Folate Metabolism, the Folate Trap, and finding the right therapy for your specific autism

  

Most of the folate and folic acid we eat must be converted into the active form, known as L-methylfolate or 5-MTHF. However, some dietary folate is already in the active form when we eat it and therefore does not rely on MTHFR.

In treating autism, folate metabolism is a key area of therapeutic focus. While folate supplementation seems simple on the surface, the biology behind it is complex — and, if misunderstood, you may even worsen symptoms.

This post explains how folate metabolism works, what the methyl folate trap is, and how different folate and B12 formulations affect outcomes in children and adults with autism, especially those with MTHFR, MTR, or MTRR mutations.

The Normal Folate Cycle 

Folate, a B-vitamin, plays a central role in:

• DNA synthesis 
• Methylation 
• Neurotransmitter production (via SAMe) 

Here is how it works, if you like details:  

• 5,10-methylene-THF helps make thymidine (for DNA).
• Some of this is converted to 5-MTHF by MTHFR.
• 5-MTHF donates a methyl group to homocysteine, converting it to methionine, in a process catalyzed by methionine synthase, which requires vitamin B12.
• This regenerates THF, which goes back into the cycle.

 

The Methyl Folate Trap

 

If there is a vitamin B12 deficiency, or methionine synthase (MTR) dysfunction, the conversion of 5-MTHF → THF is blocked. This causes:

·         5-MTHF to accumulate (it’s “trapped”)

·         THF and 5,10-methylene-THF to fall

·         DNA synthesis to halt

·         Elevated homocysteine, and low SAMe

The result:

·         Anemia

·         Neurological symptoms

·         Behavioral worsening in autism

This is known as the methyl folate trap — and it explains why giving high-dose folate without enough B12 can backfire.

In summary, the methyl folate trap occurs when B12 deficiency or methionine synthase dysfunction prevents 5-MTHF from recycling to THF, stalling DNA synthesis and methylation, even if folate levels are high.

  

Could the Folate Trap Cause Aggressive or Behavioral Regression?

Yes. In autism, worsening behaviors (irritability, aggression etc) after high-dose folinic acid may reflect a relative B12 deficiency or impaired methionine synthase, leading to:

·    Folate trapping

·   Disrupted neurotransmitter synthesis (especially dopamine/serotonin)

·    Low SAMe

In these cases, adding B12 (methylcobalamin or hydroxycobalamin) often improves tolerance to folate therapy and reduces side effects.

 

Other reasons for a possible negative reaction to calcium folinate

Folate metabolism is tightly connected to glutamate and GABA balance.

High folate dosing in some sensitive individuals may cause excess glutamate activity (excitatory), triggering aggression or anxiety-like behaviors.

Children with fragile neurochemical balance may not tolerate sudden shifts in methylation or neurotransmitter levels. A rapid increase in serotonin, dopamine, or norepinephrine can destabilize mood or cause agitation/aggression. This is why you start low and gradually increase your folate supplement.

In such children 5-MTHF may work better, but you still B12.

Apparently, some doctors prescribe antipsychotics to treat agitation caused by calcium folinate; I am not sure that is a good idea.

 

 Choosing the Right Folate: Folinic Acid vs 5-MTHF

	Calcium Folinate / Leucovorin	5-MTHF
Form	Precursor to 5-MTHF	Final active form
Requires MTHFR?	Yes	No
Can enter CSF?	Indirectly	Directly
Behavioral reactions?	More common in some	Usually better tolerated

For whom is 5-MTHF better?

1.      Those with MTHFR mutations (esp. C677T)

2.      Those who react negatively to folinic acid

3.      Those needing direct CNS access

Folinic acid /Leucovorin is converted to 5-MTHF (active folate) through a series of enzymatic steps. First, it is converted into 5,10-methylenetetrahydrofolate, and then the enzyme MTHFR  converts it to 5-MTHF.

In people with MTHFR mutations, this final step may be slower or impaired, meaning folinic acid may not fully convert to active folate. Direct supplementation with 5-MTHF is often preferred in those with these genetic variants.

 

  

The Problem with Synthetic Folic Acid

 Status of mandatory folic acid fortification in 2019

 

In countries like the US folic acid is added to many foods such as flour, bread, pasta and rice in addition to products like breakfast cereals. This is to reduce the incidence of neural tube defects like spina bifida that occur when a fetus lacks sufficient folate in the first 28 days of life.

