After initial constriction of the pupils, they become dilated and death results from respiratory failure or arrest followed by cardiac arrest. 1 Non-barbiturate sedative hypnotics include drugs such as qualude, chloryl hydrate, methaqualone. These drugs are infrequently used medically and are seen as very dangerous because they cause a significant reduction in heart rate, respiration, and muscular coordination. Like all sedative hypnotic drugs, both barbiturates and non-barbiturates, sedative hypnotics, can create a tolerance with even a single dose. The issues with overdose and withdrawal are very similar with these two classes of drugs.
Benzodiazepines are also central nervous system depressants.
These are the most widely prescribed group of drugs in the treatment of anxiety and insomnia, and include medications such as Valium, Atavan, Librium, Zanax, Lorazapam, etc. They are considered to be less dangerous than barbiturates because they are less lethal and tend to be shorter acting in nature. The peak effect tends to occur within two to four hours. They are physically addicting and upon withdrawal there may be prolonged experiences of problems with sleep, high anxiety, panic attacks and frightening dreams. They tend to be used for an anti-anxiety medication and therefore create a sense of relaxation or detachment in the user.