Ketamine oral administration has what type of onset?

Ketamine oral administration has what type of onset?

• A. IV: 30-60 Sec
• B. IM: 2-4 Min
• C. PO: Variable
• D. IN: 5-10 Min

Answer: (C)

Onset depends on how quickly enough drug reaches the systemic circulation to produce an effect. For oral ketamine, a large portion is destroyed or modified during first-pass metabolism in the liver, and absorption from the gastrointestinal tract is not consistent. This combination gives low and highly variable bioavailability, so the time to noticeable effect can vary widely between individuals and even between doses in the same person. Because of that unpredictability, the onset of oral ketamine is described as variable. In contrast, other routes provide much more predictable timing: intravenous is almost immediate, intramuscular is a few minutes, and intranasal is typically several minutes.

Onset depends on how quickly enough drug reaches the systemic circulation to produce an effect. For oral ketamine, a large portion is destroyed or modified during first-pass metabolism in the liver, and absorption from the gastrointestinal tract is not consistent. This combination gives low and highly variable bioavailability, so the time to noticeable effect can vary widely between individuals and even between doses in the same person. Because of that unpredictability, the onset of oral ketamine is described as variable. In contrast, other routes provide much more predictable timing: intravenous is almost immediate, intramuscular is a few minutes, and intranasal is typically several minutes.