Meds A-Z
Melarsomine
Detailed information about Melarsomine
Pet Owner Quick Guide
Start here: what this medicine is for, what it does, and when it's usually needed.
Usually used for:
For the treatment of stabilized Class 1, 2, and 3 heartworm disease caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis .
What it does:
Treatment of stabilized, class 1, 2, and 3 heartworm disease (asymptomatic to mild, moderate, and severe, respectively) caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis in dogs...
When it's needed:
Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than...
Call your vet sooner if you notice:
- Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Not for use in breeding animals and lactating or pregnant bitches. IMMITICIDE® should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Commonly reported reactions:
- (2 reports)
- (1 reports)
- (1 reports)
What to ask your vet today:
- Is this medicine the right fit for my pet’s current symptoms?
- Which warning signs mean I should call back right away?
- How should I handle missed doses or refusal to take the medicine?
Melarsomine
Drug type: Generic ingredient • Branded profile • FDA branded products available
Species: Both
Manufacturer: MSK
Quick Facts
Official label facts first, then secondary summaries. Marketing content is separated below.
- https://animaldrugsatfda.fda.gov/adafda/views/#/home/previewsearch/200609 · official_label · FDA application profile
- https://animaldrugsatfda.fda.gov/adafda/views/#/home/previewsearch/141042 · official_label · FDA application profile
- https://animaldrugsatfda.fda.gov · fda_animal_drugs · Medication usage source
Warnings / Contraindications
Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Not for use in breeding animals and lactating or pregnant bitches. IMMITICIDE® should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
- High: Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Not for use in breeding animals and lactating or pregnant bitches. IMMITICIDE® should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
- https://animaldrugsatfda.fda.gov · fda_animal_drugs · Contraindication source
Adverse Reactions
Snapshot first, detailed rows second. This section summarizes signal data and is not a diagnosis.
Tap or hover a reaction to see what it means in plain language.
Most Reported Reactions
| Reaction | Cases | Species | Serious cases |
|---|---|---|---|
| 2 | Cat, Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 | |
| 1 | Dog | 1 |
Species coverage: Dog (21) Cat (11)
View detailed reaction table
| Reaction | Species | Seriousness | Frequency | Reports |
|---|---|---|---|---|
| Cat | Non-serious | - | 1 | |
| Cat | Non-serious | - | 1 | |
| Cat | Non-serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Cat | Non-serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Cat | Non-serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Cat | Non-serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Dog | Serious | - | 1 | |
| Cat | Unknown | - | - | |
| Cat | Unknown | - | - | |
| Cat | Unknown | - | - | |
| Cat | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Dog | Unknown | - | - | |
| Cat | Unknown | - | - |
- https://api.fda.gov/animalandveterinary/event.json · adverse_reaction · openFDA case USA-USFDACVM-2022-US-061285
Storage & Handling
No storage/handling guidance is linked yet.
Documents
Official label facts are separated from secondary summaries.
Official documents: 3 • Secondary summaries: 0
No source yet.
- https://animaldrugsatfda.fda.gov/adafda/app/search/public/document/downloadFoi/201 · document · FOI
- https://animaldrugsatfda.fda.gov/adafda/app/search/public/spl/file/2593/DIROBAN%C2%AE · document · SPL
- https://animaldrugsatfda.fda.gov/adafda/app/search/public/spl/file/1211/Immiticide%20Sterile%20Powder · document · SPL
Promotional Materials (Marketing)
This content is marketing material and not clinical guidance.
No marketing assets are linked yet.
No source yet.
Technical appendix (vet reference)
Canonical medication sections are above. This legacy block remains available for deeper cross-reference without cluttering the primary workflow.
At a Glance
Quick facts and links to official labeling and safety signals.
- Medication catalog: Source PetWisePlus | Refreshed Feb 12, 2026, 10:44 PM UTC
-
Animal Drugs @ FDA:
Source FDA
| Refreshed Feb 16, 2026, 11:00 AM UTC
Applications/products are imported from FDA export data.
-
Animal Drugs @ FDA previews:
Source FDA
| Refreshed Feb 9, 2026, 3:05 AM UTC
Label highlights/doc links are fetched from FDA preview endpoints.
-
Animal Drug Product Listing Directory (NDC):
Source FDA
| Refreshed Feb 16, 2026, 11:00 AM UTC
Package/product NDCs from FDA’s electronic listing directory (XLS).
- openFDA reaction terms: Source FDA openFDA | Refreshed Feb 16, 2026, 11:04 AM UTC
- openFDA case summaries: Source FDA openFDA | Refreshed Feb 9, 2026, 3:22 AM UTC
Counseling and Monitoring Highlights
Global Pet owner/Vet mode is controlled in the header. This section avoids duplicate in-page persona tabs.
- Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Not for use in breeding animals and lactating or pregnant bitches. IMMITICIDE® should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. (Contraindication, High)
Identifiers & Packages
Normalized identifiers (NDC/NADA/ANADA) and package metadata from regulator listings.
| Package NDC | Product NDC | Form / Route | Status |
|---|---|---|---|
| 54771-1920-1 | 54771 | - |
Enriched Documents
Documents are tiered by source trust: Official, Clinical, Manufacturer, Marketing.
-
FOI Summary oA 200-609 Approved February 17, 2017.pdf
• FOI summary • Official
• Jan. 28, 2020
FDA FOI summary for application 200609
Data Sources & Revision History
Every non-trivial field is expected to include provenance and update timestamps.
- contraindications: Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 p… (Official, 2026-02-12)
- side_effects: Top reported reactions (openFDA): Lack of efficacy (endoparasite) - heartworm, INEFFECTIVE, HEARTWORM LARVAE, Vomiting, Weight gain, Other abnormal test result… (Official, 2026-02-12)
- usage: Treatment of stabilized, class 1, 2, and 3 heartworm disease (asymptomatic to mild, moderate, and severe, respectively) caused by immature (4 month-old, stage … (Official, 2026-02-12)
- side_effects updated 2026-02-12 22:44 by etl_backfill • Backfilled from existing medication fields
- contraindications updated 2026-02-12 22:44 by etl_backfill • Backfilled from existing medication fields
- usage updated 2026-02-12 22:44 by etl_backfill • Backfilled from existing medication fields
FDA Products & Applications (Animal Drugs @ FDA)
Official sponsor/proprietary-name/application-status records linked by active ingredient.
| Product | Sponsor | Application | Status | Published |
|---|---|---|---|---|
|
DIROBAN®
RX
Melarsomine Dihydrochloride
Powder
• Intramuscular
|
Anzac Animal Health, LLC | ANADA 200-609 | Approved | Jan 28, 2020 |
|
Immiticide Sterile Powder
RX
Melarsomine Dihydrochloride
Liquid (Solution)
• Intramuscular
|
Boehringer lngelheim Animal Health USA, Inc. | NADA 141-042 | Approved | Jun 1, 2016 |
Data source: FDA Animal Drugs @ FDA (public search export).
What It's For (FDA Label Highlights)
Extracted from FDA Animal Drugs @ FDA product labeling. Always confirm details with your veterinarian.
Composition / specifications
For the treatment of stabilized Class 1, 2, and 3 heartworm disease caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis.
For severe (class 3) heartworm disease: administer a single injection of 2.5 mg/kg then approximately 1 month later with 2.5 mg/kg administered twice 24 hours apart.
For asymptomatic to moderate (class 1 to 2) heartworm disease: administer 2.5 mg/kg intramuscularly in the lumbar (L3 - L5) muscles twice, 24 hours apart. Four months following treatment, a second treatment series (2.5 mg/kg twice, 24 hours apart) can be elected taking into consideration the response to the first treatment and the condition, age, and use of the dog.
Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
FDA page: Open in Animal Drugs @ FDA
Composition / specifications
1 vial: when reconstituted with 2 mL of sterile water for injection (provided) contains 25 mg/mL of active ingredient.
FDA page: Open in Animal Drugs @ FDA
Official Documents (FDA)
Direct links to FDA-hosted PDFs and SPL packages (when available).
-
Summary
DIROBAN Sterile Powder for Injection is indicated for the treatment of stabilized Class 1, 2, and 3 heartworm disease caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis.
- DIROBAN® (ZIP)
FDA page: Open in Animal Drugs @ FDA
FDA page: Open in Animal Drugs @ FDA
Usage
Treatment of stabilized, class 1, 2, and 3 heartworm disease (asymptomatic to mild, moderate, and severe, respectively) caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis in dogs. For the treatment of stabilized Class 1, 2, and 3 heartworm disease caused by immature (4 month-old, stage L5) to mature adult infections of Dirofilaria immitis .
