Ammonium Molybdate, Ammonium Tetrathiomolybdate (Molypen)

Copper Poisoning Treatment

Highlights Of Prescribing Information

Used primarily to treat copper poisoning in food animals (esp. sheep)

Consider contacting FDA for guidance in treating food animals

What Is Ammonium Molybdate, Ammonium Tetrathiomolybdate Used For?

Ammonium molybdate and ammonium tetrathiomolybdate (TTM) are used for the investigational or compassionate treatment of copper poisoning in food animals, primarily sheep.

Adverse Effects

After apparent successful treatment for copper poisoning with ammonium tetrathiomolybdate (TTM), a flock of sheep became infertile, progressively unthrifty, and died 2-3 years later. The authors concluded the TTM was retained in the CNS, pituitary and adrenal glands and caused a toxic endocrinopathy ().

Reproductive / Nursing Safety

In humans, the FDA categorizes this drug as category C for use during pregnancy (Animal studies have shown an adverse effect on the fetus, hut there are no adequate studies in humans; or there are no animal reproduction studies and no adequate studies in humans.)

How to use Ammonium Molybdate, Ammonium Tetrathiomolybdate

Note: In food animals, FARAD recommends a minimum 10 day pre-slaughter withdrawal time and a minimum 5 day milk withholding interval. ()

Ammonium tetrathiomolybdate does not go into solution readily and ammonium molybdate administered orally is often preferred.

Ammonium Molybdate, Ammonium Tetrathiomolybdate dosage for sheep:

For treatment of copper poisoning:

a) Food animals: Ammonium molybdate: 200 mg per head PO once daily for 3 weeks. Ammonium tetrathiomolybdate: 1.7-3.4 mg per head IV or SC every other day for 3 treatments ()

b) 100 mg with 1 -gram sodium sulfate by mouth daily ()

c) 200 mg ammonium or sodium molybdate plus 500 mg of sodium thiosulfate given daily PO for up to 3 weeks ()

d) Ammonium tetrathiomolybdate: 1.7 mg/kg IV or 3.4 mg/kg SC every other day for 3 treatments. Alternatively, ammonium molybdate 50-500 mg PO once daily and sodium thiosulfate 300-1000 mg PO once daily for 3 weeks. ()

Dosage Forms / Regulatory Status / Synonyms

Veterinary-Labeled Products: None.

Note: Ammonium Molybdate or ammonium tetrathiomolybdate can be obtained from various chemical supply houses, but it is recommended to contact the FDA before treating for guidance when contemplating using molybdate.

Human-Labeled Products:

Ammonium Molybdate Injection: 25 mcg/mL (as 46 mcg/mL ammonium molybdate tetrahydrate) in 10 mL vial); Molypen (American Pharmaceutical Partners); generic; (Rx)

Ammonium molybdate may also be known as: Molybdene Intertable, or Molypen. Ammonium tetrathiomolybdate may also be known as TTM.