Lecture 2 Flashcards
A subspecialty of pharmacology that concentrates on:
1. the impact of drugs on the brain
2. the impact of diseases on the central nervous system
3. the behavioural consequences of psychiatric medicine
Psychopharmacology
Nervous systemis composed of:
Central nervous system
Peripheral Nervous System
Contains the brain and spinal cord
Central Nervous System
Contains:
Autonomic Nervous System
Somatic Nervous System
Peripheral Nervous System
Contains:
Parasympathetic System
Sympathetic System
Autonomic Nervous System
With the increased need to reduce the stigma of mental illness across the globe, many individuals are using the term “chemical imbalance of the brain” to describe mental illness.
According to David Anderson, what is the ramification of this oversimplification?
Doesn’t address the complexity of mental illness
The target of psychiatric medications is primarily the ____
CNS
The basic unit of the nervous system is the _______
Neuron
also called sensory neurons, are the nerve fibers responsible for bringing sensory information from the outside world into the brain. Sensory information may involve special senses, such as vision, hearing, smell, or taste, as well as the sense of touch, pain, and temperature.
Afferent neurons
As the name suggests, _________ are the ones in between -they connect spinal motor and sensory neurons. As well as transferring signals between sensory and motor neurons, can also communicate with each other, forming circuits of various complexity.
interneurons
also called motor neurons, are the nerve fibers responsible for carrying signals from the brain to the peripheral nervous system in order to initiate an action. In other words, they are the neurons that tell your body to perform an action, such as removing your hand from a hot pan.
Efferent neurons
Composed of:
Afferent Neurons
Interneurons
Efferent Neurons
Peripheral Nervous System (PNS)
Effects on the _____ contribute to the pharmacological profile of psychiatric drugs
Regulates autonomic or unconscious responses to stimuli
Autonomic Nervous System (ANS)
Is the nerve cell or the neuron
Transmit messages from other neurons and communicate with one another
______ can affect this transmission.
Drugs
have 4 basic parts:
Soma (Cell Body)
Dendrites
Axon
Axon Terminals
Neurons
cell body
Soma
large and small branches of the neuron
Dendrites
long slender tube
Axon
are found at the end of axons, they contain small sacs or vesicles that hold neurotransmitters
Axon Terminals
Neural communication facilitated:
Electrically
Chemically
occurs within the neuron (nerve impulse)
Electrically
occurs between the neurons
Chemically
Nerves send messages through
action potentials
how electric signals are transmitted from one neuron to the next
Action Potential
Electrical action potentials are transmitted across the synapse by __________.
neurotransmitters
causes this electrical charge
Sodium Potassium Pump
Stimulation of the nerve causes
Depolarization
needs to occur prior to the nerve being able to be depolarized again
Repolarization
At the end of the ____ there is a halt in electrical communication
axon
Chemical communication is required between 2 neurons or between a neuron and a
gland/muscle
are the chemical messengers that are released into the synaptic cleft (between neurons)
Neurotransmitters
is the same as the synaptic gap
Synaptic cleft
Have receptors
Receptors are proteins that are embedded in the cell membrane and have binding sites for endogenous substances and drugs.
____________ needs to return to a resting state so that it can be activated again
Post-Synaptic Effector Cell
found within the body
Endogenous
The neuron transmitting the electrical impulse away from the synapse is called post-synaptic neuron,if the post-synaptic cell is not neuronal it is sometimes referred to as an _______. Synapses can be classified by the type of cellular structures serving as the pre- and post-synaptic components
effector cell
Is what the drug does to the body or how the drug behaves in the body
Pharmacodynamics
Most drugs exert their effect by chemically binding with receptors at the cellular level
This is the ______ theory of action
Receptor Theory of Action
_________ produce reactions one of three ways:
1. Enzyme Alteration
2. Open or Close Ion Channels
3. Neurohormone Alteration
Drugs
“Feel good” pathways
Movement, coordination, judgement, release of prolactin
↑Mania, anxiety, schizophrenia, addiction
↓ Parkinson’s disease, depression, ADHD
Dopamine (D2)
Fight or flight
Mood, cognition, perception, motion, cardiovascular function, sleep, arousal
↑Mania, anxiety, schizophrenia
↓Depression
Norepinephrine (NE)
“Excitatory” neurotransmitter
Sleep, arousal, libido, appetite, mood, aggression, pain, coordination
↑Anxiety
↓ Depression, anxiety
Serotonin (5-HT)
Wakefulness, pain, inflammation
↑Sleep disorders, anxiety, Alzheimer’s disease, psychosis
↓Depression
Histamine
Synaptic communication
Parasympathetic system
Sleep, arousal, pain, movement, memory
↑Depression
↓Alzheimer’s disease, Huntington’s disease, Parkinson’s disease
