Subject: alt.support.asthma FAQ: Asthma -- General Information

From: [email-masked] (Patricia Rose Wrean)
Date: 2 Nov 1994 01:13:30 GMT

Archive-name: asthma/general-info
Posting-Frequency: monthly
Last-modified: 1 Nov 1994
Version: 3.0

          alt.support.asthma FAQ:  Asthma -- General Information
          ======================================================

Introduction:
------------

Welcome to alt.support.asthma!  This newsgroup provides a forum for
the discussion of asthma, its symptoms, causes, and forms of treatment.
Please note that postings to alt.support.asthma are intended to be
for discussion purposes only and are in no way to be construed as
medical advice.  Asthma is a serious medical condition requiring
direct supervision by a physician.

Please be aware that the information in this FAQ is intended for
educational purposes only and should not be used as a substitute
for consulting with a doctor.  Many of the contributors are not
health care professionals; this FAQ is a collection of personal
experiences, suggestions, and practical information.  Please remember
when reading this that every asthmatic responds differently; what is
true for some asthmatics may or may not be true for you.  Although
every effort is made to keep this information accurate, this FAQ
should not be used as an authoritative reference.

Comments, additions, and corrections are requested; if you do not
wish your name to be included in the contributors list, please state
that explicitly when contributing.  I will accept additions upon my
own judgement -- I'll warn you right now that I'm a confirmed skeptic
and am not a great believer in alternative medicine.  All
unattributed portions are my own contributions.  For more
information about asthma medications, there is also an Asthma
Medications FAQ that is posted as a companion to this one.

* = not added yet
+ = added since last version
& = updated/corrected since last version

======================================================================

Table of Contents:
-----------------

General Information:
&    1.0  What is asthma?
+         1.0.1  What is emphysema?
*         1.0.2  What is COPD?
+         1.0.3  What is status asthmaticus?
+         1.0.4  What is anaphylactic shock?
+    1.1  How is asthma normally treated?
+         1.1.1  How is an acute asthma attack treated?
*         1.1.2  What is a peak flow meter?
*    1.2  How is asthma diagnosed?
*    1.3  What are the common triggers of asthma?
     1.4  What are some of the most common misconceptions about asthma?

Medications:
+    2.0  What are the major classes of asthma medications?
     2.1  What are the names of the various asthma medications?
          2.1.1  Are salbutamol and albuterol the same drug?
+         2.1.2  Are some asthma drugs banned in athletic competitions?
     2.2  What kinds of inhalers are there?
&         2.2.1  Which kind of inhaler should I use?
&         2.2.2  What is a spacer?
&         2.2.3  What is "thrush mouth" and how can I avoid it?
&         2.2.4  Is Fisons still making the Intal Spinhaler?
+         2.2.5  What's the difference between Spinhalers and Rotahalers?
+         2.2.6  Should I use an inhaler or take pills?
*         2.2.7  How can I tell when my MDI is empty?
     2.3  What kinds of tablets are there?
+         2.3.1  Why do I need a blood test when taking theophylline?
+         2.3.2  Why are combination pills not commonly prescribed?
+    2.4  What is a nebulizer?
+    2.5  What medications should I avoid if I have asthma?

Allergen Avoidance/Environmental Control:

+    3.0  What does HEPA stand for?

Miscellaneous:
     4.0  What resources are there for asthmatics?

======================================================================

1.0  What is asthma?
--------------------

     Asthma is defined as *reversible* obstruction (blockage) of the
     airways inside the lungs.  The 'reversible' part is important;
     if the condition is NOT reversible, either with medication or
     spontaneously, then the diagnosis is not that of asthma, but of
     some other condition, usually chronic obstructive pulmonary
     disease.

     Quickly reviewing the structure of the lung:  air reaches the
     lung by passing through the windpipe (trachea), which divides
     into two large tubes (bronchi), one for each lung.  Each
     bronchi further divides into many little tubes (bronchioles),
     which eventually lead to tiny air sacs (alveoli), in which
     oxygen from the air is transferred to the bloodstream, and
     carbon dioxide from the bloodstream is transferred to the air.
     Asthma involves only the airways (bronchi and bronchioles),
     and not the air sacs.

     Although everyone's airways have the potential for constricting
     in response to allergens or irritants, the asthmatic patient's
     airways are oversensitive, or hyperreactive.  In response to
     stimuli, the airways may become obstructed by one of the
     following:
         - constriction of the muscles surrounding the airway;
         - inflammation and swelling of the airway; or
         - increased mucus production which clogs the airway.

