Pimobendan

Indications

VETMEDIN Solution (pimobendan oral solution) is indicated for the delay of onset of congestive heart failure in dogs with Stage B2 preclinical myxomatous mitral valve disease. Stage B2 preclinical myxomatous mitral valve disease (MMVD) refers to dogs with asymptomatic MMVD that have a moderate or loud mitral murmur due to mitral regurgitation and cardiomegaly. VETMEDIN Solution (pimobendan oral solution) is indicated for the management of the signs of mild, moderate, or severe congestive heart failure (CHF) in dogs due to clinical MMVD or dilated cardiomyopathy (DCM). VETMEDIN Solution is indicated for use with concurrent therapy for congestive heart failure (e.g., furosemide, etc.) as appropriate on a case-by-case basis.

Dosage and Administration

VETMEDIN Solution should be administered orally at a total daily dose of 0.23 mg/lb (0.5 mg/kg) body weight. The total daily dose should be divided into 2 equal portions administered approximately 12 hours apart (i.e., morning and evening). The syringe is calibrated to deliver the appropriate morning or evening dose when drawn to the dog’s nearest weight in pounds. VETMEDIN Solution should be administered directly into the mouth. Do not mix into food. VETMEDIN Solution includes an amber glass bottle sealed with a white cap (A), an orange cap with integrated plastic plug (B), and an orange dosing syringe (C). Do not shake the bottle before or during use to avoid foaming. VETMEDIN Solution should be administered using the orange dosing syringe provided in the package. At the time of first use, the white cap should be removed and discarded. Once the orange cap has been screwed onto the bottle and the integrated plastic plug is in place, the dosing syringe fits onto plug. The dosing syringe has 1 pound incremental marks. Each dose should be rounded to the nearest 1 pound increment (e.g., a dose for a dog 5.5 lb or greater should be rounded up to 6 lb). An in-use video demonstration can be found using the URL https://go.boehringer.com/q7lKE or the QR code below. Close the bottle tightly using the orange cap. After administration, clean the outside of the syringe by wiping with a clean, dry cloth or tissue after each use. If the syringe clogs, rinse without removing the plunger by using water and wiping the outside of the syringe dry with a clean cloth or tissue. Image of bottle, cap and syringe. QR code

Contraindications

Do not administer VETMEDIN Solution in cases of hypertrophic cardiomyopathy, aortic stenosis, or any other clinical condition where an augmentation of cardiac output is inappropriate for functional or anatomical reasons. Do not administer VETMEDIN Solution to dogs with Stage A or B1 preclinical MMVD due to the risk of cardiac pathology associated with exaggerated hemodynamic responses to VETMEDIN Solution.

Warnings

User Safety Warnings: Not for use in humans. Keep this and all medications out of reach of children. Consult a physician in case of accidental ingestion by humans. Wash hands after use. This product may cause eye irritation. Avoid contact with eyes. In case of contact, flush affected eye(s) immediately and thoroughly with water. If wearing contact lenses, flush the eyes first with water and then remove the lens(es) and continue to flush thoroughly with water. If eye irritation continues, seek medical advice and provide this product information to the physician. Exposure to product may induce a local or systemic allergic reaction in sensitized individuals. Animal Safety Warnings: Only for use in dogs with Stage B2 preclinical MMVD or clinical evidence of CHF. At 3 and 5 times the recommended dosage, administered over a 6-month period of time, pimobendan caused an exaggerated hemodynamic response in the normal dog heart, which was associated with cardiac pathology (See Target Animal Safety ). Keep VETMEDIN Solution in a secure location out of reach of dogs, cats, and other animals to prevent accidental ingestion or overdose.

