Suspected Albuterol Intoxication In A Dog

Rebound hyperkalemia in a dog with albuterol toxicosis after cessation of potassium supplementation

OBJECTIVE

To describe the presentation of rebound hyperkalemia as a delayed side effect of albuterol toxicity in a dog.

CASE SUMMARY

A 3-year-old female neutered mixed-breed dog was presented for albuterol toxicosis that led to a severe hypokalemia, hyperlactatemia, and hyperglycemia. The dog also experienced sinus tachycardia and generalized weakness. Treatment was instituted with intravenous fluid therapy and potassium supplementation, and the dog was monitored with a continuous electrocardiogram. Resolution of hypokalemia was documented 12 hours after initial presentation, at which time fluid therapy and potassium supplementation were discontinued. There were no further periods of sinus tachycardia, but instead the dog developed ventricular ectopy with rapid couplets (instantaneous rates of 300/min). An echocardiogram revealed normal cardiac size and function. Twenty-four hours after presentation, the patient developed severe hyperkalemia, despite discontinuation of fluids and potassium supplementation for 12 hours. Serial venous and urinary electrolytes were performed for determination of the fractional excretion of electrolytes. These data confirmed rebound hyperkalemia (7.0 mmol/L), consistent with a markedly increased fractional excretion of potassium, and secondary to the release of potassium from inside the cells. Fluid therapy with dextrose supplementation was provided until 36 hours postpresentation. The hyperkalemia resolved, and the dog was discharged after 44 hours of hospitalization.

NEW OR UNIQUE INFORMATION PROVIDED

This case documents rebound hyperkalemia following treatment of albuterol toxicosis in a dog. This case highlights the importance of understanding the distribution of total body potassium when treating serum hypokalemia. Transcellular shifts of potassium, as in the case of albuterol toxicosis, can lead to rebound hyperkalemia even after discontinuation of potassium supplementation. This case further explores the utility of fractional excretion of electrolytes in elucidating the etiology and management of electrolyte disturbances.

Retrospective evaluation of acute salbutamol (albuterol) exposure in dogs: 501 cases

OBJECTIVE

To determine the common clinical signs, with onset and duration, treatments given, and outcome in dogs with acute, accidental exposure to salbutamol.

DESIGN

Retrospective study.

ANIMALS

Five hundred and one canine cases reported to the UK's Veterinary Poisons Information Service (VPIS).

MEASUREMENTS AND MAIN RESULTS

A review of all records in the VPIS database for dogs exposed to salbutamol was carried out. After applying inclusion and exclusion criteria, the records of 501 dogs were further analyzed. The most common clinical signs were tachycardia (80.6%), tachypnea (32.9%), depression (21.0%), and vomiting (19.2%). The dose was unknown in most cases as the dogs typically pierced a salbutamol inhaler. The blood potassium concentration was measured in at least 142 dogs and hypokalemia was reported in 21.2% (106/501), 18 (17%) of which had associated weakness, twitching, or collapse. Three dogs had paralysis probably as a result of hypokalemia, although no potassium concentration was reported in these cases. Arrhythmias occurred in 17 dogs (3.4%), and 7 required pharmacological intervention. There were no reports of persistent cardiac injury or thermal injury from the compressed gas present in some salbutamol products. Signs were rapid in onset, generally within 1-3 h, and, where time to outcome was recorded (n = 172), 78% of dogs recovered within 24 h. Of the 501 dogs, no treatment was required in 27.9%. Beta-blockers were used in 39.5%, intravenous fluids in 28.7%, and potassium supplementation in 15.8%. Overall, 30 dogs remained asymptomatic (6.0%), 469 recovered (93.6%), and 2 dogs (0.4%) died.

CONCLUSIONS

Most dogs exposed to salbutamol rapidly develop clinical signs; these were commonly increased heart and respiration rates. Hypokalemia and arrhythmias (particularly ventricular arrhythmias) are potential complications. Any dog that chews a salbutamol inhaler should be assessed promptly for signs of toxicosis. Prognosis in dogs with acute salbutamol exposure is good, but more guarded in those with severe tachycardia and at risk of cardiac injury.

