1. Contact your veterinarian immediately for further advice. It is highly recommended that you take your pet to your veterinarian for decontamination as soon as possible due to the potential severity of clinical signs. Treatment and monitoring is warranted in all patients that have ingested a potentially toxic dose.
  2. Bring the drug your pet has ingested, with its package insert and/or label for confirmation of the specific drug involved and calculation of dose ingested to give the vet an idea of the severity of toxicity and treatment plan.
  3. Veterinary care may involve inducing vomiting if ingestion occurred within two hours and if your pet is well enough.
  4. Do not use syrup of Ipecac to induce vomiting in beta blocker overdoses as it can lead to collapse.
  5. Stomach pumping may also be performed to evacuate the contents in your pet’s stomach to get rid of any remaining drugs in its system. Multiple doses of activated charcoal would also be given to absorb any more circulating drugs in the system.
  6. Your pet may need to be hospitalised for further treatment. This may involve intravenous fluid therapy to flush out the drugs from its system and maintain normal blood pressure and correct any electrolyte imbalances. Close monitoring of heart rate, rhythm, blood pressure and breathing is essential as major changes can occur rapidly. In severe cases, your pet may require mechanical ventilation or a temporary pacemaker.

OTHER NAMES

There are various classes of Beta-blockers and many different brand names of these drugs on the market. Some examples are listed below.

TOXICITY

MODERATE/SEVERE

Beta blockers in animals can have a potentially life-threatening effect on heart rate, blood pressure and respiratory functions.

CLINICAL SIGNS

  • Lethargy, dullness (due to low blood pressure)
  • Slow heart rate (bradycardia)
  • Difficulty breathing or increased breathing rate (dyspnoea, tachypnoea)
  • Fainting episode (syncope)
  • Collapse
  • Seizures (propranolol overdose)
  • Death (propranolol overdose)

EFFECTS OF TOXICITY

  • There are three different classes of Beta-blockers which target different beta-receptors, causing different effects on the body. Beta receptors are mainly found in the heart, kidneys, lungs, gastrointestinal tract, liver, uterus, blood vessel wall and muscles. The main body systems affected due to overdose of heart disease beta-blockers are usually the heart and lungs, causing reduced heart rate, blood pressure and respiratory depression.
  • Beta blockers can also cross the placenta and enter the mother’s milk.

REFERENCES

Buckley NA, Dawson AH, Reith DM, Sayer GP & Whyte IM (1996) Journal of Toxicology: Clinical Toxicology 34(3): 273

Gordon SG & Kittleson MD (2008) Drugs used in the management of heart disease and cardiac arrythmias In: Small Animal Clinical Pharmacology. 2nd ed. Maddison JE, Page SW & Church DB. USA: Saunders Elsevier

Langemeijer J, de Wildt D, de Groot G & Sangster B (1985) Respiratory arrest as main determinant of toxicity due to overdose with different beta-blockers in rats. Acta pharmacologica et toxicologica 75(5): 352-356

Plumb DC (2011) Plumb’s Veterinary Drug Handbook 7th Edn. Wiley-Blackwell, Iowa, USA.