In Europe there is much less mandatory supplementation of folic acid due to the negative effects. In older people folic acid supplementation can mask vitamin B12 deficiency. High intake of synthetic folic acid can correct the anemia caused by B12 deficiency without correcting the neurological damage. This can lead to delayed diagnosis of B12 deficiency, increasing the risk of irreversible nerve damage, cognitive decline, and dementia in the elderly.

Folic acid is synthetic and must be converted by DHFR (slow, limited in humans).

It competes with both folinic acid and 5-MTHF for cellular entry.

High levels of unmetabolized folic acid can block folate receptors and worsen autism symptoms in some.

Some people with autism should avoid folic acid supplements and fortified foods.

 

The Dilemma: One Size Does not Fit All

While folic acid fortification benefits the general population, especially women of childbearing age, it may pose risks for other groups:

·    Elderly: Risk of masking B12 deficiency

·    Children with autism or FRAA: Risk of blocked folate receptors and behavioral regression

·    Those with MTHFR variants. They have reduced ability to activate folic acid because their ability to convert folic acid into the active form, 5-MTHF, is reduced. This can lead to unmetabolized folic acid (UMFA) in the blood, which may interfere with normal folate metabolism. It can lead to blocking the transport of natural folates into the brain.

 

Here is a study showing that folic acid impairs the transport of active folate (5-MTHF) across the blood brain barrier.

 

Folic acid inhibits 5-methyltetrahydrofolate transport across the blood–cerebrospinal fluid barrier:Clinical biochemical data from two cases

Results: Both patients had low CSF 5MTHF before treatment and high-dose FA therapy did not normalize CSF 5MTHF. There was a dissociation between serum total folate and 5MTHF concentrations during FA therapy, which was considered to be due to the appearance of unmetabolized FA. The addition of folinic acid did not improve low CSF 5MTHF in the KSS patient and the cessation of FA resulted in the normalization of CSF 5MTHF. In the patient homozygous for MTHFR C677T, minimization of the FA dosage resulted in the normalization of CSF 5MTHF and an increased CSF-to-serum 5MTHF ratio.

Conclusions: Our data suggest that excess supplementation of FA impaired 5MTHF transport across the blood-CSF barrier. In the treatment of CFD, supplementation of folinic acid or 5MTHF (in cases of impaired 5MTHF synthesis) is preferred over the use of FA. The reference values of CSF 5MTHF concentration based on 600 pediatric cases were also provided.

  

B12 - Forms and why it matters

To prevent the folate trap, adequate B12 is critical.

                          

Methylcobalamin        Active, supports methylation directly

Hydroxycobalamin      Longer-lasting, converted to methyl- or adeno-B12

Adenosylcobalamin     Active in mitochondria

Cyanocobalamin         Synthetic, less ideal, may not work in autism

 

Methylcobalamin or hydroxycobalamin are best for autism and CFD.

 

Can it be oral?

Yes, but high doses needed (1–5 mg daily)

Subcutaneous injections may be better absorbed in some

 

What About Betaine / TMG?

Betaine (trimethylglycine) provides methyl groups to convert homocysteine to methionine via the BHMT pathway (mostly in the liver, not brain).

Useful if:

·         Homocysteine is high

·         B12 metabolism is impaired

·         Need extra methylation support

 But, it does not bypass the folate trap in the brain — you still need functional methionine synthase and B12.

 

When Do You Need More SAMe?

SAMe (S-adenosylmethionine) is the body’s master methyl donor, essential for: 

·         Neurotransmitter synthesis

·         Myelination

·         Detox pathways

 

You may need extra SAMe if:

·         You have low methionine/SAMe

·         There is fatigue, depression, or tics

·         Homocysteine is high despite folate + B12

Oral SAMe is poorly absorbed unless enteric-coated.

Do not assume “more folate = better” without addressing B12

 

Conclusion

Whether a person with autism stands to benefit from tuning up their folate metabolism will depend on their unique situation. Many people need no intervention at all.

For others it is highly beneficial to customise an intervention plan. It would include some, or all, of the following. 

·   Reduce expose to synthetic folic acid used to fortify flour, pasta, bread, rice, breakfast cereals etc.

·   Supplement with 5-MTHF or calcium folinate / Leucovorin

·   Supplement vitamin B12, in the form of methylcobalamin or hydroxycobalamin

·    Supplement Betaine/TMG

·    Supplement SAM

     ·  Consider supplementing PQQ if positive for FRAA 

 

The only substance that is prescription-only is calcium folinate / Leucovorin. It looks like 5-MTHF is actually the better choice for most people and it is much more accessible.

