Hydrogen Peroxide 3%
Hydrogen peroxide 3% is a widely available topical antiseptic that is frequently utilized in veterinary medicine as an **emergency oral emetic**, primarily in dogs. * **Clinical Pearl:** While it is a household staple, its use as an emetic is generally reserved for situations where immediate veterinary care is inaccessible and rapid decontamination is required. In a clinical setting, centrally acting emetics like **apomorphine** (for dogs) or **xylazine/dexmedetomidine** (for cats) are preferred due to higher efficacy and a lower risk of severe mucosal irritation. * **Feline Caution:** Its use in cats is increasingly discouraged by toxicologists due to a high risk of severe necrotizing hemorrhagic gastritis. * **Efficacy:** Successful induction of emesis does not ensure that stomach contents have been completely emptied; significant quantities of the ingested drug/toxin may remain or may have already been absorbed.
Mechanism: Orally administered hydrogen peroxide (3%) induces a vomiting reflex via direct irritant effects on the oropharynx and gastric lining. * **Mechanism:** HโOโ interacts with the enzyme **catalase** present in tissue and blood โ rapid release of water (HโO) and oxygen gas (Oโ) โ massive bubbling and gastric distension. * The combination of direct mucosal irritation and sudden gastric distension stimulates visceral afferent vagal and sympathetic nerves โ signals the **emetic center** in the medulla oblongata โ triggers the vomiting reflex. * Emesis typically ensues within 10 minutes of administration.
Dosing by species
- As an emetic ยท 1 teaspoon (5 mL) per 5 lbs. (2.3 kg) of body weight (approximately 2 mL/kg) not to exceed 3 tablespoons (45 mL). ยท PO ยท can be repeated once if not initially successful ยท Vomiting usually occurs within minutes. Note: Use in cats is generally discouraged due to risk of severe gastric ulceration.
- As an emetic ยท 1-2 mL/kg PO up to 2-3 times ยท PO ยท up to 2-3 times
- As an emetic ยท 1-5 mL/kg PO; generally not to exceed 50 mL for dogs and 10 mL for cats; may repeat one time if after 10 minutes emesis does not occur. ยท PO ยท may repeat one time if after 10 minutes emesis does not occur ยท Inducing emesis is most effective if administered after a small meal.
- As an emetic ยท 1 teaspoon (5 mL) per 5 lbs. (2.3 kg) of body weight (approximately 2 mL/kg) not to exceed 3 tablespoons (45 mL). ยท PO ยท can be repeated once if not initially successful ยท Vomiting usually occurs within minutes.
- As an emetic ยท 1-2 mL/kg PO up to 2-3 times ยท PO ยท up to 2-3 times
- As an emetic ยท 1-5 mL/kg PO; may repeat one time if after 10 minutes emesis does not occur. ยท PO ยท may repeat one time if after 10 minutes emesis does not occur ยท Inducing emesis is most effective if administered after a small meal.
- As an emetic (pot-bellied pigs) ยท 1 teaspoon (5 mL) per 5 lbs. (2.3 kg) of body weight (approximately 2 mL/kg) not to exceed 3 tablespoons (45 mL). ยท PO ยท can be repeated once if not initially successful ยท Vomiting usually occurs within minutes.
Routes of administration
Contraindications
- Animals already vomiting
- Severely lethargic, comatose, or debilitated animals (e.g., respiratory distress, decreased swallowing reflex, bradycardia)
- Seizuring or hyperactive animals
- Recent abdominal surgery
- Megaesophagus
- Ingestion of corrosives/caustics (e.g., acids, alkalis)
- Ingestion of sharp objects
- Ingestion of bagged illicit drugs
- Ingestion of hydrocarbons or petroleum distillates
- Rodents or rabbits (incapable of vomiting)
Adverse effects
- Aspiration of hydrogen peroxide solution or stomach contents
- Vasovagal (bradycardic) response in animals with cardiovascular compromise
- Gastric ulceration (particularly in cats)
- Gastric-dilatation-volvulus (GDV) in dogs
Drug interactions
- ACETYLCYSTEINE (oral) ยท Hydrogen peroxide can oxidize acetylcysteine in the gut; alternative emetics are preferred for acetaminophen overdoses.
- ANTIEMETICS (e.g., ondansetron, maropitant) ยท Preadministration or ingestion of these products may negate the emetic effects of hydrogen peroxide.
Monitoring
- Efficacy (emesis, signs associated with toxicity of the substance ingested, blood levels of toxicants if applicable)
- Heart rate and respiration rate
- Thoracic auscultation after emesis (to monitor for aspiration pneumonia)
Overdose
Hydrogen peroxide 3% solution is relatively non-toxic after oral ingestion, though it can cause gastric irritation, vomiting, and rarely gastric ulceration or GDV. > **DANGER:** Hydrogen peroxide in concentrations of **10% or greater** (such as hair bleach or industrial peroxide) can be very corrosive, causing severe burns to the oral and gastric mucosa, and can induce fatal oxygen emboli after oral ingestion.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerโs current label.