Out with the old and in with the new? Maybe for iPhones but not for Autism therapies

 

It is important to move with the times, but it is equally important to realize that some old ideas remain better than some new ideas.

I was both pleased and surprised that my new car came with a full sized spare wheel in the boot/trunk. Where we live you can expect at least one puncture a year. In theory you do not need a spare wheel because cars rarely have punctures and you can carry an aerosol spray that will temporarily inflate the tire and fill a small hole. Some cars have skinny space-saver spare wheels. Neither of these is actually a good alternative.  

Old vs new autism therapies

People definitely are interested in new and “cutting edge” therapies for autism.

I was recently contacted again by a reader of this blog who has been struggling to control self injurious behaviors in her child for years. I have provided many ideas that have each worked a sub-group of those with SIB. One idea I had not yet suggested was Memantine/Namenda.

Memantine is a cheap, old, and not very effective Alzheimer’s drug.

It blocks NMDA receptors in the brain to prevent excessive stimulation by glutamate. It does actually have many other modes of action.

It has weak inhibitory effects on L-type calcium channels that add to its neuroprotective profile. This secondary mechanism helps regulate calcium influx, protect neurons from excitotoxicity, and mitigate oxidative stress, making it beneficial for managing various neurodegenerative and excitotoxic conditions.

Memantine has mild inhibitory effects on AMPA receptors, reducing overall excitotoxicity.

Memantine may block certain sodium ion channels, which can reduce neuronal excitability and help prevent excitotoxicity.

Memantine has been found to interact with serotonin (5-HT3) receptors, modulating their activity, which might contribute to cognitive and mood improvements.

Memantine reduces microglial activation, which is associated with neuroinflammation. This anti-inflammatory action can protect against secondary neuronal damage in neurodegenerative conditions.

By preventing excessive calcium influx through NMDA receptors, memantine reduces the production of reactive oxygen species (ROS), protecting neurons from oxidative damage.

Memantine's ability to stabilize calcium homeostasis helps maintain mitochondrial function, reducing energy deficits and apoptosis (programmed cell death).

Memantine may enhance synaptic plasticity by reducing pathological over activation of glutamate receptors. This improves synaptic connectivity and cognitive function.

Some studies suggest that memantine may partially activate or modulate nicotinic acetylcholine receptors, which are important for attention and memory.

Memantine may increase brain-derived neurotrophic factor (BDNF) levels, promoting neuronal survival and plasticity.

Memantine as a treatment for SIB in some, but a cause of it in others

It is clear from the above summary of Memantine’s modes of action that it should indeed be effective for some people’s SIB (self injurious behavior). Unfortunately, all these changes in the excitatory-inhibitory balance can cause problems in some other people where Memantine actually causes SIB.

Too much glutamate can be very damaging

Glutamate excitotoxicity refers to the pathological process in which excessive activation of glutamate receptors, particularly NMDA and AMPA receptors, leads to over-excitation of neurons. This over-excitation can result in cellular dysfunction, oxidative stress, and ultimately neuron death. It is a common mechanism underlying many neurological and neurodegenerative conditions.

NMDA and AMPA receptors, over activated by the high levels of glutamate, trigger a massive influx of calcium (Ca²⁺) ions into neurons.

High intracellular Ca²⁺ levels disrupt cellular homeostasis. It activates enzymes that damage cellular structures it causes oxidative stress, mitochondrial dysfunction and eventually cell death.

Elevated intracellular Ca²⁺ from allergy causing elevated glutamate and SIB

As we know from this blog, some SIB is triggered by allergy. You can halt it via treating the allergy, blocking the L-type calcium channels or targeting other inflammatory pathways.

In this allergy-driven self injurious behavior (SIB), glutamate is likely a significant downstream effector. Allergic reactions and inflammation can disrupt calcium homeostasis and activate pathways that increase glutamate signaling, leading to heightened excitotoxicity and contributing to behaviors such as SIB.

Allergic reactions significantly impact calcium homeostasis, primarily through the activation of immune cells, release of inflammatory mediators, and systemic effects on calcium metabolism. These disruptions contribute to the symptoms and complications of allergic diseases and highlight potential therapeutic targets to restore calcium balance.