We have seen that the potency of generic calcium folinate / Leucovorin is highly variable, possibly due to different excipients that are added. How reliable the OTC 5-MTHF supplements are is an open question.

If you find this subject confusing, use ChatGPT to help you. You can even upload a screenshot of your MTHFR/MTR/MTRR mutations and then get tailored advice. It is free !!  (for now)

 

If you are someone who likes lab tests, the options include: 

• Folate receptor antibodies (FRAA) – to check for blocking autoantibodies www.fratnow.com
• Serum and CSF 5-MTHF – to detect cerebral folate deficiency
• Homocysteine – elevated if methylation is impaired
• MMA (methylmalonic acid) – elevated in B12 deficiency
• Vitamin B12 – ideally with active B12
• Genetic testing – particularly MTHFR, MTR, and MTRR variants to assess methylation capacity

High MMA = likely B12 deficiency, even if serum B12 is "normal".

This is especially important in people with neurological symptoms or MTHFR-related metabolism issues.

 

Measuring serum (blood) 5-MTHF provides insight into how much active folate is circulating in the body. This helps detect:

• Folate trap from B12 deficiency (high folate, low methylation)
• Impaired folate metabolism in MTHFR or MTR/MTRR variants
• Folate absorption or transport problems, especially if CSF 5-MTHF is also tested
  It’s particularly useful when deciding whether folinic acid, 5-MTHF, or B12 supplementation is effective or needed.

CSF 5-MTHF (cerebrospinal fluid via lumbar puncture) gives a direct measure of active folate availability inside the brain. This is important because:

• Some children with autism or FRAA (folate receptor autoantibodies) have low CSF 5-MTHF even with normal blood folate. Some have FRAA and normal CSF 5-MTHF
• High serum folic acid can block transport of 5-MTHF into the brain, lowering CSF levels.
• It can help diagnose Cerebral Folate Deficiency (CFD), especially if symptoms improve with folinic acid.

Low CSF 5-MTHF with normal serum levels suggests a transport problem, not a folate intake issue.

PQQ as a Folate Transport Enhancer

A supplement called Pyrroloquinoline quinone (PQQ) may help bypass folate receptor autoantibody (FRAA) blockage by upregulating alternative folate transporters (RFC and PCFT) in the brain. This could improve delivery of both calcium folinate (leucovorin) and 5-MTHF into the brain when folate receptor alpha (FRα) is blocked.

Human data is lacking; all evidence from animal/cell studies. Some people report adverse effects (e.g. fatigue, overactivation)

For individuals with FRAA, PQQ might enhance the effectiveness of folinic acid or 5-MTHF by improving alternative transport into the brain.

Suramin - Why do Clinical Trials in Autism Struggle to be Convincing? And Oxytocin fails in a large trial.

 

Results from the PaxMedica trial of Suramin

For me, Bumetanide for Autism is now ten-year-old news, for us it has been working since 2012; the next interesting drugs in the pipeline include Suramin and Leucovorin.

It is extremely difficult to trial Suramin at home, or indeed anywhere, and this makes it ever more desirable to many parents.

Leucovorin (calcium folinate) is easy to obtain; you can even buy liquid calcium folinate from iHerb.  You can find out pretty quickly if it produces a profound benefit on your child’s type of autism.

I wish Dr Frye and Professor Ramaekers good luck with the phase 3 trial of Leucovorin.  It certainly works for our adult reader Roger, but not for my 18 year old son, Monty.  Our reader SB’s child recently joined the group of confirmed responders.

After I started writing this post, the results came in of a large (250 children) trial of intranasal oxytocin.  This trial failed to show any benefit, over the placebo, in increasing social behaviors in autistic children. As I have mentioned previously, there is an inherent problem with intranasal oxytocin, the hormone has a very short action, its half-life is 2-6 minutes. It would be much more effective to provide a sustained release of oxytocin, which can indeed be achieved via adding a specific bacterium to the gut. The other problem with intranasal delivery is that you are not supposed to inhale the drug into your lungs, it has to stay in upper part of your nose. How likely is it that parents/children use the spray correctly?  There is even a special dispenser developed for drug delivery to the brain, but did they use it?

In my trials of L. reuteri DSM 17938 it was obvious that the oxytocin improved social behaviors, but I concluded that this was not such a big deal and certainly was not a treatment priority. How would you assess the effect? Very simple, you just count how many times your child is shaking boys’ hands and kissing the girls. I don’t suppose that was the measurement that Duke University used.

