|Analgesia and Pain management
|Sedation and Analgesia on ITU
|Neuropathic Pain Management
|Naloxone (Narcan) Opiate antagonist
- Give IV doses slowly. Titrate to effects. The antidote is Naloxone.
Mode of action
- Opiates act on central opioid mu receptors to cause usefully analgesia and Euphoria
- Opiate effects can be quickly reversed with IV naloxone which must always be available where IV opiates are being administered.
- Pain control, Peri operatively anaesthesia, Persistent cough - codeine used
- Palliative care and Malignant disease - addiction is not an issue when opiates are used for pain control. One must be ready to increase the dose as tolerance occurs. One gives enough to render the patient comfortable.
- Acute Myocardial Infarction
- Respiratory failure, Cardiogenic shock
- Cautions with other depressant drugs - Alcohol, Phenothiazine, Tricyclic antidepressants
- Morphine, Diamorphine - more potent and lipid-soluble metabolised to morphine
- Fentanyl - used IV and also due to high lipid solubility as transdermal patches. However, the patches are highly potent and this is often not appreciated. It is wise to start on oral MST first and work up the dose and then convert to a patch if needed.
- Oxycodone, Dihydrocodeine, Codeine - 10% metabolised to Morphine
- Depress respiration, Hypotension, Constipation, Nausea, vomiting
- Cough suppression, Releases ADH - SIADH
- Biliary spasm, Histamine release and bronchoconstriction
- Vasodilatation, Itching, Tolerance and addiction
It can be important to switch the method of opiate delivery and between different formulations. To avoid over and underdosing the equivalent doses are shown here.
|This is only an approximate guide (doses may not correspond with those given in clinical practice); patients should be carefully monitored after any change in medication and dose titration may be required|
|Diamorphine||IM, IV, SC||3mg|
|Morphine||IM, IV, SC||5mg|
| Tramadol ||PO||100mg|
|PO = by mouth; IM = intramuscular, IV = intravenous, SC = subcutaneous|