Category Archives: Veterinary Drugs

Thioguanine: 40 mg Tablets

Thioguanine ANTINEOPLASTIC Highlights of Prescribing Information Oral purine analog antineoplastic that may be useful as adjunctive treatment for acute lymphocytic or granulocytic leukemia in dogs or cats Contraindications: Hypersensitivity to thioguanine Caution: Hepatic dysfunction, bone marrow depression, infection, renal function impairment (adjust dosage), or history of urate urinary stones Potentially mutagenic & teratogenic; use milk replacer if nursing Adverse Effects: GI effects, bone marrow suppression, hepatotoxicity, pancreatitis, GI (including oral) ulceration, & dermatologic reactions Cats may be more susceptible than dogs to adverse effects Low therapeutic index; monitoring mandatory What Is Drug Used For? Thioguanine may be useful as adjunctive therapy for acute lymphocytic or granulocytic leukemia in dogs or cats. Pharmacology / Actions Intracellularly, thioguanine is converted to ribonucleotides that cause the synthesis and utilization of purine nucleotides to be blocked. The drug’s cytotoxic effects are believed to occur when these substituted nucleotides are inserted into RNA and DNA. Thioguanine has limited immunosuppressive activity. Extensive cross-resistance Read more […]

Thiotepa Lyophilized Powder for Injection: 15 mg & 30 mg in vials

Thiotepa ANTINEOPLASTIC Highlights of Prescribing Information Antineoplastic used systemically for carcinomas, intracavitary for neoplastic effusions, & intravesical for transitional carcinomas; rarely used in small animal oncology Contraindications: Hypersensitivity to thiotepa; Caution: Hepatic dysfunction, bone marrow depression, infection, tumor cell infiltration of bone marrow, renal dysfunction, or history of urate urinary stones Adverse Effects: Leukopenia most likely adverse effect; other hematopoietic toxicity (thrombocytopenia, anemia, pancytopenia), GI toxicity possible. Intracavitary or intravesical instillation can also cause hematologic toxicity. Potentially teratogenic; use milk replacer if patient nursing Monitor diligently What Is Drug Used For? Veterinary indications for thiotepa include: systemic use for adjunctive therapy against carcinomas, and intracavitary use for neoplastic effusions. In dogs with transitional cell bladder carcinoma, intravesical instillation of thiotepa had significantly less efficacy (mean survival time = 57 days) when compared to a systemic doxorubicin/ cyclophosphamide protocol (mean survival time = 259 days). Pharmacology / Actions Thiotepa is an Read more […]

Thiola (Tiopronin): 100 mg Tablets

Tiopronin (Thiola) 2-MPG ANTIUROLITHIC (CYSTINE) AGENT Highlights of Prescribing Information Drug for prevention (& treatment) of cystine urolithiasis Cautions: Agranulocytosis, aplastic anemia, thrombocytopenia or other significant hematologic abnormality, impaired renal or hepatic function, or sensitivity to either tiopronin or penicillamine Adverse Effects: Coombs’-positive regenerative sphero-cyte anemia, aggressiveness, proteinuria, thrombocytopenia, elevations in liver enzymes, dermatologic effects, & myopathy What Is Drug Used For? Tiopronin is indicated for the prevention of cystine urolithiasis in patients where dietary therapy combined with urinary alkalinization is not completely effective. It may also be useful in combination with urine alkalinization to dissolve stones. Pharmacology / Actions Tiopronin is considered an antiurolithic agent. It undergoes thioldisulfide exchange with cystine (cysteine-cysteine disulfide) to form tiopronin-cystine disulfide. This complex is more water-soluble and is readily excreted thereby preventing cystine calculi from forming. Pharmacokinetics Tiopronin has a rapid onset of action and in humans, up to 48% of a dose is found in the urine within Read more […]