Many parents do use Syntocinon nasal spray and this failed trial does not mean they are imagining the effects.  If I was them, I would try L. reuteri DSM 17938 and compare the effect and use whichever is the most beneficial.

  

Suramin 

Suramin is moving towards its Phase 3 clinical trials and, very unusually, two different companies are trying to commercialize the same drug.  One company is PaxMedica and the other is Kuzani, who are ones that cooperate with Dr Naviaux.

In the background is Bayer, the German giant, who have been making Suramin for a hundred years as a therapy for African sleeping sickness and river blindness.  We are told that making Suramin is quite difficult, it is a large molecule; but if they could make it a century ago, how difficult can it really be?  The reality appears to be that Bayer do not want to supply PaxMedica or Kuzani and so they will have to figure out how to make it.  Suramin is sold as a research chemical, but there seem to be questions about its purity. The very cheap Suramin sold on the internet is very likely to be fake.

Today we will look at the data from the South African trial carried out by PaxMedica and take a look at their patent for their intranasal formulation.

We have heard very positive anecdotal reports from the very small initial trials carried out by Professor Naviaux.  Naviaux himself is very interesting, because even though he is not an autism researcher, he is far more knowledgeable than almost all of them on the subject of autism. If you read his papers, they show a rare global understanding of the subject.  This “big picture” is what you need to understand such a heterogenous condition as autism.

In the PaxMedica trial, 44 children completed the trial, so that should be enough to tell us something insightful about whether this drug is effective.

A recurring problem in all autism trials is how well the placebo performs.  Here again in the Paxmedica data we have a very impressive blue line – the placebo.  It is just salt and water and yet it is nearly as good as the trial drug (the orange line).

 

A big part of clinical trials is the statistics used to validate them.

Although I do have a mathematical background, I believe in “seeing is believing”.  The data should be crying out to you what it means.  If it is so nuanced that it needs a statistician to prove the effect, there likely is no effect.

In the above chart we want to see a decreasing slope that would possibly level off as the drug achieved its maximum effect.

What we see are two apparently effective therapies, blue and orange. 

The problem is that blue line is just water, with a bit of salt.

 

Show me the data

What we really want to see are results of each of the 44 participants, not the average.

There are likely groups:

·        Super responders

·        Responders

·        Partial responders

·        Non-responders

 

No statistician is needed.

 

The data from the Suramin trial needs to be presented in the kind of form used in the stem cell trial below:-

Since many hundreds of different biological conditions can lead to an autism diagnosis, we really should not expect there to be any unifying therapy that works for everyone.  Indeed, we should perhaps be suspicious of any therapy claimed to work for everyone.

We always get to hear about the super-responders in anecdotal reports.

We heard great things about Memantine/Namenda, but the phase 3 trial was a failure.  We heard great things about Arbaclofen (R-Baclofen), but the phase 3 trial failed. In Romania our reader Dragos is currently seeing great benefits from the standard version of Baclofen (a mixture of R-Baclofen and S-Baclofen).

My son is a super-responder to Bumetanide, but I know that most people are not. However, when I came across the “bumetanide has stopped” working phenomena, it became clear that the situation is more complex than a single one-time evaluation. We know why bumetanide can “stop working” and how to make it “start working again”.  An increase in inflammatory cytokines from the periphery (i.e. outside the brain) further increases the expression of NKCC1 in the brain and negates the effect of bumetanide; reduce the inflammation and bumetanide will start to work again.

  

Why does the placebo always do well in autism trials?

The assessments used to measure outcome are all observational, they are not blood tests or MRI scans.  They are highly subjective.

It has been suggested that just being in an autism trial improves symptoms of autism.  The parents give more attention to the child and this then skews the results.

My way round this problem in my n=1 trials was always to tell nobody about the new trial I was making and wait for unprompted feedback.  This works really well.

 

 

Who chooses the trial goal (the primary endpoint)?

I like the fact that in the Leucovorin trial the goal is speech.  It is a very simple target and relatively easy to measure.

For Bumetanide, I did suggest to the researchers that they used change in IQ as an endpoint.  Nice and simple, start with kids with IQ<70 and then recruit those who have a negative reaction (paradoxical response) to Valium/diazepam.  Then expect an increase in measured IQ of 10 to 40 points.  Then you would have a successful phase 3 trial.    

In many previous trials that ultimately failed, some people did see a benefit, but they were different benefits.  I did get a reader telling me how great Memantine (Namenda) had been for her child, when I asked why she told me that it was the only therapy that had ever solved her child GI problems.  That certainly was never considered as a trial goal/endpoint.