     Contributed in part by:
         Ruth Ginzberg                    [email-masked]

1.0.1  What is emphysema?
-------------------------

     Emphysema is the disease in which the air sacs themselves, rather
     than the airways, are either damaged or destroyed.  This is an
     irreversible condition, leading to poor exchange of oxygen and
     carbon dioxide between the air in the lungs and the bloodstream.

1.0.2  What is COPD?
-----------------------------

     - to be added in a future version

1.0.3  What is status asthmaticus?
----------------------------------

     Status asthmaticus is defined as a severe asthma attack that
     fails to respond to routine treatment, such as inhaled
     bronchodilators, injected epinephrine (adrenalin), or
     intravenous theophylline.

1.0.4  What is anaphylactic shock?
----------------------------------

     Anaphylactic shock is defined as a severe and potentially
     life-threatening allergic reaction throughout the entire
     body.  It occurs when an allergen, instead of provoking a
     localized reaction, enters the bloodstream and circulates
     through the entire body, causing a systemic reaction.
     (There may also be an intrinsic trigger, as some cases of
     exercise-induced anaphylaxis have been reported.)

     The symptoms of anaphylactic shock begin with a rapid
     heartrate, flushing, swelling of the throat, nausea, coughing,
     and chest tightness.  Severe wheezing, cramping, and a rapid
     drop in blood pressure follow, which may lead to cardiac
     arrest.  The treatment for anaphylaxis is intravenous
     epinephrine (adrenalin).

1.1  How is asthma normally treated?
------------------------------------

     Treatment of asthma attempts to alleviate both the constriction
     and inflammation of the airways.  Drugs used for relieving the
     constriction are called bronchodilators, because they dilate
     (open up) the constricted bronchi.  Drugs aimed at reducing
     inflammation of the airways are called anti-inflammatories,
     and come in both steroidal and nonsteroidal forms.  If the
     asthma is triggered by allergies, then reducing the patient's
     exposure to the allergens or taking shots for desensitization
     are other alternatives.

     There are two main classes of bronchodilators, beta-agonists
     which are usually taken in an inhaled form, and xanthines,
     which are chemically related to caffeine.  The major xanthine,
     theophylline, is present in coffee and tea, and is taken
     orally.  Beta-agonists are chemically related to adrenalin.

     The inflammation component is treated primarily with steroids,
     which are a type of hormone.  The steroids used in the treatment
     of asthma are corticosteroids, which are not the same as the
     anabolic steroids that have become notorious for their abuse by
     muscle builders and athletes.  Up until fairly recently, doctors
     did not usually prescribe corticosteroids for asthma except as a
     final resort, when all else was not working to achieve the
     desired result.  Now that has completely reversed.  Steroid
     inhalers are now among the first line of drugs that a
     doctor will try in asthma management after an acute attack has
     resolved.  They work by reducing inflammation of the bronchi, and
     making future acute attacks less likely.  There are also two
     nonsteroidal anti-inflammatories available, cromolyn sodium and
     nedocromil, which are a popular alternative to inhaled
     corticosteroids.

     *IT IS IMPORTANT TO NOTE THAT OBTAINING RELIEF FROM AN ACUTE
     EPISODE OF ASTHMA (an asthma "attack") IS NOT THE SAME THING AS
     TREATING THE ASTHMA.*   Years ago it was thought that "asthma"
     consisted only of the acute "attacks" which were suffered
     intermittently;  when you weren't wheezing, you didn't have
     asthma any more.  This is no longer thought to be the case.  New
     asthma research emphasizes the role of the inflammation component
     of asthma, pointing out that bronchodilation alone does not
     reverse or treat the inflammation, although it does offer
     dramatic relief from an acute "attack".  New thinking on the
     subject is that if the underlying inflammation is successfully
     treated, then the person with asthma will be much less
     susceptible to the airway constriction, wheezing, and increased
     mucus secretion which accompany an acute "attack".  People with
     asthma have been found often to have ongoing inflammation which
     does not subside between acute "attacks", even when they are not
     wheezing.  However, treatment of the inflammation cannot be done
     on an emergency basis.  Treatment of the inflammation component
     is done after control is regained from an acute episode.  Without
     treating the underlying inflammation, the asthma itself is not
     being addressed and the acute attacks will continue to recur.
     For this reason, it is particularly important for parents of
     asthmatic children NOT to use the emergency room as the *only*
     place or occasion for treating their children's asthma (during
     acute attacks).  That is not actually treating the asthma;  it is
     just alleviating the most acute symptoms.  The child needs to be
     seen when it is NOT an emergency, for evaluation of the asthma &
     development of a treatment plan.

