Definition of pharmacology
= knowledge about drugs or medicines: the art of preparing medication. The science that deals with studying the
interactions between pharmacological substances and physiological processes.
● Effect on behavior
● Important to check if behaviors of clients are really because of behavior and not just side effects of
medication
● Mainly about the science: what happens on the neuronal and neurotransmission level?
● Pharmacon = latin word for medicine
● ‘Drug’: English meaning is ‘pharmacologically active substance (medication)’, but in Dutch it means
‘psychoactive substance for abuse which can lead to addiction’ → so we don't use the word drug
Classification
3 ways of classification. Based on:
1. Chemical structure: not very useful because the same structure can have different effects
2. Working mechanisms: ideal, but we don't truly know how medication actually works, or the theories
change, so also not very useful
3. Behavioral effects: easiest and best way to explain medication
Classification (in the literature)
ATC: Anatomical Therapeutic Chemical NbN: Neuroscience-based Nomenclature
● Based on behavior effect ● Based on working mechanisms
● Oldest (1976) ● Newer (2018)
● Indication based: the name is based on the ● Not recognized by clinical practice, WHO,
indication (the disorder) it is prescribed for scientific community
● Gold standard: WHO and scientific research ○ Lack of sufficient evidence
● What we use in this course, but in the book
they use NbN;
Antipsychotic medication Serotonin/dopamine antagonists with antipsychotic
actions
= not clear for the patiënt what they are getting
● Cons: ● Cons:
○ Stigmatization/patient adherence ○ We only partly know the working
○ Use for other than primary disorder mechanisms so there is a lack of
■ If people with anxiety have to scientific evidence
take antidepressants they feel ○ Not clear for patients what they are
like it doesn't suit them getting
■ But also if you have depression,
anxiety medication could work
too but patiënts maybe won't
believe that or look into that
,ATC Classification we will be focusing on
1. Antipsychotics: psychosis and schizophrenia
2. Antidepressants: mood
3. Anxiolytics: anti-anxiety
4. Mood stabilisers
Examples (don't learn them by heart)
Antipsychotics
1. Conventional antipsychotics = first used antipsychotics
a. ‘Typical’ side effects because they were the first side effects discovered
2. Atypical antipsychotics = new medication with side effects different from the first used antipsychotics,
which is why it is called atypical (‘atypical’ side effects)
Antidepressants: 3 main ways → will also be discussed in depression lecture
● Tricyclic → imperamine
● Selective serotonin reuptake inhibitors (ssri’s) → prozac
● Monoamine oxidase inhibitors (moai) → nardil
Anxiolytics
● Benzodiazepines → valium
● Non-benzodiazepines → buspirone
Mood stabilizers
● Lithium
Hypnotics: not relevant for this course
Other relevant drug classes
1. Anti-epileptics: benzodiazepines (also anti-anxiety), clonazepam, clorazepate
2. Stimulants: cocaine, amphetamine, caffeine, nicotine
3. Narcotic painkillers: opioids, morphine, codeine, heroin
a. Also used to lower anxiety levels
4. CNS suppressors
5. Psychedelics and hallucinogens: LSD, marijuana, hashish, mescaline, psilocybin
a. Mescaline (LSD): pro being not addictive, because it starts with vomiting and diarrhoea and
b. Often used for self medication
Administration
4 stages
1. Absorption: from site of administration into the bloodstream
2. Distribution: throughout the entire body mainly via blood stream and enters the tissues where it has an
effect
3. Metabolism: body does something with it = conversion
4. Excretion: breaking down the medication = elimination
,Ways to get medication inside body
1. Oral (pill)
a. Con: has to go through liver first where portion is metabolized before reaching bloodstream and
also GI degradatioin before absorption → higher dose needed because this eliminates 2/3d of the
medication
2. Rectal: takes away 1/3rd of the medication
3. Tropical (in one specific spot)
a. Often on the skin
i. Patches
b. Oral mucosa = moist inside of the mouth with a lot of blood vessels
i. ex. With migraine attacks because you want them to go away quickly
➔ Sublingual: under the tongue → blood vessels → bloodstream = very fast absorption
➔ Buccal: inside the cheek (between cheek and gum) → lining of cheek → bloodstream =
slower and sustained absorption
4. Parenteral (injection/infusion)
a. Intravenous: into the vein
i. Fastest way of administering drugs because it goes directly into the bloodstream
b. Intramuscular: into the muscle → gets into the bloodstream over a longer period of time
c. Subcutaneously: under the skin into fatty tissue
5. Inhalation: via mucosa
a. Example: asthma medication
Conclusion
● Quickest: tropical and parenteral (intravenous)
● Oral: easy, safer when expecting side effects (because it breaks down more and injection can be given
when medication is too much), but you lose a lot of effects of the medication
● When you want it localized: parenteral
○ If you don't want medicine to go through all the veins, for example with chemotherapy where this
