What are Fentanyl and carfentanil?

HOUSTON, Texas (KTRK) -- Fentanyl and carfentanil are both powerful synthetic opioids that pose a risk on the streets.

First synthesized in the 1960s, Fentanyl was intended as a pain medication. Its use expanded in the 1990s with the introduction of patches, lollipops, sprays and dissolving tablets.

Fentanyl is 100 times more potent than morphine. Carfentanil is 100 times more potent than Fentanyl, making it roughly 10,000 times the potency of morphine.

Created as a anesthetic for large animals such as elephants, even a small amount of carfentanil can kill thousands of people.

SEE ALSO: Houston police cracking down on highly addictive and deadly drug