What is the ketamine dose for an adult with hyperactive delirium?

• A. Ketamine 4 mg/kg
• B. Ketamine 2 mg/kg
• C. Ketamine 6 mg/kg
• D. Ketamine 1 mg/kg

Answer: (A)

In severe, hyperactive delirium in adults, you want a rapid-acting sedative that preserves breathing and airway reflexes. Ketamine fits that need, and giving it intramuscularly at 4 mg/kg is the dose that reliably brings agitation under control quickly. This high IM dose acts within minutes and provides enough sedation for the patient to be safely assessed and managed, typically lasting long enough to facilitate airway protection and monitoring.

Lower doses, like 2 mg/kg or 1 mg/kg, are often not sufficient to quell intense agitation and may require repeated dosing or fail to prevent harm. A much higher dose, such as 6 mg/kg, increases the risk of adverse effects—cardiovascular stimulation, potassium shifts, excessive salivation, and emergence reactions—without clear additional benefit in this setting. So the 4 mg/kg IM dose is the best choice for rapid, effective control of hyperactive delirium in adults.