A composition of matter for an analgesia and its method of use is disclosed. The composition comprises selected single cobrotoxin molecule which is characterized by its high affinity binding to nicotinic acetylcholine receptors, rapid onset, and better safety profile comparing to a cobrotoxins complexes. The method of use is for the treatment of pain, especially for the treatment of refractory pain as associated with advanced cancer, rheumatoid arthritis, chronic neuropathic, migraine, and viral infections.
