Be careful with T4 toxic buildup

[thunderin]

My heart rate has been quite elevated for some time, and now I know why. The half life of T4 is 5-7 days. So, if you take it at low dose (100mcg) everyday for an extended period of time, you will get a toxic buildup that could easily lead to serious health problems including heart seizure.

Read on.

http://www.emedicine.com/EMERG/topic800.htm

Toxicity, Thyroid Hormone

Last Updated: January 5, 2006

Synonyms and related keywords: thyroid hormone toxicity, tyrosine, monoiodotyrosine, MIT, diiodotyrosine, DIT, thyroxine, T4, triiodothyronine, T3, thyroid-stimulating hormone, TSH, thyrotropin-releasing hormone, TRH, levothyroxine, LT4, thyroid hormone overdose, thyroid hormone, thyroid hormone poisoning, thyroid hormone exposure, thyroid hormone ingestion

Author: Lisandro Irizarry, MD, MPH, FAAEM, Chair and Program Director, ***artment of Emergency Medicine, Brooklyn Hospital Center; Assistant Professor, ***artment of Emergency Medicine, Weill Cornell School of Medicine Coauthor(s): Andrew Lawrence, MD, Consulting Staff, ***artment of Emergency Medicine, Great Plains Regional Medical Center

Lisandro Irizarry, MD, MPH, FAAEM, is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American College of Medical Toxicology, and Society for Academic Emergency Medicine Editor(s): Jeffrey Glenn Bowman, MD, MS, Consulting Staff, ***artment of Emergency Medicine, Mercy Springfield Hospital; John T VanDeVoort, PharmD, Clinical Assistant Professor, College of Pharmacy, University of Minnesota; Fred Harchelroad, MD, FACMT, Chair, ***artment of Emergency Medicine, Director of Medical Toxicology, Associate Professor, ***artment of Emergency Medicine, Allegheny General Hospital; John Halamka, MD, Chief Information Officer, CareGroup Healthcare System, Assistant Professor of Medicine, ***artment of Emergency Medicine, Beth Israel Deaconess Medical Center; Assistant Professor of Medicine, Harvard Medical School; and Raymond J Roberge, MD, MPH, FAAEM, FACMT, Clinical Associate Professor of Emergency Medicine, University of Pittsburgh School of Medicine; Consulting Staff, ***artment of Emergency Medicine, Magee-Women's Hospital of the University of Pittsburgh Medical Center
Disclosure

Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography
Background: Iodine absorbed from the GI tract is transferred to the thyroid gland where oxidization and incorporation into tyrosyl residues of thyroglobulin occurs. Tyrosine is further oxidized to form monoiodotyrosine (MIT) and diiodotyrosine (DIT). The combination of 2 molecules of DIT form thyroxine (T4). Triiodothyronine (T3), is made by the combination of MIT and DIT and by the monodeiodination of T4 in the periphery.
T3 is 4 times more active than the more abundant T4. The half-life of T4 is 5-7 days; the half-life of T3 is only 1 day. Approximately 99% of the circulating thyroid hormone is bound to plasma protein and is metabolized primarily by the liver.
Thyroid-stimulating hormone (TSH), secreted by the anterior pituitary, causes release of T3 and T4. Thyrotropin-releasing hormone (TRH) and a negative feedback mechanism regulate TSH.
The most common thyroid hormone used clinically is levothyroxine (LT4), which is available in intravenously and orally administered forms to treat hypothyroidism and myxedema coma. Usual dosage ranges from 25-500 mcg/d.