Precautions

The safety of VETMEDIN Solution has not been established in dogs with asymptomatic heart disease caused by etiologies other than MMVD or in CHF caused by etiologies other than MMVD or DCM. The safety of VETMEDIN Solution has not been evaluated in dogs younger than 6 months of age, dogs with congenital heart defects, dogs with diabetes mellitus or other serious metabolic diseases, dogs used for breeding, or pregnant or lactating bitches. For Stage B2 preclinical MMVD, use only in dogs that have a moderate or loud mitral murmur due to mitral regurgitation and cardiomegaly. A diagnosis of MMVD should be made by means of a comprehensive physical and cardiac examination which should include radiography and echocardiography. Stage B2 cardiomegaly 1 is diagnosed based on meeting all three of the following criteria: • Radiographic vertebral heart score (VHS) >10.5, and • Echocardiographic left atrium/aorta ratio (LA/Ao ratio) ≥ 1.6, and • Echocardiographic left ventricular internal diastolic diameter normalized to body weight (LVIDDN) ≥ 1.7. Echocardiographic examination is recommended in all cases to diagnose MMVD and confirm cardiomegaly. If therapy is initiated prior to the development of cardiomegaly, treated dogs are at risk for cardiac pathology associated with exaggerated hemodynamic responses to VETMEDIN Solution. If only radiographic examination is possible, cardiomegaly may be diagnosed in cases where the VHS ≥ 11.5 and the vertebral left atrial size (VLAS) ≥ 3.0 1,2 . If radiographic cardiomegaly does not meet both of these criteria, an echocardiogram should be performed prior to the initiation of therapy with VETMEDIN Solution. VETMEDIN Solution has not been evaluated in Stage B2 preclinical MMVD dogs receiving concomitant heart medications. Dogs in Stage B2 preclinical MMVD may eventually progress to clinical stages of MMVD (Stages C and D). A plan to recheck dogs at regular intervals is recommended as temporal changes in radiographic findings and clinical variables may be useful in diagnosing progression to CHF. In addition, it is recommended that dog owners be educated to recognize clinical signs associated with CHF (e.g., coughing or tachypnea) so they may promptly present the dog for an examination.

