WEEK 7 Flashcards
A very important structure of the CNS is its protective mechanisms that not all chemicals can pass through it, this affects the pharmacodynamics of drugs because some of them cannot penetrate the CNS.
Brain & Spinal Cord
Electrical transmission of
impulses happen by_______ and____________ make use of neurotransmitters to achieve its functions
action potential
chemical processes
Synapses made by the peripheral nervous system conduct impulses that are chemical in nature.
Autonomic Nervous System & Somatic Nervous System
conduct impulses by Action Potential
Neurons
movement of sodium into the cells causing
depolarization
potassium out of the cells to cause
repolarization
feeling of tension, nervousness, apprehension or fear that usually involves unpleasant reactions to a stimulus, whether actual or unknown
Anxiety
Anxiety is classified as
mild, moderate, severe and panic
severe sedation.
Hypnosis
loss of awareness and reaction to environmental stimuli
Sedation
GABA
Gamma
Amino Butyric Acid
an inhibitory neurotransmitter to decrease impulses in the synapses of the brain, therefore decreasing conduction of rapid impulses causing symptoms of anxiety.
Gamma
Amino Butyric Acid
drug action is to enhance GABA
effect. This is used to be the drug of choice to manage anxiety but its depressant effect may cause severe respiratory depression that this is not primarily used for anxiety today
Barbiturates
drug action is to enhance GABA effect to cause inhibition of impulse transmission.
Benzodiazepines
For overdose of Benzodiazepine
Flumazenil
affective disorder is recognized by its clinical manifestations such as sleep disturbances, they have little energy, inability to perform daily activity. They may describe overwhelming feelings of sadness, despair, hopelessness and disorganization.
Depression
This theory explains that depression occurs due to decreasing neurotransmitters, norepinephrine, serotonin and dopamine.
Biogenic Amine Theory.
inhibit
presynaptic reuptake of neurotransmitter, norepinephrine and serotonin, which leads to accumulation of these neurotransmitters in the synaptic cleft and increased stimulation of postsynaptic receptors.
Tricyclic Antidepressants (TCA)
CASH
C – Cardiovascular effects
A – Anticholinergic effects
S – Sedation
H – Hypotension or Hypertension
These drugs inactivate the enzyme MAO
to increase the neurotransmitters in the
synapses.
MonoAmine Oxidase Inhibitors
rich food which normally broken down by MAO enzymes in the GIT maybe absorbed in high concentration in the presence of MAOI and may cause hypertensive crises.
Tyramine
these drugs specifically block the reuptake of serotonin with little or no effect on Norepinephrine. SSRIs do not have the many adverse effects of TCAs and MAOIs
Selective Serotonin Reuptake Inhibitors (SSRI)
Have_______ or another________ for hypertensive crisis
phentolamine
adrenergic blocker
is the most common type of psychotic disorder. This prevents an individual from functioning in society. Some clinical manifestations include, hallucinations, delusions, paranoia, speech abnormalities and affective problems.
Schizophrenia
is associated with Bipolar illness.
is characterized by periods of extreme overactivity and excitement
Mania
Drugs for mental disorders
Psychotherapeutic drugs
Drugs for Schizophrenia
Antipsychotic Drugs
drugs for Mania
Anti Manic Drugs.
block
Dopamine receptors in the limbic system, in the reticular activating system and the brain. This group of antipsychotic may block all dopamine receptors including those not associated with psychoses
Typical Antipsychotic drugs
block Dopamine and Serotonin receptors. This group will lock only the receptors of Dopamine and Serotonin which are responsible for occurrence of psychosis
Atypical Antipsychotic drugs
ASHE
■ A – Anti cholinergic effect
■ S – Sedation
■ H – Hypotension
■ E – Extra pyramidal Symptoms
alters sodium transport in the nerve and muscle, inhibits the release of norepinephrine and dopamine slightly and decreases intraneuronal content of second messengers.
Lithium
CNS problems including lethargy, slurred speech, muscle weakness, fine tremor; polyuria, beginning gastric toxicity
Serum level less than 1.5 mmol/L
Intensification of the above plus ECG changes
Serum level 1.5 – 2 mmol/L
LProgression of CNS symptoms to ataxia, hyperreflexia and seizure, hypotension
Serum levels of 2.0 – 2.5 mmol/L
complex multi organ toxicity and death
Serum levels more than 2.5 mmol/L
Toxicity associated with serum level of Lithium. ( Therapeutic level
0.6 – 1.2
is a collection of different syndromes characterized by abnormal and excessive impulse transmission in the brain
Seizure
disorder has no known cause; this is often called Epilepsy.