When allergens bind to IgE on mast cells or basophils, they activate receptors that trigger intracellular calcium release from the endoplasmic reticulum (via IP3 signaling). Recall Prof Gargus proposed IP3 signaling as a nexus point in autism.

Is dysregulated IP3R calcium signaling a nexus where genes altered in ASD converge to exert their deleterious effect?

This calcium influx promotes the degranulation of histamine, serotonin, and other inflammatory mediators.

Abnormal calcium levels may trigger unregulated, spontaneous release of glutamate, even in the absence of an action potential.

Elevated calcium levels can impair the function of glutamate transporters (e.g., EAATs), responsible for clearing excess glutamate from the synaptic cleft.

Dysfunctional transporters exacerbate extracellular glutamate accumulation, amplifying excitotoxicity.

Memantine in broader autism

Memantine was extensively studied in a large clinical trial in autism that concluded that it was no better than a placebo.

You might well conclude that the matter should end there.

Memantine for Aspies

While looking for information about Memantine for SIB I came across some very positive reviews from Aspies.

If you believed social media you would think that people with level 1 autism are all anti-treatment and see autism as their superpower. In fact the majority of people contacting me about treating autism are actually those with level 1 autism and their parents.

I am really much more familiar with treatments for level 3 autism.

The symptoms may be slightly different, but the potential therapies are exactly the same.

 

https://www.drugs.com/comments/memantine/for-autism.html

"A life saver. I have autism. It is pretty bad autism. I saw help on day one. But it isn't a fix-it-all for me. Being able to understand nonverbal communication and verbal communication is huge improvements. This helps me with social interaction. This helps me with anxiety. Helps my expressive myself and respond better. Less meltdowns. Helps my cognitive functions. Helps me think. Helps my thought issue due to my autism and auditory processing disorder. Helps me slow down my mind to pay attention more and can respond to changes and sensory problems. Not a full fix for me but huge help. I am more polite. I can talk about others' interests not just my needs or wants or questions that I had trouble asking. Better behavior." 

"I was first prescribed this for Asperger's syndrome at the age of 24. I've been on numerous types of medications since I was a teenager, but this is the first one that I've been on that has significantly helped. My quality of life is much better. I don't have as many ruminating, obsessive thoughts that make me miserable." 

"I take 20 mg of memantine for my slight autism! And this has been a miracle drug! It helps me in social interactions, I can recognize social cues and skills that I couldn't before! It also helps with my obsessive and aggressive problems! Thank you to whoever made this drug." 

"I take 10 mg twice daily for autism spectrum disorder. It stops the intrusive thoughts, rumination, and repetitive thinking, which is a godsend. It also reduces repetitive behavior/stereotypes. I haven't noticed any side effects, maybe a little brain fog, but that has disappeared with continued use."

"Memantine has helped my social anxiety greatly, not through direct anxiolysis, but indirectly through dissociation from reality, albeit mild. It works perfectly for sensory overload as the autistic brain does not filter out unnecessary external stimuli due to NMDAR current blockade, similar to endogenous magnesium. Amazing, wonderful."

 

Conclusion

Don’t ignore all the therapies from the last 50 years and jump to the latest expensive therapy that is trending. You may after all find one of the oldies like Propranol, Pentoxifylline, Zoloft, Baclofen or Memantine is your Gamechanger. They each worked for some people.

Even though it failed in its phase 3 clinical trial, Memantine continues to have its believers. It is a cheap safe drug that clearly does provide a benefit to a sub group of autism that includes all levels of severity. It clearly does not work for all Aspies, but it certainly is worth trialing.

I think understanding glutamate excitotoxicity is very useful if you are trying to figure out a case of self injurious behavior.

In individuals where the GABA developmental switch has not occurred, oral GABA supplementation could potentially exacerbate glutamate excitotoxicity and trigger/worsen self injurious behavior. These are the people who react badly to benzodiazepine drugs and should respond very well to bumetanide.

Memantine – yet another failed Autism Trial

Memantine (Namenda/ Ebixa) is an Alzheimer’s drug that has been used off-label in autism for many years; but does it actually work?

More than a thousand people with autism have completed clinical trials and yet more trials are in progress. 

A few years ago, at the FDA’s request, the producer of the drug, Forest Laboratories, funded two clinical trials enrolling 903 children with autism.  The results were never fully published because the trials were deemed to have failed to find any positive effect and a note to reflect this is included in each pack of Namenda.