could be highly toxic
○ But con: a very quick effect, so there needs to be saline so the veins can be flushed when
necessary
How medication is transported in the blood
Via albumin: protein in the blood plasma that binds to medication and acts as a transport protein
Distribution
1. Extracellular space: in the blood plasma → no immediate effect, because medication is in extracellular
space ‘in transit’ being transported to target the cells so it hasn't reached the site where it can act
2. Intracellular space:water in body cells → immediate effect because this is where medication needs to be to
work → therapeutic response
● Medication needs equal distribution between spaces to ensure adequate availability in the target area
without being overly concentrated in this area: so equal amounts in the extracellular as in the intracellular
,Speed of distribution (how quickly it gets to the place you want action) depends on lipid solubility (vet
oplosbaarheid) because the medication has to pass several membranes. Psychological medication has to pass
the blood-brain barrier
● The easier it goes over the membrane (= higher lipid solubility) the more intense and quicker the effect is
● Heroine has a higher lipid solubility → crosses the blood-brain barrier faster because it goed easier over
the membrane → more quick and intense effects → you need less medication to have a great effect
compared to for example morphine with a lower lipid solubility
Pharmacokinetics and pharmacodynamics
Pharmacokinetics (latin for movement)
= how does the body process the medication/ how does the drug move through the body? = change over time in
terms of concentration of medication and metabolites
● Metabolites = parts of the medication that have been broken down by the body
● Key processes: absorption, distribution, metabolism, excretion
● Goal: understand how long the drug stays in the body and at what levels
● Most important thing in pharmacokinetics: blood circulation
○ The entire blood circulation is about 1 minute which is why intravenous injection/infusion has a
quick effect
■ Because we have a lot of capillaries and every cell is very close to a capillary → compact
network which makes it possible for medication to registrate very fast
Pharmacodynamics
= how does the body respond to the medication/how does the medication affect the body?
● How does the medication work? What are the side effects? Relation between drug dose and its effect?
● Medication-receptor interaction = medication has to bind to a specific sight (receptor sight) → interaction
with this receptor → behavior response
○ Useful because if the body responds to the medication → therapeutic effect or a toxic effect with
too much medication
Pharmacokinetics Psychodynamics
How does medication move through the body How does body respond to medication
Paracetamol gets absorbed in the stomach, travels Paracetamol reduces pain and fever by blocking
through the bloodstream, broken down by the liver, chemicals in the brain
excreted in urine
● Subtherapeutic range: body notices
quickly that there is something in the
system but not enough for the desired
effect
● For a more continuous effect: always
give the medication in a therapeutic
range and not let it go down to the
subtherapeutic range because then the
effects are no longer optimal. You should
then take one dosage after the peak
, when it starts going down/being eliminated by the body
○ ADHD, antidepressants etc,
● Toxic range: too much medication
Time-concentration relation
= over time the concentration changes → has an effect on the behavior
1. Time 0: when you give the medication
a. Large peak in medication concentration in plasma
2. Decrease in medication concentration in plasma → leaves bloodstream and enters tissue
2 important half lives (time it takes for the medication to half)
1. Distribution half life: alpha phase = 100% to 50% of medication left in the plasma = how fast can it get to
the tissue to have an effect?
a. The other half of the medication is no longer in the bloodstream but in the tissue you want it to have
an effect on
b. How long it takes from the concentration to go from 100% to 50% in the bloodstream → 50% in the
tissue where it has effect → at this distribution half-life time the medication will start to have
effect
2. Elimination half life: beta phase = when 50% of the medication has been excreted by the body (kidney)
and degraded (liver) → no longer has an effect on the person's functioning = how fast can the action be
stopped?
a. So if the elimination half life is 1,5 hours→ after 1,5 hrs 50% of the medication is out of the body
b. It doesn't matter how much medication there is in the system, it will always take as long: when
going from 100 to 50 or 25 to 12,5 or 2 to 1
● All medication stops working after 6 elimination half lifes
● So if 1 half life is 1,5 hrs then after 6 half lifes (9 hours) you can say the medication is no longer having an
effect on the functioning of the person
○ If the elimination half life is 60 hrs you have to do 60 x 6 etc.
Neurotransmission - anatomy
3 most important parts
1. Cell body = soma