NOT TRUE regarding sevoflurane
**Core Concept**
Sevoflurane is a commonly used inhalational anesthetic agent that belongs to the class of volatile anesthetics. It is known for its rapid onset and recovery profiles, making it a popular choice in various clinical settings. The pharmacological effects of sevoflurane are mediated through its action on the central nervous system, specifically the GABA_A receptor.
**Why the Correct Answer is Right**
Sevoflurane exerts its anesthetic effects by potentiating the inhibitory effects of GABA (gamma-aminobutyric acid) on the GABA_A receptor. This results in a decrease in neuronal excitability and an overall decrease in the activity of the central nervous system. The rapid onset of action of sevoflurane is due to its high blood-gas partition coefficient, which allows for a more rapid increase in the concentration of the drug in the brain.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because sevoflurane is known to be metabolized by liver enzymes, specifically cytochrome P450 2E1, to a lesser extent compared to other volatile anesthetics.
**Option B:** This option is incorrect because the "not true" statement regarding sevoflurane is not specified, but typically, sevoflurane is known for its low risk of causing malignant hyperthermia.
**Option C:** This option is incorrect because sevoflurane is a known nephrotoxin, but its nephrotoxic effects are more related to its metabolites, which can cause renal vasoconstriction and decreased renal blood flow.
**Option D:** This option is incorrect because sevoflurane is known to be a substrate for the enzyme glutathione S-transferase, which helps to detoxify the drug and its metabolites.
**Clinical Pearl / High-Yield Fact**
A key consideration when using sevoflurane is its potential to cause renal toxicity, particularly in patients with pre-existing renal disease. This is due to the formation of compound A, a nephrotoxic metabolite that can cause renal vasoconstriction and decreased renal blood flow.
**Correct Answer:** B.