In my trial of Pioglitazone, I read the research about both the mechanism of action and the observed effects listed in the phase 2 trial:

"improvement was observed in social withdrawal, repetitive behaviors, and externalizing behaviors as measured by the Aberrant Behavior Checklist (ABC), Child Yale-Brown Obsessive Compulsive Scale (CY-BOCS), and Repetitive Behavior Scale–Revised (RBS-R)."

I was targeting something entirely different.  Based on the mechanism of action, specifically the reduction of the inflammatory cytokine IL-6, I expected a reduction in summertime raging.  It worked exactly as hoped for. This is the second summer we have used it.

Our reader Sara’s initial assessment of the effect of Pioglitazone is focused on the improvement in sleeping patterns.  This is great, assuming the benefit is maintained, but it is an entirely different benefit.

 

Was the trial drug actually taken?

I suspect in the bumetanide trial, many parents did not give the trial drug every day, as per their instructions, because the diuresis was too much bother.  I know from reader comments and emails that many parents stop giving bumetanide, even though their child is a responder.  Some schools refuse to allow bumetanide because of the disruption caused by frequent toilet breaks.

Because Suramin is given once a month by infusion, there is 100% certainty that the drug or placebo was actually taken.  This is a big plus.

Was the intranasal oxytocin correctly administered in the recent trial? I doubt it.

The problem with Leucovorin is that in a minority of children is causes aggression, even if you follow Prof Ramaeker’s advice and very slowly increase the dosage.  In the phase 3 trial parents should be informed of this possibility and told to report it and be invited to withdraw from the trial.  If they just stop the therapy to halt the aggression, but their data remains included in the study, the results are invalidated.

 

Intranasal Suramin

Patents are often a good source of information and they do also tell you something about the people who wrote them.

Here below is PaxMedica's patent for intranasal suramin:-

Compositions and methods for treating central nervous system disorders

These results demonstrate that an antipurinergic agent such as suramin can be delivered intranasally to achieve plasma and brain tissue levels and that variations in the brain tissue to plasma partitioning ratio can be observed. These results demonstrate that an antipurinergic agent such as suramin can be delivered to the brain of a mammal by intranasal (IN) administration. 

The following Table 1 provides the averaged accumulated amount, in mg, of suramin that has penetrated as a function of time

But how can the accumulated level after 6 hours be less than after 5 hours?

The results of the study are also shown graphically in FIG. 1 where the cumulative amount (mg) of drug permeated was plotted versus time in hours. These data demonstrate that Formulation B containing methyl β-cyclodextrin (methyl betadex) provides significantly better penetration, versus Formulations, A , C, and D in the tissue permeation assay. Also, as is seen from a comparison of Formulations A and D, having a higher drug concentration can be advantageous to increasing permeation.

 

Formulation A - suramin hexa-sodium salt at 100 mg/mL in water (no excipients) Formulation B - suramin hexa-sodium salt at 100 mg/mL in water, with 40% methyl β-cyclodextrin (methyl betadex) Formulation C - suramin hexa-sodium salt at 100 mg/mL in water, with 40% HP (hydroxyl propyl) -cyclodextrin Formulation D - suramin hexa-sodium salt at 160 mg/mL in water (no excipients)

 

FIG. 7 shows a plot comparing the total percentage of suramin in plasma in mice when administered by intraperitoneal (IP) injection once weekly for 4 weeks (28 days), intranasally (IN) daily for 28 days, intranasally (IN) every other day for 28 days, and intranasally (IN) once per week for 4 weeks (28 days).

 

FIG. 8 shows a plot comparing the total percentage of suramin in brain tissue in mice when administered by intraperitoneal (IP) injection once weekly for 4 weeks (28 days), intranasally (IN) daily for 28 days, intranasally (IN) every other day for 28 days, and intranasally (IN) once per week for 4 weeks (28 days).

 

Does anyone think the above chart makes any sense? 

 

The mice were maintained in group cages (6 mice per cage based on treatment group) in a controlled environment (temperature: 2 1.5 ± 4.5 °C and relative humidity: 35-55%) under a standard 12-hour light/1 2-hour dark lighting cycle (lights on at 06:00). Mice were accommodated to the research facility for approximately a week. Body weights of all mice were recorded for health monitoring purposes.

The mice were divided into the following 5 test groups, with 6 mice per group.

Group 1: Intraperitoneal (IP) injection of suramin, 20 mg/kg, administered weekly to animals beginning at 9 weeks of age and continuing for four weeks (i.e. given at Age Weeks 9 , 10 , 11 and 12). The suramin was formulated in Normal saline solution.

