Showing posts with label Candesartan. Show all posts
Showing posts with label Candesartan. Show all posts

Wednesday 3 June 2015

Primary and Secondary Dysfunctions in Autism - plus Candesartan

Sometimes the secondary event can completely overshadow the primary event.  
The above relates to dust explosions (in large silos containing grain, sugar etc.) rather than autism.

As we continue to investigate the science behind autism and associated possible therapies, it is becoming necessary to introduce some further segmentation.

I have referred to autism “flare-ups” many times, but even that term means very different things to different people.

We now have many examples of autism treatments (NAC, Bumetanide etc), once effective, suddenly stopping working in certain people.  This needs explaining.

We know from the research that in most cases, autism is caused by multiple “hits”, only when taken together do they lead to autism.

We also see the “double tap” variety of autism, when relatively mild autism later develops into something more serious, following some event, or trigger.  

Thanks to the internet, we know have numerous n=1 examples of certain drugs showing a positive effect in some people.  You do have to discount all those people trying to sell you something, or support the cause of others trying to sell you something.  We also have full access to all those people who have patented their clever ideas, although 99% never develop them.

Within all this information there are some very useful insights, which can help further our understanding of autism


A case in point is Candesartan, which one reader of this blog brought to my attention, in the comment below.  This drug is used to treat high blood pressure and is often combined with a diuretic.

A very recent study relating to neurodegenerative disease and Parkinson's especially:

discusses the use of a new drug as well as another blood pressure drug sometimes used in conjunction with Bumetanide called Candesartan. Their goal in this study was to explore how to attenuate chronic microglial activation (a hallmark of autism) by targeting toll-like receptors TLR1 and TLR2 via these two drugs.

Candesartan also modulates NKCC2 activity:

which is interesting considering the original cited research above deals with attenuating microglial activation, rather than modulating the chloride levels within GABA inhibitory neurons as Bumetanide does.

Note that Bumetanide affects both NKCC1 and NKCC2 transporters.  NKCC1 is present in the brain at birth, but should not be present in the adult brain.  However, it appears to remain in a large sub-group of those with autism, causing GABA to remain excitatory.  NKCC2 is found specifically in the kidney, where it serves to extract sodium, potassium, and chloride from the urine so that they can be reabsorbed into the blood

This drug is, along with Minocycline, is one of the few that is known to have an effect on microglial activation.

In a clinical trial, Minocycline was shown to have no effect on autism.

I do feel this kind of assessment is too simplistic; so I was interested to see the actual effect of Candesartan in autism, albeit with n=1.

Conveniently somebody has filed a patent for the use of Candesartan in autism.  Within the document is the n=1 case report of its effect.

[00047] A 16 year old boy with autism was evaluated for behavioral management. He was frequently aggressive, primarily directed to himself but to others as well. These episodes were usually unprovoked but would also occur when his parents attempted to re direct him. The child was essentially non verbal except for echolalia. His comprehension to verbal re direction was limited, making non pharmacological interventions to his aggression limited.

[00048] His neurological exam was otherwise normal.

[00049] An MRI, EEG were normal. Routine studies, including examination for fragile x and other metabolic disorders were negative.

[00050] Prior medication trials included anti convulsants which were without benefit and atypical neuroleptics, which resulted in weight gain and unsatisfactory effects on behavior.

[00051] After obtaining consent from his parents, Candesartan was started. An initial dose of 8 mg resulted in significant attenuation of aggressive behavior. Blood pressure remained stable. After 2 weeks, the dose was raised to 16 mg. Further improvement in aggression was noted with no adverse lowering of blood pressure.

[00052] The patient has remained on Candesartan with beneficial anti aggression effects being maintained over one year.

[00053] A preferred dose found by the inventor to treat autism is approximately O.lmg/kg. In children, a liquid form may be used.

So we can conclude from this that in a non-verbal 16 year old boy with autism, with significant aggressive tendencies, this drug successfully reduced aggression.  Since he was on the drug for a year, there were no other major changes, such as language or cognitive function, otherwise they would surely be mentioned to support the patent.

I can of course look further into why Candesartan might have been effective.

Our blog reader suggested this research:-

"The real job of microglia is to keep the brain healthy by getting rid of pathogens as well as cellular debris," says Maguire-Zeiss, "However, in a diseased state microglia can become chronically activated, leading to a continuous onslaught of inflammation which is damaging to the brain."
In this study, the Maguire-Zeiss lab found that only a certain size structures of misfolded α-synuclein can activate microglial cells -- normal protein and even smaller forms of misfolded α-synuclein cannot. Then the researchers sought to discover precisely how microglia responded to misfolded α-synuclein; that is, which of its many "pattern recognition receptors" reacted to the toxic protein.
Microglia use many different pattern recognition proteins, called toll-like receptors (TLR), to recognize potential threats. The investigators found that misfolded α-synuclein caused TLR1 and TLR2 to come together into one complex (receptor), creating TLR1/2. They traced the entire molecular pathway from the protein's engagement of TLR1/2 at the cell surface to the production of inflammatory molecules.
Then Maguire-Zeiss and her team tested a drug, developed by researchers at the University of Colorado, which specifically targets TLR1/2. They also tested the hypertension drug candesartan, which can target TLR2. Both agents significantly reduced inflammation.

