Your questions about danger of long term use of ATDs

[Guest guest]

Okay, you guys, calm down. I was afraid of causing a furor by

mentioning this, but after due consideration, decided that it just

wouldn't be right to keep the information to myself. Please

understand the context: it is a RARE consequence, just as is

agranulosis. Do not abruptly discontinue ATDs just because another

rare danger is known.

I'm not going to try to address questions about symptoms unless/until

the person involved wishes to share this.

Here is some of what Elaine said, as we anticipated some

concern: " Again, a review of the literature shows only 56 moderate to

severe cases of drug related illness from PTU and all cases resolved

when the drug was withdrawn. And all were illnesses that occurred

within a few weeks of starting PTU and even sooner if the drug was

stopped and later started again. Another study says that long-term

use of PTU causes the develop of P-ANCA, but again the antibodies

decline when the drug is stopped.

From everything I've found, I'd suspect that she's developed an

additional autoimmune or other systemic disease if she stopped the

PTU several months ago when she first contacted me. If she was still

taking the PTU, I suppose a pulmonary related vasculitis could be the

cause. "

" In one case, a 14 year old girl, they though she may have had a

preexisting IgA neuropathy, with acute pauci-immune

glomerulonephritis (kidney disorder) secondary to PTU, or this may be

the first description of an overlap syndrome of IgAN and ANCA

vasculitis all cuased by PTU therapy. The article was in Pediatr

Nephrol 2002 April by Winters MJ, et al, abstract on Pub Med

Then there's a case of monozygotic triplets with hyperthyroidism who

were on PTU. 2 developed a positive ANCA, suggesting a genetic factor

that makes them susceptible to developing a pos ANCA while on PTU,

much like the genetic predisposition seen in those people who develop

drug related lupus.

In another case, a 12 year old boy from Taiwan developed ANCA-

positive vasculitis during PTU therapy for GD. His symptoms and signs

were indistinguishable from anaphylactoid purpura. Symptoms resolved

after discontinuation of PTU and immunosuppressant medication. 11

months follow-up he remains symptom free

Probably the best reference is Frequency of appearance of

myeloperoxidase-antineutrophil cytoplasmic antibody (MPO_ANCA) in

Graves' disease patients treated with PTU and the relationship

between MPO_ANCA and clinical manifestiations' by Noh JY, Asari T, et

al Clin Edocrinol (Oxf) 2001 May

The other article I mentioned in is European J Endocrinol 2000 June

and mentions finding 32 cases in the English literture. Prevalence of

positive ANCA in patients receiving anti-thyroid medications, Gunton,

JE, Stiel J, et al.

You can attach this information to your post. Overall, I'd say the

incidence of positive ANCA associated vasculitis is a rare

complication similar to drug related lupus. But it is a reason for

using the lowest dose necessary and a reason for using Tapazole over

PTU when possible. It's also a symptom to watch for while on PTU.

Hope this helps, Elaine "