Ketamine Pfizer (Ketamine)

• Ketamine acts on the NMDA receptor pathway to provide dissociative anesthesia and analgesia.
• Induction and maintenance of anesthesia: Provides rapid onset of unconsciousness and muscle relaxation for surgical procedures.
• Procedural sedation analgesia: Delivers analgesic and sedative effects for short‑duration diagnostic or therapeutic interventions.
• Adjunct for treatment‑resistant depression (off‑label): Offers rapid antidepressant effects in patients who have not responded to conventional therapies.

• Ketamine is a non‑competitive antagonist of the N‑methyl‑D‑aspartate (NMDA) receptor. By binding to the phencyclidine site within the receptor channel, it blocks calcium influx and disrupts excitatory neurotransmission. This inhibition leads to dissociative anesthesia, analgesia, and modulation of synaptic plasticity, which underlies its rapid antidepressant action. The drug also interacts with opioid receptors, monoaminergic pathways, and voltage‑gated ion channels, contributing to its complex pharmacodynamic profile.

Ketamine may produce a range of adverse reactions, varying from transient to serious.

Common Side Effects

• Hypertension or tachycardia: transient increase in blood pressure and heart rate.
• Nausea or vomiting: gastrointestinal upset during or after administration.
• Dissociation or vivid dreams: perceptual disturbances and altered consciousness.
• Salivation or airway secretions: increased oral secretions.
• Mild respiratory depression: reduced breathing effort at higher doses.

Serious or Rare Side Effects

• Severe respiratory depression: risk of apnea requiring airway support.
• Psychotomimetic reactions: emergence of hallucinations or delirium.
• Cardiac arrhythmias: irregular heart rhythms in susceptible patients.
• Elevated intracranial pressure: worsening of pre‑existing conditions.
• Allergic reactions: anaphylaxis or severe skin rash.

When using ketamine, clinicians should observe specific safety measures to minimize risks.

• Cardiovascular monitoring: observe blood pressure and heart rate due to possible hypertension or tachycardia.
• Respiratory support: ensure airway patency and oxygenation, especially at high doses.
• Psychiatric evaluation: assess for history of psychosis before administration.
• Drug interactions: review concomitant CNS depressants and sympathomimetics.
• Pregnancy and lactation: weigh benefits against potential fetal or neonatal effects.
• Store below 25°C: keep in the original container, protect from light and moisture.

Ketamine can interact with several medications, altering its safety or efficacy profile.

Major Interactions (Avoid)

• CNS depressants (e.g., benzodiazepines, barbiturates): may potentiate sedation and respiratory depression.
• Monoamine oxidase inhibitors (MAOIs): increase risk of hypertensive crisis.
• Sympathomimetic agents (e.g., epinephrine): may exacerbate cardiovascular effects.

Moderate Interactions (Monitor Closely)

• Alcohol: additive depressant effects on respiration and cognition.
• Other anesthetic agents (e.g., propofol, volatile gases): may require dose adjustments.
• Serotonergic drugs (e.g., SSRIs, SNRIs): potential for serotonin syndrome.