CNS P1 (antiprakesonsim & Sedative-hypnotic ) Flashcards
what is the Parkinson disease
- its movement disorder characterized by M.s rigidity and tremors and postural instability duo to loss of Dopaminergic neurons in the Sub-statntia nigrea and locus ceruleus resulting in imbalance of Dopaminergic ( inhibitory ) and cholinergic ( excitatory ) influence on the Extrapyramdial systems
what is the classification of antiprakonsnism ?
-1-Dopaminergic drugs :
1-LevoDopa
2-Selegiline
3-Dopamine agonist
4-Amantadine
explain the drugs that needed to treat Parkonsinsim
1-Drug:L-Dopa ( LevoDopa)
—-pharmacokinetics:
-absorbed rapidly from small intestine
-amino acid so drugs like : leucin and isoleucine compete with it
- mechanism of action :
Dopamine cant cross BBB but the L-Dope can thats why we give L-dopa then after it pass the BBB the L-Dopa get carboxylated to convert to Dopamine
- but to prevent any chance pf carboxylate in the Body tissue we used a drug called Carbidopa which inhibit the carboxylation in peripheral
- and bcs the L-Dopa has short duration of action bcs its metabolise by COMT enzyme so we should give A COMT inhibitor ( Tolcapone or Entacapon )
—Adverse effect :
1-neuasa and vomiting
2-mood changes
3-Dyskinisa
4-on/off phenomenon
——
2-Drug: Selegiline
-mechanism: its selective MAO-B inhibitor which located in the Braine Nd break down the Dopamine
-adverse effect :
1- nausea and vomiting
2- halosanation
3- insomnia
——
3- Drug : Bromocriptine ( dopamine agonists)
-mechanism: its dopamine (D2) agonist differ from L-Dopa in faster and longer duration so it will has no On/off phenomenon
-uses :
1-Parkinsosm
2-hyperprolactimia
3-Acromgly
4- drug Amantadine
-mechanism: its antiviral drug for influenza A2 in the Antiprakonsim the mechanism is unclear but maybe duo to increase Dopamine release and decreasing the reuptake
-adverse effect :
1-nausea and vomiting
2-skin pigmentations
3-hallosantion and mood changes
what is the activity of CNS ?
1-Anxiolytic
2-Normal CNS activity
3-Sedative
4-Hypnotic
5-general anaesthetic
6-Coma
what is the families of Sedative-hypnotic drugs
1-Barbiturates
2-Benzodiazepines
3- Z drugs
4- other drugs
explain the Barbiturates drugs
-1-Chemistry :
- all are derivatives from barbituric acid so they are acidic drugs
2- Classification:
2-1 ultra short acting : Thiopental
2-2 long action : phenobarbital
3-pharmacokinetics:
— all pass BBB and placenta and secreted in the breast milk
4- mechanism of action :
- its dose dependent so :
4-1 normal dose : Allostric modulation of GABA action of GABA - receptor > Enhancement of Cl- conduce > hyperpolarzion > pharmacological effect 4-2 in case of large dose the Barbiturates will compete in the same site of The GABA receptor»_space; and will do the same as before but there be CNS depression
5-pharmacological effect :
5-1 Antianixty effect : in small dose (not much used in this purpose )
5-2 hypnotic effect: in large dose ( and its main use of the drug )
5-3 anaesthetic effect : thiopental drug
5-4 AntiConvaltions effect : phenobarbital
5-5 S.K muscles relaxation
5-6 General CNS depression in large dose including medullary centre
6- uses or treatment:
6-1 phenobarbital: for tonic clonic
6-2 thiopental : for short acting anaesthesia
6-3 promodine used for antiConvaltions
7-treatment of toxicity:
7-1 mechanical ventilator
7-2 iv fluids
explain the benzodiazepines
-1-Chemistry :
- all membranes containes fusion of benzen ring with diazepine ring
2- Classification:
2-1 short acting : Midazolam
2-2 intermediate acting : Lorazepam - oxazepam
2-3 long acting : Diazepam - clonazepam
3-pharmacokinetics:
— all pass BBB and placenta and secreted in the breast milk