Pathophysiology: Mechanism of toxicity involves stimulation of the cardiovascular (CV), GI, and neurologic systems through presumed activation of the adrenergic system.
Clinical effects of acute LT4 ingestion occur approximately 1 week postexposure. Conversion of T4 to the more potent T4 produces this lag time. If the ingested preparation contains T3, clinical symptoms may begin within 24 hours of ingestion. Mixtures of T4 and T3 have immediate and delayed clinical effects.
Frequency:

• In the US: According to the annual report of the American Association of Poison Control Centers, published in the September 1999 issue of the American Journal of Emergency Medicine, 6844 exposures to thyroid hormone preparations were documented in 1998; of those exposures, 4110 were associated with children younger than 6 years. A total of 1895 exposures were reported in persons older than 19 years. Overall, 13 people had major adverse outcomes, and 2 deaths were reported.

Mortality/Morbidity: One large retrospective study reported 27,680 cases of thyroid hormone ingestion. Of these cases, 2516 (9.1%) were secondary to suicidal intentions, with only 3 (0.01%) being fatal. Co-ingestants were believed to be the major cause of these fatalities. Among all groups, incidence of a major outcome (described as symptoms that are life threatening or resulting in significant residual disability) was 0.02%.
Race: No scientific data demonstrate that outcomes following a toxic thyroid hormone ingestion are based on race.
Sex: No scientific data demonstrate that outcomes following a toxic thyroid hormone ingestion are based on sex.
Age: Inadvertent excessive thyroid hormone ingestion occurs primarily in pediatric patients.

Author Information Introduction Clinical Differentials Workup Treatment Medication Follow-up Miscellaneous Bibliography

Physical: Focus the physical examination on findings consistent with symptoms of increased adrenergic activity and on the following signs:

• Acute

• • Abdominal pain

• • Nausea or vomiting

• • Diarrhea

• • Increased appetite

• • Insomnia

• • Anxiousness

• • Agitation

• • Tremor

• • Seizures

• • Weakness

• • Diaphoresis

• • Palpitations

• • Hypertension or hypotension

• • Hyperpyrexia

• Chronic

• • Supraventricular tachycardia (SVT)
  • High output left ventricular failure
  • Hypotension

• • Hemiparesis
  • Delirium
  • Coma

• • Pneumonia
  • Sepsis
  • Hyperthermia
  • Acute renal failure

• • Myopathy
  • Palmar and plantar desquamation

Causes: Long-term abuse of thyroid supplements has been reported in obese patients as a method of weight control.

[Random]

Very nice post man...

CD

[soo2bhuge]

thanx for the post bro......i stopped doing T4 earlier in the week cause my heart was ready to jump out of my chest. excellent post...thanx again!

[Microbrew]

Good post

Micro

[Lexed]

thunderin, I wish I was a kid so you could adopt me.

[goose]

Thank god I dont use T4 with my HGH cycle,never liked the idea.Great post dude....

[*Narkissos*]

I find this interesting.

Also.. i take it with a grain of salt as the parameters of 'excessive' and 'extended' aren't defined in the least.

It isn't a structured study.. but rather a cross-sectional compilation of observations.

Albeit by doctors.. but observations based on potentialities none-the-less.

-N

[*Narkissos*]

My heart rate has been quite elevated for some time, and now I know why.

No.. you don't.

If you haven't seen a doc... go see one.

Drawing correlations based on an article you read is a bad judgement call.

Further, if i'm not mistaken, i've read your logs.

The doses of slin, steroids (etc.) which you administer are high by this board's standards.

Thus it is impossible, and irresponsible, to pinpoint one factor definitively.

The half life of T4 is 5-7 days. So, if you take it at low dose (100mcg) everyday for an extended period of time, you will get a toxic buildup that could easily lead to serious health problems including heart seizure.

Replace 'will' with 'may' ... and 'easily' with 'possibly'.

Because there is no direct correlation.

That's like saying: "If you use slin pwo for an extended time you could easily become diabetic."

Again... there's no correlation.

Look at the hundreds of people who've been misdiagnosed with thyroid disorders...and placed on t4 with no ill effects.

Closer to home.. look bodybuilders who're on for extended period.

Hell i've used t4 for months on end with no problems.

