Throughout dynastic and Roman Egypt, the Asp was a symbol of royalty. Moreover, in both Egypt and Greece, its potent venom made it useful as a means of execution for criminals who were thought deserving of a more dignified death than that of typical executions.
According to Plutarch (quoted by Ussher), Cleopatra tested various deadly poisons on condemned persons and animals for daily entertainment and concluded that the bite of the Asp was the least terrible way to die; the venom brought sleepiness and heaviness without spasms of pain. The Asp is perhaps most famous for its role in Cleopatra's suicide (some believe it to have been a horned viper, Cerastes cerastes), as immortalized by both history and legend:
With thy sharp teeth this knot intrinsicate
Of life at once untie: poor venomous fool
Be angry, and dispatch.
Envenomation is usually followed by swelling, hemorrhage, necrosis, nausea, vomiting and hematuria. A high phospholipase A2 content may cause cardiotoxicity and myotoxicity. Studies of venom from both C. cerastes and C. vipera list a total of eight venom fractions, the most powerful of which has hemorrhagic activity. Venom yields vary, with anywhere from 19–27 mg to 100 mg of dried venom being reported. An estimated lethal dose for humans is 40–50 mg.