Heads-up’ issued for ol’ faithful aspirin: may aggravate respiratory disease

 

A “pay attention” article was recently published in the Journal of Allergy and Clinical Immunology cautioning adults with asthma to be more aware that aspirin may aggravate their condition.

The authors pointed out that while some adult asthmatics with Aspirin Exacerbated Respiratory Disease (AERD) are cognizant of the negative effects aspirin can have on their health, most are not.

Studies have shown that AERD is more likely to occur if adult asthmatics also have chronic sinus problems and/or nasal polyps. Overall, seven percent of asthmatics have AERD, but 15 percent with severe asthma have it.

Unfortunately there is no simple blood or skin test to diagnose Aspirin Exacerbated Respiratory Disease. Right now, only two ways are available for these patients to become aware of the possibility: 1.) Monitoring their breathing symptoms after ingesting aspirin or other NSAIDS (non-steroid anti-inflammatories). 2.) Doing an aspirin challenge in a doctor’s office by measuring baseline pulmonary function tests and then incrementally increasing doses of aspirin, while repeating the pulmonary tests.

 

Dear Doc: Penicillin/Cephalosporin — cross-reactive?

Dear Dr. K: I’m allergic to penicillin but my pharmacist has also labeled me cephalosporin-allergic. I’ve never taken cephalosporin. Should I follow her advice?

I can’t give you an answer with a 100 percent surety, but I can come close. As luck would have it, Kaiser Permanent Health Care just finished a research project on cephalosporin allergy.

Their study included 820,000 patients who received a total of 1.4-million courses of cephalosporin (often prescribed as Keflex). Of these, 66,000 were allergic to penicillin. Only one-half a percent of the 820,000 had an allergy to cephalosporin.

The reason your pharmacy warns of a possible cross-reactivity is that penicillins and cephalosporins share a common structural feature called the Beta-lactam ring. The thing that distinguishes penicillins from cephalosporins are side-chain molecules that attach to the Beta-lactam ring. Luckily, most allergy to penicillin is directed against the side chain and not the ring structure. Hence, there would not be cross-reactivity.

The Kaiser Permanent researchers felt that since the potential for cross-reactivity is so low, penicillin-allergic individuals can go ahead and take cephalosporins in most cases. They did advise members of this group who have had anaphylaxis to consider antibiotic testing prior to receiving cephalosporins. (Also, see first item in Q-Tips this issue.)

Hookworms highlighted again: hitches and hopefulness this time

Do you remember a previous newsletter article about a crazy British physician with asthma? He was able to put his asthma into total remission by ingesting hookworms. The worms end up living in the GI tract and for some strange reason, they switch the body from the allergy-promoting TH-2 mode to TH-1, which eliminated allergy (See Promising New Asthma Drug this issue.)

Now his crazy Australian brethren are doing research on celiac disease and hookworms. The Australian scientists found that by inducing an experimental hookworm infestation in patients with celiac disease, and at the same time giving them small amounts of gluten, they were able to induce a state of gluten tolerance.

As well as the hookworm treatments work, the downside is that the worms cause the patients to become anemic and, thus, are not a viable long-term treatment. The researchers, however, hope these experiments will lead to a safe method of switching TH-2 to TH-1. One never knows where research can lead.

Promising new asthma drug nears testing finish line

Research on a very exciting new medicine for asthma was featured several weeks ago in The New England Journal of Medicine. This drug — the first ever to work on both the acute and late phases of allergic response — is an enzyme that inactivates GATA-3 messenger RNA, and is being called SB010.

GATA-3 is a signal that favors T-helper cells to follow the TH-2 pathway, which promotes allergy. TH-1 eliminates allergy. Or, to use a Star Wars analogy: TH-1 is the Force, while TH-2 is the Dark Side of the Force.

All allergic reactions, including asthma, are bimodal; that is, after exposure to the allergen there is an immediate response occurring right away and lasting minutes to a few hours, but also a delayed response that builds gradually and lasts for many days. This late phase accounts for the chronic nature of allergies and asthma.

SB010 blocks both responses. In research done at Hannover Medical Center in Germany, patients received SB010 once a day via nebulizer. The results were immediate and dramatic, with most asthmatics experiencing dramatic reduction in their symptoms — even if they were purposely exposed to their causative allergen, such as cat dander.

Also, the medication was very well tolerated with minimal or no side effects. Other medical centers are also completing research on SB010. Hopefully, this will lead to it soon becoming clinically available.

