Presentation on theme: "Drugs acting on the CNSI"— Presentation transcript:
1 Drugs acting on the CNSI Unit 8Week 5Dr.Mohammed HassanDrugs acting on the CNSIAl-Hamadi , Drugs acting on the CNSI. 4medstudents.com 2003
2 Drugs acting on the CNS 1The psychotic disorders are classified into 3 major groups:Anxiety disorders (phobia and sleeping disorders).Effective/mood disorders (depression)Personality disorders (Schizophrenia)
3 Drugs acting on the CNS 1 Anxiolytic Drugs: Antidepressant Drugs: Benzodiazepines(BDZ)Barbiturate.BuspironeAntidepressant Drugs:Tricyclic/PlycyclicMonoamine oxidase inhibitorsSelective serotonin-reuptake inhibitors (SSRI)Neurolytic Drugs:PhenothiazinButeopheanol
4 Anxiety and Anxiolytic Drugs: Definition:Unpleasant state of tension or a fear that seems to arise from an unknown source.Symptoms:TachycardiaSweatingPalpitationsSympathetic activation
5 Anxiolytic Drugs (Benzodiazapine) Diazepam,Lurazepam, MidazolamMode of action:Binding of GABA to its receptor trigger an opening of chloride conductance. The influx of chloride ions causes hyperpolarization that moves the post synaptic potential away from its firing threshold and thus inhibits the formation of action potential and neural firing>Actions:Reduction of anxiety( at low doses)Sedative and hypotonic actions (at higher doses)AnticonvulsantMuscle relaxant
7 Benzodiazapine Pharmacokinetics: Dependence: Duration of action: Fate: Short, intermediate and long acting.Fate:Metabolized by the hepatic microsomal metabolism system.Dependence:At high dosesResults in withdrawal symptoms:Confusion, anxiety, restlessness and tension.
8 Benzodiazapine Adverse effects: Precautions: Drowsiness and confusion. Cautiously in treating patients with liver disease.Goodbye BDZ
9 Welcome (Barbiturate) Phenobarbiturate, amobarbiturateMode of action:Interfere with sodium and potassium transport across cell membranes.Actions:Depression of CNS (at low doses)Hypnosis and anesthesia ( at high doses)Respiratory depression.Enzyme induction (P-450 microsomal enzyme in liver)
10 Barbiturate Therapeutic uses: Pharmacokinetics: Anesthesia AnticonvulsantAnxietyPharmacokinetics:Metabolized by the liverDistributed to:Splanchnic areaSkeletal musclesAdipose tissue
11 Barbiturate Adverse effects: CNS: Drug hangover Addiction: Poisoning: Drowsiness, impaired concentration and mental sluggishnessDrug hangoverTiredness, nausea and dizzinessAddiction:Tremor, anxiety, tiredness, restlessness, nausea and vomitingPoisoning:deathGoodbye Barbiturate
12 Goodbye all Anxiolytic Drugs Welcome BuspironeUseful in the treatment of generalized anxiety disorders.Action:The action is mediated by serotonin receptors.Adverse effects:DizzinessNervousnessligthheadnessThe action is mediated by serotonin receptorsGoodbye all Anxiolytic Drugs
13 Depression and Antidepressant drugs: Definition:Pervasive mood altering illness affecting energy, sleep, appetite and the ability to function.Symptoms:DepressionSadnessHopelessnessInability to experience pleasure in usual activity
14 Antidepressant Drugs (Tricyclic/Polycyclic) Amitriptyline, ImipramineMode of action:Inhibit the neuronal reuptake of norepinephrine and serotonin into presynaptic nerve terminals which leads to increased concentration of monoamine in the synaptic clef.Blocking serotonergic,a-adrenergic, histamine and muscurinic receptors.Actions:Elevate moodsImprove mental alertnessIncrease physical activity
15 Tricyclic/Polycyclic Therapeutic uses:DepressionPanic disorderBed-wetting in childrenPharmacokinetics:Absorption and distribution:LipophilicLow bioavailabilityMetabolized by hepatic microsomal system
17 Welcome (monoamine oxidase inhibitors) Hydralazine, phenelzineMode of action:Reverrsibly or irreversibly inactivate the enzyme, this result in increased norepinephrine, serotonin and dopamine with in the neuron.
19 monoamine oxidase inhibitors Adverse effects:Inability to degraded tyramine obtained from the gutCheeseChicken liverTyramine causes the release of large amounts of stored catecholamines from verve terminals resulting in:HeadacheTachycardiaNauseahypertensionGoodbye MAO Inhibitors
21 Selective Serotonin-Reuptake Inhibitors Pharmacokinetics:Slowly cleared from the bodyPotent inhibitor of a hepatic cytochrome P-450.Adverse effects:NauseaAnxietyInsomniaSexual dysfunctionWeight losstremorsGoodbye SSRI
22 Personality disorders and antipsycotic (neuroleptic) Drugs: schizophreniaDefinition:Mental disorder caused by some inherited dysfunction of the brain.Symptoms:DelusionsHallucinationThinking or speech disturbance
23 (neuroleptic drugs)Five important classes. Most important classes are:PhenothiazinesFluphenazinePromethazineButyrophenonesHaloperidolDoroperidolMode of action:Block dopamine and serotonin receptor in the brainMany of these drugs also block cholinergic, adrenergic and histamine receptors
24 neuroleptic drugs Actions: Antipsychotic actions: Reduce hallucinations by blocking dopamine receptors.Extrapyramidal effects:Parkinson syndrome by blocking the dopamine receptors in the nigrostriatal pathway.Antiemetic effects:By blocking dopaminergic receptors.Antimuscarinic effects:Blurred vision, dry mouth, sedation and confusion.Other effects:Hypotension and lightheadedness by blocking a-adrenergic receptors
25 Goodbye Neuroleptic Drugs Therapeutic uses:SchizophreniaPrevention of severe nauseaTreatment of severe painAdverse effects:TremorsPostural hypotensionConstipationUrinary retentionConfusionSexual dysfunctionGoodbye Neuroleptic Drugs
Your consent to our cookies if you continue to use this website.