A quick look at ClinicalTrials.gov website shows yet more autism trials in the pipeline.

What is going on?

When Dr Chez made a trial in 2007 he found Memantine to be effective; he has since moved on to stem cell therapy which he also finds to be effective.

The latest study to be published includes Dr Hardan from Stanford, who published that study showing NAC to be effective in autism.  This time his study shows no positive effect.

If you look on the clinical trials site you can see some data for the primary endpoint used in the very big trial funded by Forest Laboratories.  It seems to show 517 responders.

By the time the results were reviewed in detail the conclusion drawn by Forest was “there was no statistically significant difference in the loss of therapeutic response rates between patients randomized to remain on full-dose memantine (n=153) and those randomized to switch to placebo”. 

In other words it does not work.

The drug itself now carries this note:-

8.4 Pediatric Use

The safety and effectiveness of memantine in pediatric patients have not been established.

Memantine failed to demonstrate efficacy in two 12-week controlled clinical studies of 578 pediatric patients aged 6-12 years with autism spectrum disorders (ASD), including autism, Asperger’s disorder, and Pervasive Development Disorder — Not Otherwise Specified (PDD-NOS). Memantine has not been studied in pediatric patients under 6 years of age or over 12 years of age. Memantine treatment was initiated at 3 mg/day and the dose was escalated to the target dose (weight-based) by week 6. Oral doses of memantine 3, 6, 9, or 15 mg extended-release capsules were administered once daily to patients with weights < 20 kg, 20-39 kg, 40-59 kg and ≥ 60 kg, respectively.

In a randomized, 12-week double-blind, placebo-controlled parallel study (Study A) in patients with autism, there was no statistically significant difference in the Social Responsiveness Scale (SRS) total raw score between patients randomized to memantine (n=54) and those randomized to placebo (n=53). In a 12-week responder-enriched randomized withdrawal study (Study B) in 471 patients with ASD, there was no statistically significant difference in the loss of therapeutic response rates between patients randomized to remain on full-dose memantine (n=153) and those randomized to switch to placebo (n=158).

So if it does not work, why do researchers continue to carry out further trials, like the recent one below, including Hardan?

Safety and Efficacy of Memantine in Children with Autism: Randomized, Placebo-Controlled Study and Open-Label Extension

OBJECTIVE:

Abnormal glutamatergic neurotransmission is implicated in the pathophysiology of autism spectrum disorder (ASD). In this study, the safety, tolerability, and efficacy of the glutamatergic N-methyl-d-aspartate (NMDA) receptor antagonist memantine (once-daily extended-release [ER]) were investigated in children with autism in a randomized, placebo-controlled, 12 week trial and a 48 week open-label extension.

METHODS:

A total of 121 children 6-12 years of age with Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Text Revision (DSM-IV-TR)-defined autistic disorder were randomized (1:1) to placebo or memantine ER for 12 weeks; 104 children entered the subsequent extension trial. Maximum memantine doses were determined by body weight and ranged from 3 to 15 mg/day.

RESULTS:

There was one serious adverse event (SAE) (affective disorder, with memantine) in the 12 week study and one SAE (lobar pneumonia) in the 48 week extension; both were deemed unrelated to treatment. Other AEs were considered mild or moderate and most were deemed not related to treatment. No clinically significant changes occurred in clinical laboratory values, vital signs, or electrocardiogram (ECG). There was no significant between-group difference on the primary efficacy outcome of caregiver/parent ratings on the Social Responsiveness Scale (SRS), although an improvement over baseline at Week 12 was observed in both groups. A trend for improvement at the end of the 48 week extension was observed. No improvements in the active group were observed on any of the secondary end-points, with one communication measure showing significant worsening with memantine compared with placebo (p = 0.02) after 12 weeks.

CONCLUSIONS:

This trial did not demonstrate clinical efficacy of memantine ER in autism; however, the tolerability and safety data were reassuring. Our results could inform future trial design in this population and may facilitate the investigation of memantine ER for other clinical applications.

  

Dr Chez? 

So how reliable then are Dr Chez’s other findings?  He is a "big name" in autism research.

Back in 2007 Dr Chez published a very positive study on the use of Memantine in autism. 

