1. Anxiolytic and hypnotic drugs

2. overview Anxiety is an unpleasant state
Disorders involving anxiety are the most common mental disturbances
Function clinically as both anxiolytic and hypnotic (sleep-inducing) agents.

3. benzodiazepines The most widely used anxiolytic drugs
More effective and safer than barbiturates and meprobamate

4. Mode of action Binding of -aminobutyric acid to its receptor
Triggers an opening of a chloride channel
Causes a small hyperpolarization that moves the postsynaptic potential away

6. Actions
Reduction of anxiety: at low doses, the benzodiazepines are anxiolytic.
Sedative and hypnotic actions:
Anticonvulsant:
Muscle relaxant:

7. Therapeutic uses
Anxiety disorders: in treating the anxiety that accompanies some forms of depression and schizophrenia.

8. Therapeutic uses
Muscular disorder: in the treatment of skeletal muscle spasms. Spasticity such as multiple sclerosis and cerebral palsy.

9. Therapeutic uses
Seizures: clonazepam is useful in the chronic treatment of epilepsy, whereas diazepam is the drug of choice in terminating grand mal epileptic seizures and status epilepticus.

10. Therapeutic uses Sleep disorders:
flurazepam: reduces both sleep-induction time and the number of awakenings, and increases the duration of sleep.
Temazepam: is useful in patients who experience frequent wakening
Triazolam: used to induce sleep in patients with recurring insomnia.

11. Pharmacokinetics
Absorption and distribution: lipophilic, rapidly and completely absorbed after oral administration
Duration of actions
Fate: metabolized by the hepatic microsomal metabolizing system and are excreted in urine

12. Dependence
Psychological and physical dependence on benzodiazepines can develop
Withdrawal symptoms: including confusion, anxiety, agitation, restlessness, insomnia, and tension.

13. Adverse effects Drowsiness and confusion: ataxia occurs at high doses
Cognitive impairment
Precautions: They potentiate alcohol and other CNS depressants.

14. barbiturates
Mode of actions: interfere with sodium and potassium transport across cell membranes. This leads to inhibition of mesencephalic reticular activating system.

15. Actions
Depression of CNS: at low doses, the barbiturates produce sedation. At higher doses, the drugs cause hyponsis, followed by anesthesia

16. Actions
Respiratory depression: suppress the hypoxic and chemoreceptor response to CO2
Enzyme induction: barbiturates induce P-450 microsomal enzymes in the liver

17. Therapeutic uses
Anesthesia: thiopental are used intravenously to induce anesthesia
Anticonvulsant: phenobarbital is used in long-term management of tonic-clonic seizures, status epilepticus, and eclampsia
Anxiety: mild sedatives to relieve anxiety, et.al Most have been replaced by the benzodiazepines

18. Pharmacokinetics
Absorbed orally and distributed widely throughout the body

19. Adverse effects
CNS: drowsiness, impaired concentration, and mental and physical sluggishness.
Drug hangover: produce a feeling of tiredness well after the patient awakes.
Precautions: increase porphyrin synthesis.
Addiction: abrupt withdrawal may cause tremors, anxiety, weakness, seizures. et.al.