Psychopharmacology Flashcards
pharmacodynamics meaning
how the drug affects the body. response of the drug
Pharmacokinetics meaning
the movement of drugs throughout the body
Pharmacokinetics involves the study of 4 things - what is it
absorption, distribution, metabolism and excretion of drugs
Factors Influencing Drug Effects
weight - the heavier the person generally the more drug they will need
age - primarily a factor with infants, children and older adults
gender - physiological differences between men and women can influence a drugs effect
physiological factors - hydration levels, electrolyte imbalance
pathological factors - disease, hepatic/renal/gastrointestinal dysfunction, vascular disorders, low blood pressure
genetic factors - there is a whole branch of pharmacology (Pharmacogenetics (see Bryant & Knights, 2011, p.147-155) dedicated to studying the unique responses to drugs based on genetic make-up
immunological factors - allergies
psychological factors - placebo effect, health beliefs, adherence
environmental factors - temperature, light, noise
drug tolerance - tolerance occurs when the initial dose of a substance loses its effectiveness over time because the body has got used to the drug
Categories of antipsychotics?
Typical and Atypical
Describe typical antipsychotics
are the older medications used to treat psychotic symptoms. Their main action is blocking dopaminergic receptors, however, growing evidence suggests that typical antipsychotics also affect other neurotransmitter systems. Typical antipsychotics are, therefore, essentially pharmacologically ‘dirty’ drugs and cause a wide variety of undesirable side-effects.
What are the Extrapyramidal side-effects (EPS) of Typical antipsychotics?
Parkinsonian symptoms; tremor, rigidity and brady-kinesia
Dystonia; sustained muscular conditions that produce abnormal postures (opisthotonos, torticollis), difficulty in swallowing and oculogyric crisis
Akathisia; a sense of inner restlessness, unrest or dysphonia. Restless movements, such as rocking from foot to foot, walking on the spot, shuffling and swinging one leg on the other while sitting.
Tardive dyskinesia (TD); is a late onset adverse effect, it is typified by involuntary hyperkinetic, choreo-athetoid movements of the orofacial, limb and truncal regions.
Atypical antipsychotics are considered
a major advance over typical antipsychotics, primarily because they are relatively free of extrapyramidal symptoms as they are more selective in targeting dopamine receptors and many also target serotonin receptors.
Another major advantage of atypical anti-psychotics is that they suppress the negative symptoms. The biggest problem with atypical anti-psychotics is the
increased risk of diabetes and metabolic syndrome.
Atypical antipsychotics. Metabolic syndrome includes
Metabolic syndrome includes weight gain, hypertriglyceridemia along with increased insulin, glucose, and low-density lipoprotein cholesterol levels. Metabolic syndrome is a serious health risk especially when people with schizophrenia and BPAD already have a genetic predisposition to developing diabetes
Common side-effects of all antipsychotics?
weight gain drowsiness constipation dizziness hypersalivation
Fairly common side-effects of all antipsychotics?
sexual dysfunction
postural hypotension
Rare but life threatening:
Agranulocytosis or Neutropenia (associated with Clozapine). What is this
low white blood cell count, therefore body is unable to fight infections. Requires careful monitoring, weekly blood tests for first 18 weeks of treatment, then monthly blood tests to monitor neutropils. Symptoms of concern - fever, rigor, sore throat, any signs of infection and cognitive changes. Person must be advised to contact doctor immediately if they develop any of these symptoms.
Neuroleptic Malignant Syndrome (NMS) (associated with all antipsychotics) -
usually occurs within a few weeks of a drug change, thought to be triggered by blockade of doperminergic receptors in the corpus straitum, resulting in spasticity of skeletal muscles (leading to excessive heat generation), and impaired hypothalmic thermoregulation.
Treatment to these effects?
stop the medication, treat the fever, hydrate, use benzodiazepines to relax the muscles
Commonly used antipsychotic medications. Name common TYPICAL antipsychotics
Chlorpromazine and Haloperidol
Commonly used antipsychotic medications. Name common ATYPICAL antipsychotics
Arpiprizole, Quetiapine, Clozapine
What information would you include in an education session for someone who is prescribed clozapine?
That they’ll need blood tests weekly for the first 18 weeks and Symptoms of concern - fever, rigor, sore throat, any signs of infection and cognitive changes. Person must be advised to contact doctor immediately if they develop any of these symptoms.
ANTIDEPRESSANTS. You need to know about the three main catergories of antidepressants, these are: there are THREE
Selective serotonin reuptake inhibitors (SSRIs) and related drugs, Tricyclic antidepressants (TCAs), Monoamine oxidase inhibitors (MAOIs)
Which antidepressant is First line treatment for depression as have less side-effects
Selective serotonin reuptake inhibitors (SSRIs) and related drugs
Describe the action and pharmacokinetics of Selective serotonin reuptake inhibitors (SSRIs) and related drugs
Action: SSRIs block the reuptake of serotonin (5HT) leading to increased neurotransmitter levels in the synaptic cleft and increased stimulation of the postsynaptic receptors.
Pharmacokinetics: They are well absorbed from the gastrointestinal (GI) tract, are metabolised in the liver and excreted in urine and feaces. They are able to cross the placenta and enter breast milk.
Selective serotonin reuptake inhibitors (SSRIs) and related drugs Side-effects: name common and uncommon
Common: drowsiness, insomnia, sexual dsyfunction, nausea and vomiting
Uncommon: bruising, dizziness, headache
SSRI’s Rare (but potentially life-threatening) side effects? Serotonin syndrome
Symptom onset is usually rapid, often occurring within minutes and is potentially life-threatening. It may occur following therapeutic drug use, interactions between drugs, overdose of particular drugs, or the recreational use of certain drugs.
Mild symptoms - increased heart rate, shivering, sweating, dilated pupils, myoclonus (intermittent tremor or twitching), as well as overresponsive reflexes.
Moderate symptoms - hyperactive bowel sounds, high blood pressure, fever, hypervigilance and agitation
Examples of SSRIs and related drugs:
Citalopram (Celexa)
Paroxetine (Paxil, Seroxat)
Fluoxetine (Prozac)
Sertraline (Zoloft, Lustral)