Tonocard (Tocainide HCL): 400 mg, 600 mg Tablets

Tocainide HCL (Tonocard) ORAL ANTIARRHYTHMIC Highlights of Prescribing Information Oral antiarrhythmic with similar activity as lidocaine; not commonly used in veterinary medicine Contraindications: Hypersensitivity reactions to it or amide-type local anesthetics, 2nd or 3rd degree AV block & not being artificially paced. Caution: Heart failure, hematologic abnormalities, or preexisting bone marrow failure. Adverse Effects: CNS effects (depression, ataxia, muscle tremors, etc.), nausea & vomiting (usually transient), cardiovascular effects (hypotension, bradycardia, tachycardia, other arrhythmias, & exacerbation of CHF) Case reports of dogs on long-term therapy (>3 mos.) developing ocular & renal toxicity What Is Drug Used For? Veterinary experience with tocainide is limited. At this time, dogs are the only veterinary species where enough clinical experience has been garnered to recommend its use. It is indicated for the oral therapy of ventricular arrhythmias, principally ventricular tachycardia and ventricular premature complexes. In humans, response to lidocaine can usually predict whether tocainide might be effective. Pharmacology / Actions Tocainide is considered a class IB Read more […]

Demadex (Torsemide): 5 mg, 10 mg, 20 mg, & 100 mg Tablets

TORSEMIDE (Demadex, Torasemide) LOOP DIURETIC Highlights of Prescribing Information Potent loop diuretic potentially useful for adjunctive treatment of CHF in dogs & cats; very little information available on clinical use in veterinary medicine Approximately 10X more potent, longer diuretic action, & more potassium-sparing (in dogs) than furosemide May be more expensive than furosemide, but tablets are now available generically What Is Drug Used For? Torsemide is a loop diuretic similar to furosemide, but it is more potent, its diuretic effects persist for a longer period, and it does not cause as much potassium excretion (in dogs). While clinical use in dogs and cats thus far has been minimal, it potentially may be a useful adjunctive treatment for congestive heart failure in dogs and cats, particularly in patients that have become refractory to furosemide. Pharmacology / Actions Torsemide, like furosemide inhibits sodium and chloride reabsorption in the ascending loop of Henle via interference with the chloride-binding site of the lNa+, 1K+, 2Cl- cotransport system. Torsemide increases renal excretion of water, sodium, potassium, chloride, calcium, magnesium, hydrogen, ammonium, and bicarbonate. Read more […]

Dyrenium (Triamterene): 50 mg, 100 mg Capsules

TRIAMTERENE (Dyrenium) POTASSIUM-SPARING DIURETIC Highlights of Prescribing Information Potassium-sparing diuretic that may be considered as an alternative to spironolactone for treating CHF in dogs; limited clinical experience with this drug in dogs/cats Contraindications: Anuria, severe or progressive renal disease, severe hepatic disease, hypersensitivity to triamterene, preexisting hyperkalemia, concurrent therapy with another potassium-sparing agent (spironolactone, amiloride) or potassium supplementation Hyperkalemia possible; must monitor serum K+ What Is Drug Used For? Triamterene is a potassium-sparing diuretic that potentially could be used as an alternative to spironolactone for the adjunctive treatment of congestive heart failure in dogs, however, there is little experience associated with its use in dogs or cats. Pharmacology / Actions By exerting a direct effect on the distal renal tubule, triamterene inhibits the reabsorption of sodium in exchange for hydrogen and potassium ions. Unlike spironolactone, it does not competitively inhibit aldosterone. Triamterene increases excretion of sodium, calcium, magnesium and bicarbonate; urinary pH may be slightly increased. Serum concentrations Read more […]

Temaril-P (Trimeprazine Tartrate 5 mg; Prednisolone 2 mg) Tablets

TRIMEPRAZINE TARTRATE WITH PREDNISOLONE (Temaril-P) PHENOTHIAZINE ANTIHISTAMINE & CORTICOSTEROID Highlights of Prescribing Information Combination phenothiazine antihistamine & corticosteroid used for pruritus & potentially as an antitussive Relatively Contraindicated: Systemic fungal infections, hypovolemia, or shock & in patients with tetanus or strychnine intoxication. Caution: Hepatic dysfunction, cardiac disease, active bacterial or viral infections, peptic ulcer, acute psychoses, corneal ulcer, Cushingoid syndrome, diabetes, osteoporosis, chronic psychotic reactions, predisposition to thrombophlebitis, hypertension, CHF, renal insufficiency, general debilitation, very young animals Goal is to use as much as is required & as little as possible for as short an amount of time as possible Primary adverse effects: Sedation, may cause significant hypotension, cardiac rate abnormalities, hypo- or hyperthermia, “Cushingoid” effects with sustained use Many potential drug & lab interactions What Is Drug Used For? Trimeprazine with prednisolone is used for the treatment of pruritic conditions, especially if induced by allergic conditions. Many dermatologists believe that when prednisolone Read more […]

