Ketamine: Absorption, Metabolism, and Excretion - Pharmacology Project

This presentation provides a detailed overview of Ketamine's journey through the human body, fulfilling the requirements of a pharmacology project. The presentation meticulously charts the drug's progress, beginning with its various routes of administration (oral, intravenous, subcutaneous, and intramuscular) and discussing absorption rates. It then explores the distribution of Ketamine throughout the body, including its entry into the bloodstream and subsequent distribution to the brain and other organs. The presentation delves into the metabolism of Ketamine, highlighting the role of the liver and specific enzymes like CYP3A4, CYP2C9, and CYP2B6, as well as detailing the formation of metabolites such as norketamine. Finally, it examines the elimination process, focusing on renal excretion and the half-lives of Ketamine and its metabolites. The presentation includes references to support the information provided, making it a comprehensive resource for understanding Ketamine's pharmacological profile. This assignment is available on Desklib, a platform offering AI-based study tools and resources for students.

KETAMINE

Administration
•Ketamine is classified as a Schedule 3
Compound. Ketamine is orally administered
whereby 16% of the administered drug is
absorbed.
•This means that about 5 mg of the administered
30mg is orally absorbed. Other routes of
Ketamine administration include intravenous,
subcutaneous and intramuscular (Harold, 2015).

Distribution
• Ketamine is distributed to all other parts of the body
through the bloodstream. The drug then enters the heart
where it is pumped to all the parts of the body including
the brain.
• Ketamine has a varied duration of action depending on the
route of administration whereby oral ketamine takes 6
hours, intramuscular is 2 hours and intravenous takes 1
hour. Peak blood levels are reached after 20 minutes after
oral ingestion.
• When used as an intravenous injection, it is rapidly
distributed to the brain and other organs and the effects are
seen in seconds (Katzung, Masters & Trevor, 2012).

Metabolism
•The drug is mostly metabolized by the liver
through N-demethylation through hepatic phase
1 and phase 2.
•The major enzyme involved is CYP3A4 while
the two minor enzymes are CYP2C9 and
CYP2B6.
•Ketamine metabolites include norketamine,
hydroxynorketamine, dehydronorketamine and
conjugates (Harold, 2015).

Elimination
• Elimination of Ketamine is mostly renal whereby almost
90% of the drug is really excreted (Katzung & Trevor,
2015). The elimination half-life of ketamine is 3-4 hours
while that of norketamine is 12 hours.
• The drug is greatly biotransformed by the liver before its
elimination. The drug is also excreted in faeces in small
amounts of about 3%, milk, sweat and expired air
(Marland, Ellerton, Andolfatto, Strapazzon, Thomassen,
Brandner & Paal, 2013).
• The Standard toxicology tests that are usually put into use
do not deter Ketamine if a “date rape” is suspected a
specific toxicology test is conducted to detect the initial
drug or its metabolites.

References
• Harold E.D, (2015). Concepts of Chemical Dependency 9th
Edition pp.
• Katzung, B. G., Masters, S. B., & Trevor, A. J.
(2012). Basic and Clinical Pharmacology (LANGE Basic
Science). McGraw-Hill Education.
• Katzung, B. G., & Trevor, A. J. (Eds.). (2015). Basic &
clinical pharmacology (pp. 753-756). New York, NY:
McGraw-Hill.
• Marland, S., Ellerton, J., Andolfatto, G., Strapazzon, G.,
Thomassen, O., Brandner, B., ... & Paal, P. (2013).
Ketamine: use in anesthesia. CNS neuroscience &
therapeutics, 19(6), 381-389.