Primary seizure
may be caused by Cerebrovascular accident, Infections, Brain Tumor, Traumatic Brain Injury, Fever and a lot more conditions that may alter impulse transmission in the brain.
Secondary Seizure
is seizure manifesting motor symptoms like tonic clonic seizure.
Convulsion
begins in one area of the brain and rapidly spreads to both hemispheres of the brain.
Generalized seizure
Tonic – Clonic Seizure formerly known as
Grand Mal Seizure
involve one area of the brain and do not spread throughout the entire organ.
Partial seizures or focal seizures
inhibit sodium influx or
depolarization along the nerve fiber.
Hydantoins
is not used for long term treatment of seizures.
Diazepam
is good for treatment of Petit Mal Seizure and Myoclonic Seizure
Clonazepam
enhanced effect of GABA, an inhibitory neurotransmitter.
Succinimides
reduces electrical activity by suppressing calcium influx and enhancing GABA effects the drug of choice for treating myoclonic seizure
Valproate or Valproic Acid
is a degenerative disorder of the central nervous system. There is no known cause. This is common among elderly 60 years old and above. The disease is characterized by degeneration of the substantia nigra in the midbrain. A dopamine secreting neurons in the brain. Therefore there is a tremendous decrease of dopamine in the brain especially affecting the basal ganglia. The basal ganglia is responsible for coordinating fine motor movement of the body.
Parkinson’s Disease
In Parkinson’s disease an imbalance of neurotransmitters, ______________and ______________results to clinical manifestations causing incoordination for unconscious muscle movements including those that control position, posture and movement
decreased dopamine
increased acetylcholine
increase the effect
of Dopamine at the receptor sites by increasing the levels of dopamine in the substantia nigra or directly stimulating the receptors
Dopaminergic drug
a precursor of Dopamine. Once it enters the BBB, it becomes dopamine and will replace the loss of dopamine
Levodopa
levodopa can be destroyed by and enzyme called
dopa decarboxylase
This drug cannot increase the level of dopamine in the brain but it inhibits the enzyme, dopa decarboxylase, therefore allowing more levodopa to pass the BBB.
Carbidopa
drug that can increase the release of dopamine. This drug can be effective as long as there is a possibility of more dopamine release.
Amantadine
acts as a direct dopamine agonist on dopamine receptor sites in the substantia nigra.
Bromocriptine
oppose the effects of acetylcholine at receptor sites in the substantia nigra.
Anticholinergic drugs
The division of the peripheral nervous system that supply involuntary muscles, glands and other effectors not innervated by the somatic nervous system.
Autonomic nervous system
cranio – sacral outflow
Parasympathetic nervous system (PNS)
Parasympathetic nervous system (PNS)
“REST AND DIGEST”
In the PNS, the neurotransmitter is
Acetylcholine
There are 2 types of cholinergic receptors
Nicotinic Receptors ○ Muscarinic receptors
thoraco- lumbar outflow
Sympathetic nervous system (SNS)
preganglionic neuron of the SNS
shorter
post ganglionic neuron
longer
Sympathetic nervous system (SNS)
“FIGHT OR FLIGHT”
two neurotransmitters in the SNS
Acetylcholine and Epinephrine and Norepinephrine ( Catecholamines )
Actylcholine is released by the
epinephrine and norepinephrine are the neurotransmitters released by the
post ganglionic neurons
Epinephrine and Norepinephrine may also be called
Adrenalin and Noradrenaline
There are 2 types of adrenergic receptors
○ Alpha receptors
○ Beta receptors
Drugs affecting the PNS are called
Cholinergic Drugs
Drugs affecting the SNS are called
Adrenergic Drugs
directly stimulates the cholinergic receptors to increase its effects
Direct acting cholinergic agonist
indicated for non – obstructive urinary retention like in neurogenic bladder
Bethanechol
indicated for glaucoma, causing pupillary constriction
Carbachol
indicated for glaucoma, causing pupillary constriction
Pilocarpine
– this drug increases acetylcholine effect by inhibiting the action of acetylcholinesterase (an enzyme that removes acetylcholine in the synapse. If acetylcholinesterase is not removed in the synaptic cleft, more acetylcholine stays in the synapse stimulating more receptors, thus enhancing their effects. These drugs are used for treatment of Myasthenia gravis and Alzheimer’s disease’
Indirect acting cholinergic agonist
is an autoimmune disease of the neuromuscular junction (NMJ). This is characterized by destruction of cholinergic receptors at the NMJ that will slow down impulses going to the skeletal muscles. This disease is characterized by the development of muscle weakness and paralysis
MYASTHENIA GRAVIS
To increase junctional transmission, an indirect acting cholinergic agonist inhibits acetylcholinesterase making more acetylcholine present in the junction to improve impulse transmission and muscle function.
anticholinesterase drugs.
short acting anticholinesterase drug used to diagnose the disease. The action lasts for 10 to 20 minutes.
