Methaqualone, is a sedative-hypnotic drug that is similar to the effects of barbiturates, a central nervous system depressant. Indian researchers first noted the effects of methaqualone in the 1950s. In the United States during 1962, methaqualone was patented by Wallace and Tiernan. In 1965, it was introduced into the pharmaceutical market as a non-addictive sleeping pill. In the 1970s, methaqualone became a hypnotic used to treat insomnia, as a sedative, and as a muscle relaxer. Methaqualone has also been used recreationally, commonly known as Quaaludes, Sporos, Ludes, or Mandrax.

Side effects can include euphoria, drowsiness, reduced heart rate, reduced respiration, increased sexual arousal (aphrodisiac), and paresthesias (numbness of the fingers and toes). Larger doses of methaqualone can result in side effects such as respiratory depression, slurred speech, headache, and photophobia (symptom of excessive sensitivity to light).

Methaqualone overdoses can result in delirium, convulsions, hypertonia, hyperreflexia, vomiting, renal failure, coma, and death due to cardiac or respiratory arrest. Methaqualone overdose resembles barbiturate poisoning, with increased motor difficulties and a lower incidence of cardiac or respiratory depression.