RESEARCH MONOGRAPH · KDC-MN-1318
Dibucaine
Dibucaine (cinchocaine, Nupercaine) is a quinoline-based amide local anesthetic synthesized at Ciba in 1929. It is the most potent local anesthetic in the amide class on a milligram basis (roughly 15-fold the potency of lidocaine for infiltration), but the high potency comes paired with high systemic toxicity that restricts modern use to topical preparations like hemorrhoidal creams. The historical use in spinal anesthesia was extensive in the early-to-mid 20th century but has been displaced by safer agents. The compound has an interesting second life as a clinical laboratory test: the dibucaine number measures plasma butyrylcholinesterase activity through the relative inhibition of cholinesterase by dibucaine. Normal individuals show 80 percent inhibition; atypical heterozygotes 40 to 60 percent; atypical homozygotes 16 to 20 percent. The number predicts succinylcholine and mivacurium duration in patients with butyrylcholinesterase variants. Not stocked by Kodiac. This monograph is provided for research and educational reference.
Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.
Amide local anesthetic (high-potency, topical)
A quinoline-based amide local anesthetic with the highest potency in the class, used principally in topical preparations and as the historical reference for cholinesterase typing.
Abstract
Dibucaine (cinchocaine; 2-butoxy-N-[2-(diethylamino)ethyl]quinoline-4-carboxamide; CAS 85-79-0; molecular formula C20H29N3O2; molecular weight 343.46) is a quinoline-based amide local anesthetic synthesized by Karl Miescher at Ciba in 1929 (Nupercaine, Cinchocaine, Sovcaine). The compound is structurally distinct in carrying a quinoline ring and a butyloxy substituent rather than the dimethylphenyl ring of lidocaine and pipecoloxylidide-family agents. Dibucaine is the most potent local anesthetic in the amide class on a milligram basis (approximately 15-fold the potency of lidocaine for infiltration block), producing intense and prolonged sodium channel block; the high potency is paired with high systemic toxicity that restricts modern clinical use to topical preparations. The historical use in spinal anesthesia (Nupercaine spinal) was extensive in the early-to-mid 20th century but has been displaced by safer agents (bupivacaine, levobupivacaine, ropivacaine). Modern indications are topical: hemorrhoidal preparations (combined with hydrocortisone in commercial products), topical anesthesia of intact skin and mucous membranes, and ENT applications. Mechanism is the standard voltage-gated sodium channel block with state-dependent kinetics. The dibucaine number is a clinical laboratory parameter measuring plasma butyrylcholinesterase activity through the relative inhibition of cholinesterase by dibucaine: normal individuals show 80 percent inhibition, atypical heterozygotes 40 to 60 percent, atypical homozygotes 16 to 20 percent. The dibucaine number predicts succinylcholine and mivacurium duration in patients with butyrylcholinesterase variants and remains a clinically used diagnostic test.
Mechanism of action
Voltage-gated sodium channel block, highest potency in amide class. Distinguished from other amides by the quinoline scaffold.
Reported research dose ranges
Reported research dose ranges vary across the published literature.
References
- Miescher K. The chemistry of local anaesthetics. Helv Chim Acta 1932.
- Kalow W, Genest K. Determination of dibucaine numbers. Can J Biochem Physiol 1957.
- Covino BG. Pharmacology of local anaesthetic agents. Br J Anaesth 1986.
Read the full monograph
Available as a research-use-only PDF download.
The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.
FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.