Genetic factors symptoms and conditions

Researchers have been doing studies for many years regarding trying to determine the role of genetic factors in patients response to Singulair (Montelukast).

This study from Spain identified the following gene variations hypothesize to be related to leukotriene pathway response. Sixty one patients with asthma were studied. Three gene types were identified:

type 1. Thirty-two patients (52.5%) were homozygous for the five repeats allele;
type 2. 17 (27.9%) were heterozygous (4/5 repeats)
type 3. 12 (19.7%) were homozygous for 4/4 repeats.

The study showed that montelukast was effective for types 1 and 2 but not effective for type 3. Type 3 represented approximately 20% of the group study.

"After the montelukast treatment decrease number of asthma exacerbations, improvement of FEV(1) and decreased use of beta(2) agonists was observed in patients with 5/5 or 4/5 repeats. Conversely, the patients with 4/4 repeats genotype did not modify these data after treatment."

So it seems logical that if it can be identified that montelukast is not effective for certain gene type variations, then montelukast could cause adverse side effects in certain gene type variations.

It is interesting that 20% of this group does not respond positively to montelukast. That is the exact same number that even Merck says gets a headache from montelukast. Headache is the highest incidence of adverse side effects that has been reported. That comparison, however, is just a coincidence because it has not been studied and proven. Maybe.

Where are the studies that pertain to gene type variations and adverse side effects? You would think that somebody could do them.

Respir Med. 2008 Jun;102(6):857-61. Epub 2008 Mar 12. Links
ALOX5 promoter genotype and response to montelukast in moderate persistent asthma.Telleria JJ, Blanco-Quiros A, Varillas D, Armentia A, Fernandez-Carvajal I, Jesus Alonso M, Diez I.
Institute of Biology and Molecular Genetics (IBGM/CSIC), University of Valladolid, Valladolid, Spain. ******

BACKGROUND: It was hypothesized that asthmatic patients with mutant alleles in the leukotriene pathway should not respond to leukotriene receptor antagonists and the concept of a tailored treatment is increasingly supported. METHODS: Sixty-one patients (mean age 24.9 years, range 14-52) with moderate persistent asthma were clinical and immunological assess prior and after a 6-month treatment with montelukast. Tandem repeat polymorphisms were genotyped in the promoter (-147 to -176) of 5-lipoxygenase gene (ALOX5). RESULTS: Thirty-two patients (52.5%) were homozygous for the five repeats allele; 17 (27.9%) were heterozygous (4/5 repeats) and 12 (19.7%) were homozygous for 4/4 repeats. After the montelukast treatment decrease number of asthma exacerbations, improvement of FEV(1) and decreased use of beta(2) agonists was observed in patients with 5/5 or 4/5 repeats. Conversely, the patients with 4/4 repeats genotype did not modify these data after treatment. CONCLUSIONS: It was confirmed that ALOX5 promoter polymorphisms have a clear influence in montelukast response in atopic moderate persistent asthma patients. The genetic study could identify those patients most likely to respond to montelukast.

PMID: 18339529

Hi to all,
I want to Thank all those who contacted me in regards to my request for help with the Media.I believe the reports are in now and the stories will be out soon.I am going to ask that if at all possible ,those that have contacted me wanting to come forward with your stories, let me keep your names for further reference if needed.If anyone does not want that, please reply and I will delete the information.I just cant thank all of you enough,you are helping many by coming forward with your stories.There is great power in numbers and every person counts that is willing to not lay down to this injustice done to our families.If you have a voice and use it, it is a tool to make a change.We all forget that years ago information was passed on by word of mouth,this maybe the only way this will get out until this investigation is over.Use every avenue possible and change will come.Thanks Again Kate and Dave M.

Clinical trial of montelukast in the Netherlands.

I noticed two things:

1. The researcher states that sides effects are 10%.
2. The researcher will not allow patients to also take drugs which are metabolized by CYP2C8 because montelukast inhibits that as proved by in vitro (test tube) studies. American studies in vitro said yes montelukast is an inhibitor but in vivo (in people) that it didn't happen. I was always confused by that and would still like to know more
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My son age 3 was diagnosed with asthma about a year ago. Since then he has been sick constantly. Most recently his doctor has prescribed Singulair. He is aggressively pushing it on us. I stated my concerns to him, and he said there is nothing wrong with the drug.. he gets all the news letters.. and all the things I listed was the first time he heard anything.. I asked for his to refer us to a specialist and he wont.. I cant find anyone for a second opinion..My son needs medicine- at night i cant leave his side cause of his breathing.. The doctor wont suggest any alternate and I am stuck. I keep reading about all the people who are not taking singulair anymore- what what are they taking? I am completely lost here!