Source: FDA Animal Drugs @ FDA • Reference
Contraindications
Administer only by deep intramuscular injection in the lumbar muscles (L3 - L4). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Not for use in breeding animals and lactating or pregnant bitches. IMMITICIDE® should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian. Not for use in breeding animals and lactating or pregnant bitches. The drug is contraindicated in dogs with class 4 (very severe) heartworm disease (Caval Syndrome). Administer only by deep intramuscular injection in the lumbar muscles (L3 – L5). Use a 23 gauge 1 inch needle for dogs less than or equal to 10 kilograms (22 pounds) and a 22 gauge 1 1/2 inch needle for dogs greater than 10 kilograms (22 pounds). Use in alternate sides with each administration. DIROBANTM should be administered by deep intramuscular injection in the lumbar (epaxial) muscles (L3 - L5) ONLY. DO NOT USE IN ANY OTHER MUSCLE GROUP. DO NOT USE INTRAVENOUSLY. Care should be taken to avoid superficial injection or leakage. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Side Effects
No approved side-effect narrative is linked yet.
openFDA reaction signals are available for Dog 14 and Cat 6 (view top reported reactions).
Top Reported Reactions (openFDA)
Aggregated reaction terms from FDA openFDA reports (not verified; does not prove causation).
Data source: FDA openFDA Animal & Veterinary adverse event reports.
Adverse Event Case Summaries (openFDA)
These are individual FDA adverse event reports. They are unverified and do not prove the medication caused the reaction.
Dog, Crossbred Canine/dog, Male, 4 year, 33.112 kilogram • Drug: MSK, Unassigned, Intramuscular • Reactions: Lack of efficacy (endoparasite) - heartworm • Outcome: Ongoing
- Report ID: USA-USFDACVM-2025-US-056101
- Serious AE: Yes
- Treated For AE: No
- Sex: Male
- Age: 4.00 Year
- Weight: 33.112 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Intramuscular
- Form: Unassigned
Dog, Shepherd Dog - German, Male, 6 year, 36.29 kilogram • Drug: MSK, Parenteral • Reactions: Lack of efficacy (endoparasite) - heartworm • Outcome: Outcome Unknown
- Report ID: USA-USFDACVM-2025-US-049979
- Serious AE: No
- Treated For AE: No
- Sex: Male
- Age: 6.00 Year
- Weight: 36.290 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Parenteral
Dog, Shepherd Dog - German, Male, 2 year • Drug: MSK, Unknown • Reactions: Lack of efficacy (endoparasite) - heartworm • Outcome: Outcome Unknown
- Report ID: USA-USFDACVM-2025-US-043577
- Serious AE: No
- Treated For AE: No
- Sex: Male
- Age: 2.00 Year
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Unknown
Dog, ['Boxer (German Boxer)', 'Dog (unknown)'], Male, 2 year, 24 kilogram • Drug: MSK, Unassigned, Unknown • Reactions: Vomiting, Tiredness (lethargy), Inappropriate defecation, Elevated alanine aminotransferase, Gall bladder inflammation… • Outcome: Ongoing
- Report ID: USA-USFDACVM-2025-US-040913
- Serious AE: Yes
- Treated For AE: Yes
- Sex: Male
- Age: 2.00 Year
- Weight: 24.000 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Unknown
- Form: Unassigned
Dog, ['Terrier - Bull - American Pit', 'Dog (unknown)'], Male, 4.5 year, 23.133 kilogram • Drug: MSK, Injection, solution, Unknown • Reactions: Lack of efficacy (endoparasite) - heartworm, Intentional misuse • Outcome: Ongoing
- Report ID: USA-USFDACVM-2025-US-042381
- Serious AE: Yes
- Treated For AE: No
- Sex: Male
- Age: 4.50 Year
- Weight: 23.133 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Unknown
- Form: Injection, solution
Cat, Domestic Mediumhair, Male, 6 week, 0.3 kilogram • Drug: MSK, Suspension, Oral • Reactions: Unsteady walking (ataxia), Tiredness (lethargy), Agitation, Aggression, Administration error NOS • Outcome: Recovered/Normal
- Report ID: USA-USFDACVM-2022-US-061285
- Serious AE: No
- Treated For AE: No
- Sex: Male
- Age: 6.00 Week
- Weight: 0.300 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Oral
- Form: Suspension
Cat, Domestic Mediumhair, Male, 6 week, 0.3 kilogram • Drug: MSK, Oral • Reactions: Unsteady walking (ataxia), Tiredness (lethargy), Agitation, Aggression • Outcome: Recovered/Normal
- Report ID: USA-USFDACVM-2022-US-042427
- Serious AE: No
- Treated For AE: No
- Sex: Male
- Age: 6.00 Week
- Weight: 0.300 Kilogram
- Case-reported brand: MSK
- Case-reported manufacturer: MSK
- Route: Oral
Data source: FDA openFDA Animal & Veterinary adverse event reports.
Overdose Information
No approved overdose-management text is linked yet. If overdose is suspected, contact a veterinarian or emergency clinic immediately.
Storage & Handling
No approved storage guidance is linked yet for this ingredient. Use manufacturer packaging and veterinary guidance for handling/storage.
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