Memantine as adjunctive therapy in children diagnosed with autistic spectrum disorders: an observationof initial clinical response and maintenance tolerability.

 

Abstract

Autism and Pervasive Developmental Disorder Not Otherwise Specified are common developmental problems often seen by child neurologists. There are currently no cures for these lifelong and socially impairing conditions that affect core domains of human behavior such as language, social interaction, and social awareness. The etiology may be multifactorial and may include autoimmune, genetic, neuroanatomic, and possibly excessive glutaminergic mechanisms. Because memantine is a moderate affinity antagonist of the N-methylD-aspartic acid (NMDA) glutamate receptor, this drug was hypothesized to potentially modulate learning, block excessive glutamate effects that can include neuroinflammatory activity, and influence neuroglial activity in autism and Pervasive Developmental Disorder Not Otherwise Specified. Open-label add-on therapy was offered to 151 patients with prior diagnoses of autism or Pervasive Developmental Disorder Not Otherwise Specified over a 21-month period. To generate a clinician-derived Clinical Global Impression Improvement score for language, behavior, and self-stimulatory behaviors, the primary author observed the subjects and questioned their caretakers within 4 to 8 weeks of the initiation of therapy. Chronic maintenance therapy with the drug was continued if there were no negative side effects. Results showed significant improvements in open-label use for language function, social behavior, and self-stimulatory behaviors, although self-stimulatory behaviors comparatively improved to a lesser degree. Chronic use so far appears to have no serious side effects.

Making sense of Memantine

Personally, I think it likely that Memantine may indeed have a positive effect in some people with autism.  For most people it probably does no good, but no harm, so it is a harmless placebo that may make the parents feel better and gives the doctor something to prescribe.

Memantine and the very similar Galantamine probably do deserve a place in the long list of drugs and supplements that may be effective in some people.  But how great is that “effect”?  I suspect this is the problem; it is big enough for Dr Chez but not big enough for the others.

I suspect this will be a recurring problem in almost all future autism drug trials.  What is a responder?  How big an effect is a worthwhile effect?

I think a better approach would be to focus on the so-called responders identified by Dr Chez and others.  Document the claimed positive effects and then see if these effects continue when the responders are given a dummy placebo.

This is the approach I use in my trials; when I stop a therapy, I look to see if there is a change.  When you suspend an effective therapy things should get worse.

The hundreds or thousands of kids currently on Memantine should do the same; take a break and see if there is any change, be it positive or negative. 

Many people believe no valid treatments for autism exist and that those thinking otherwise are all deluded.

I think that many people are giving their kids drugs and supplements of no therapeutic value and in some cases are making the situation worse.

However, effective therapies do exist for many people with autism and they stand up to scrutiny.  The effect is apparent to third parties, like teachers and therapists, and when you stop the therapy the positive effect is lost and people notice, only to return when it is restarted.  Then you know it is not wishful thinking and at that point what the FDA says does not really matter and you do not need bother with what subsequent trials say.

So when a reader asked me what I thought about the recent “failed” trial of NAC, to treat social impairment in autism, I took a very relaxed view.  If they had identified 50 kids with classic autism and stereotypy and looked at whether NAC reduced this, I would take note.  They choose the wrong primary endpoint, social impairment, and wasted a lot of money.

A randomized placebo-controlled pilot study of N-acetylcysteine in youth with autism spectrum disorder

Conclusions
The results of this trial indicate that NAC treatment was well tolerated, had the expected effect of boosting GSH production, but had no significant impact on social impairment in youth with ASD.

      

I only wait to see what happens when Ben Ari publishes the results of his large trial on Bumetanide.  Whatever data they choose to collect, is it going to convince the European Medicines Agency that it is an effective therapy?  I hope so, but nothing would surprise me.

I would love to know how Dr Chez rationalizes the fact that so many others cannot replicate his positive research findings.  But he keeps on going.

Rather off-topic, a recent comment on my post on Clonidine, informed us that this drug, often prescribed off-label in autism and ADHD, really is acting as a sedative to calm the person down. So no effect on core autism.  Sedation does have a role to play in some people’s disorders.  Very low doses of Mirtazapine (Remeron) are also sedating via its effect of central H1 receptors; it occurred to me that this might be a safe long term therapy for some "out of control" people with severe autism; likely safer than the usual antipsychotics.