     Contributed in part by:
         Ruth Ginzberg                    [email-masked]

1.1.1  How is an acute asthma attack treated?
---------------------------------------------

     Treatment of acute asthma (an asthma "attack") usually is
     directed mainly toward alleviating the constriction of the
     airway.  Drugs used for this effect are called bronchodilators,
     because they dilate (open up) the constricted bronchi.  Adrenalin
     is often used in emergency rooms for this purpose, for an acute
     asthma "attack" that is seriously out of control.  Theophylline
     also relaxes the muscles surrounding the airways, and may be
     given intravenously in the emergency room.

     Contributed in part by:
         Ruth Ginzberg                    [email-masked]

1.1.2  What is a peak flow meter?
---------------------------------

     - to be added in a future version

1.2  How is asthma diagnosed?
-----------------------------

     - to be added in a future version

1.3  What are the common triggers of asthma?
--------------------------------------------

     - to be added in a future version

1.4  What are some of the most common misconceptions about asthma?
------------------------------------------------------------------

     People with asthma must not exercise because exercise might make
     them ill.  They must live sedentary lives.
          (FALSE)

     Asthma is primarily a psychogenic illness caused by
     repressed emotions.
          (FALSE)

     All children outgrow their asthma eventually.
          (FALSE, but many do.)

     Childhood asthma turns into adult emphysema.
          (FALSE)

     All asthma is caused by allergies.
          (FALSE)

     Moving to another state or region will cure asthma.
          (FALSE)

     Food allergies are a frequent cause of children's asthma.
          (FALSE, though rarely they are)

     Asthma in children is made worse by paying attention to it,
     because it is just a way of trying to get attention in the first
     place.
          (FALSE)

     Asthma in children is caused by so-called "smother-mothers".
          (FALSE)

     Asthma is a drag, but it's not fatal.
          (FALSE.  Especially among African-American children and
                   young adults it is a growing cause of death for
                   reasons not fully understood.)

     Smoking marijuana improves asthma.
          (FALSE)

     Asthma inhalers are addictive.
          (FALSE)

     Contributed by:  Ruth Ginzberg       [email-masked]

======================================================================

2.0  What are the major classes of asthma medications?
------------------------------------------------------

     There are five major classes of asthma medications:
         - steroidal anti-inflammatories,
         - non-steroidal anti-inflammatories,
         - anti-cholinergics,
         - beta-agonists, and
         - xanthines.
     The first two categories of drug treat the underlying
     inflammation of the lung, while the latter two categories are
     bronchodilators.  Once I understand what anti-cholinergics
     do, I'll be sure to include a description for them, also.

2.1  What are the names of the various asthma medications?
----------------------------------------------------------

     For a complete listing of asthma medications, please see the
     alt.support.asthma FAQ:  Asthma Medications.  It is posted
     monthly as the companion to this general information FAQ.

2.1.1  Are salbutamol and albuterol the same drug?
--------------------------------------------------

     Ventolin is the brand name of salbutamol, which is the WHO
     (World Health Organization) recommended name for the medication.
     Unfortunately, in the US this same drug is called albuterol,
     leading to endless confusion.  In fact, it's one of the few
     drugs in which the brand name stays the same from country
     to country, while the chemical name changes!  Ventolin is made
     in the U.S. by Allen & Hanburys, and Proventil is the same drug
     manufactured by Schering.  You can also get this drug in
     a sustained-action tablet, called either Repetabs (by Schering,
     again) or Volmax (Muro).

2.1.2  Are some asthma drugs banned in athletic competitions?
-------------------------------------------------------------

     Many asthma drugs are BANNED and may result in disqualification
     of an athlete from international and Olympic competition or
     other qualifying events, for a 2 year period for the first
     offense if urine drug analysis tests are positive.  The USOC
     follows protocol in the US for the International Olympic
     Committee, so the banned substances are banned in both US and
     international competition.

     Banned substances unfortunately are not defined by whether they
     are medically necessary but by whether they enhance performance
     (and thus give an unfair advantage).  A partial list of such
     substances includes:  ephedrine, bitolterol, metaproterenol,
     orciprenaline, rimiterol, and pirbuterol.  Albuterol,
     terbutaline, beclomethasone, dexamethasone, and triamcinolone,
     previously banned, are now allowed for use in Olympic competition
     in inhaler/or nasal form only with written notification from the
     physician in question on file with the United States Olympic
     Committee prior to competition.  Oral use of certain beta-2
     agonists is banned.  Cromolyn sodium is allowed.

     ** However, athletes should be aware that recommendations
        regarding the use of asthma medications (i.e. allowed vs.
        banned) in athletic competition may be revised.
        Ultimately, it is the athlete's responsibility to check
        with the USOC Drug Hotline, (800) 233-0393, and the
        athlete's coaches and/or National Sport Governing Body
        to get the most current recommendations.

