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This is a trade name for oral morphine. See Morphine.



Ketamine is a non-competitive NMDA receptor antagonist and a sodium channel blocker. It may have an agonist effect at opioid receptors. It is useful for:

  1. induction of anaesthesia—can be used as a sole agent in situations where resources are limited

  2. analgesia for acute pain

  3. treatment of chronic pain

  4. treatment of depression

  5. asthma treatment.

Dose for GA

For induction of anaesthesia—1.5–2 mg/kg IV. If no IV access, consider for the adult IM doses of 200 mg titrated to effect and for children use 4–6 mg/kg IM.

Ketamine for pain management

Brief painful procedures

For brief painful procedures, consider IV doses of 20–30 mg in the adult. Ketamine can also be given sublingually for this purpose at the same dose. Alternatively, oral ketamine 100–200 mg for adults or 6 mg/kg for children can be given.

Ketamine intraoperatively for reduction of intraoperative and postoperative opioid requirements

Bolus of IV ketamine 0.5 mg/kg then an infusion of 0.25 mg/kg/h. Cease the infusion 30–45 min before completion of surgery. 0.5 mg/kg/h is another suggested infusion rate.

Ketamine subcut or IV for postoperative analgesia

Used to treat opioid resistant acute pain and patients with, or at risk of, neuropathic pain. In adults, add 200 mg of ketamine to 50 mL N/S (4 mg/mL). Run the infusion at 1–2 mL/h. Adding 1 mg of haloperidol to the ketamine solution (200 mg in 50 mL N/S) may reduce ketamine induced dysphoria.


  1. Does not cause respiratory depression.

  2. Causes cardiovascular stimulation via the sympathetic nervous system. This could also be a disadvantage in certain conditions such as hypertrophic cardiomyopathy.

  3. Causes bronchodilation.

  4. Airway reflexes are well preserved compared with other anaesthetic drugs. This increases the safety of ketamine when used in remote locations e.g. disaster zones.

  5. Potent analgesic effects resulting in reduced opioid requirements.

  6. Can be given IM or PO in uncooperative patients.


  1. Relatively slow onset.

  2. Induction may be associated with involuntary movements.

  3. Disturbing emergence and postoperative psychogenic reactions may occur, such as hallucinations and dysphoria.

  4. There may be excessive salivation.

  5. It may be associated with increased PONV.

  6. Causes increased intraocular and intracranial pressure.

  7. Has direct myocardial depressant effects.

  8. Hepatic toxicity can occur with prolonged infusions.

  9. Subject to addiction and recreational use. This can lead to bladder damage.

  10. Patients on tacrolimus may become infused when receiving a ketamine infusion.


Antihypertensive drug used to treat pulmonary hypertension caused by protamine. It may also be helpful in treating carcinoid related ...

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