CNS stimulants Dr Manodeep Chakraborty CNS stimulants Classification
CNS stimulants Dr. Manodeep Chakraborty
CNS stimulants: Classification: a. Convulsants: Strychnine, picrotoxin, bicuculline, Pentylenetetrazol b. Analeptics: Doxapram c. Psychostimulants: Amphetamines, Methyl phenidate, cocaine, caffeine, pemoline. Strychnine -Strychnos nux-vomica; • blocking Post-synaptic inhibition produced by glycine Picrotoxin -Anamirta cocculus (fish berries) • blocking Pre-synaptic inhibition through GABA (Diazepam in toxicity)
Bicuculline: Competitive GABAA receptor antagonist Pentylenetetrazol (PTZ): • direct depolarization of central neurones, • interfere with GABAergic inhibition Ø Low doses cause excitation, Iarger doses produce convulsions
Analeptics (Respiratory Stimulants) (a) (b) (c) (d) As an expedient measure in hypnotic drug poisoning Suffocation on drowning, acute respiratory insufficiency Apnoea in premature infant Failure to ventilate spontaneously after general anaesthesia Doxapram: promote excitation of central neurones • Respiration is stimulated through carotid and aortic body chemoreceptors.
Psychostimulant: • Cortical action, psychic effects more. Amphetamines: central sympathomimetics. stimulate mental rather than motor activity. Alertness, ↑concentration, euphoria, talkativeness, ↑ work capacity Methylphenidate: Chemically, pharmacologically relate amphetamine Act by releasing NA, DA in brain
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