     Asthma medications do not cause false positives on drug tests,
     at least for substances tested for in drug control with sports
     testing.  Most importantly, any athlete who is competing at the
     level where drug testing is being performed can check with the
     United States Olympic Committee Drug Hotline, (800) 233-0393,
     24 hours, to confirm whether a particular drug is allowed or
     banned.  Such an athlete should also discuss with both their
     coach and physician whether the drug is allowed or banned, and
     if banned, when should the drug be stopped prior to competition
     to get the medical benefits but avoid testing positive and
     suspension from competition.  The USOC Drug Control Program also
     has a wide range of literature for athletes on what asthma
     medications are banned, allowed, and allowed with prior
     notification.

     Contributed by:  Lyn Frumkin, M.D., Ph.D. [email-masked]

2.2  What kinds of inhalers are there?
--------------------------------------

     aerosol inhalers:
     ----------------

     MDI        - metered-dose inhaler, consisting of an aerosol unit
                  and plastic mouthpiece

     autohaler  - MDI made by 3M which is activated by one's breath,
                  and doesn't need the breath-hand coordination that
                  a regular MDI does

     respihaler - aerosol inhaler for Decadron.  I have no idea how
                  this differs from the usual MDI

     dry powder inhalers:
     -------------------

     rotahaler  - dry powder inhaler used with Ventolin Rotacaps (see
                  table above), i.e.  albuterol sulfate in capsules.
                  Each capsule contains one dose; the inhaler opens
                  the capsule such that the powder may be inhaled
                  through the mouthpiece.  Available in the U.S.,
                  Canada, and UK.

     spinhaler  - dry powder inhaler used with Intal capsules for
                  spinhaler.  Each capsule contains one dose; the
                  inhaler opens the capsule such that the powder
                  may be inhaled through the mouthpiece.  Available
                  in Canada, UK, and the U.S.

     diskhaler  - dry powder inhaler.  The drug is kept in a series of
                  little pouches on a disk; the diskhaler punctures
                  the pouch and drug is inhaled through the mouthpiece.
                  Currently available in Canada and UK, not in U.S.

     turbohaler - dry powder inhaler.  The drug is in form of a pellet;
                  when body of inhaler is rotated, prescribed amount of
                  drug is ground off this pellet.  The powder is then
                  inhaled through a fluted aperture on top.  Available
                  in Australia.

2.2.1  Which kind of inhaler should I use?
------------------------------------------

     Some asthmatics find the dry powder inhalers more effective than
     their MDI (aerosol) counterparts.  It is suspected that the
     aerosol or propellent in the MDI may act as an irritant to some
     asthmatics, as in the following article:

     J.R.W. Wilkinson et al., Paradoxical bronchoconstriction in
     asthmatic patients after salmeterol by metered dose inhaler,
     British Medical Journal 305 (1992) 931.  The first sentence
     in the conclusion is:  "Bronchoconstriction after both
     salmeterol and placebo by metered dose inhaler but not after
     salmeterol by diskhaler suggests that the irritant is not
     the salmeterol itself."  . . . "The similarity in characteristics
     of bronchoconstriction after beclomethasone by metered dose
     inhalers implicates one or both chlorofluorocarbons . . . as
     the irritant.  That salbutamol caused no bronchoconstriction was
     attributed to its faster onset of action opposing any
     bronchoconstrictor effects of the propellants."

     ** However, according to the 1994 Physicians' Desk Reference,
        Intal Spinhaler capsules are "contraindicated in those
        patients who have shown hypersensitivity to . . . lactose."
        So asthmatics who are lactose-intolerant may not have this
        form of cromolyn sodium as an option.

2.2.2  What is a spacer?
------------------------

     A spacer is a device that simplifies the inhalation of aerosol
     metered-dose-inhalers (MDIs).

     Most people find it difficult (at least initially) to time the
     spraying of an MDI and the inhalation of the medicine, and, thus,
     most of the medicine is deposited in their mouths or the backs
     of their throats instead of their lungs.  Besides being less
     effective, this can lead to other side effects (e.g., for inhaled
     steroids, an increased potential for thrush, an oral fungal
     infection).

     The spacer is basically a temporary holding chamber for the
     medication.  You spray the medicine into the chamber where it
     temporarily remains suspended, and then you inhale deeply and
     SLOWLY.  The column of medication rapidly passes through the mouth
     and goes into the lungs.

     There are a few different types of spacers.  The one I'm most
     familiar with is the Aerochamber.  It's a plastic tube with a
     mouthpiece on one end and a place to insert the MDI on the other.
     The mouthpiece has a delicate one-way valve built in so that you
     can exhale without displacing the medication in the chamber and
     then inhale.

