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Inhaled Medications
This page describes asthma medications delivered by inhalation.
It covers: commonly prescribed
inhaled medications, Dr. Philip Padrid's
protocol, proper use and maintenance of
feline aerosol chambers and
metered dose inhalers. See the
Treatment
Hints page on how to achieve
successful acceptance with even the most
skeptical of cats (or caregiver!). Other links
above
cover additional
treatment options for feline asthma.
The AeroDawg® is now available.
This is a
step forward in the treatment
of chronic bronchitis in dogs. For more
information, contact the folks
at AeroKat®.
Get free Adobe
Reader® to read the .pdf
protocol.
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This page was awarded the CWA
Muse Medallion
in the category of Online Article - Health and General Care
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Permission is granted to
print for veterinarian and personal purposes, and don't forget to also
bring along a printout of the
inhaled
medications protocol
(treatment guidelines). Topics
covered in this page include:
- Inhaled therapy
- Inhaled medications
in detail
- Aerosol chamber
and mask
- Instructions for
use and cleaning
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Inhaled Therapy
Asthma, whether in humans or cats, is for the most
part manageable but not curable. Inflammation of the lung tissue
is reduced with corticosteroids,
and for the acute onset
of symptoms, restricted airways
may be opened with a bronchodilator.
Conventional injection and
oral use of these drugs
send the medicine to the lungs through the bloodstream and affect tissues
throughout the body (systemic). Long-term use of oral or
injected steroids increase
the risk of feline diabetes and significant behavioral changes in
addition to polyuria, cystitis, and inappropriate urination. Excessive
weight gain is common which makes the lungs work harder. Cats with
these conditions may not be
able to continue the most effective
conventional methods of asthma
treatment, and live limited lives
as a result.
A Metered Dose Inhaler (MDI)
coupled with an appropriate
chamber for cats is the preferred
delivery system. Inhaled medications have
the main benefit of directing
the medicine to the
lung tissues. Two medications are used:
a corticosteroid, typically Flovent®, to minimize the asthma's ever-present
inflammation and a bronchodilator, i.e. Albuterol, to
open restricted airways on an as needed basis during times of respiratory
distress.
An
aerosol chamber designed for
a cat's face, the volume of
breath, and specific medications
results in the most efficient
delivery of the drug to the
small recesses of the lungs.
Most cats quickly to learn to
accept the aerosol
chamber and mask. See Photos
& Video
and Treatment
Hints (Learning How).
In an article by Tom Ewing
in Cat
Watch Newsletter, April 2005:
Dr. Goldstein, from Cornell
University's College of Veterinary
Medicine says: "this technique
and the device that enables
it have been embraced by virtually
all veterinarians at large universites
and hospitals, and he trusts
that inhalant therapy will soon
be adopted by all smaller, local
clinics in the U.S. and accepted
by owners of asthmatic cats
nationwide." The
news has spread even further
because the AeroKat™ is now used
in most countries around the
world.
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Corticosteroid
Medication
Detail: fluticasone
proprionate (Flovent®, Flixotide®)
The inhaled steroid, fluticasone, is a large molecule
and does not pass into the bloodstream from the airways.
Because of this, it does not cause the side-effects that oral steroids
do. The use of inhaled medications using a chamber and spacer was developed by Dr. Philip Padrid.
It is equally potent to oral prednisone 1 mg/kg bid. There have been
no serious demonstrated side-effects. Many caregivers find inhaled therapy
is faster and less invasive than giving oral or injectable medications.
Other inhaled corticosteroids have been used with lesser success
than the Flovent®. Please note that the dosage number may
vary among different countries but they are equivalent - 110 mcg
in the US equals 125 mcg in Canada and Europe. Ask your pharmacist or
veterinarian for clarification.
The cost of Flovent® may be more per day than conventional therapies,
but for moderate to severe asthmatics the improved stability of
the cat's health results in far lower vet bills (not to mention
less anxiety).
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It is vitally important to follow
veterinarian instructions when tapering doses of oral
corticosteriods.