Edrophonium HCL (Tensilon)
long acting anticholinesterase drugs used for therapeutic purposes. The onset of action starts 20 to 30 minutes and may last for 3 – 6 hours.
Neostigmine, Physostigmine, Pyridostigmine
is a degenerative disease of the CNS characterized by loss of neurons in the CNS which may slow down impulse transmission across the synapses of the CNS. One important cause of this is explained by loss of acetylcholine receptors in the postsynaptic neurons, like myasthenia gravis, less receptors mean lesser impulse transmission
ALZHEIMER’S DISEASE
Cholinergic antagonist is also being referred to as an
anticholinergic drug or parasympatholytic.
indicated to decrease
secretions, treat bradycardia, pylorospasm, ureteral colic, cause pupil dilation (mydriasis) indicated as preop drug for cataract extraction. Use as antidote for cholinergic crisis
Atropine
use for hyperactive bowel in adults
Dicyclomine
use in motion sickness, indicated to decrease secretion, pupil dilation
Scopolamine
Vascular smooth muscles, iris, visceral smooth muscles like the urinary bladder and iris
Alpha 1 receptors
CNS neurons, pancreatic islets
Alpha 2 receptors
Myocardium, Kidneys, CNS neurons
Beta 1 receptors
Visceral smooth muscles like in the lungs, some vascular smooth muscles, CNS neurons
Beta 2 receptors
these drugs stimulate all adrenergic receptors to enhance their effects
Alpha and Beta adrenergic drugs ( Sympathomimetic drugs )
the drug of choice
during CPR, indicated for
treatment of shock
Epinephrine
used for treatment
of congestive heart failure
Dobutamine
usually given for
congestive heart failure and cardiogenic shock
Dopamine
like epinephrine, may be indicated for
cardiac arrest
Norepinephrine
these drugs specifically stimulate only the alpha receptors and not the beta receptors
Alpha specific adrenergic agonist
used for treatment of common colds and allergy. This drug causes vasoconstriction to lessen congestion in the nose therefore called decongestants
Phenylephrine
better known for its brand name as Catapres acting on the CNS neurons to decrease norepinephrine flow. This drug is indicated for treatment of hypertension
Clonidine
these drugs specifically stimulate the beta receptors and not the alpha receptors.
Beta specific adrenergic agonist
for treatment of cardiogenic shock and heart block in transplanted hearts.
Isoproterenol
for treatment of
obstructive respiratory disease like COPD and bronchial asthma
Salbutamol
these drugs block all adrenergic receptors
Alpha and Beta adrenergic antagonist
these drugs block only the alpha receptors, specific drugs act on the alpha 1 and alpha 2 receptors.
Alpha adrenergic antagonist
more specific
drug hypertension in pheochromocytoma, that will have less adverse effects
Phentolamine
these drugs block only the alpha receptors, specific drugs act on the alpha receptors on the blood vessels and urinary bladder to cause vasodilation for treatment of hypertension and bladder emptying for treatment of urinary retention. Although some drugs may act in both blood vessels and urinary bladder at the same time
Alpha 1 selective adrenergic antagonist
these drugs block only the alpha receptors, specific drugs act on the alpha receptors on the blood vessels and urinary bladder to cause vasodilation for treatment of hypertension and bladder emptying for treatment of urinary retention. Although some drugs may act in both blood vessels and urinary bladder at the same time
Alpha 1 selective adrenergic antagonist
these drugs block
both beta 1 and beta 2 receptors, particularly affecting both the heart and the lungs, these drugs increase heart rate and bronchoconstriction of the lungs
Beta adrenergic antagonists
These drugs are known teratogenic in animals as
Beta 1 specific adrenergic antagonist
this is a rapid change in the membrane potential that explains how impulses are conducted along the nerves
Action Potential
control of signs and symptoms of the disease
Palliative Treatment
conduction of impulses across the junction between neurons
Synaptic Transmission