Adverse Reactions

The safety and effectiveness of VETMEDIN Solution was established by demonstrating bioequivalence with VETMEDIN Chewable Tablets. (See Clinical Pharmacology ). Pre-Approval Experience in Stage B2 Preclinical MMVD: Clinical findings/adverse reactions were recorded in two multi-site field studies of dogs diagnosed with Stage B2 preclinical MMVD. Study 1 : In the first study, 363 dogs with Stage B2 preclinical MMVD received at least one dose of VETMEDIN (n=182) or the vehicle control chewable tablets (n=181). Dogs were followed until the development of left-sided CHF, cardiac-related death or euthanasia, or until the end of the study (up to 3 years). Adverse reactions were seen in both treatment groups with many findings associated with MMVD and comorbidities consistent with the age of the enrolled dogs. Cough was the most frequently reported adverse reaction in this study. This clinical finding is commonly reported in cases of MMVD, and the incidence was similar between treatment groups. Gastrointestinal upset (vomiting and diarrhea) was the most frequently reported non-cardiac adverse reaction associated with VETMEDIN. Mortality rate, regardless of reason, prior to CHF was similar between the VETMEDIN and the control groups. Table 1: Cardiac Related Adverse Reactions a (Study 1) Adverse Reaction VETMEDIN Group (n=182) Vehicle Control (n=181) Cough 39 (21.4%) 42 (23.2%) Lethargy 16 (8.8%) 13 (7.2%) Inappetence 14 (7.7%) 13 (7.2%) Tachypnea/panting 13 (7.1%) 12 (6.6%) Arrhythmia 7 (3.9%) 3 (1.7%) Collapse b 4 (2.2%) 2 (1.1%) Dyspnea 4 (2.2%) 3 (1.7%) Syncope b 0 (0.0%) 5 (2.8%) Table 2: Non-cardiac Adverse Reactions (Study 1) Adverse Reaction VETMEDIN Group (n=182) Vehicle Control (n=181) Musculoskeletal pain 24 (13.2%) 12 (6.6%) Diarrhea 21 (11.5%) 16 (8.8%) Vomiting 18 (9.9%) 24 (13.3%) Seizure b 7 (3.8%) 2 (1.1%) Pruritus 7 (3.9%) 3 (1.7%) Lameness 7 (3.9%) 3 (1.7%) Urinary tract infection 7 (3.9%) 2 (1.1%) Restlessness 4 (2.2%) 0 (0%) a These adverse reactions are commonly associated with cardiac disease, although some cases may have non-cardiac causes. b Most cases of collapse, syncope, and seizure were reported by the owner. These clinical signs can be difficult to differentiate. Study 2: In the second study, 161 dogs with Stage B2 preclinical MMVD were treated with at least one dose of VETMEDIN. All enrolled dogs were treated with VETMEDIN. The dogs were followed for up to 1 year (365 days), or until the development of left-sided CHF, malignant arrhythmias, syncope, advanced coughing, increased resting respiration rate (RRR), or death. Adverse reactions identified in this study were similar to the first study with many findings associated with MMVD and age-related comorbidities. Cough was the most frequently reported cardiac related adverse reaction and gastrointestinal upset (vomiting and diarrhea) was the most frequently reported non-cardiac adverse reaction associated with VETMEDIN. Chordae tendineae rupture occurred in 3 dogs receiving VETMEDIN in Study 2, resulting in the euthanasia of one dog. In Study 1, chordae tendineae rupture was observed in 3 control dogs and in 0 VETMEDIN-treated dogs. In Study 2, 14 VETMEDIN-treated dogs died or were euthanized by Day 365; 8 for cardiac related reasons and 6 for reasons unrelated to MMVD or treatment with VETMEDIN. Table 3: Cardiac Related Adverse Reactions a (Study 2) Adverse Reaction VETMEDIN (n=161) Cough 48 (29.8%) Inappetence 30 (18.6%) Lethargy 25 (15.5%) Tachypnea/panting 17 (10.6%) Arrhythmia 13 (8.1%) Dyspnea 6 (3.7%) Syncope b 5 (3.1%) Collapse b 2 (1.2%) Table 4: Non-cardiac Adverse Reactions (Study 2) Adverse Reaction VETMEDIN (n=161) Vomiting 59 (36.6%) Diarrhea 53 (32.9%) Musculoskeletal pain 12 (7.5%) Lameness 10 (6.2%) Dermal mass 9 (5.6%) Polydipsia 9 (5.6%) Pruritus 7 (4.3%) Polyuria 6 (3.7%) Urinary tract infection 6 (3.7%) Restlessness 4 (2.5%) Seizure b 3 (1.9%) a These adverse reactions are commonly associated with cardiac disease, although some cases may have non-cardiac causes. b Most cases of collapse, syncope, and seizure were reported by the owner. These clinical signs can be difficult to differentiate. Pre-Approval Experience in Clinical MMVD or DCM: In a separate study, clinical findings/adverse reactions were recorded in a 56-day field study of dogs with CHF due to MMVD (256 dogs) or DCM (99 dogs). Dogs were treated with either VETMEDIN (175 dogs) or the active control enalapril maleate (180 dogs). Dogs in both treatment groups received additional background cardiac therapy (See Effectiveness for details and the difference in digoxin administration between treatment groups). The VETMEDIN group had the following incidence (percent of dogs with at least one occurrence) of common adverse reactions/new clinical findings (not present in a dog prior to beginning study treatments). Incidence was similar in the active control group. The incidence of renal failure was higher in the active control group (4%) compared to the VETMEDIN group (1%). Table 5: Adverse Reactions (Clinical MMVD or DCM) Adverse Reaction VETMEDIN (n=175) Poor appetite 67 (38%) Lethargy 58 (33%) Diarrhea 53 (30%) Dyspnea 51 (29%) Azotemia 25 (14%) Weakness/ataxia 23 (13%) Pleural effusion 18 (10%) Syncope 16 (9%) Cough 12 (7%) Sudden death 11 (6%) Ascites 11 (6%) Heart Murmur 5 (3%) Adverse reactions/new clinical findings were seen in both treatment groups and were potentially related to CHF, the therapy of CHF, or both. The following adverse reactions/new clinical findings are listed according to body system and are not in order of prevalence: CHF death, sudden death, chordae tendineae rupture, left atrial tear, arrhythmias overall, tachycardia, syncope, weak pulses, irregular pulses, increased pulmonary edema, dyspnea, increased respiratory rate, coughing, gagging, pleural effusion, ascites, hepatic congestion, decreased appetite, vomiting, diarrhea, melena, weight loss, lethargy, depression, weakness, collapse, shaking, trembling, ataxia, seizures, restlessness, agitation, pruritus, increased water consumption, increased urination, urinary accidents, azotemia, dehydration, abnormal serum electrolyte, protein, and glucose values, mild increases in serum hepatic enzyme levels, and mildly decreased platelet counts. See Table 6 for mortality due to CHF (including euthanasia, natural death, and sudden death) and for the development of new arrhythmias (not present in a dog prior to beginning study treatments) by treatment group and type of heart disease (MMVD or DCM) in the 56-day field study. Table 6: CHF Death and New Arrhythmias in the 56-Day Field Study VETMEDIN Group Active Control Group Dogs that died due to CHF 14.3% n = 175 14.4% n = 180 9 of 126 dogs with MMVD 16 of 130 dogs with MMVD 16 of 49 dogs with DCM 10 of 50 dogs with DCM Dogs that developed new arrhythmias a 39.4% n = 175 45.0% n = 180 45 of 126 dogs with MMVD 59 of 130 dogs with MMVD 24 of 49 dogs with DCM 22 of 50 dogs with DCM a New arrhythmias included supraventricular premature beats and tachycardia, atrial fibrillation, atrioventricular block, sinus bradycardia, ventricular premature beats and tachycardia, and bundle branch block. Following the 56-day masked field study, 137 dogs in the VETMEDIN group were allowed to continue on VETMEDIN in an open-label extended-use study without restrictions on concurrent therapy. The adverse reactions/new clinical findings in the extended-use study were consistent with those reported in the 56-day study, with the following exception: One dog in the extended-use study developed acute cholestatic liver failure after 140 days on VETMEDIN and furosemide. Post-Approval Experience (2023): The following adverse events are based on post-approval adverse drug experience reporting for VETMEDIN. Not all adverse events are reported to FDA/CVM. It is not always possible to reliably estimate the adverse event frequency or establish a causal relationship to product exposure using these data. The following adverse events reported in dogs, are listed in decreasing order of reporting frequency: Diarrhea, lethargy, anorexia, emesis, cough, tachycardia, ataxia, dyspnea, convulsion, elevated liver enzymes (ALT, ALP), increased BUN and/or creatinine, tremors, hyperactivity, pruritus, syncope, allergic reactions (including allergic edema/facial edema, erythema, and hives), hypotension, hypertension, coagulation abnormalities (including thrombocytopenia, hemorrhage and petechia), and hyperglycemia (with or without diabetes mellitus). Death has been reported in some cases.