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Considerations for Flovent® are:
- The drug takes 7-10 days (sometimes more) to reach full effect
- The face mask needs to properly fit to ensure the drug
is being inhaled - it should fit snugly around the muzzle
including the corners of the mouth. This has been solved
by the availability of the AeroKat®
Feline Aerosol Chamber.
- The caregiver needs to be aware of when the MDI canister is empty.
Record keeping of puffs
is essential and easily
planned with a calendar.
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Potential Side-effects:
Thrush
There has been concern to vets and caregivers in the
possibility of thrush (Candidiasis aka candida), a form of fungus, which is common
among human users of Flovent® or other steroidal MDIs. This has not been seen in the feline. The difference in feline and human anatomy is thought to
be the reason why cat's oral/nasal cavities do not have the same
chemistry in which to provide a medium for the Candidiasis growth.
Coughing
Some have noted that in the first few weeks of starting
Flovent®, or other inhaled medications, the cat may cough after receiving the medication (puffs). This
has been in a minority and seems to disappear after these initial incidents.
Contact Dermatitis/rash
Rarely, small red or white bumps
appear where the mask sits on the muzzle and can be transferred to areas
where the cat licks (namely paws and hind-quarters).
Cats who presented this clinically have been tested for bacterial and
fungal (Microsporum canis) infections. The results were all negative. This is a benign contact
dermatitis from the accumulation of the corticosteroid. The main escape
route for the corticosteroid is between the mask and the muzzle.
Hair may fall out in small patches in these areas, however, no itching or discomfort to
the cat has been noted. There is a possibility of infection should the
licked areas, without the fur protection, become open.
To prevent or solve this occurrence, simply wash the face where
the mask contacts
with a dampened square
of paper towel after every treatment. Using a disposable wipe in this
manner prevents the possibility of continued contamination from reusing
wash-cloth. Keep the AeroKat® clean, particularly the mask.
Long term side effects
Cats have used Flovent® regularly since
2000 and there have been no reported long term side effects
correlated with Flovent® (fluticasone).
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Can Flovent® be used after a steroid injection?
"The inhaled steroid, fluticasone, is a large molecule that
takes about a week to be fully absorbed into the respiratory mucosa,
and because it is so large, does not pass easily into the vascular
(blood) system. That is why it doesn't cause side effects, and that
is why it takes at least a week to have its peak effect.
"The steroid injection has a variable rise and fall in the
blood stream of each cat, each time. The AVERAGE length of time
it will have a positive effect in your cat is around three weeks,
this is very unpredictable. Most importantly, the inhaled steroid
should be given throughout! It, by itself will have no side effects
if given while the injected steroid is still circulating, and if
you wait until the injected steroid wears off to start the inhaled
meds, remember, it will then take another week to get the
clinical benefit of the inhaled steroid." Padrid
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Corticosteroid
Medication
Detail: beclomethasone dipropionate
(Qvar®)
Qvar®
has been used successfully with
a few isolated cats; to the
best of our knowledge it has
not been studied for use in
cats at all, unlike
Flovent® which has well-documented
success.
Because Qvar® is also an inhaled
corticosteroid, the safety and
side-effects issues are similar
to Flovent®. There is no protocol
available for Qvar®, so your
veterinarian will need to use
clinical judgment. Follow the same
instructions for using Qvar®
in
the How to Use an MDI with a
Feline Aerosol Chamber further
down this page in addition to
product insert instructions.
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Bronchodilator
Medication
Detail: Albuterol (Proventil®,
Ventolin®, Salbutamol)
The bronchodilator albuterol acts more rapidly than the oral
or injected terbutaline and is more effective than the theophylline
compounds. It can be easily and quickly administered by the caregiver
during signs of respiratory
distress. It is typically used
on an as-needed basis for asthmatic cats already on daily steroids and
displaying cough or wheezing. Albuterol is regarded as a safe drug. Side
effects may include temporary
musculoskeletal twitchiness, elevated heart rate, excitability, insomnia, anorexia,
although extremely uncommon.