Shingles Protection Aging Badly

When the shingles vaccine was being researched and developed, the patient population was studied for five years. These initial studies showed the vaccine to be 90 percent effective after five years.

Based on that research it was therefore felt that Zostavax (shingles vaccine) could be given once in a lifetime.  Unfortunately, it is starting to look like that won’t be the case.

Now that longer-term studies are being completed, it is apparent that immunity wanes with time. In fact, efficacy falls to 46 percent after seven years; 14 percent after 10 years, and roughly zero after 11 years.

Since these long-term research projects have just been completed, the medical community awaits advice from the Centers for Disease Control and Prevention (CDC) regarding re-vaccination protocols.

Q – Tips: Dog days of summer!

Alas, we’ve entered the “dog days” of Florida heat and humidity. Persons who are allergic to dust mite and/or mold should be aware that even with continuous air conditioning, ambient indoor humidity can creep up and allow dust mites and mold to flourish. Ideal indoor humidity is 50 percent or lower. If your level is higher, consider using a dehumidifier during the summer months.

Q – Tips: C. diff

C. diff (Clostridium difficile) is the most common cause of severe antibiotic-induced diarrhea. New research indicates that once an individual has C. diff, it never totally leaves their GI tract. New guidelines therefore, recommend lifelong use of probiotics.

HAE drug works for ACE problem

It is hoped that recent research into expanding the use of a targeted, expensive drug could bring financial relief to many who share symptoms with those covered by the drug’s current restrictive application.

At issue are serious symptoms caused by ACE-inhibitor-induced angioedema. The drug studied is Icatibant (brand name Firazyr), but its only approved application at present is for Hereditary Angioneurotic Edema, or HAE — a rare, but significant disease.

People with HAE suffer repeated bouts of swelling (angioedema) of different body parts, from lips and tongue to throat and even the intestines. The attacks can be severe and occasionally life-threatening when the airway is compromised. They are caused by the build-up and release of bradykinin, a powerful vasodilator. Icatibant works by blocking the tissue receptor where bradykinin exerts its mischief.

Not so rare is ACE-inhibitor-induced angioedema, which also occurs because of a build-up and release of bradykinin. Unlike HAE in which any part of the body is susceptible to swelling, ACE angioedema tends to occur primarily around the head and neck — lips, tongue, face, palate and throat.

Also unlike HAE which is caused by a genetic deficiency in an enzyme, ACE angioedema is caused in susceptible individuals by the medications called ACE-inhibitors, which are antihypertensives. At the current time the only FDA-approved use of Icatibant is in HAE; therefore, using it in ACE-angioedema would be an “off-label” use.

Which comes around to the crazy world of insurance. At this point insurance carriers will only cover the cost (roughly $8,000 per dose) for people with HAE. Hopefully, this research study will change things, as ACE-angioedema is a common reason for emergency room visits.

Dear Doc: Wheezing when exercising? Learn facts

Dear Dr. K: I wheeze when I exercise. Does that mean I should stop aerobic activities?

 The unequivocal answer to your question is “no” — and I’m sure Roger Bannister would second my answer.

Roger Bannister was the first runner to break the 4-minute mile. What many people don’t know is that he was a medical student when he performed that feat. (Pun intended.) In fact, in the 1950s when he broke four minutes the physicians at that time were mistakenly telling asthmatics not to exercise. Bannister actually changed that approach because of research he did in exercise physiology. He learned that exercise itself might stimulate wheezing with the activity but in the long run (pun intended), it helped lessen the asthma tendency.

Exercise can bring on wheezing for several reasons: airway cooling, airway dehydration and inhalation of allergens and pollutants. The latter is not surprising as the mouth breathing associated with aerobic exercise leads to inhalation of non-filtered air (bypassing the nose and sinuses).

Certain situations are more likely to elicit wheezing: running in cold/dry air, swimming in heavily chlorinated pools and biking along exhaust-laden roadways.

Sometimes exercise-induced asthma manifests as a cough rather than wheezing. This cough can happen during the activity or afterward (when it is known as “locker-room cough”).

The most important fact about exercise-related asthma is that improved aerobic conditioning lessens the asthmatic tendency and, in effect, “strengthens the lungs.”

General measures to manage the problem include identifying triggers such as high chlorine levels or pollutants, and avoiding them. Avoid exercising in extreme cold or dryness and engage in pre-exercise warm-up. For runners, if the asthma occurs while running fast, slowing the pace for a while can allow you to “run through” the asthma.

Finally, using an inhaled bronchodilator prior to exercise often eliminates the problem entirely.