Ursodiol: 250 mg & 500 mg Tablets

URSODIOL (Actigall, Ursodeoxycholic acid) BILE ACID Highlights of Prescribing Information Bile acid that may be useful for treatment of hepatobiliary disease in dogs/cats. May also be used for cholesterol containing gallstones Contraindications: Rabbits & other hindgut fermenters. Caution: Complications associated with gallstones (e.g., biliary obstruction, biliary fistulas, cholecystitis, pancreatitis, cholangitis) Adverse Effects: Appears to be well tolerated in dogs/cats What Is Drug Used For? In small animals, ursodiol may be useful as adjunctive therapy for the medical management of cholesterol-containing gallstones and/or in patients with chronic liver disease, particularly where cholestasis (bile toxicity) plays an important role. Ursodiol’s benefit in treating canine or feline hepatobiliary disease is unknown at the time of writing (studies are ongoing), but it may be of help in slowing the progression of inflammatory hepatic disorders, particularly autoimmune hepatitis and acute hepatotoxicity. Pharmacology / Actions After oral administration, ursodiol suppresses hepatic synthesis and secretion of cholesterol. Ursodiol also decreases intestinal absorption of cholesterol. By reducing cholesterol Read more […]

Calan (Verapamil HCl): 40 mg, 80 mg & 120 mg Tablets

VERAPAMIL HCL (Calan, Isoptin, Verelan) CALCIUM-CHANNEL BLOCKER Highlights of Prescribing Information Calcium channel blocking agent used for supraventricular tachycardias in dogs & cats Contraindications: Cardiogenic shock or severe CHF (unless secondary to a supraventricular tachycardia), hypotension, sick sinus syndrome, 2nd or 3rd degree AV block, digoxin intoxication, or hypersensitive to verapamil. IV is contraindicated within a few hours of IV beta-adrenergic blockers. Caution: Heart failure, hypertrophic cardiomyopathy, & hepatic or renal impairment. Use very cautiously in patients with atrial fibrillation & Wolff-Parkinson-White (WPW) syndrome. Adverse Effects: Hypotension, bradycardia, tachycardia, exacerbation of CHF, peripheral edema, AV block, pulmonary edema, nausea, constipation, dizziness, headache, or fatigue Drug Interactions What Is Drug Used For? Veterinary experience with this agent is somewhat limited, but in dogs and cats verapamil may be useful for supraventricular tachycardias and, possibly, treatment of atrial flutter or fibrillation. Pharmacology / Actions A slow-channel calcium blocking agent, verapamil is classified as a class IV antiarrhythmic drug. Verapamil Read more […]

Velban (Vinblastine) for Injection

ANTINEOPLASTIC Highlights of Prescribing Information A Vinca alkaloid antineoplastic used for a variety of tumors in dogs (& sometimes cats) Contraindications: Preexisting leukopenia or granulocytopenia (unless a result of the disease being treated) or active bacterial infection; reduce dose if hepatic disease Adverse Effects: Gastroenterocolitis (nausea/vomiting), myelosuppression (more so than with vincristine); may also cause constipation, alopecia, stomatitis, ileus, inappropriate ADH secretion, jaw & muscle pain, & loss of deep tendon reflexes CATS can develop neurotoxicity causing constipation or paralytic ileus & aggravating anorexia; can also develop reversible axon swelling & paranodal demyelination Potentially teratogenic Avoid extravasation; wear gloves & protective clothing when preparing or administering Drug Interactions What Is Drug Used For? Vinblastine may be employed in the treatment of lymphomas, carcinomas, mastocytomas, and splenic tumors in small animals. It is more effective than vincristine in the treatment of canine mast cell tumors. Pharmacology / Actions Vinblastine apparently binds to microtubular proteins (tubulin) in the mitotic spindle, thereby Read more […]