Acute nontraumatic rhabdomyolysis in a Greyhound after albuterol toxicosis

OBJECTIVE

To describe the clinical features of rhabdomyolysis due to albuterol toxicosis in a Greyhound.

CASE SUMMARY

A 4-year-old neutered male Greyhound was presented for albuterol toxicosis leading to severe hypokalemia and respiratory paralysis. After 3 hours of mechanical ventilation, pigmenturia and marked enlargement, firmness, and pain of the left thigh muscles were noted. Severe hyperkalemia and cardiac arrhythmias were identified after turning the patient. After discontinuation of mechanical ventilation, other muscles became involved, and the patient developed acute kidney injury and concern for multiple organ dysfunction syndrome over the next 5 days. On day 6, the patient was euthanized, and necropsy revealed myocardial and skeletal muscle necrosis, myoglobinuria, and acute tubular degeneration.

NEW OR UNIQUE INFORMATION PROVIDED

To the authors' knowledge, this is the first case of albuterol toxicosis leading to rhabdomyolysis.

Retrospective evaluation of albuterol inhalant exposure in dogs: 36 cases (2007-2017)

OBJECTIVE

To describe the clinical features, clinicopathological features, treatment, and outcome of dogs presented for albuterol exposure.

DESIGN

Retrospective case series from January 2007 to December 2017.

SETTING

Tertiary veterinary facility.

ANIMALS

Thirty-six client-owned dogs presenting for known or suspected albuterol exposure secondary to chewing on albuterol metered-dose inhalers (MDIs).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

All dogs presented with clinical signs attributable to albuterol exposure. The most common physical examination abnormality was sinus tachycardia, noted in 34 of 36 (94%) dogs. Twenty-seven patients (75%) were admitted to the hospital for therapy, with a median length of hospitalization of 20.5 hours (16.75-24.5). Thirty-two of 36 dogs had serum electrolytes evaluated at admission, with 22 of 32 (69%) presenting with hypokalemia ([K+] < 3.62 mmol/L]). Hyperlactatemia ([lactate] > 2.80 mmol/L) was noted in 23 of 28 (82%) dogs. A negative correlation was found between serum lactate and potassium (r = -0.64, r²  = 0.40, P = 0.0003). Hyperglycemia ([glucose] > 6.44 mmol/L) was noted in 20 of 30 (67%) dogs. Beta antagonist therapy was utilized in 20 of 36 (56%) of dogs.

CONCLUSIONS

Although uncommon, albuterol intoxication can lead to significant clinical and electrolyte abnormalities. Albuterol-induced hypokalemia and associated tachyarrhythmias can be successfully managed, and albuterol intoxication has an excellent prognosis for survival to discharge. A minimum database should be evaluated in all dogs presenting for suspected albuterol exposure, with lactate and glucose monitored carefully in dogs with moderate or severe hypokalemia given the correlation found.

Poisoning of dogs and cats by drugs intended for human use

One of the main causes of poisoning of small animals is exposure to drugs intended for human use. Poisoning may result from misuse by pet owners, off-label use of medicines or, more frequently, accidental ingestion of drugs that are improperly stored. This review focuses on classes of drugs intended for human use that are most commonly involved in the poisoning of small animals and provides an overview of poisoning episodes reported in the literature. To perform this review a comprehensive search of public databases (PubMed, Web of Science, Scopus, Google Scholar) using key search terms was conducted. Additionally, relevant textbooks and reference lists of articles pertaining to the topic were reviewed to locate additional related articles. Most published information on small animal poisoning by drugs intended for human use was from animal and human poison control centres or from single case reports. The dog was the species most frequently poisoned. The major drugs involved included analgesics (nonsteroidal anti-inflammatory drugs), antihistamines (H1-antihistamines), cardiovascular drugs (calcium channel blockers), central nervous system drugs (selective serotonin reuptake inhibitors, baclofen, benzodiazepines and zolpidem), gastrointestinal drugs (loperamide), nutritional supplements (vitamin D and iron salts) and respiratory drugs (β2-adrenergic receptor agonists).