Potassium perchlorate

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:

direct observations: clinical cases, poisoning incidents and other

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Published case review

Data source

Reference

Reference Type:

publication

Title:

Long-term use of potassium perchlorate

Author:

Connell JMC

Year:

1981

Bibliographic source:

Postgraduate Medical Journal : 57, 516-517

Materials and methods

Study type:

clinical case study

Endpoint addressed:

repeated dose toxicity: oral

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Published case review, focussing on thyroid effects

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Potassium perchlorate

EC Number:

231-912-9

EC Name:

Potassium perchlorate

Cas Number:

7778-74-7

Molecular formula:

ClHO4.K

IUPAC Name:

potassium perchlorate

Test material form:

not specified

Method

Type of population:

general

Subjects:

Single case

Ethical approval:

not applicable

Route of exposure:

oral

Reason of exposure:

intentional

Exposure assessment:

measured

Details on exposure:

Single male patient adminstered potassium perchlorate for 22 years without adverse effect, for the treatment of hyperthyroidism.

Results and discussion

Clinical signs:

On referral to the Thyroid Clinic the patient was clinically thyrotoxic, had moist warm palms, hyperkinetic movements, tachycardia (120beats/min). A small goitre was palpable, no bruit was audible, left lobe larger than right. No ophthamological change and other examinations were unremarkable.

Applicant's summary and conclusion

Conclusions:

Thyrotoxicosis recurred 4 weeks after the medication was withdrawn suggesting euthyroidism had been maintained by chronic exposure to potassium perchlorate.

Executive summary:

Potassium perchlorate was used extensively in the mid 19th centrury as an antithyroid agent. By competitive inhibition of the trapping of iodide by the thyroid, it functioned by reducing thyroid hormone production and relieving symptoms of thyrotoxicosis. Following reports of toxic side effects, including bone marrow hypoplasia, potassium perchlorate use as an antithyroid agent declined, although other uses persisted. This paper reviews the effects of long term exposure to low levels of potassium perchlorate (22 years) in a case study of a patient with Graves' disease. The patient used potassium perchlorate without adverse effect for 22 years for disease control. However thyrotoxicosis recurred 4 weeks after the medication was withdrawn suggesting euthyroidism had been maintained by chronic exposure to potassium perchlorate.