     Some spacers are clear, some have a little whistle built in that
     tells you if you're inhaling too fast.  I've read (and believe)
     that the medication is more efficiently delivered using a spacer
     than if it were merely inhaled directly from the MDI.  Some
     packages (AeroBID, I believe, and others) come with a spacer
     built into its MDI housing.

     There are special spacers for younger children.  There's an
     Aerochamber that has a mask built in; the child breathes normally
     for a few seconds with the mask held over his/her mouth and nose.
     This is typically used when a nebulizer is not available or not
     required, and for medications that cannot be nebulized, such as
     Beclovent or Vanceril.

     There is also a device for children called InspirEase, which is
     kind of like a plastic bellows or balloon with a plastic
     mouthpiece.  The child inflates it, the medicine is sprayed into
     it, and the child inhales, holds his/her breath for the count of
     5 (or whatever the doctor recommends), exhales into the device,
     and then repeats.  It's really helpful for younger children who
     don't really know about breathing in and breathing out or how to
     hold their breath or breathe evenly and slowly.  It gives them
     immediate physical feedback, and also  has a whistle built in to
     tell them when they're breathing too fast (although they seem to
     like making it whistle, so it's positive reinforcement for
     something that they shouldn't be doing).  As the child grows, the
     Inspirease becomes less effective, since it has a limited
     capacity.

     Although spacers are sometimes provided by some HMOs and covered
     by some insurers, I don't believe that a prescription is required.

     Contributed by:  Mark Feblowitz                [email-masked]

2.2.3  What is "thrush mouth" and how can I avoid it?
-----------------------------------------------------

     Thrush mouth is the popular term for a yeast infection
     (candida albicans) in the back of throat.  The major symptom
     of thrush is a white film located at the back of the throat
     and tonsil area.  It is usually cured by the use of an
     antifungal mouthwash.

     Thrush is a very common side effect of taking inhaled
     corticosteroids.  The way to avoid this complication is to
     ensure that the back of the throat doesn't remain coated with
     corticosteroid after use of the inhaler, either by using
     a spacer or by rinsing the mouth very thoroughly afterwards.
     Unfortunately, some people still get it even when they are very
     thorough about rinsing.

2.2.4  Is Fisons still making the Intal Spinhaler?
--------------------------------------------------

     Yes, Fisons is still manufacturing both the Intal Spinhaler
     (a dry powder inhaler for cromolyn sodium) and the capsules
     for it.  Many pharmacists in the U.S. are under the impression
     that it is unobtainable, probably due to the fact that the
     Spinhaler was unavailable for a short time in the U.S. some
     while back due to a change in formulation.  During this time,
     some wholesalers stopped buying the inhaler, and didn't
     restock it once the Spinhaler was back in production.  So
     your pharmacist's regular wholesaler still may not be
     carrying this product.  For further information,
     Fisons Corporation's number for Rx Customer Service is
     (800) 334-6433.

     Contributed in part by:  Paula Ford            [email-masked]

2.2.5  What's the difference between Spinhalers and Rotahalers?
---------------------------------------------------------------

     [Maintainer's note:  the Rotahaler is a dry powder inhaler
     for Ventolin (albuterol), manufactured by Allen & Hanburys,
     while the Spinhaler is a dry powder inhaler for Intal
     (cromolyn sodium), manufactured by Fisons Corporation.  Both
     inhalers are available in the U.S.]

     The Rotahaler and the Spinhaler are very different animals.
     The Rotahaler is a pussycat, the Spinhaler a ferocious lion.

     The Rotahaler is a two-part mouthpiece that you snap apart,
     put a capsule in, twist, and inhale.  When you twist the device,
     the capsule breaks open.  When you inhale, the medicine lands
     in your lungs.

     The Spinhaler is a three-piece device: a mouthpiece, a tiny
     fan, and a cap to cover the fan.  You open it, put the capsule
     in a space on the fan, close it, push down then up on the cap
     (this breaks the capsule) and then tilt your head back, put
     the mouthpiece in your mouth, and inhale.  The fan throws the
     medicine into the back of your throat.  Then you gag.

     I don't like the propellants in MDIs, so I was highly motivated
     to get a Spinhaler.  It took me a month to get my drugstore to
     find it, and now I must admit I'm disappointed.  I tried using
     a capsule in the Rotahaler, since that device works so well, but
     the medicine seems to be of the wrong consistency, and the capsule
     is too small for the space it should go into.

     Another difference: The Spinhaler comes in a little container
     like a medicine bottle, but the lid doesn't stay on very well in
     a purse.  The Rotahaler comes in a little plastic case sort of
     like a compact and stays shut (i.e. clean) in a purse, backpack,
     or jeans pocket.

