Ketamine

Ketamine

Ketamine
INN
Drug class	NMDA receptor antagonist; general anesthetic; dissociative hallucinogen; analgesic; antidepressant
Routes of administration	Any
Pregnancy category
Bioavailability	* Intravenous: 100% Intramuscular: 93% Epidural: 77% Intranasal: 45–50% Sublingual: 24–30% Rectal: 25–30% By mouth: 16–20%
Metabolism	Liver, intestine (oral): Major: CYP3A4, CYP2B6 Intramuscular: 1–5 min Subcutaneous: 15–30 min Insufflation: 5–10 min By mouth: 15–30 min
Elimination half-life	* Ketamine: 2.5–3 hours Norketamine: 12 hours
Excretion	* Urine: 91% Feces: 3%
Legal status	In general Rx-only
CAS Number	6740-88-1
PubChem	3821
DrugBank	DB01221
ChemSpider	3689
KEGG	D08098

Ketamine is a dissociative anesthetic. It is a type of drug that is commonly administered by physicians to induce anesthesia during surgery or medical procedures. Ketamine can also be used as a painkiller and as a bronchodilator, which facilitates easier airflow into the lungs.

Occasionally, ketamine use can lead to a specific type of hallucination that produces feelings of detachment from one's body and surroundings. This property has made it a popular recreational drug despite its potentially severe side effects. For this reason, ketamine is not typically available as an over-the-counter drug.

Medical Use

In clinical settings, ketamine is most commonly administered via injection into a vein (intravenous) or a muscle (intramuscular).

While ketamine is not the preferred anesthetic in many cases due to its hallucinogenic effects, it offers distinct advantages. Unlike most other anesthetics that suppress respiration and necessitate the use of mechanical ventilation, ketamine does not significantly inhibit breathing.

Ketamine is particularly valuable in situations where advanced medical equipment is unavailable, such as in war zones or emergency field medicine. ^{(December 2013)}

Side Effects

Short-Term Side Effects

Short-term side effects are experienced by approximately 40% of individuals and include:

• Dizziness
• Double vision
• Euphoria
• Blurred vision
• Difficulty expressing emotions
• High blood pressure
• Tachycardia (Fast heart rate)
• Nausea and vomiting
• Speech difficulties
• Nightmares
• Illusions
• Hallucinations
• Altered body image
• Memory and attention impairments.

Long-Term Side Effects

Long-term effects of ketamine are mostly observed in recreational users or from prolonged exposure in animal studies.

Urinary Tract Effects

Chronic ketamine use has been associated with urinary tract issues, including:

• Increased urgency to urinate
• Pain during urination with hematuria (blood in urine)
• Reduced bladder capacity

Neurological Effects

Frequent recreational use (more than 4 times a week) has been linked to impaired cognitive functions, including memory deficits and increased depression.

Mechanism of Action

Ketamine functions as an NMDA receptor antagonist in the central nervous system (CNS). By inhibiting these receptors, ketamine prevents excessive excitatory neurotransmission, resulting in an anesthetic effect. Additionally, it produces sympathomimetic effects that help maintain blood pressure and airway reflexes. These properties make it a critical option for patients with shock or requiring emergency surgery.

Research

Treating Addiction

Studies have explored ketamine's role in managing alcohol addiction and opioid use disorder.

Antidepressant Effects

Preliminary studies suggest that a single dose of ketamine can significantly alleviate symptoms of treatment-resistant depression within hours, with effects lasting up to a week.

Recreational Use

Recreational users typically consume ketamine at sub-anesthetic doses. The dissociative effects, often referred to as a "K-hole," include hallucinations and a profound sense of detachment. Chronic use, however, may lead to serious consequences such as bladder damage, cognitive decline, and psychological dependence.

References

Ketamine Resources
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