Yohimbine hydrochloride: what the FDA reviewed for dog products
1 Freedom of Information summary from the FDA Center for Veterinary Medicine for products containing Yohimbine hydrochloride, as typed records: every value below is followed by the verbatim passage it was taken from. Species as stated by each summary: Dogs.
Products
- Yobine® Injection (NADA/ANADA 140-866)
Yobine® Injection NADA 140-866, Original approval, September 26, 1989; sponsor Cronus Pharma Specialities India Private Ltd.; species: Dogs; foi_id 1990; FDA PDF
Indication
Xylazine reversing agent and antidote for use in dogs only
Dose regimen
0.05 mg/lb (0.11 mg/kg), given as 0.5 mL per 20 pound body weight, Intravenous, Single injection after xylazine, Dose is that used in the pivotal field study (General Information lists no recommended dosage); in the field study yohimbine was injected 15 minutes after IV xylazine and 25 minutes after IM or SC xylazine
Dose in study was 0.5 mL yohimbine per 20 pound body weight (0.05 mg/lb or 0.11 mg/kg).
Target-animal safety
dose multiples 0X, 1X, 3X, 5X; duration 3 IV doses at 6 hr intervals (0, 6 and 12 hr); each dog observed for > or = 28 days with intensive testing for 24 hr after treatment; animals 12 female and 12 male young healthy adult mixed-breed dogs in 4 groups.
The study was designed to test the safety of yohimbine in dogs treated at 0, 1x, 3x, and 5x the intended dose. c. Test Animals: 12 female and 12 male young healthy adult dogs of mixed breed, which were randomly assigned to 4 test groups.
| Finding | Quote |
|---|---|
| Dose groups: 0X diluent control (volume of 5X dose), 1X 0.05 mg/lb, 3X 0.15 mg/lb and 5X 0.25 mg/lb yohimbine, each given IV 3 times at 6 hr intervals | Each dog was administered the prescribed dose I.V. in a cephalic or saphenous vein 3 times at 6 hr intervals (0 time, 6 hr, and 12 hr). |
| No significant differences between control and treated groups in hematology, serum chemistry or urinalysis (Dunnett test) | there were no significant differences in hematology, serum chemistry, and urinalysis. |
| Necropsy and histopathology detected no treatment-related changes | A routine necropsy and a histopathology failed to detect any treatment related changes. |
| Yobine judged safe when dosed IV at 0.05, 0.15 and 0.25 mg/lb three times at 6 hour intervals | dosed I.V. at 0.05, 0.15 and 0.25 mg/lb body weight 3 times at 6 hour intervals. |
Effectiveness
Multi-site placebo-controlled clinical field study (sites started after October 10, 1986; terminated June 1, 1987). Client-owned dogs of random age, sex, weight and breed sedated with xylazine (IV 0.5 mg/lb, IM 1.0 or 0.5 mg/lb, or SC 1.0 mg/lb, route assigned by random table) then received Yobine 0.05 mg/lb IV or placebo; each dog also served as its own pre/post-injection control. 258 cases enrolled, 71 unusable; n = 187; primary endpoint: Sedation times (recumbency, arousal, walk), analgesia (prick response), clinical signs, heart rate and respiration rate, observed for at least 35 minutes; result: Yobine significantly shortened arousal time (least-squares means: 12.25 vs 21.55 min after IV xylazine, 17.59 vs 21.75 after IM, 14.81 vs 26.27 after SC) and walk time (14.55 vs 32.25, 19.39 vs 44.85, 17.19 vs 35.52 min), increased heart and respiratory rates, and decreased analgesia (prick test) versus placebo in xylazine-treated dogs; no adverse effects reported
Therefore, 187 cases were used in the trials.
Adverse reactions
| Term | Treated | Control | Quote |
|---|---|---|---|
| No adverse effects reported (pivotal field study, Yobine vs placebo after xylazine) | No adverse effects were reported. 6. | ||
| Increased CNS activity (brief seizures and muscle 'tumors' [sic]) in dose-titration group four (1x xylazine 0.5 mg/lb followed by 5x yohimbine 0.25 mg/lb IV) | two dogs in group four | No adverse effects were reported, except increase CNS activity (brief seizures 6. and muscle tumors) in two dogs in group four. |
Extraction notes: Original NADA. General Information gives no recommended dosage, so dose_regimen is the pivotal field-study dose (0.05 mg/lb IV). Field-study Table I (least-squares means) was flattened by PDF extraction; column order is IV-xylazine/Yohimbine, IV/Placebo, IM/Yohimbine, IM/Placebo, SC/Yohimbine, SC/Placebo: 'Arousal time 12.25 21.55 17.59 21.75 14.81 26.27'; 'Walk time 14.55 32.25 19.39 44.85 17.19 35.52'; 'Difference in heart rate prior to and post injection 15.90 61.45 13.17 58.83 18.28 60.03'. Study conclusion verbatim (PDF typo): 'Yobin e significantly shortened the arousal time, increased the heart and respiratory rates, and decreased analgesia in xylazine-treated dogs.' A separate dose-titration study (15 female and 15 male dogs in five groups; xylazine 1x 0.5 mg/lb or 5x 2.5 mg/lb IV followed 5 minutes later by yohimbine 0x, 0.2x 0.01 mg/lb, 1x 0.05 mg/lb or 5x 0.25 mg/lb IV) concluded Yobine was safe at 0.01 to 0.25 mg/lb and effective at 0.05 to 0.25 mg/lb; its only adverse event (group four) is recorded under adverse_reactions. target_animal_safety is the acute toxicity study (0X/1X/3X/5X, 6 dogs per group, 3 doses at 6 hr intervals). Several quotes contain interleaved outline numerals ('6.') from PDF extraction. No PK data in the summary.
Reproduce: foi_structured_search(query="Yohimbine hydrochloride") and foi_summary_get(foi_id=...) in dog-geroscience-mcp; dataset foi-summaries-dog (config structured).