Acetylcholine (ACh)
(Cholinergic)
Inhibitory
Slow down body activity, reduces activity in neurons
↑Toxic levels - encephalopathy
↓Huntington’s disease, anxiety disorders, schizophrenia, and forms of epilepsy
Gamma-amino-butyric acid (GABA)
(Amino Acid)
Communicate sensory information
↑Huntington’s disease, forms of epilepsy, anxiety, depression
↓ Schizophrenia
Glutamate
(Amino Acid)
makes it’s own antidepressants, anxiolytics and hallucinogens
Brain
Therefore pharmaceuticals often ______ the brain’s natural neurotransmitters
mimic
Drugs act on a specific receptor site
The drugs chemical composition is similar to the neurotransmitter for that receptor
Psychopharmacologic Action
When attached to a receptor, the ____ can have one of two actions:
1. agonist
2. antagonist
drug
is the degree of strength in the bond between a drug and the receptor
Affinity
the ability of a drug to be specific to a certain receptor
Selectivity
ability of the drug to produce a biological response once attached to the receptor
Intrinsic Activity
Use of multiple medications
Polypharmacy
Leads to:
Greater complications
Diminished mental status
Increase in the risk-to-benefit ratio
Polypharmacy
*Maybe slowed
Decreased function of ventricles, intestines and the blood flow to intestines
ABSORPTION
*Decreased distribution of water soluble drugs
*Increased distribution of lipid soluble drugs
Increase in body fat due to aging
DISTRIBUTION
*Hepatic metabolism may be reduced
Decreased hepatic blood flow and liver mass
METABOLISM
*Renal elimination is reduced
Decreased glomerular filtrationrate
EXCRETION
affinity to water (water soluble)
Hydrophilic drugs
affinity to lipids (lipid soluble) – most meds stored in adipose tissue (as most meds are lipid soluble) Need to be lipid soluble to pass the B-Brain barrier
Lipophilic drugs
Take a thorough list of medications taken by the client (including OTC, herbal and prescription)
Assess clients’ ability for excretion (kidney function)
Assess clients ability for metabolism (liver function)
Assess therapeutic drug levels
Educate the client about potential drug interactions
Educate client about generic and trade names to prevent overmedication
Assess the clients adherence to medication
Provide client with medication administration aids
Prevention of Adverse Effects
Water soluble drugs are more diluted and therefore drug dosage requirements may increase.
Increased plasma volume and body water.
Increased cardiac output and increased blood flow to uterus, kidneys, skin and breasts.
ABSORPTION in Pregnant People
Fat soluble drugs more widely distributed and stay in the body longer.
Decreased capacity of drug binding
Increased weight and body fat
Decreased serum albumin
DISTRIBUTION in Pregnant People
Increased ________ and clearance of many drugs
Increased hormones (e.g. estrogen and progesterone) induce drug metabolizing hormones in the liver
METABOLISM in Pregnant People
Increased _______ of drugs by the kidneys
Decreased when women is supine
Increased renal blood glow and glomerular filtration
Renal blood flow may decrease when the woman assumes a supine position
EXCRETION in Pregnant People
Numerous medications also cause a _______ risk by crossing the placenta and are also secreted in breast milk
teratogenic
______is sensitive to drug effects because:
Size
Few plasma proteins that can bind drug molecules
Weak capacity for metabolizing and excreting drugs
Fetus
Molecular size, weight, and lipid solubility determine which substances (chemicals, drugs and antibodies) are readily _____ into the fetal circulation from the maternal circulation
absorbed
Difference in body composition
Immature systems
Genetic make up
Pharmacodynamic differences are caused by
Throughout ______ the effectiveness of drugs are also influenced by
Total body water
Fat stores
Protein amounts
childhood
Oral medications most likely will need to have dosage adjustments
IM medications should be avoided
Topical drugs have a higher rate of absorption
Age of the child, gastric emptying, and intestinal motility
Unpredictable absorption
Skin permeability
ABSORPTION in Pediatrics
Serum levels of highly protein-bound drugs may be higher in infants and toxicity may occur
Adverse effects of drugs that affect the CNS occur in neonates
Percentage of body water
Degree of protein binding
Development of blood brain barrier
DISTRIBUTION in Pediatrics
Drugs will either metabolize too quickly or too slowly
Immaturity level of liver in children and infants causes a difference in the metabolism of drugs
METABOLISM in Pediatrics
Drugs may stay in the system longer
Slower renal clearance
Reduced glomerular filtration rate
EXCRETION in Pediatrics
Who said these things?
Brain is a bag of chemicals - some imbalances in flavour profile
Create treatments that target the problem without causing side effects
Medications now address the entire brain - not a specific spot (not specific enough area that medication effects)
David Anderson
Post-Synaptic Effector Cell can be activated again by
- Reuptake
- Enzyme
