Central nervous system depressants

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Editor: Jacqueline L. Longe
Date: Apr. 4, 2018
Publisher: Gale, a Cengage Company
Document Type: Drug overview
Length: 389 words

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Central nervous system (CNS) depressants are drugs that reduce brain activity.


These drugs are used to treat anxiety, muscle tension, pain, insomnia, acute stress reactions, panic attacks, and seizure disorders. In higher doses, some of them produce coma and anesthesia.


Throughout history, humans have sought relief from anxiety and insomnia by using substances that induce a drowsy or calming effect. CNS depressants include a wide range of drugs such as alcohol, the most widely used depressant, narcotics, barbiturates (Amytal, Nembutal, Seconal), benzodiazepines (Ativan, Halcion, Librium, Valium, Xanax), chloral hydrate, Buspirone (Buspar), and Zolpidem (Ambien). Street names for illegal CNS depressants include Reds, Yellows, Blues, Barbs, and Downers.


  • Most CNS depressants have the potential to be physically and psychologically addictive.
  • The body tends to develop tolerance for CNS depressants, and larger doses are needed to achieve the same effects.
  • Sudden withdrawal from some CNS depressants can produce rebound insomnia or anxiety, occasionally resulting in life-threatening seizures.
  • When depressant medications is discontinued, it should be done gradually to give the body time to adjust.
  • The difference is small between effective doses and overdoses for some CNS depressants, such as barbiturates.
  • Elderly people are subject to more profound and prolonged effects from CNS depressants.

Side effects

Adverse effects include confusion, dizziness, slurred speech, loss of muscle coordination, and impaired thinking and judgment.


Interactions with benzodiazepines (Xanax, Ativan, Valium) include:

  • These drugs can increase the effects of narcotics and other pain management medications.
  • Antifungal drugs, Diflucan, Nizoral, Sporanox, greatly increase and prolong the effects of benzodiazepines.
  • Anti-seizure medications, like Tegretol, can decrease the effectiveness of benzodiazepines.
  • Cimetidine (Tagamet) can increase the effectiveness of benzodiazepines.
  • Calcium channel blockers, like Cardizem, can increase and prolong the effects of benzodiazepines.
  • Grapefruit juice can increase the effects of benzodiazepines.
  • Macrolide antibiotics (erythromycin, Biaxin) can increase and prolong the effects of benzodiazepines.
  • Modifinil (Provigil) may reduce the effects of benzodiazepines.
  • AIDS and antiretroviral drugs may increase and prolong the effects of benzodiazepines.

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Questions to ask your doctor

  • What kind of changes can I expect to see or feel when taking central nervous system depressants?
  • What are the side effects associated with central nervous system depressants?
  • Will central nervous system depressants interact or interfere with other medications I am currently taking?
  • What symptoms or adverse effects are important enough that I should seek immediate treatment?
  • Can you recommend any support groups for me and my family?

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

Source Citation

Source Citation   (MLA 8th Edition)
Quigley, Ann, et al. "Central nervous system depressants." The Gale Encyclopedia of Medicine, edited by Jacqueline L. Longe, 5th ed., Gale, 2015. Gale Health and Wellness, https%3A%2F%2Flink.gale.com%2Fapps%2Fdoc%2FIMHIUV887414166%2FHWRC%3Fu%3Dmnkanokahs%26sid%3DHWRC%26xid%3D9cbbd673. Accessed 14 Dec. 2019.

Gale Document Number: GALE|IMHIUV887414166