OnestopGate   OnestopGate
   Thursday, April 27, 2017 Login  
Home | Overview | Syllabus | Tutorials | FAQs | Downloads | Recommended Websites | Advertise | Payments | Contact Us | Forum

GATE Resources
Gate Articles
Gate Books
Gate Colleges 
Gate Downloads 
Gate Faqs
Gate Jobs
Gate News 
Gate Sample Papers
Training Institutes

GATE Overview
GATE Eligibility
Structure Of GATE
GATE Coaching Centers
Colleges Providing M.Tech/M.E.
GATE Score
GATE Results
PG with Scholarships
Article On GATE
Admission Process For M.Tech/ MCP-PhD
GATE Topper 2012-13
GATE Forum

GATE 2018 Exclusive
Organizing Institute
Important Dates
How to Apply
Discipline Codes
GATE 2018 Exam Structure

GATE 2018 Syllabus
Aerospace Engg..
Agricultural Engg..
Architecture and Planning
Chemical Engg..
Civil Engg..
Computer Science / IT
Electronics & Communication Engg..
Electrical Engg..
Engineering Sciences
Geology and Geophysics
Instrumentation Engineering
Life Sciences
Mechanical Engg..
Metallurgical Engg..
Mining Engg..
Production & Industrial Engg..
Pharmaceutical Sciences
Textile Engineering and Fibre Science

GATE Study Material
Aerospace Engg..
Agricultural Engg..
Chemical Engg..
Civil Engg..
Computer Science / IT
Electronics & Communication Engg..
Electrical Engg..
Engineering Sciences
Instrumentation Engg..
Life Sciences
Mechanical Engg..
Pharmaceutical Sciences
Textile Engineering  and Fibre Science

GATE Preparation
GATE Pattern
GATE Tips N Tricks
Compare Evaluation
Sample Papers 
Gate Downloads 
Experts View

CEED 2013
CEED Exams
Application Forms
Important Dates
Contact Address
Examination Centres
CEED Sample Papers

Discuss GATE
GATE Forum
Exam Cities
Contact Details
Bank Details

Contact Us

Home » GATE Study Material » Pharmaceutical Science » Medicinal Chemistry » Sedative-Hypnotics


Looking for GATE Preparation Material? Join & Get here now!

** Gate 2013 Question Papers.. ** CEED 2013 Results.. ** Gate 2013 Question Papers With Solutions.. ** GATE 2013 CUT-OFFs.. ** GATE 2013 Results.. **



History of Sedative-hypnotics

In 1903, barbital, a derivative of barbituric acid, was introduced. Its sleep-inducing and anxiolytic effects made it very popular in clinical medicine. It soon became popular as a treatment for anxiety and as the first "sleeping pill". In 1912, phenobarbital was introduced. Phenobarbital, in addition to sedative-hypnotic properties, has anticonvulsant properties and has become one of the most important pharmacological treatments for epilepsy. The success of barbital and phenobarbital spawned the synthesis of over 2,500 barbiturates. Of these many barbiturate analogues, only about 20 are still on the market. The effects of these various barbiturates are generally similar, differing primarily in potency and duration of action.

The partial separation of sedative-hypnotic-anesthetic from anticonvulsant properties, found in phenobarbital, led researchers to search for agents with more selective effects on the functions of the CNS. In the late 1930's, relatively nonsedative anticonvulsants were developed (e.g., phenytoin and trimethadione). In 1957 the first benzodiazepine, chlordiazepoxide (Librium) was synthesized. Benzodiazepines have demonstrated the ability to relieve symptoms of anxiety with relatively little interference with cognitive function or wakefulness. Benzodiazepines and barbiturates share very similar properties but the benzodiazepines have demonstrated to have a much safer pharmacological profile. Benzodiazepines have therefore replaced barbiturates for most uses, particularly for treatment of anxiety and sleep disturbances.

Behavioral Effects in Humans

Sedative-hypnotic drugs depress behavior, moderate excitement, and induce calmness. These drugs depress the central nervous system, however, they usually produce therapeutic benefits at far lower doses than those causing substantial generalized depression of behavior.

Barbiturates have a wider and more powerful effect on the central nervous system than the other sedatives. The barbiturates can produce varying degrees of depression of the CNS, ranging from mild sedation to general anesthesia. In low doses barbiturates have a calming effect, and some of the barbiturates (e.g., phenobarbital) have demonstrated selective anticonvulsant properties. In moderate doses they produce a drunken euphoric state, similar to alcohol. Sedation and sleep result from increased doses, and even higher doses produce surgical anesthesia. Because of their ability to produce sedation and decrease sleep latency, barbiturates were popular in the treatment of insomnia prior to the advent of benzodiazepines. However, because of the high incidence of tolerance and physical dependence following chronic use and the relatively high danger of overdose, these drugs are rarely used today for the treatment of anxiety or sleep disturbances.

Benzodiazepines share the sedative-hypnotic properties, but produce fewer side effects than barbiturates. Like barbiturates, benzodiazepines have also been reported to produce anticonvulsant effects. In addition, these drugs are used clinically as muscle relaxants, antiepilieptic agents, and to produce sedation before operative procedures. The antianxiety effects of benzodiazepines are more selective than those of other sedative-hypnotics -- they relieve anxiety at lower doses and thus produce minimal sedation and motor impairment. The benzodiazepines are currently the most important class of drugs for treatment of anxiety and sleep disorders.

