As I recall (it's been years since I read the novel), the form of government Huxley describes can be called totalitarianism. The people are controlled, economically, socially and even sexually by the government. The government in power accomplishes this by drugging the people into thinking they are happy. Without the drugs, they might realize they are not happy.
For parallel examples in history or in the contemporary world, there really are none. No government uses pharmaceuticals to maintain control. You can make a parallel or analogy with governments that use propaganda to convince people that all is well. Most notably, the Third Reich in Germany did just that. Another example is Stalinist Russia (Soviet Union). Another might be military rule in Argentina in the late 20th century (not so long ago). Or Pinochet in Chile, or Cambodia under dictatorial rule in the 1980s.
Make sure you understand what totalitarianism is. Read about the concept by putting the word in your search engine (Google, Bing, whatever you use) and find articles that define it and give examples. Also look up oligarchy and communism. Communism is an economic system, not a form of government, although it's often confused with Russian and Chinese totalitarianism or oligarchies.