     Contributed by:  Paula Ford                    [email-masked]

2.2.6  Should I use an inhaler or take pills?  What's the difference?
---------------------------------------------------------------------

     Medications taken orally almost always have a much higher
     systemic concentration (concentration in your entire body)
     than inhaled medications.  So if the side effects are due
     to systemic concentrations, then an inhaled drug is less
     likely to have these side effects, or may have them much
     less severely.

     The idea behind an inhaler is that the full dose is delivered to
     the lungs, where it is immediately absorbed by the lung tissue,
     and starts to take effect locally.  Excess drug may be absorbed
     by the bloodstream and delivered to the rest of your body, but
     this amount tends to be minimal.  So your lungs receive an
     immediate, high concentration of the drug, and the rest of your
     body receives very little.

     If you take the drug orally in tablet or capsule form, then you
     need a much higher dose.  The reason is that for the same amount
     of drug to reach the lungs through the bloodstream, you need the
     same concentration of drug in the rest of your body.  For example,
     most people take one or two puffs of albuterol (Ventolin or
     Proventil) every four to six hours, and each puff is 90 micrograms
     of albuterol.  The usual dosage of Ventolin in tablets is 2-4
     milligrams three or four times a day, which is something like 200
     times the amount inhaled.

     However, one advantage that tablets have is that the medication
     may be available in a time-release format.  So for a short-acting
     medication like albuterol, the inhaled version might need to be
     taken every four to six hours, while a extended-release tablet
     such as Volmax would need to be taken only every twelve hours.

2.2.7  How can I tell when my MDI is empty?
-------------------------------------------

     - to be added in a future version

2.3  What kinds of tablets are there?
-------------------------------------

     SA  - sustained action.  SA and CR (below) have been used
           interchangeably and almost mean the same thing,
           except SA refers to the pharmacologic action while
           CR refers to the drug release process.  Any drug
           release which is controlled in a zero-order fashion
           (constant rate of release) is generally referred to
           as Sustained or Controlled Release.
     CR  - controlled release.  See SA.
     DR  - delayed release.  This generally refers to enteric-
           coated tablets which are designed to release the drug
           in the intestine where the pH is in the alkaline range.
     ER  - extended release.  Dosage forms which are designed to
           release the drug over an extended period of time,
           e.g. implants which release drug over a period of
           one or two months or years.
     TD  - time delayed.  This is slightly different from DR in
           that the drug release is designed to occur after a
           certain period of time, e.g. pellets coated to a
           certain thickness or multi-layered tablets or tablets
           within a capsule or double-compressed tablets.

     Contributed by:  Susan Graham                  [email-masked]

2.3.1  Why do I need a blood test when taking theophylline?
-----------------------------------------------------------

     Theophylline is a very effective drug but unfortunately its
     therapeutic level is quite close to its toxic level.  This
     means that the dose that the patient needs to get the full
     benefit of the drug is not very much lower than the dose
     which causes side effects which range from unpleasant to
     dangerous.  This would not be such a problem if there weren't
     such large variations in the rate at which people metabolize
     theophylline.  Apparently, if a group of people are given
     the same dose of theophylline, the concentration of the
     drug in their bloodstreams may vary by up to a factor of
     seven.  Therefore, the best way to monitor that the patient
     is receiving the optimal amount of theophylline is to take
     a blood level concentration.

2.3.2  Why are combination pills not commonly prescribed?
---------------------------------------------------------

     The combination drugs such as Tedral and Marax commonly
     contain theophylline, ephedrine, and some form of sedative
     such as phenobarbital.  These combination pills are no longer
     commonly prescribed because the amount of theophylline in
     the pill cannot be varied with respect to the other drugs.
     Since there is great variation in the rate at which an
     individual metabolizes theophylline, it is now considered
     better to take theophylline separately, for better adjustment
     of theophylline levels.  In fact, Tedral is no longer
     manufactured by Parke-Davis.

     Also, ephedrine is no longer considered the bronchodilator
     of choice.  From Drs. Haas, _The Essential Asthma Book_,
     "ephedrine initiates the release of catecholamines -- including
     adrenaline -- that are already stored in the body.  This is
     its biggest drawback.  Its effects depend on the availability
     of catecholamine in the body at the time it is given, and
     these concentrations vary."  Since much better bronchodilators
     are now available, ephedrine is no longer commonly prescribed.

2.4  What is a nebulizer?
-------------------------

     A nebulizer is a device that uses pressurized air to turn a
     liquid medication into a fine mist for inhalation.  If you've
     ever received emergency treatment for asthma, they've probably
     used a nebulizer on you.

     The term nebulizer is often used to describe both the pump
     that pressurizes the air, and the part that holds and
     "nebulizes" the medication.  There are hand-held nebulizer
     units and ones with masks that you strap onto your face.

