Chloroquine symptoms and conditions

Singulair, montelukast, contains a chloroquine in it's molecular structure. I am praying that the FDA takes this investigation seriously. Other countries are concerned about the neuro-psychiatric side effects of these categories of drugs for some very good reasons.

"In summary, we have used a combination of electrophysiology, ligand binding, homology modelling and simulated docking to define the mechanisms by which quinine, chloroquine and mefloquine inhibit the 5-HT3 receptor response. Our observations further extend the number of receptors known to be affected by these compounds and the growing diversity of targets may account for the broad spectrum of side effects that have been reported by patients receiving them (Luzzi and Peto, 1993; Palmer et al., 1993; Taylor and White, 2004). Inhibition of the 5-HT3-mediated current could have wide-ranging effects in the nervous system, as 5-HT3 receptors can modulate a variety of neurotransmitter responses such as those to GABA, dopamine and cholecystokinin (Thompson et al., 2006b)."

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Sorry, I can't just walk away.

When you find patents or patent applications for certain purposes, then you know that your ideas are well founded. There are several patents for using an anti-malaria drug for asthma. I would bet that somebody had that idea all the way back to the 1960's. So it is very possibly no coincidence at all that a chloroquinoline or other quinoline ring would be part of montelukast's chemical structure.

Here is one of the patents.

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It is well known that quinoline rings can be toxic to some people even very rapidly. As in this very extreme example.
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PEDIATRICS Vol. 27 No. 1 January 1961, pp. 95-102 This Article

FATAL ACUTE CHLOROQUINE POISONING IN CHILDREN
Howard M. Cann M.D.1 and Henry L. Verhulst M.S.1

1 National Clearinghouse for Poison Control Centers, Accident Prevention Program, Public Health Service, U. S. Department of Health, Education, and Welfare
Four cases of acute chloroquine poisoning in children are presented. In three instances death occurred within 2 hours of ingestion of larger than therapeutic amounts of the drug. The rapid occurrence of death in acute chloroquine poisoning is probably explained by complete and rapid absorption of the drug from the gastrointestinal tract resulting in high blood concentrations which depress vasomotor function and respiration. Cardiac arrest follows and may be caused by the direct myocardial action of chloroquine, to anoxia, or to both. The similarity of the manifestations of acute chloroquine poisoning and those of acute quinine and quinidine poisoning suggests that acute toxicity may be attributed to the quinoline ring portion of these drugs.

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I don't think that we are seeing extreme examples. But we may be seeing less extreme immediate reactions or reactions where the toxicity builds up over time.

Quinoline rings are know to cause neurotoxicity. There are theories about how that happens. One of the theories is about blocking connexins which are gap junction proteins in the brains.

I don't know how montelukast could be breaking up so that it causes toxicity. Or if the problem is the how rapidly the liver enzymes can metabolize it. But there is plenty, plenty, plenty of clinical evidence that there is a quinoline ring culprit somewhere in the picture. Or some by-product of that causing problems.

Somehow it was decided that montelukast did not have the safety issues that the other drugs in the same category have. See this.

"The starting point in the development of montelukast appears to be a quinoline-containing structure, likely identified as a weak random screening lead (Figure 3). The Merck group hypothesized that this molecule was mimicking the olefin backbone of cysLTs, and that the addition of mimics for the acid and peptide regions of LTD4, might improve its potency. As a first step, the dithioacetal linkage first seen in some SmithKline compounds was incorporated; this led to a compound with greatly increased in vitro potency but poor oral bioavailability. When one of the carboxylic acids was replaced by an amide, forming MK-571, the new antagonist had even greater potency and good efficacy following oral administration. The enantiomers were resolved to yield MK-679 (verlukast), a compound with better clinical effects than MK-571, but whose clinical development was stopped for safety reasons. Further structure-activity relationship studies led to the development of montelukast (16), an antagonist that appears free of the safety concerns plaguing earlier members of this series."

If we can find out why the earlier versions were not safe and how they thought fixed it, then maybe we can find out what is going on with the quinoline ring in some people.

I would be very surprised if the FDA will address our concerns. Why does it always seem like they wait for enough people to die like in Vioxx? Wasn't Vioxx responsible for thousands of deaths?