Not a low dose...definately an extended protocol.

Those around me have done the same.

Drawing a definitive conclusion is irresponsible.

Good post all the same

-Nark

[thunderin]

Replace 'will' with 'may' ... and 'easily' with 'possibly'.

Because there is no direct correlation.

That's like saying: "If you use slin pwo for an extended time you could easily become diabetic."

Again... there's no correlation.

Look at the hundreds of people who've been misdiagnosed with thyroid disorders...and placed on t4 with no ill effects.

Closer to home.. look bodybuilders who're on for extended period.

Hell i've used t4 for months on end with no problems.

Not a low dose...definately an extended protocol.

Those around me have done the same.

Drawing a definitive conclusion is irresponsible.

Good post all the same

-Nark

I do appreciate your opinion and life experience, and you do have a point. However, if you have any medical studies to back up your opinion on extended protocol for both T4 and insulin, please post them?

[NotSmall]

I do appreciate your opinion and life experience, and you do have a point. However, if you have any medical studies to back up your opinion on extended protocol for both T4 and insulin, please post them?

Sometimes real life anecdotal information is more relevant to us than studies as studies are rarely based on bodybuilding type protocols.

[jeepman06]

Would it be better to run T4 100mcg per day at a 5/2 or a 6/1 ratio similar to my HGH cycle? Do you think this would prevent toxic buildup, or at least be a safer way to go...?

[vein5]

I find this hard to believe, people are prescribed t-4 for hypothyroidism by doctors all the time. So t-4 is a waste of money????

[Fixr]

I am in my 6th week of my Gh cycle and have discontinued taking the T4 after about 10 days of use (around week 4-5). I was having racing heart rates for no reason, mood swings and constipation all starting at the same time as T4 was being taken. I didnt like its effects at all. I was at 100mcg a day. I am on no other substances, so it was pretty easily to identify the cause of my symptoms. They have all gone away in the week or so since T4 was stopped.

[thunderin]

I am in my 6th week of my Gh cycle and have discontinued taking the T4 after about 10 days of use (around week 4-5). I was having racing heart rates for no reason, mood swings and constipation all starting at the same time as T4 was being taken. I didnt like its effects at all. I was at 100mcg a day. I am on no other substances, so it was pretty easily to identify the cause of my symptoms. They have all gone away in the week or so since T4 was stopped.

My heart rate is lower now too and I am feeling better also. Thanks for the information.

[goldenFloyd]

Hi Thunderin,

Thank you for your interesting posts. The study you refer to seems to be an inquiry into instances when T4 has proven toxic and its mechanism of toxicity, but the conclusion seems to be drawn by you that it is the half-life of 5-7 days that can cause the harmful buildup that leads to toxicity.

This is worrisome in light of general health and how popular the combination of GH and T4 appears. The obvious question is how so many people can be prescribed T4 at doses of 50-500mcg/day and not be suffering from thyroid toxicity?

Of course, if you don't feel well taking something and feel better when you stop, that is worth sharing. I seem to have the opposite problem: I am taking 100mcg ed with 6iu HGH only, no stimulants much stronger than coffee (prescribed methylphenidate taken as needed) and my resting heart rate is 60s and cardio heart rate seems fine; in fact I found this post from your HGH log and am trying to determine whether I need to take more of my Eltroxin T4 or whether it was faked... mine came from Thailand and not India, where a bust of fakes was recently found on 03/20/07 (http://www.safemedicines.org/resources/003458.php).

Anyway, just adding to the discussion. I suppose a TSH test will determine whether this particular Eltroxin is fake, but fwiw I have been using 100mcg for months with no acute cardiac events.

