Background
The opioid crisis continues and is not an exclusively human problem. Opioid prescription rates in an area were proportional to the rate of accidental opioid ingestion in dogs. This report describes the successful treatment of heroin intoxication in a dog and outlines insights in opioid intoxication.
Case Presentation
An 11-month-old, intact male boxer cross was presented having become unconscious shortly after it consumed 1 g of powdered heroin. On physical examination the dog was comatose and laterally recumbent. There was bilateral pupillary miosis and marked ptyalism. The heart rate was 60 bpm and respiratory rate was 20 bpm. The dog was normothermic (37.4°C) and normotensive (163/103 (123) mm Hg) with a 96% SpO2. Intravenous naloxone (0.02 mg/kg) quickly reversed clinical signs. The owners were unable to afford hospitalization and the animal was discharged against medical advice with no rebound opioid toxicity signs reported at 2-month followup.
New/Unique Information
The classic toxidrome of opioid intoxication consists of respiratory and central nervous system depression and miosis. Many substances cause miosis and coma, but without respiratory depression.
Heroin is commonly mixed with other drugs, such as fentanyl. Delayed gastric emptying, enzyme saturation and the resulting zero-order elimination cause oral opioid intoxications to be unpredictable. The different pharmacokinetics of various opioid agents are rarely relevant in the event of oral overdose. Therefore, the management of opioid intoxication, regardless of which opioid is involved, is founded on naloxone administration.
Naloxone is a safe drug and should be given if opioid intoxication is suspected. If clinical signs do not improve, opioid intoxication is unlikely. It is effective when given intranasally (IN). Atomized formulas are ideal, but the injectable formula is effective IN with less predictable results. A suggested dose is 2–4 mg/25 kg. If unavailable, butorphanol at 0.4 mg/kg may be useful. The short duration of intravenous naloxone (90 minutes) in relation to the opioids involved in overdose means rebound opioid toxicities occur. Large-scale human studies suggest a low risk in discharging a heroin intoxication patient 1 hour post reversal, provided the patient is neurologically appropriate and has normal vitals.
Disclosures
No disclosures to report.