Didn't prevent heartworm after Melarsomine (Immiticide) in dogs

7,132 reports to the FDA describe didn't prevent heartworm in dogs given Melarsomine. That is 31% of all reports for this medicine, compared with 13% across reports for all dog medicines, so it is reported unusually often with this medicine.

7,132Reports

51%Marked serious

11%Recovered

0.7%Died or euthanised

217 daysTypical onset

How soon it started

Same day

33 1.2%

1–2 days

5 0.2%

3–7 days

9 0.3%

1–4 weeks

37 1.3%

Over a month

2,719 97%

How the animals did

Recovered

111 1.6%

Recovered with lasting effects

658 9.2%

Still unwell when reported

1,900 27%

Died

37 0.5%

Euthanised

14 0.2%

Not known

4,412 62%

Problems reported at the same time

Cardiac disorder

529 7.4%

Didn't work as expected

412 5.8%

170 2.4%

146 2.0%

116 1.6%

101 1.4%

82 1.1%

68 1.0%

Age of the animals

Under 1 year

1–3 years

3,118

4–7 years

2,649

8–11 years

829

12+ years

104

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 didn't prevent heartworm in dogs?: 7,132 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 217 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).

Didn't prevent heartworm with similar medicines

Didn't prevent heartworm after Diphenhydramine 71 reports · 1.5% of its reports
Didn't prevent heartworm after Butorphanol 33 reports · 0.7% of its reports
Didn't prevent heartworm after Cefpodoxime 24 reports · 0.6% of its reports
Didn't prevent heartworm after Tramadol 79 reports · 2.1% of its reports
Didn't prevent heartworm after Cephalexin 43 reports · 1.6% of its reports
Didn't prevent heartworm after Chondroitin + Glucosamine 35 reports · 1.3% of its reports
Didn't prevent heartworm after Glucosamine 24 reports · 1.3% of its reports
Didn't prevent heartworm after Acepromazine 43 reports · 2.4% of its reports
Didn't prevent heartworm after Enalapril 24 reports · 1.5% of its reports
Didn't prevent heartworm after Phenobarbital 25 reports · 1.6% of its reports

All reported side effects of Melarsomine in dogs · Medicines most reported with didn't prevent heartworm