CHOICE OF OPIATE
| OPIATE | PROS | CONS |
| Morphine | Cheap Familiar Long acting |
Histamine release/Urticarial reactions (local streaking on the vein does not count - give it slower or smaller boluses) Not recommended in renal failure ??Makes biliary/renal colic worse |
| Fentanyl | No histamine release Novel routes such as intranasal, patches Does not accumulate in renal failure |
Expensive Short-acting Increased additive potential Truncal rigidity (in high doses) |
| Pethidine | No histimine release Cheap Long-acting |
Increased Additive potential Neurotoxic/Seizures/Confusion (in repeated doses) Not recommend in renal failure Excessively sedating Painful when given SC |
| Codeine | Cheap Long-acting |
Weak opioid Constipating |
| Tramadol | No histamine release Less constipating |
Expensive Serotonergic side-effects |