“Pharmacokinetics” of a typical drug
Today’s post is about what should be the optimal anti-oxidant therapy for autism, schizophrenia, COPD and any other disease in which oxidative stress is present. You will have to be able to swallow pills, to fully benefit.
NAC seems to be the most potent, safe, anti-oxidant, the only drawbacks are:-
· Short half-life
· Can taste/smell bad
In autism, NAC is normally given three times a day, but often it is not practical to give a drug at precise intervals throughout the day.
This is a common problem with many drugs and has been solved long ago – with the sustained release pill.
If you find that four hours after giving NAC there is an increase in irritability, anxiety or stimming, it may be that oxidative stress has already returned. It may be that other factors have triggered a higher load of oxidative stress. The way to be sure is just to give a small extra dose of NAC and wait 15 minutes. If everything returns to normal, you found the problem.
Since you cannot always be present with an extra half dose of NAC, the answer is the sustained release form of NAC.
Since we have seen that oxidative stress triggers all kinds of secondary dysfunctions, the sustained release form of NAC might also help minimize them, since you could have 24 hour protection. Oxidative stress does not go away while you sleep.
For example, I recall the Polish researcher at Harvard who suggested that oxidative stress might cause central hypothyroidism in autism (low levels of T3 in the brain).
For example, I recall the Polish researcher at Harvard who suggested that oxidative stress might cause central hypothyroidism in autism (low levels of T3 in the brain).
Your body produces the pro-hormone T4 in the thyroid which then circulates throughout the body. Special enzymes, produced locally, then convert the T4 into the active hormone called T3. The researcher found that in the autistic brain this enzyme was reduced by oxidative stress.
Many “alternative” doctors, mainly in the US, do prescribe extra T3 hormone to people with autism and indeed other conditions. Some older ladies across the world are buying T3 hormone, online from Mexico, since their doctor will not prescribe it. They say it makes them feel better.
As your endocrinologist will tell you, hormones are controlled by so-called feedback loops. So if you start adding extra T3 hormone, your thyroid will start producing less T4. Then you need even more supplemental T3.
I did do a little experiment with a small dose of T3, to see if a short term increase in T3 affects “my” kind of autism. It most definitely does; as does a short term spike in potassium levels. These are useful diagnostic tests, rather than therapies.
This would suggest that minimizing oxidative stress 24 hours a day, may not just be possible, but also highly beneficial.
OTC Sustained Release NAC (NAC SR)
There actually is an inexpensive Sustained Release NAC , available OTC (without prescription).
The problem with currently-available granulated and effervescent tablet compositions is that they release N-acetyl cysteine very rapidly. Thus, the effervescent compositions as well as the granulate compositions currently available on the market achieve a maximum blood plasma level within 1 hr from administration. One matrix tablet formulation does show a maximum blood plasma level at 2-2.5 hrs after administration, although its recipe indicates that granulation was required. The problem with granulation of acetyl cysteine is that if any dissolves, the dissolved material starts to decompose into impurities.
In accordance with the present invention, this problem of overly-rapid release is obviated by providing the N-acetyl cysteine in the form of a tablet or other article made with the rheology modifying acrylic or methacrylic acid-based polymers, or analogues, described in commonly-assigned application Ser. No. 09/559,687, filed Apr. 27, 2000. Tablets made in this manner exhibit controlled release characteristics, thereby allowing the N-acetyl cysteine active ingredient to be released over a longer period of time.
The rheology modifying polymers used in the present invention provide controlled release of the N-acetyl cysteine and other biologically active compounds contained in the inventive tablet, if any, so that when placed in water or body fluid, the polymer swells to form a viscous gel which retards diffusion of the active material.
The advanced bilayer Sustain™ tablets combine 1/3 Quick Release and 2/3 Sustained Release formats to both immediately raise and to maintain blood levels over a longer period of time.* NAC Sustain® releases in the small intestine over a 8 hour period, compared to the 1.5 hour biological half-life of NAC in the bloodstream.*
NAC in published research
Much currently available data is from very early studies on NAC that indicated that the half-life was about 5 hours, but subsequent studies suggested it is very much shorter, perhaps just 90 minutes.
The following study is quite old, but compares the behaviour of different NAC formulations in 10 volunteers.
Some definitions:-
A biological half-life or elimination half-life is the time it takes for a substance (drug, radioactive nuclide, or other) to lose one-half of its pharmacologic, physiologic, or radiological activity. In a medical context, the half-life may also describe the time that it takes for the concentration in blood plasma of a substance to reach one-half of its steady-state value (the "plasma half-life").
The relationship between the biological and plasma half-lives of a substance can be complex, due to factors including accumulation in tissues, active metabolites, and receptor interactions
Mean Residence Time
For the medical field, residence time often refers to the amount of time that a drug spends in the body. This is dependent on an individual’s body size, the rate at which the Drug will move through and react within the person’s body, and the amount of the Drug administered. The Mean Residence Time (MRT) in Drug deviates from the previous equations as it is based on a statistical derivation. This still runs off a steady-state volume assumption but then uses the area under a distribution curve to find the average drug dose clearance time. The distribution is determined by numerical data derived from either urinary or plasma data collected. Each drug will have a different residence time based on its chemical composition and technique of administration. Some of these drug molecules will remain in the system for a very short time while others may remain for a lifetime. Since individual molecules are hard to trace, groups of molecules are tracked and the distribution of these is plotted to find a mean residence time.
Conclusion
This post may have been more useful for adult readers, with Asperger’s, who are self-treating. Many people with Schizophrenia also self-treat with NAC, but they probably do not read autism blogs.
For those unable (yet) to swallow, pills you can have the option of breaking the effervescent tablets in half (or even quarters) to try and maintain a more stable level of NAC. We sometimes do this, half a 600 mg tablet at school at 11 am, when needed. It only seems to be really needed in the pollen allergy season, which seems to trigger more oxidative stress as well as histamine and IL-6. It works.
One reader of this blog is doing something similar with Bumetanide, he/she is giving it in three daily doses. Bumetanide also has a short half-life, as does Verapamil. There is no sustained release form of Bumetanide, but there is for Verapamil.
A final point raised is whether the benefit from NAC comes from it being a precursor to Glutathione (GSH), the body' own master antioxidant, or whether it is actually NAC's own free radical scavenging properties that really matter. It would appear to be the latter, based on the short half life of NAC and the short term beneficial effect. This would imply that just normalizing GSH is not enough. Studies have shown that normalizing the reduced levels of GSH levels found in autism is readily achievable.
A final point raised is whether the benefit from NAC comes from it being a precursor to Glutathione (GSH), the body' own master antioxidant, or whether it is actually NAC's own free radical scavenging properties that really matter. It would appear to be the latter, based on the short half life of NAC and the short term beneficial effect. This would imply that just normalizing GSH is not enough. Studies have shown that normalizing the reduced levels of GSH levels found in autism is readily achievable.