Types of Psychoactive drug based on action on typical diseases. examples : stimulants , depressants , narcotics , sedatives and hypnotics.

1. GOVERNMENT INSTITUTE OF SCIENCE
DEPARTMENT OF CHEMISTRY
SEMINAR ON
PSYCHOACTIVE DRUG
AND
SYNTHESIS OF BARBITURATE AND
PHENOBARBITAL
PRESENTED BY-
KIRAN A. BARBATKAR
M.SC. II SEMESTER III

2. WHAT ARE PSYCHOACTIVE DRUG…..
 A chemical substance that alters sensory perceptions , moods,
thinking and behavior.
 Impacts on neurotransmitter function.
 Neurotransmitter are the chemical signals that affect how happy ,
thirsty , anxious , scared , or tired you are. Eg., dopamine , GABA ,
noradrenalin etc.
 There are four general types of psychoactive drugs-
1. Stimulants
2. Depressant
3. Narcotics
4. Hallucinogens
 Example of common psychoactive drugs:
caffeine, cocaine , cannabis , ephedrine etc.

3. CLASSIFICATION OF PSYCHOACTIVE DRUGS
Antipsychotic Antianxiety Psychotomimetics
useful for anxiety
and phobic states
Antidepressant
useful in phobic states,
obsessive compulsive
behavior ,minor and major
depressive illness and some
anxiety disorder
Antimaniac
useful in all
types of
psychosis,
Particularly
‘schizophrenia’
known as ‘mood
stabilizer ’
Effective for mania
and to break cyclic
effective disorder
known as
‘hallucinogens’

4. STIMULANTS :
 Range from nicotine and caffeine to cocaine and crystal
meth.
 Block the reuptake or reabsorption of neurotransmitter
e.g. ., serotonin and dopamine which can lead to
increased energy , panic and anxiety.
Think about how coffee and cigarette can make you
jittery….

5. DEPRESSANTS :
 Increases the production of
neurotransmitter GABA (
gamma – Amino butyric acid ).
 Which decreases reaction in brain.
 Affects cognition impairing memory.
 Depressants like benzodiazepines help GABA
neurotransmitter bind to receptors that receive the
chemical signals , leading to reduced CNS activity and
inducing sleep.

6. NARCOTICS :
 Administered as painkillers.
 Used recreationally to create a sense of
euphoria .
 They stimulate your endorphins , which are
neurotransmitter that naturally reduces
pain .
 e.g., morphine , heroine and codeine etc.

7. HALLUCINOGENS :
 They trick the brain into seeing or hearing things
that aren't there actually .
 Warps a persons sense of time and space.
 These altered states of consciousness can lead to
paranoia and anxiety .
 Eg., includes LSD ( Lysergic acid diethylamide ) ,
mescaline and ecstasy.

8. CNS DEPRESSANTS
Sedative Hypnotic
Depressants which
reduce restlessness and
emotional tension
without producing sleep.
Exert a calming effect.
Compel the users to
sleep.
Reduce emotional tension
and restlessness.
Produce drowsiness.

9. SEDATIVE - HYPNOTICS
Benzodiazepines Barbiturates Miscellaneous Agents
Short
action
Intermediate
action
Long action
Ultra action
Short action
Long action
Buspirone
Chloral
Hydrate
Zaleplan
Zolpidem
Phenobarbitone

10.  Derivatives of Barbituric acid or
malonylurea : combination of urea and
malonic acid .
 Depressants of the central nervous system
.
 impair or reduce activity of the brain by
acting as a Gamma Amino Butyric Acid (GABA)
potentiators.
 Produce alcohol like symptoms such as ataxia
(impaired motor control ), dizziness and slow breathing
and heart rate.
BARBITURIC ACID
BARBITURATE :

