and mast cells,
promote inflammation. Drugs that block
leukotrienes are fairly new and are being used in
the treatment of asthma and allergy. They
include:
 Montelukast (Singulair)
 Zafirlukast (Accolate)
 Zileuton (Zyflo)
Some studies have implicated leukotrienes in
inflammation of the bladder in IC. The receptors
have been found in the bladder muscle in IC
patients. A study of 10 IC patients in Denmark
who took Singulair for three months showed
significant reductions in frequency and pain.
Tagamet, Zantac, Axid, and Pepcid are available
over the counter.
Immunosuppresants
Cyclosporine, an immunosuppressive drug used in
organ transplantation, is also a treatment for
several autoimmune disorders with good results.
Because IC may have an autoimmune
component, this medicine is being studied as a
possible IC treatment. So far the results of testing
in humans have been encouraging, but the drug
does have many potential side-effects—some
serious—which is why the AUA guidelines list them
as a last line of treatment for IC. Work with a
healthcare professional experienced with
immunosupressants if you a considering this
option.
Mycophenolate (CellCept) works in the body by
reducing the immune system's ability to produce
certain reactions that can cause inflammation,
pain, and discomfort.
Interstitial Cystitis Association © 2012
www.ichelp.org
RFZ/ Updated Dec 2012
Printed Dec 2012
The ICA provides advocacy, research funding, and
education to ensure early diagnosis and optimal
care with dignity for people affected by IC.
Your donation dollars also enable the ICA to
continue to fund new IC research projects, as well
as work closely with Congress to ensure ongoing
IC-specific research funding at the federal level.
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