     The pressurized air typically comes from a portable pump unit
     that internally consists of a motor-driven air pump that
     resembles the fancier types of aquarium pumps.  It forces air
     through a plastic tube into the plastic nebulizer unit.  Inside,
     the nebulizer unit acts much like a perfume atomizer, creating
     a fine mist that is directed either through a tube that you
     inhale through or a mask that directs the mist into your nose
     and mouth.

     Since the nebulizer takes a few minutes to deliver the medication,
     you inhale it over a longer period of time than if you were using
     an inhaler.  This can really help, especially if your passages are
     not fully open and you're taking a bronchodilator.  As you breathe
     the medication, your lungs can gradually accept more and more of
     the medication.  In addition to the medication, many people find
     the accompanying mist (typically a sterile saline solution) to be
     soothing.

     For very young children, the nebulizer is the only practical
     means of administering inhaled medications.  Older children and
     adults have the options of using inhalers and a variety of
     spacers to make the timing a bit easier.  The doctor overseeing
     the treatment decides which is the most effective/appropriate
     delivery mechanism.

     At least in Massachusetts, the nebulizer pump unit, the
     hand-held nebulizers, the medications, and the sterile saline
     inhalation solution are all prescription items.  Replacement
     parts for the pumps are not available to the general public
     (if there are sources, I'd like to hear about them).

     The portable nebulizer pump units cost little ($100-$300)
     relative to the cost of an emergency room visit, so some health
     plans / insurers provide them to patients for times when an
     asthma episode is "manageable but not dangerous." This seems to
     be a trend in the management of pediatric asthma.

     Our family has been able to successfully avoid a few trips to
     the ER, and have even been able to head off some more severe
     allergic asthma episodes with early intervention.  After a few
     rather gruesome visits to the Mass. General Hospital's waiting
     room on a Saturday night, we welcome opportunity to treat our
     children at home, when it's safe.  We tend to go in to the doctor
     or ER for the more severe episodes or those that don't respond
     well enough to early intervention.

     Contributed by:  Mark Feblowitz                [email-masked]

2.5  What medications should I avoid if I have asthma?
-----------------------------------------------------

     Aspirin can trigger an asthma attack in approximately one in
     five asthmatics.  This is especially common in those patients
     who also have nasal polyps.  As acetominophen (Tylenol) doesn't
     have this effect, it may be used as an alternative for anyone
     who suspects that they might have aspirin sensitivity.

======================================================================

3.0  What does HEPA stand for?
------------------------------

     Maintainer's contribution:
     -------------------------
     HEPA is an acronym that has been around for so long that people
     no longer remember what it stands for.  I personally have seen:
     High Efficiency Particulate Arrestor, High Efficiency PArticle,
     High Efficiency Particle Air, High Efficiency Particulate Air,
     and High Efficiency Particulate Abatement.  Either the first
     or last seem to me to be the most likely.  (At least there is
     some consensus on what the `HE' stands for.)  At any rate, it
     is a standard for the filtration of particles in air.

     From National Allergy Supply's product literature:
     "Filtering efficiency on a HEPA air cleaner, by law, has to
     be at least 99.97% on all particles down to 1/3 micron in
     size (a hair is about 60 microns, or 180 times larger than
     that!)  The term "HEPA" may not be used by any manufacturer
     unless these two requirements are met.  In addition, HEPA
     filters lose no efficiency and stay at 99.97% for years."

     Andrew M. Gough's contribution:
     ------------------------------
     HEPA filters are basically folded (to increase surface area)
     high-density fiberglass sheets.

     HEPA filters for home use usually have a capture efficiency
     rating of 99.97% at 0.3 micron size.  This means that 99.97%
     of particles of 0.3 micron diameter, or larger, are captured
     when passing through the filter.  Below 0.3 micron, the capture
     efficiency will drop quickly.

     Other filter types (disposable foam/fiberglass, electronic,
     electrostatic) typically have high capture efficiencies for
     particles above 10 microns in diameter.  They are absolutely
     useless for particles below 1 micron in diameter, where they
     have capture efficiencies of about 1%.

     Why is this important you ask?  Many common allergens are below
     10 microns in size, with many below 1 micron.  A "micron" is a
     micrometer, or one millionth (10E-6) of a meter.  For comparison,
     a strand of human hair is typically 75 to 100 microns in diameter.
     The sizes (diameter in microns) of allergens and other items of
     interest are:

          Pollens              8    - 80
          Molds                4    - 12
          Mold spores          5    - 15, with some down to 0.4*
          Dust mites           0.8  -  1 micron
          Dust mite feces      0.2  -  0.02
          Animal dander        0.4  - 10
          Tobacco smoke        0.02 - 1
          Ragweed pollen      21
          Red blood cell       8
          Polio virus          0.025
          Bacteria             0.2  - 40
          Smallest visible    40    - 10 depending on individual
                                          & conditions

     * I recall reading once that the spore diameter for aspergillus
       is 0.4 micron.  The 5-15 range comes off a chart I have, but
       I need to look out for further information, as I believe a lot
       of mold spores are below 1 micron.

