The opening sequence is taken (word for word) from the opening sequence of the 1936 film, Reefer Madness. The only difference is that the word, Marijuana, is replaced with the word, Caffeine.
April is based off of the character of Mae from "Reefer Madness (1936)" and "Reefer Madness: The Movie Musical (2005)." The writer/director made the name change due to the month, April (due to "May" also being a month), the release date of the film being in April, and because the writer/director's birthday is in April.