Description

VETMEDIN® Solution (pimobendan oral solution) is a clear to yellow to slightly green to slightly brown aqueous solution containing 1.5 mg/mL pimobendan. Pimobendan, a benzimidazole-pyridazinone derivative, is a non-sympathomimetic, non-glycoside inotropic drug with vasodilatative properties. The chemical name of pimobendan is 4,5-dihydro-6-[2-(4-methoxyphenyl)-1H-benzimidazole-5-yl]-5-methyl-,(±)-3(2H)-pyridazinone. The structural formula of pimobendan is: Image of structural formula of pimobendan

Storage

Store at or below 77°F (25°C) with excursions permitted up to 86°F (30°C). Once the bottle is opened, use the contents within 8 weeks.

Other labels for this ingredient

These labels are also stored for the same active ingredient. They are not identical to the one reprinted above, and each is listed by product and set id rather than merged with it.

• Vetmedin®-CA1 (pimobendan) Chewable Tablets, Boehringer Ingelheim Animal Health USA Inc.. Set id b461035d-9c3c-42e2-ae1a-3ad611fd5e8d.
• Pimobendan Chewable Tablets, ASPEN VETERINARY RESOURCES®, LTD. Set id 2be5a8d4-185e-40b4-800f-3cdbb2a1fa3c.
• Pimobendan Chewable Tablets, Cronus Pharma LLC. Set id 4e5af451-5e13-4bbd-99ad-24885f9eedfc.
• Pimobendan Chewable Tablets, Covetrus. Set id 5ff993b9-6fb0-4cca-b946-61f830fe698e.
• VET One CaniBendan™ (pimobendan chewable tablets), MWI Animal Health. Set id 4d7a643e-319b-4d8e-872b-cd7e1c07722e.
• Vetmedin ® (pimobendan) Chewable Tablets, Boehringer Ingelheim Animal Health USA Inc.. Set id 5441e5b2-cdc0-477a-bd9a-ec5f8d912281.

FDA adverse event reports

The FDA Center for Veterinary Medicine publishes the adverse event reports it receives through openFDA. The counts below are the reports naming pimobendan as an active ingredient for each species this label names, as returned on 2026-09-16, coded by the VeDDRA reaction term the reporter chose. Reactions are counted per report, so one report can appear under several terms.

These are counts, not rates. Reporting is voluntary, the number of animals treated is not known, and a widely used product accumulates reports for that reason alone. A report records that an event followed a dose; it does not establish that the product caused it. The counts say nothing about how one product compares with another.