Group 2 : Intraperitoneal (IP) injection of saline, 5 mL/g, administered weekly to animals beginning at 9 weeks of age and continuing for four weeks (i.e. given at Age Weeks 9 , 10 , 11 and 12). This was a control group.

Group 3 : Intranasal (IN) administration of a formulation, described below, of suramin, at a concentration of 100 mg/mL x 6 mL per spray, administered as one spray per nostril, one time per day, (interval of each application is around 2 minutes to ensure absorption) for 28 days (total of 56 sprays over 28 day period) beginning at 9 weeks of age (i.e. given daily during Age Weeks 9 , 10 , 11 and 12).

Group 4 : Intranasal (IN) administration of a formulation, described below, of suramin, at a concentration of 100 mg/mL x 6 mL per spray, administered as one spray per nostril, one time every other day, for 28 days (total of 28 sprays over 28 day period) beginning at 9 weeks of age (i.e. given once every other day during Age Weeks 9 , 10, 11 and 12).

Group 5 : Intranasal (IN) administration of a formulation, described below, of suramin, at a concentration of 100 mg/mL x 6 ml_ per spray, administered as one spray per nostril, one time every week, for 4 weeks (28 days) (total of 8 sprays over 28 day period) beginning at 9 weeks of age (i.e. given once weekly during Age Weeks 9 , 10 , 11 and 12).

 

This question was posed to me:-

A nasal spray in a human is about 0.1 ml, how do you give a tiny mouse 6 ml per nostril?  Even 0.6 ml looks implausible.

 

Conclusion

Will Suramin pass a phase 3 trial?  I think if it is trialed on a random group of 400 young people with moderate or severe autism, it will very likely fail.

Professor Naviaux believes Suramin may be a unifying therapy, one that works in all autism.  The results from the PaxMedica study do not support this.

PaxMedica has the data showing the individual results.  Are there super-responders? Are there non-responders? Does Suramin perhaps make some people's autism worse?  All we can see is the average response, which is marginally better than the placebo; not what we expected after seeing the initial study.

Expecting Suramin to work well for everyone is raising the bar too high.  Try and identify markers for the responders and super-responders and then limit the phase 3 trial to these people.

Is intranasal delivery of Suramin going to achieve a therapeutic level inside the human brain?  Hopefully yes, but it may not work.

Is long term use of Suramin going to be safe? Will it require ever-increasing doses? Nobody knows, and note that safety was the original concern when Suramin’s use was proposed by Naviaux.

Intranasal administration has the best chance of being totally safe.  Spend a little extra money on the clever dispenser covered in this old post, that keeps 100% of the drug in the right place.

 

https://epiphanyasd.blogspot.com/2015/09/opn-300-oxytocin-and-autism.html

 

Maybe get someone other than a lawyer, to proof read your patent.

 

 

Pentoxifylline – Clearly an Effective add-on Autism Therapy for some

 

They also had Pentoxifylline for autism back in the 1970s – time for a revival?

 

Pentoxifylline and other more modern PDE inhibitors have been mentioned many times in this blog.

https://epiphanyasd.blogspot.com/search/label/PDE4

https://epiphanyasd.blogspot.com/search/label/Pentoxifylline

Pentoxifylline has been used in autism clinical trials dating back almost 50 years. A casual observer would naturally assume it cannot possibly be effective, or else surely its use would have caught on by now.

Some readers have long been using a PDE inhibitor as part of their child’s autism polytherapy. People have been asking me to let them know my thoughts on Pentoxifylline, the most accessible PDE inhibitor.

I think the key is that we are talking about an add-on, or adjunct, therapy.  We are no longer talking about pentoxifylline therapy vs no therapy, as they were in the 1970s.  Even in those decades-old studies there was a sub group of “super responders”.  Either the percentage of such responders, or the “super-response” itself was just too small to create waves leading to wider adoption.

In my autism world, I had been trying to develop more expressive language using sulforaphane and calcium folinate (leucovorin). A comment from Valentina prompted me to finally start my trial of Pentoxifylline.  It became apparent that the amount of expressive language was increasing, but the major factor was the Pentoxifylline not the calcium folinate (leucovorin).  To avoid GI side effects, I give Pentoxifylline after meals, which means it does sometimes get omitted/forgotten. It emerged that expressive language was clearly correlated to whether Pentoxifylline was taken or forgotten.

Reviewing the old studies, increased use of language does get a mention as an effect of Pentoxifylline.

