stupefacient vs stupefactive

stupefacient

adj

  • Inducing stupor or drowsiness (with a drug such as a narcotic or an anaesthetic). 

noun

  • Any drug that induces stupor or drowsiness. 

stupefactive

adj

  • Inducing stupor; making drowsy; stupefacient. 

How often have the words stupefacient and stupefactive occurred in a corpus of books? (source: Google Ngram Viewer )