I found some other possible explanations:-

Brain inflammation has a critical role in the pathophysiology of brain diseases of high prevalence and economic impact, such as major depression, schizophrenia, post-traumatic stress disorder, Parkinson's and Alzheimer's disease, and traumatic brain injury. Our results demonstrate that systemic administration of the centrally acting angiotensin II AT1 receptor blocker (ARB) candesartan to normotensive rats decreases the acute brain inflammatory response to administration of the bacterial endotoxin lipopolysaccharide (LPS), a model of brain inflammation. The broad anti-inflammatory effects of candesartan were seen across the entire inflammatory cascade, including decreased production and release to the circulation of centrally acting proinflammatory cytokines, repression of nuclear transcription factors activation in the brain, reduction of gene expression of brain proinflammatory cytokines, cytokine and prostanoid receptors, adhesion molecules, proinflammatory inducible enzymes, and reduced microglia activation. These effects are widespread, occurring not only in well-known brain target areas for circulating proinflammatory factors and LPS, that is, hypothalamic paraventricular nucleus and the subfornical organ, but also in the prefrontal cortex, hippocampus, and amygdala. Candesartan reduced the associated anorexic effects, and ameliorated associated body weight loss and anxiety. Direct anti-inflammatory effects of candesartan were also documented in cultured rat microglia, cerebellar granule cells, and cerebral microvascular endothelial cells. ARBs are widely used in the treatment of hypertension and stroke, and their anti-inflammatory effects contribute to reduce renal and cardiac failure. Our results indicate that these compounds may offer a novel and safe therapeutic approach for the treatment of brain disorders.

However the underlying mechanism may indeed be (yet again) activating PPAR γ.

Involvement of PPAR-γ in the neuroprotective and anti-inflammatory effects of angiotensin type 1 receptor inhibition: effects of the receptor antagonist telmisartan and receptor deletion in a mouse MPTP modelof Parkinson's disease

This paper suggests that the effect of Candesartan on microglia is :-

"Several recent studies have shown that angiotensin type 1 receptor (AT1) antagonists such as candesartan inhibit the microglial inflammatory response and dopaminergic cell loss in animal models of Parkinson's disease. However, the mechanisms involved in the neuroprotective and anti-inflammatory effects of AT1 blockers in the brain have not been clarified. A number of studies have reported that AT1 blockers activate peroxisome proliferator-activated receptor gamma (PPAR γ). PPAR-γ activation inhibits inflammation, and may be responsible for neuroprotective effects, independently of AT1 blocking actions."

Primary Autism Dysfunctions

I define Primary Autism Dysfunctions as those core dysfunctions that are always present.

So in the case of Monty, aged 11 with ASD, the primary dysfunctions include:-

·        GABAA dysfunction, due to over expression of NKCC1,  leading to excitatory imbalance
·        Oxidative stress

In some other people the primary dysfunctions are quite different:-

·        Mitochondrial disease

·        etc...

I think that most aggressive behavior resulting from these dysfunctions can be traced back to communication problems and frustration.  So if the person is non-verbal and cannot get what he/she wants, aggression may follow; or if the person has pain and cannot understand it or seek help he may lash out at his care giver.

Secondary Autism Dysfunctions

I define Secondary Autism Dysfunctions as additional dysfunctions that can appear and disappear over time, these are my "flare-ups".

These dysfunctions can be more disabling that the Primary Autism Dysfunctions and it appears these are the dysfunctions that may trigger un-prompted self-injury and other random aggression.

These secondary dysfunctions can be so strong that they completely outweigh the primary dysfunction, giving the effect that the treatment for the primary dysfunction has “stopped working”.

It appears that many  Secondary Autism Dysfunctions are linked to an “over activated immune system”.  It does appear that from the research that activated microglia is an expression of this immune state and we saw one researcher calling the microglia the brain's “immunostat”. 

So in the case of Monty, aged 11 with ASD, the secondary dysfunctions are:-

·        over activated immune system / activated microglia
·        mast cell degranulation as a trigger
·        Il-6 from dissolving milk teeth as a trigger
·        Emotional distress (aged 8, when his long-time assistant left) as trigger (Emotional distress is known to cause oxidative stress)

In other people the secondary dysfunctions may be similar or quite different, for example:-

·        over activated immune system / activated microglia
·        leaky gut with GI problems as a trigger
·        food intolerance as a trigger
·        bacterial infection, with remission while on antibiotics, as a trigger
·        etc …

So I think the trial of Minocycline may have failed because the subjects were only affected by Primary Autism Dysfunctions.

I think the 16 year old aggressive boy in the Candersartan patent most likely had big Secondary Autism Dysfunctions.  The drug reduced microglial activation and so damped the effect of whatever his particular triggers were.

So probably Minocycline should be trialed again, but only in people with autism and regular SIB and aggression.  Success would be measured as a reduction in violent events.

Drugs targeting Primary Autism Dysfunctions should show things like:-

·        Cognitive improvement
·        Increased speech
·        Improved social interactions
·        Reduction in stereotypy
·        Reduction in anxiety (in higher functioning cases)

So I could classify my own interventions as


·        Bumetanide
·        Low dose Clonazepam
·        NAC
·        Sulforaphane (broccoli)
·        Atorvastatin
·        Potassium


·        Verapamil
·        Sytrinol/Tangeretin PPAR-γ agonist for microglia

·        Occasional use of Ibuprofen (anti IL-6 therapy)
·        Quercetin/Azelastine/ Fluticasone Propionate for mast cells

The over activated immune system/activated microglia needs a trigger

Just like a modern plastic explosive is completely harmless to touch and needs the combination of extreme heat and shock wave from a detonator, it appears that the activated microglia, commonly found in autism, is in itself harmless, like Play-Doh, without a trigger.

But with a trigger, you probably know what can happen next.

What about all those failed clinical trials? False Negatives?

So now you not only need to match the trial therapy with the correct sub-type of autism, but you also cannot reliably trial a drug for a Primary Dysfunction, if there is an "active" Secondary Dysfunction.

This is indeed the reason why I do not try new therapies during the summer pollen season.

Perhaps this partly explains why clinical trials in autism always seem to fail.