Lymphopenia after Melarsomine (Immiticide) in dogs

The FDA has received 43 reports of lymphopenia in dogs after Melarsomine. That is 0.2% of all reports for this medicine, compared with 0.3% across reports for all dog medicines.

43Reports

77%Marked serious

0.0%Recovered

16%Died or euthanised

32 daysTypical onset

How soon it started

Same day

3 9.4%

1–2 days

2 6.3%

3–7 days

4 13%

1–4 weeks

6 19%

Over a month

17 53%

How the animals did

Still unwell when reported

9 21%

Died

3 7.0%

Euthanised

4 9.3%

Not known

27 63%

Problems reported at the same time

23 53%

21 49%

20 47%

15 35%

14 33%

13 30%

13 30%

13 30%

Age of the animals

Under 1 year

1–3 years

4–7 years

8–11 years

12+ years

About this medicine

Melarsomine treats adult heartworm infection (a series of injections given by a vet).

Products with this ingredient include Immiticide, Diroban. The FDA hides brand names in its public data, so these reports cover every product with the same active ingredients.

Questions owners ask

Can Melarsomine cause lymphopenia in dogs?: 43 reports link the two, but a report alone does not prove the medicine was the cause: other illnesses, other medicines or coincidence can be involved. Your vet can judge it for your animal.
How soon after a dose was it reported?: In half of the reports with dates, it started within 32 days of the first dose.
What should I do?: Don't give another dose until you've spoken to your vet, and keep the packaging so you can tell them the product and dose. Your vet can also report it to the FDA (or you can, through the manufacturer or FDA form 1932a).

Lymphopenia with similar medicines

Lymphopenia after Polysulfated Glycosaminoglycan 50 reports · 0.9% of its reports
Lymphopenia after Diphenhydramine 75 reports · 1.6% of its reports
Lymphopenia after Butorphanol 44 reports · 1.0% of its reports
Lymphopenia after Cefpodoxime 54 reports · 1.3% of its reports
Lymphopenia after Tramadol 62 reports · 1.6% of its reports
Lymphopenia after Florfenicol + Mometasone + Terbinafine 21 reports · 0.6% of its reports
Lymphopenia after Propofol 24 reports · 0.8% of its reports
Lymphopenia after Isoflurane 29 reports · 1.0% of its reports
Lymphopenia after Cephalexin 30 reports · 1.1% of its reports
Lymphopenia after Atipamezole 22 reports · 0.8% of its reports

All reported side effects of Melarsomine in dogs · Medicines most reported with lymphopenia