SEDATIVES, HYPNOTIC &
ANXIOLYTIC DRUGS
DR. MASIKA
2025
, CNS – Brain and Spinal cord
• Brain disorders may result structural or functional disturbances
of the sensory, integrative or motor activities of CNS
• Associated with a variety of disease processes e.g. degenerative,
ischemic and physiologic disturbances
• Role of drugs mainly to relieve the symptoms of brain
dysfunction, but usually do not correct the underlying disorder
• Drug therapy for many brain disorders is therefore a lifelong
process.
• Short term Rx may be effective in relieving acute symptoms e.g.
pain and insomnia
, General mechanism of action
• Drugs act by affecting the synthesis, storage/release, re-uptake or degradation of
neurotransmitters; or by activating receptors thereby causing various changes in the
brain
• The mechanisms of signal transduction for neurotransmitters in the CNS are similar
to those for neurotransmitters in the ANS
• Common NTs
– Acetylcholine
– Amino acids: GABA, glutamate/aspartate, glycine
– Biogenic amines: Dopamine, norepinephrine, serotonin (5HT),
histamine
– Peptides: Opioids, enkephalins, neurokinins, substance P
– Others-NO, CO, purines
, Neurotransmitters and Receptors
Two main groups of receptors
• Ionotropic receptors, also called ligand-gated ion channels, which are directly
associated with ion channels
• Metabotropic receptors – are typical G protein–coupled receptors
Neurotransmitters
1) Acetylcholine: Acts as excitatory or inhibitory NT in neural tracts that innervate celebral
cortex and basal ganglia in the brain ; areas that participate in memory, sensory
processing and motor co-ordination
Receptors
Muscarinic: M1, M3, M5 - Excitatory; role in arousal and consciousness, memory
consolidation
- M2, M4 - Inhibitory; autoreceptor and heteroreceptor ,decreases NT release
Nicotinic - Excitatory; increases NT release, role in nicotine dependence
ANXIOLYTIC DRUGS
DR. MASIKA
2025
, CNS – Brain and Spinal cord
• Brain disorders may result structural or functional disturbances
of the sensory, integrative or motor activities of CNS
• Associated with a variety of disease processes e.g. degenerative,
ischemic and physiologic disturbances
• Role of drugs mainly to relieve the symptoms of brain
dysfunction, but usually do not correct the underlying disorder
• Drug therapy for many brain disorders is therefore a lifelong
process.
• Short term Rx may be effective in relieving acute symptoms e.g.
pain and insomnia
, General mechanism of action
• Drugs act by affecting the synthesis, storage/release, re-uptake or degradation of
neurotransmitters; or by activating receptors thereby causing various changes in the
brain
• The mechanisms of signal transduction for neurotransmitters in the CNS are similar
to those for neurotransmitters in the ANS
• Common NTs
– Acetylcholine
– Amino acids: GABA, glutamate/aspartate, glycine
– Biogenic amines: Dopamine, norepinephrine, serotonin (5HT),
histamine
– Peptides: Opioids, enkephalins, neurokinins, substance P
– Others-NO, CO, purines
, Neurotransmitters and Receptors
Two main groups of receptors
• Ionotropic receptors, also called ligand-gated ion channels, which are directly
associated with ion channels
• Metabotropic receptors – are typical G protein–coupled receptors
Neurotransmitters
1) Acetylcholine: Acts as excitatory or inhibitory NT in neural tracts that innervate celebral
cortex and basal ganglia in the brain ; areas that participate in memory, sensory
processing and motor co-ordination
Receptors
Muscarinic: M1, M3, M5 - Excitatory; role in arousal and consciousness, memory
consolidation
- M2, M4 - Inhibitory; autoreceptor and heteroreceptor ,decreases NT release
Nicotinic - Excitatory; increases NT release, role in nicotine dependence
