Local Anesthetics Mnemonic

All Local anesthetics contain suffix “-caine”. Local Anesthetics (LA) can be classified as: Esters and Amides.

Esters vs Amides

A mnemonic device is that the names of amides contain 2 “i”s compared with only 1 “i” seen in esters.

Remember: One-eyed ester or Amide word has an “i” in it and hence an extra “i”.

Amides – Contains 2 “i”

Properties:

1. Longer acting than esters
2. Metabolized by liver enzymes
3. Excreted in urine

Medicines:

1. Lignocaine
2. Lidocaine (Xylocaine)
3. Prilocaine
4. Mepivacaine
5. Bupivacaine (Marcaine/Sensoricaine)
6. Etidocaine
7. Ropivacaine
8. Dibucaine
9. Articaine
10. Trimecaine
11. Dexivacaine
12. Butanilacaine

Exceptions:

Amides with only single “i” are –

1. Oxetacaine
2. Tolycaine
3. Pyrrocaine
4. Rodocaine

Amide without suffix “caine” – Diperodon

Esters – Contains single “i”

Properties:

• Short acting
• Metabolized in plasma and tissue fluids
• Excreted in urine
• More propensity for allergic reactions

Medicines:

1. Amethocaine
2. Benzocaine
3. Chlorprocaine
4. Procaine (Novocaine)
5. Cocaine
6. Hexylcaine
7. Proparacaine
8. Tetracaine

Exceptions:

Ester with double “i” –

1. Primacaine
2. Piperocaine
3. Dimethocaine

Ester without suffix “-caine” –

1. Butamben
2. Butethamine
3. Naepaine

Rate of systemic absorption of Local Anesthetics

Mnemonic: In descending order – ICE BALLS

1. Intravenous > Tracheal > Intercostal
2. Caudal
3. Epidural
4. Brachial plexus
5. Axillary
6. Lower extremity (femoral)
7. Subcutaneous

Dr. Sulabh Kumar Shrestha, MS Orthopedics

He is the section editor of Orthopedics in Epomedicine. He searches for and share simpler ways to make complicated medical topics simple. He also loves writing poetry, listening and playing music.