 

What is the biological effect of Pentoxifylline?

Pentoxifylline is a non-selective PDE inhibitor, which you might think is a bad thing, since it looks like is it just PDE4 that we want to inhibit.

Pentoxifylline is also a non-selective antagonist of adenosine receptors A₁ and A_2A that are located in both the heart and brain.  These two adenosine receptors have important roles in the brain, regulating the release of other neurotransmitters such as dopamine and glutamate.

Pentoxifylline is normally prescribed because of its effects on your blood.  It improves red blood cell deformability, reduces blood viscosity and decreases the potential for platelet aggregation and blood clot formation.  So not a bad potential drug for the effects of severe Covid (which causes "sticky" blood), or indeed the extremely rare negative reaction to Astra Zeneca’s vaccine reported in Norway.  I had my Astra Zeneca Covid shot last week and Monty will be having his. Even young children with severe autism have been vaccinated where we live, at the parents' insistence. It looks like crossing international borders is going to to be much easier with proof of vaccination, so even if you had the virus the vaccine is useful.  Most people we know have had the virus, since where we live public policy was more towards protecting livelihoods than lives.  A lack of obesity and very old people kept the death rate quite low.  Now we seem to have more vaccines than demand for them.

Studies show that Pentoxifylline increases blood flow to the brain.  We know that blood flow to the brain in autism is impaired; the research describes it as unstable rather than just weak.

It sounds like Pentoxifylline is a polytherapy in itself, it has so many effects possibly relevant to autism.

 

Are Ibudilast and Roflumilast/Daxas an alternative to Pentoxifylline?

This question has come up already in the comments section.

We know that Ibudilast and Roflumilast are much more selective for PDE4 than Pentoxifylline.  We know that both Ibudilast and Roflumilast have interesting effects on the brain.

Pentoxifylline has some potentially beneficial effects that are not shared by Ibudilast or Roflumilast.  Pentoxifylline is cheap and proven safe in a series of trials in young children. 

I think that the typical autism dose of Pentoxifylline, 200mg twice a day, likely does not provide the effect on PDE4 provided by the small dose of Roflumilast/Daxas used in trials to improve cognition and sensory gating.

I think you would need to trial the drugs separately and, if they indeed provide a benefit, find the effective combination.  

So far I have trialed the 100 mcg dose of Roflumilast/Daxas on myself to check for GI side effects and see if it affects how thoughts and sensory inputs are processed, as the research suggests it does. I think it does indeed have the cognitive effects, but in me personally the GI effects also appear.  Some readers have told me this 100 mcg dose works for Aspies, and without side effects.

Some readers have tried Ibudilast.

Ling favours Pterostilbene, a natural PDE4 inhibitor. Pterostilbene has many other modes of action, including relating to inflammation, diabetes, aging and even cancer.

  

Conclusion 

Polytherapy is becoming fashionable these days and it is about time too.  Here it is all about MS (Multiple Sclerosis):-

 

UK to test existing drugs as treatment for MS in world-first trial

“Ultimately, MS will be treated with a combination of drugs,” said Gray. “You’ll have immunomodulatory drugs and anti-inflammatory drugs that stop the immune attacks, and they will be combined with treatments that can protect nerves from damage, and treatments that can repair the damaged myelin. That should stop MS.”

 

Each drug, given individually, will not deliver a dramatic result, but in combination the effective can be substantial.

Autism also requires polytherapy.  A few small steps can take you a large stride forwards. 

I did once consider using the analogy of fixing an old car, but I thought people might not like it and also autism develops very early in life not at the end; but Professor Ramaekers used the analogy on me, so I will follow suit.

You may need to fix many things on an old car, to get it back to its former glory.  The more problems you fix, the better the result will be.  You just have to start and keep on going.

In autism, and car restoration, the order in which you fix things does matter.  You probably need to learn this the hard way.

In a near perfect car (Asperger’s) really small issues, like faulty electric windows or squeaky suspension, can be extremely annoying, though the car remains perfectly functional; it gets you from A to B.

Pentoxifylline, by itself, is not going to “cure” anyone’s autism, but for some people it will be another step in that direction.

 

Another old idea has resurfaced - sodium phenylbutyrate (shortened to NaPB).

I think this drug was used for completely the wrong reasons, by a tiny number of people, a decade ago, but now common mouse models of autism are showing that this pan-HDAC inhibitor and ER-stress inhibitor has potent beneficial effects.  It is changing gene expression via an epigenetic mechanism.

If you look on Google, it appears as another quack therapy.