     HEPA filters are the only type that are really effective in
     eliminating allergens from the air, especially if you are allergic
     to molds.

     I am aware of two choices for HEPA filters for the home market:
     freestanding and whole-house:

     Freestanding units are short circular tubes which suck in air
     from the sides and exhaust filter air at the base.  An example
     is the Honeywell Enviracare.  You put it in a closed room and
     run it all day, and at night if you can stand the noise (they
     can be quite noisy).  Freestanding units will go for $250-$350
     and are available in retail stores or mail order.  I used one
     for my apartment, where I tried to cheat fate by trying to
     filter all the apartment air by placing it near the air return.
     It helped.  HEPA filters need to be replaced every 2-3 years,
     depending on conditions, and will cost $70-$90.  You need to
     change prefilters every 3 months, but they are cheap.

     I am aware of one company that makes a whole-house unit, Pure
     Air Systems, Inc. in Plainfield Indiana, phone (800) 869-8025.
     They make a system that attaches to the air return of a furnace
     in a bypass configuration.  The unit has its own blower, as a
     normal furnace blower wouldn't be able to pull air through a
     HEPA filter (very dense, remember) and transport it through the
     house.  The unit operates whenever the furnace/AC does, but of
     course you can leave your thermostat in the "fan on" position
     and run it as long as you want.  This will run you $1000-1200
     installed.

     From the personal experience with HEPA air, I recommend it.  I
     used to work in a semiconductor fabrication clean room, of class
     10, which means that there were only 10 particles per cubic foot
     that were 0.5 microns in diameter or larger.  Whenever I would
     walk into the cleanroom, my nose would instantly clear up and I
     would feel much better.

     Contributed by:  Andrew M. Gough  [email-masked]

======================================================================

4.0  What resources are there for asthmatics?
---------------------------------------------

     Please see the alt.support.asthma Reading/Resource List.  It
     is maintained by Lynn Short <[email-masked]>, and is
     posted monthly to alt.support.asthma, alt.med.allergy,
     sci.med, and misc.kids.  I highly recommend it!

======================================================================

Contributors:
------------

  Mark Delany                              [email-masked]
  Mark Feblowitz                                    [email-masked]
  Paula Ford                                        [email-masked]
  Lyn Frumkin, M.D., Ph.D.                     [email-masked]
  Ruth Ginzberg                           [email-masked]
  Andrew M. Gough                      [email-masked]
  Susan Graham                                      [email-masked]

======================================================================

References:
----------

The Physicians' Desk Reference is published annually by:
      Medical Economics Data Production Company
      Montvale, NJ 07645-1742
      ISBN 1-56363-061-3
It is a compendium of official, FDA-approved prescription
drug labeling.  The FDA is the U.S. Food and Drug Administration.

Drs. Francois Haas and Sheila Sperber Haas, _The
  Essential Asthma Book_, (Ballentine Books, USA) 1987.

      ISBN 0-8041-0287-2

  Dr. Francois Haas is the director of the Pulmonary Function
  Laboratory at the Medical Center of the New York University
  School of Medicine, and is on the faculty of the Dept. of
  Physiology there.

Paul J. Hannaway, M.D.  _The Asthma Self Help Book_,
  2nd ed., (Prima Publishing, USA) 1992.

      ISBN 1-55958-166-2
           1-55958-434-3 paperback

  The author is Assistant Clinical Professor of Tufts
  University School of Medicine.  The first edition of
  this book won an American Medical Writers Association
  Award.

Allan M. Weinstein, M.D., _Asthma - The Complete Guide
  to Self-Management of Asthma and Allergies for Patients
  and their Families_, (Fawcett Crest, NY, USA) 1987.

      ISBN 0-449-21562-8

  The author is Assistant Clinical Professor of Medicine at
  Georgetown University, and is a board-certified allergist
  who practices in Washington, D.C.

======================================================================

Disclaimer:  I am not a physician; I am only a reasonably
             well-informed asthmatic.  This information is for
             educational purposes only, and should be used only as
             a supplement to, not a substitute for, professional
             medical advice.

Copyright 1994 by Patricia Wrean.  Permission is given to freely
copy or distribute this FAQ provided that it is distributed in full
without modification, and that such distribution is not intended for
profit.

-- 
Patricia Wrean                             [email-masked]