Sedative hypnotics are drugs that produce calming and sleep-inducing effects through central nervous system depression. They are classified into benzodiazepines, barbiturates, and newer agents. Benzodiazepines like diazepam are commonly used as they are safer and less addictive than barbiturates. They work by enhancing the inhibitory neurotransmitter GABA. Common side effects include drowsiness and impaired motor skills. Barbiturates directly activate GABA receptors but have greater risks of tolerance, dependence, and respiratory depression. Newer non-benzodiazepine drugs like zolpidem are promoted as effective hypnotics with fewer side effects than other

1. SEDATIVE HYPNOTICS
Sedatives are the 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:
 Long acting: 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 was the 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 reduces anxiety 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 the derivatives 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: hangover may 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 is a 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 is used 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.