======================

Also fwiw, the recommended dosage of Thyroxine Sodium (Eltroxin from GlaxoSmithKline from here: http://www.gsk.ca/en/products/prescr...m_09132005.pdf) suggests:

Recommended Dose and Dosage Adjustment

Adult Dosage

Hypothyroidism

The usual full replacement dose of levothyroxine sodium for younger, healthy adults is
approximately 1.7 mcg/kg/day administered once daily. In the elderly, the full
replacement dose may be altered by decreases in T4 metabolism and levothyroxine
sodium absorption. Older patients may require less than 1 mcg/kg/day. Children
generally require higher doses (see Pediatric Dosage). Women who are maintained on
levothyroxine sodium during pregnancy may require increased doses (see WARNINGS
AND PRECAUTIONS-Special Populations-Pregnant Women).

Therapy is usually initiated in younger, healthy adults at the anticipated full replacement
dose. Clinical and laboratory evaluations should be performed at 6 to 8 week intervals (2
to 3 weeks in severely hypothyroid patients), and the dosage adjusted until the serum
TSH concentration is normalized and signs and symptoms resolve. In older patients or in
younger patients with a history of cardiovascular disease, the starting dose should be
lowered and gradually increased every 3 to 6 weeks until TSH is normalized and signs
and symptoms resolve. If cardiac symptoms develop or worsen, the cardiac disease
should be evaluated and the dose of levothyroxine sodium reduced. Rarely, worsening
angina or other signs of cardiac ischemia may prevent achieving a TSH in the normal
range.

Treatment of subclinical hypothyroidism may require lower than usual replacement
doses, e.g. 1.0 mcg/kg/day. Patients for whom treatment is not initiated should be
monitored yearly for changes in clinical status, TSH, and thyroid antibodies.
Few patients require doses greater than 200 mcg/day. An inadequate response to daily
doses of 300 to 400 mcg/day is rare, and may suggest malabsorption, poor patient
compliance, and/or drug interactions.

Once optimal replacement is achieved, clinical and laboratory evaluations should be
conducted at least annually or whenever warranted by a change in patient status.
Levothyroxine sodium products from different manufacturers should not be used
interchangeably unless retesting of the patient and retitration of the dosage, as
necessary, accompanies the product switch.

======================

[notanormalgent]

I've been taking 100mcg of T4 for five days now and I'm feeling fine at the moment. Although today when I took a dump I have to admit I was slightly constipated, but not sure if it was related to the T4. I'll keep this thread updated with my observations, everyone else please do the same!

Gent

[thunderin]

Thanks goldenFloyd. Through more postings we have of real-life experiences, we will be better able to draw conclusions. I hope what you have is real T4.

Please keep us posted.

Thanks notanormalgent also. I hope this cycle goes well for you and please keep us up-to-date.

The best to all of you.

[Booz]

i just got my T4 in and will be starting it tommorrow so will keep my eye on things and post how it goes..............

[jeepman06]

I have been taking 100mcg of T4 per day (India) for 3 weeks with no sides.

[goldenFloyd]

jeep - might want to double check lot numbers if that is possible - there was a bust on fake t4 that was centered in India...

thunderin and others - I agree that sharing experiences is great and I am always thankful to board members who do...

So query then - would the appropriate way to test t4 be to take baseline temperatures in the morning upon waking and stop the t4 to see if there is a gradual decrease over 2 weeks before stabilizing? This whole t4 / GH synergy would only be useful if the T4 was real :P While I am at it I should get a pregnancy test since I'm using Hyge's GH (I have my 1k ius of Jinos waiting for me when I finish the last few vials of this stuff) and there is another thread saying that the gentleman is having HCG sides with the Hyge... It is definitely HGH (i've used jinos before), but strangely, since starting the Hyge's I've been having what I can only describe as hot flashes... face gets flush, but could also be psychosomatic... anyway off topic.

Recs on the proper way to test the efficacy of t4 would be appreciated and something that might be easy for me to do since I am not on any other supps besides GH...

[vein5]

We should start a seperate thread showing t-4, t-3 test results. I have tried t-3 with no luck and now just got my t-4 in and am waiting to start my cycle.