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Bronchodilator Medication Detail: Salmeterol xinafoate (Serevent®)
Salmeterol is a long-acting bronchodilator that takes 15-30 min. to
reach effect but will last for 12 hours. It is available in Canada and
parts of Europe but no longer in the USA in MDI form. This is not a
rescue inhaler. Albuterol is the appropriate medication for respiratory
crisis and is noted in the above paragraph. Your veterinarian will be
able to advise on the best medication combination. Daily use of any
bronchodilator is prescribed with caution since it can mask underlying
inflammation that may need to be addressed with a change in
corticosteroid prescription.
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How to Use a Metered Dose Inhaler with
Feline Aerosol Chamber:
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- Remove cap from MDI.
- Look for foreign objects and ensure all components are intact.
- Insert inhaler (MDI) into back and shake for 15 seconds.*
- Apply mask to face of cat. If you cat experiences anxiety,
speak to your veterinarian.
- Depress inhaler and hold mask in place for at least 5 breaths
(approx.
10 seconds).
- Wait 5-10 seconds before repeating steps 3-5 if prescribed.
- Keep
written
record track
of each
puff used
or note
date to
discard
according
to your
prescribed
dosage.
Never use
it for more
than the
guaranteed
number of
actuations
listed on
the side.
*Shaking the canister is vital
in order to load the internal mechanism for effective
aerosol delivery. Must be shaken before each
actuation.
To obtain the AeroKat® Feline
Aerosol Chamber, go to the AeroKat®
website.
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Aerosol Chamber
and Mask
The chamber
and mask eliminates the need to coordinate MDI actuation and inhalation.
It:
- Allows MDIs to be used in cats
- Decreases the velocity of aerosol particles
- Facilitates the evaporation of propellant producing "respirable"
particles in the 1-5 micron range
- Decreases the local side effects such as medication taste,
cough, and the cold freon effect
- Reduces systemic drug side effects
- Provides superior benefit to nebulized therapy
at a greatly reduced cost
Thousands
of cats worldwide have been using AeroKat®,
a feline aerosol chamber, with great success.
Dr. Philip Padrid worked in conjunction with the medical device designer
to evaluate its effectiveness in clinical trials.
To view a sampling of cats currently using Inhaled
Medication Therapy for control of asthma, see the
AeroKat Testimonials page.
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Cleaning a Feline Aerosol Chamber and Mask
- Remove back piece from chamber (where the MDI fits in).
- Soak all parts for 15 min. in luke warm water with
liquid detergent. Agitate gently, do NOT rinse.
- Rinse all parts in clean water.
- Shake out excess water. Do not rub dry.
- Let air dry in vertical position.
- Replace back piece and mask when unit is completely
dry and ready for use.
Clean the Feline Aerosol Chamber as above prior
to first use and then weekly or when obviously dirty.
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inside a chamber is normal.
It is a surfactant
- a fatty acid (oleic
acid) added to a MDI formula
to keep the respirable particles
separated and prevent them from
attaching to each other, thus
allowing the smaller particles
to be available for the cat
to breathe in.
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Cleaning the Metered Dose Inhaler (MDI)
These instructions are intended
for human patients who have
direct mouth contact with the
MDI canister. When inserted
in a spacer, there is less concern
for contamination. Use your
and your vet's best judgment
to determine the cleaning schedule.
In addition, ignore any rumors about the "float test"
to determine amount of medication
inside, this is inaccurate
and can damage the canister.
- The inhaler should be cleaned at least once a week.
- Pull the metal canister out of the plastic casing of the
inhaler and remove the mouthpiece cover.
- Rinse the plastic casing and mouthpiece cover in warm water.
A mild detergent may be added to the water. Then rinse thoroughly
with clean water before drying. DO NOT PUT THE METAL CANISTER
INTO WATER.
- Leave the casing and mouthpiece to dry in a warm place.
Avoid excessive heat.
- Replace the canister and mouthpiece cover.
- After cleaning, release one puff into the air to make sure
that the inhaler works. (Source: GlaxoSmithKline)
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Continue Reading
with Conventional
Medications
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