Doses - QUINIDINE GLUCONATE, QUINIDINE POLYGALACTURONATE, QUINIDINE SULFATE

Dogs:

a) Quinidine sulfate: 6 - 16 mg/kg PO q6h (conventional tabs/caps); q8h (Extentabs®)
Quinidine gluconate: 6 - 20 mg/kg IM q6h; 8 - 20 mg/kg PO q6-8h (sustained-release)
Quinidine polygalacturonate: 8 - 20 mg/kg q6-8h (Miller 1985)
b) Quinidine gluconate (sustained-release): 8 - 20 mg/kg PO q8-12h; Injection: 8 - 20mg/kg IM q8-12h or slow IV q8h
Quinidine sulfate: 8 - 20 mg/kg PO q6-8h
Quinidine polygalcturonate: 8 - 20 mg/kg PO q8-12h (Kirk 1986)
c) For VPC's or V. tach:
Quinidine gluconate: 6.6 - 22 mg/kg IM q2-4h or q8-12h PO (delayed dosage forms).
Quinidine Sulfate: 6.6 - 22 mg/kg PO q6-8h; may be given initially q2h as a loadingdose until arrhythmias is controlled or toxicity is induced. (Ettinger 1989)
d) For conversion of atrial fib to sinus rhythm: Initially attempted with quinidine gluconateat 6 - 11 mg/kg IM q6h. Most dogs will convert in the first 24 hours of threapy. If rapidventricular response occurs, may give either digoxin or a beta blocker to slow rate ofconduction across AV node. (Russell and Rush 1995)

Cats:

a) 4 - 8 mg/kg IM tid (Morgan 1988)
b) 10 - 20 mg/kg q6h PO (Neff-Davis 1985)

Horses:

a) Oral Dosing:
Method 1: Give quinidine sulfate powder by stomach tube or in large gelatin capsules.
Day 1: Give 5 gram test dose; if no adverse reactions (see Adverse Effects) may continuetherapy
Days 2, 3: 10 gram bid
Days 4, 5: 10 gram tid
Days 6, 7: 10 gram qid
Days 8, 9: 10 gram every 5 hours
Day 10 and thereafter: 15 gram qid
Method 2:
Day 1: 5 gram test dose
Day 2: 10 gram every 2 hours until a total dose of 80 grams or less has been given.
Once the arrhythmia is halted, reduce dose total dose by 1/2 every other day until amaintenance dose is reached that prevents recurrence of arrhythmia. If treating atrialfibrillation, quinidine can usually be discontinued 1-2 days after conversion to sinusrhythm. Doses greater than 40 grams per day tend to cause undesirable effects. (Hilwig1987)
Monitoring Parameters - 1) ECG; 2) Blood pressure if possible, during IV administration; 3)
Symptoms of toxicity (see Adverse Reactions/Overdosage); 4) Serum levels. Therapeutic serumlevels are believed to range from 2.5 - 5.0 micrograms/ml. Levels greater than 10 micrograms/ml areconsidered to be toxic.
Client Information - Oral products should be administered at evenly spaced intervals throughoutthe day/night. GI upset may be decreased if administered with food. Do not allow animal to chew orcrush sustained-release oral dosage forms. Notify veterinarian if animal's condition deteriorates orsymptoms of toxicity (e.g., vomiting, diarrhea, weakness, etc.) occur.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None

Human-Approved Products:

Quinidine Sulfate (contains 83% anhydrous quinidine alkaloid) Tablets 200 mg, 300 mg;
Quinora® (Key), Generic; (Rx)
Quinidine Sulfate (contains 83% anhydrous quinidine alkaloid) Sustained-Release Tablets 300mg; Quinidex® Extentabs (Robins); (Rx)
Quinidine Gluconate (contains 62% anhydrous quinidine alkaloid); Sustained-release Tablets324 mg; Quinaglute® Dura-Tabs (Berlex); Quinalan® (Lannett); Generic; (Rx)
Quinidine Gluconate Injection 80 mg/ml (50 mg/ml of quinidine), 10 ml vials; Generic (Lilly);(Rx)
Quinidine Polygalacturonate (contains 80% anhydrous quinidine alkaloid); Tablets 275 mg;
Cardioquin® (Purdue-Frederick); (Rx)