2) SEDATIVES HYPNOTICS AND PHARMACOTHERAPY OF SLEEP DISORDERS.ppt

2) SEDATIVES HYPNOTICS AND PHARMACOTHERAPY OF SLEEP DISORDERS.ppt

• 1.
  SEDATIVE HYPNOTICS Sedatives arethe drugs that produces a calming or quieting effect and reduces excitement. It may cause drowsiness. Hypnotic is a drug that induces sleep resembling natural sleep. Both sedation and hypnosis may be considered as different grades of CNS depression. Sleep can be classified into two types depending on the physiological characteristics:  NREM (non rapid eye movement) sleep  REM (rapid eye movement) sleep
• 2.
  CLASSIFICATION: 1) Benzodiazepines:  Longacting: Diazepam, chlordiazepoxide, flurazepam  Short acting: temazepam, lorazepam, triazolam 2) Barbiturates:  Phenobarbitone, mephobarbitone, secobarbitone, pentobarbitone. 3) Newer agents:  Zolpidem, zopiclone. 4) Miscellaneous:  Paraldehyde, chloral hydrate, glutethimide.
• 3.
  BENZODIAZEPINES:  Chlordiazepoxide wasthe first BZD to be introduced into clinical medicine.  BZD’s are useful:  Sedation and hypnotics  Reduces anxiety  Causes muscle relaxation  Anticonvulsant effects  Causes quick onset of sleep and increases the duration of sleep.  Quality of sleep resembles to natural sleep more closely when compared to other hypnotics.
• 4.
  It also reducesanxiety and aggression and thus produces a calming effect. MOA: these drugs bind to BZD receptors and enhance the effect of GABA-the inhibitory neurotransmitter. Adverse effects: drowsiness, confusion, amnesia, lethargy, impaired motor coordination such as driving skills. When compared to barbiturates, tolerance and dependance of BZD’s are less, these are safer, donot effect the respiratory and CV functions.
• 5.
  BARBITURATES: These are thederivatives of Barbituritic acid. Classified as:  Long acting: phenobarbitone  Short acting: pentobarbitone  Ultra short acting: thiopentone  MAO: these drugs bind to GABA receptors and enhance the effect of GABA-the inhibitory neurotransmitter.  Causes sedation and induces sleep.  Also reduces anxiety and impairs memory.
• 6.
  Adverse reactions: hangovermay be accompanied by nausea, vomiting, vertigo and diarrhoea. Hypotension, depression of respiration, decreased excitability of neuromuscular junction are also seen. Tolerance is developed in patients with repeated intake of barbiturates. These drugs are used in sedation, hypnotics, anaesthesia, pre anesthetic medication, as an anti- epileptic, and in neonatal jaundice.
• 7.
  NEWER AGENTS: Zolpidem isa hypnotic. It is a non BZD drug. Claimed to be a better hypnotic than other classes. Adverse effects: drowsiness, confusion, amnesia, lethargy, impaired motor coordination such as driving skills. Zopiclone is another hypnotic used Actions resemble to BZD’s
• 8.
  MISCELLANEOUS: Chloral hydrate isused as an alternative to BZD. Has a bad taste and is an irritant. Causes nausea, vomiting. Produces hypnosis without affecting respiratory and CV functions. Paraldehyde is irritant and can dissolve plastic hence cannot be given by plastic syringe. It is a good hypnotic causing little hangover. It can be given rectally, intramuscularly or orally. Also has anticonvulsant properties.