Four autism treatments that worry physicians – LA Times in 2009

Four that worry physicians. The Chicago Tribune examined four treatments in depth. Medical experts said that the therapies have not been proved to help children with autism and that each also carries risks. 

#4 Phenylbutyrate

Kennedy Krieger Institute: “No research conducted into use for autism.” -- Trine Tsouderos and Patricia Callahan

 

https://www.chicagotribune.com/lifestyles/ct-xpm-2009-11-23-chi-autism-science-nov23-story.html

Patricia Kane, who calls herself "the queen of fatty acid therapy," initially sounds like a skeptic of alternative autism treatments. She distances herself from the Defeat Autism Now! approach and says hyperbaric oxygen therapy, IVIG and chelation drugs all can be harmful.

"If you could see what happens to children when they're given some of these crazy interventions that ruin their life, and it's so painful," said Kane, whose office is in New Jersey. "Parents say, 'Patricia Kane will tell us the truth,' and I believe parents deserve the medical truth when it comes to their children."

One of her fans is Kent Heckenlively, a California science teacher who writes for ageofautism.com, self-described as the "daily web newspaper of the autism epidemic." After spending "a couple of hundred thousands" on treatments, from chelation to stem cell therapy, for his daughter with autism, Heckenlively said Kane appealed to him in part because her protocol includes lab tests run by the prestigious Kennedy Krieger Institute.

"I can trust them, I think," Heckenlively said.

Kane, who points to neuroinflammation as a feature of autism, discusses Pardo's study in a chapter she co-wrote on autism treatments for the book "Food and Nutrients in Disease Management."

Kane says many children with autism have a buildup in their brains of a substance called very-long-chain fatty acids. Her "PK Protocol" -- named after her initials -- is aimed at burning them off with a prescription drug, phenylbutyrate, that is normally used to treat extremely rare genetic disorders in which ammonia builds up in the body.

Side effects of phenylbutyrate include vomiting, rectal bleeding, peptic ulcer disease, irregular heartbeat and depression. No clinical trials have evaluated this drug as an autism therapy, and the idea that very-long-chain fatty acids have a role in autism is not proven by science.

Kane is not a medical doctor. When treating children with autism, she says, she works in concert with the child's physician, who supervises treatment.

She said she holds a doctorate in nutrition that was issued by Columbia Pacific University, an unaccredited institution that was shut down after a lengthy court battle with the state of California. An administrative law judge in 1997 found that the school awarded excessive credit for prior experiential learning, failed to employ qualified faculty and didn't meet requirements for issuing degrees.

Kane said Columbia Pacific granted her a doctorate after the school "consolidated my work," which Kane described as "clinical work" and continuing medical education courses for doctors. Her doctorate is valid, she said, because it was issued before the university ran into problems with the state.

Last year she was the subject of a television news investigation about her work with patients with ALS, also known as Lou Gehrig's disease. The disease, which affects motor neurons, is a death sentence.

but now in 2021, things have changed:-

 

Sodium phenylbutyrate reduces repetitive self-grooming behavior and rescues social and cognitive deficits in mouse models of autism

We found that acute and chronic treatment of NaPB remarkably improved, not only core ASD symptoms, including repetitive behaviors and sociability deficit, but also cognitive impairment in the BTBR mice. NaPB substantially induced histone acetylation in the brain of the BTBR mice. Intriguingly, the therapeutic effects of NaPB on autistic-like behaviors, such as repetitive behaviors, impaired sociability, and cognitive deficit also showed in the valproic acid (VPA)–induced mouse model of autism

These findings suggest that NaPB may provide a novel therapeutic approach for the treatment of patients with ASD.

Correcting miss-expressed genes is the holy grail for the treatment of many diseases and in particular for all those parents whose child has a single gene type of autism.  In this blog I also call them DEGs (differentially expressed genes); everyone with autism has some DEGs. There is a lot in this blog about HDAC inhibitors, these can modify gene expression via the epigenome.  HDAC inhitors therefore can potentially fix DEGs.  NaPB was approved 25 years ago by the FDA to treat urea cycle disorders and is used in children over 20 kg.  It is not cheap and as usual it is much more expensive in the United States, at a high dose it is crazily expensive like cancer drugs, many of which are also HDAC inhibitors.  NaPB is another bulk chemical they put in tablets and multiply that cost by whatever they feel like. There is a reaction against this trend in some countries, for example using cheap generic Potassium Bromide for Dravet syndrome, instead of the overly expensive tablets. 

NaPB is used off-label to treat ALS/motor neuron disease.