11.  It was first prepared by a German scientist
Adolf Von Baeyer in 1864 .
 combining urea from animal and malonic
acid from apples.
 It was used as sleeping acid ( hypnotic
only) from 1903-1950 . Since 1950 they
are popular drug in the UK.
 It was estimated that 27000 people died
from barbiturates overdose in the UK
between 1959-1974.
HISTORY :
Adolf Von Baeyer
(1835-1917)

12. SYNTHESIS OF BARBITURATE :
 Condensation reaction are generally used in the
preparation of barbiturates.
 These reactions may take place in acidic , alkaline or
neutral media.
 In alkaline medium : In an alkaline medium
condensation reactions involve malonic esters ,
cyanoacetic esters and malonic amides on one hand
and urea or thiourea on the other hand .

13. Where X= O or S
Pharmacokinetics :
 Barbiturates are well absorbed from the
gastrointestinal tract.
 They are widely distributed in the body .
 Barbiturate with low lipid solubility are significantly
excreted unchanged in urine .

14. MODE OF ACTION :
 In sufficient concentration barbiturate changes the
permeability of the cell membrane .
 thus causes reduction in excitability of the photosynaptic
cell .
 Barbiturate appears to act on the central synaptic
transmission process of the reticular activating system,
hence cerebral cortex becomes deactivated.
 They are antidepolarizing blocking agents.
 The cerebral electrical activity of a normal man
increases with anxiety, or consumption of a CNS
stimulants like caffeine , LAD etc.

15.  Barbiturate potentiate the GABA- mediated Cl ion
conductance and also interact at the picrotoxin
binding site .
 Administration of the barbiturates in large doses has
a calming effect

16. MECHANISM OF ACTION :
 Barbiturates potentiate the effect of GABA at the GABA-
A receptor.
 The GABA-A receptor is a ligand gated ion channel
membrane receptor that allows for the flow of Cl
through the membrane in neurons .
 GABA is present in all portion of brain and it inhibits all
CNS neurons ,
 thus stabilizing resting membrane potential to remain in
a depolarized state.
 This makes it an inhibitory neurotransmitter .

17.  Uses : except for phenobarbitone in epilepsy and
thiopentone in anesthesia barbiturates are rarely used
now.
Adverse effects :
 When repeatedly used in night ,they accumulate in the
body .
 May cause dependence , tolerance , impaired
performance, mental confusion and traffic accidents.
 In an occasional user , they produces excitement.
 Hangover is a common effect after the use of barbiturate
as hypnotic

18. PHENOBARBITAL :
 It is a type of long acting barbiturates.
 Because the duration of action lasts for 6-10 hours.
 They are largely excreted by kidney.
 Phenobarbital is used in the treatment of all types of
seizures except absence seizures.
 It is no less effective at seizure control than phenytoin
.

19. MODE OF ACTION :
 Through its action on GABA receptors, phenobarbital
increases flux of chloride ions into the neuron which
decreases excitability.
 Direct blockade of excitatory glutamate signaling is also
believed to contribute to the hypnotic/anticonvulsant
effect that is observed with the barbiturates.

21. SYNTHESIS :

22. USES :
 Agent in high purity and dosage for lethal injection of
"death row" criminals.
 As a secondary agent to treat newborns with neonatal
abstinence syndrome
 a condition of withdrawal symptoms from exposure to
opioid drugs in utero.
 In massive doses, phenobarbital is prescribed to
terminally ill patients to allow them to end their life
through physician assisted suicide.

23. DISADVANTAGES :
 Decreased level of consciousness along with a
decreased effort to breathe.
 There is concern about both abuse and withdrawal
following long-term use .
 It may also increase the risk of suicide.

24. REFERENCES :
 Medicinal chemistry by Ashutosh Kar.
 Medicinal chemistry by Chatwal.
 Medicinal chemistry by Alka Gupta .
 www.google.com
 www.sciencedaily.com
 www.slideshare.net
 https://en.wikipedia.org/wiki/Phenobarbital#Mechanism
_of_action
 https://images.slideplayer.com
 clinicalgate.com
 cdn.britannica.com