Mechanism of Action

Barbiturates and benzodiazepines act similarly to produce depression of central nervous system function and behavior. Both classes of drugs enhance the ability of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA), to activate a type of receptors known as GABA-A receptors. These drugs increase the effectiveness of GABA by altering the receptor so that GABA can bind more easily, an effect known as allosteric regulation. Activation of the GABA-A receptor opens an ion channel, allowing negatively charged chloride ions to enter the cell, producing an inhibition of neuronal activity.

In addition to barbiturates and benzodiazepines, ethanol appears to produce depression of central nervous system function, in part by enhancing the ability of GABA to bind to the GABA-A receptor. This may explain why these three classes of drugs potentiate each others' effects and why tolerance to one results in cross-tolerance to another.


Anxiolytic and
Generic Name Trade Name
Benzodiazepines Alprazolam Xanax
  Chlordiazepoxide Librium
Clonazepam Klonopin
Clorazepate Tranxene
Diazepam Valium
Estazolam ProSom
Flurazepam Dalmane
Lorazepam Ativan
Midazolam Versed
Oxazepam Serax
Quazepam Doral
Temazepam Restoril
Triazolam Halcion
Halazepam Paxipam
Prazepam Centrax
Non-Benzodiazepine anxiolytics
and hypnotics
Buspirone BuSpar
Chloral hydrate Noctec
Zolpidem tartrate Ambien

Thought Questions and Quick Quiz

Thought Questions


  • Drugs, such as benzodiazepines and alcohol, that are generally depressant on behavior often produce excitatory effects, particularly at low doses. How would you explain these apparently paradoxical effects?


  • Barbiturates and benzodiazepines are effective for a variety of clinical problems, ranging from anxiety and sleep disturbances to seizures. Given their pharmacological effects, why do you suppose this is the case?

Discussion Center







Email ID:

  Forgot Password?
 New User? Register!

Get 9,000+ Interview Questions & Answers in an eBook. Interview Question & Answer Guide
  • 9,000+ Interview Questions
  • All Questions Answered
  • 5 FREE Bonuses
  • Free Upgrades
  • Gate Books
  • Training Institutes
  • Gate FAQs
  • Mechanical Engineeering Books
  • Robotics Automations Engineering Books
  • Civil Engineering Books
  • Chemical Engineering Books
  • Environmental Engineering Books
  • Electrical Engineering Books
  • Electronics Engineering Books
  • Information Technology Books
  • Software Engineering Books
  • GATE Preparation Books
  • Exciting Offers

    GATE Exam, Gate 2009, Gate Papers, Gate Preparation & Related Pages

    GATE Overview | GATE Eligibility | Structure Of GATE | GATE Training Institutes | Colleges Providing M.Tech/M.E. | GATE Score | GATE Results | PG with Scholarships | Article On GATE | GATE Forum | GATE 2009 Exclusive | GATE 2009 Syllabus | GATE Organizing Institute | Important Dates for GATE Exam | How to Apply for GATE | Discipline / Branch Codes | GATE Syllabus for Aerospace Engineering | GATE Syllabus for Agricultural Engineering | GATE Syllabus for Architecture and Planning | GATE Syllabus for Chemical Engineering | GATE Syllabus for Chemistry | GATE Syllabus for Civil Engineering | GATE Syllabus for Computer Science / IT | GATE Syllabus for Electronics and Communication Engineering | GATE Syllabus for Engineering Sciences | GATE Syllabus for Geology and Geophysics | GATE Syllabus for Instrumentation Engineering | GATE Syllabus for Life Sciences | GATE Syllabus for Mathematics | GATE Syllabus for Mechanical Engineering | GATE Syllabus for Metallurgical Engineering | GATE Syllabus for Mining Engineering | GATE Syllabus for Physics | GATE Syllabus for Production and Industrial Engineering | GATE Syllabus for Pharmaceutical Sciences | GATE Syllabus for Textile Engineering and Fibre Science | GATE Preparation | GATE Pattern | GATE Tips & Tricks | GATE Compare Evaluation | GATE Sample Papers | GATE Downloads | Experts View on GATE | CEED 2009 | CEED 2009 Exam | Eligibility for CEED Exam | Application forms of CEED Exam | Important Dates of CEED Exam | Contact Address for CEED Exam | CEED Examination Centres | CEED Sample Papers | Discuss GATE | GATE Forum of | GATE Exam Cities | Contact Details for GATE | Bank Details for GATE | GATE Miscellaneous Info | GATE FAQs | Advertisement on GATE | Contact Us on OneStopGATE |
    Copyright © 2017. One Stop All rights reserved Testimonials |Link To Us |Sitemap |Privacy Policy | Terms and Conditions|About Us
    Our Portals : Academic Tutorials | Best eBooksworld | Beyond Stats | City Details | Interview Questions | India Job Forum | Excellent Mobiles | Free Bangalore | Give Me The Code | Gog Logo | Free Classifieds | Jobs Assist | Interview Questions | One Stop FAQs | One Stop GATE | One Stop GRE | One Stop IAS | One Stop MBA | One Stop SAP | One Stop Testing | Web Hosting | Quick Site Kit | Sirf Dosti | Source Codes World | Tasty Food | Tech Archive | Software Testing Interview Questions | Free Online Exams | The Galz | Top Masala | Vyom | Vyom eBooks | Vyom International | Vyom Links | Vyoms | Vyom World
    C Interview Questions | C++ Interview Questions | Send Free SMS | Placement Papers | SMS Jokes | Cool Forwards | Romantic Shayari