4- mechanism of action :
4-1 normal dose : Allostric modulation of GABA action of GABA - receptor > Enhancement of Cl- conduce > hyperpolarzion > pharmacological effect 5-pharmacological effect :
5-1 Antianixty effect : in small dose (good results and main use for this perpus)
5-2 hypnotic effect: in large dose
5-3 anaesthetic effect : midazolam
5-4 AntiConvaltions effect : Diazepam - clonazepam
5-5 S.K muscles relaxation
5-6 antergred amnesia
6- uses or treatment:
6-1 Antianxiaty
6-2 insomnia : temazepam
6-3 AntiConvlation: clonazepam
6-4 abscinse seizures : Diazepam
6-5 status epileptics : Diazepam IV
6-6 short surgical operation: midazolam
7-treatment of toxicity:
7-1 drug called : Flumazenil
explain the sedative hypnotic drug ( Z )
-Drug : Zolpidem Tab 10mg
- mechanism of action : they are structurally different from BZD but they act bu the same mechanism but bind to GABA-A receptor at site close to BDZ
-pharmacological effect:
1- they are specific hypnotics only
-treatment or uses :
1- to treat insomnia
-adverse effect : risk of dependent and tolerance
- treatment of toxicity:
drug : Flumazenil
explain the Buspirone drug
-Drug : Buspirone
-mechanism: its 5-HT1A agonist in mid brain
NB! Presynaptic autoreceptors on serotonergic cell bodies in the raphe nuclei , Upon stimulation, these receptors inhibit the firing of 5-HT neurons
-pharmacological effect:
1- selective Antianxiety so no hypnotic effect or Mc relaxation effect
2-its suppress anxiety after long delay 10-14 D
-precaution : don’t mix buspirone with SSRIs it will cause a serotonin syndrome
explain the Melatonin
-Drug : Melatonin
melatonin is hormone screated by the Pineal gland and its sleep regular
- mechanism : its act on two types of receptors
1- MT1 : mediate sleep
2- MT2 : regulate the Circadian rhythm
- uses : 1-natural hypnotic
2- to over come of jet lag problems
explain the Antihistamine drugs
-Drugs : -Diphenhydramine 50mg
- Doxylamine tab 15mg
-mechanism: its non-selective H1-H2 histamine blocker can cross BBB and block H1 receptor in the CNS
-pharmacological: by blocking the H1 receptor that cause sedation
-uses : in CNS to treat insomnia
explain the types of Epilepsy
1- generalized
1-1 Absences seizures
1-2 myoclonic seizures
1-3 tonic clonic
—-
2- focal
2-1 preserved awareness
2-2 impaired awareness
2-3 secondary generalization
—-
NB! if the epilepsy cor more 20 min its called Status epileptics
NB! Fibril seizures occurs in the children when the high fever
classification of epilepsy drugs
1- first generation :
1-1 phenytoin
1-2 carbamazepine
1-3 Valproate
1-4 ethosuximid
1-5 phenobarbital
1-6 benzodiazepines
——
2- 2nd generation :
2-1 Vigabatrin
2-2 Lamotrigine
2-3 Levetiracetam
2-4 Gabapentin
2-5 Tiagabine
explain the drug Phenytoin
-Drug : Phenytoin tab 0.117
-its first generation drug
-mechanism: inhibit the electrical excitability of neuron by blocking the Na+ channel
-uses :
1- tonic clonic
2-Status epileptics
explain the drug Carbamazepine
-Drug : Carbamazepine tab 0.2
-its first generation drug
-mechanism: inhibit the electrical excitability of neuron by blocking the Na+ channel
-uses :
1- tonic clonic
2-Focal seizures
3-trigmenal neuralgia
explain the drug Valproate
-Drug : Valproate tab 0.3
-its first generation drug
-mechanism: mixed mechanism :
1-inhibit the electrical excitability of neuron by blocking the Na+ channel
2-inhibit GABA-t so GABA decrease the neuronal firing
3-block Ca2+ channel
-uses :
1- all epileptic seizures but more favorable tonic clonic and myoclonic
explain the drug Ethosuximide
-Drug : Ethosuximide tab 0.25
-its first generation drug
-mechanism: block T-type Ca2+ channel in the thalami cortical neurons
-uses : Absence seizures
