5- Psychoactive Drugs Flashcards
5 types of drugs that act on the dopamine system
L-DOPA
Antipsychotic drugs
Recreational drugs
Cocaine
Amphetamine
What does L-DOPA treat?
Parkinson’s disease
What is Parkinson’s caused by?
A loss of dopamine neurons
What do Parkinson’s patients have difficulty doing?
Initiating movements
How does L-DOPA treat Parkinson’s?
Compensates for the loss of neurons
What can L-DOPA do to make dopamine?
Cross the blood-brain barrier and enzymes in neurons convert precursor to dopamine
How does L-DOPA cause relief from Parkinson’s symptoms?
It increases in the brain
What side effects are common with L-DOPA?
Hallucinations, delusions, other psychotic symptoms
What do antipsychotic drugs treat?
Psychotic disorders
What is schizophrenia caused by?
An excess of dopamine- thought to be an excess of mesolimbic dopamine
How do antipsychotic drugs operate?
By interfering with dopamine receptors in the brain- acting as blockers
What receptor do antipsychotic drugs block?
D2
What do antipsychotic drugs reduce operation of?
The dopamine system
What does antipsychotic drugs efficacy hinge on?
Ability to bind to a D2 receptor
What is the side effect of antipsychotic drugs often binding to nigrostriatal pathways by mistake?
Can affect motor functions- very similar to Parkinson’s disease
Why is dopamine implicated in recreational drugs?
Dopamine is involved in producing reward and pleasure
What was cocaine previously used as?
As mental illness treatment and a coca-cola ingredient
When and why was cocaine banned?
In 1922 because people became aware of harmful effects
Short-term effects of cocaine use (7 points)
- Increased energy levels
- Decreased appetite
- Mental alertness
- Increased heart rate and blood pressure
- Constricted blood vessels
- Increased temperature
- Dilated pupils
Long-term effects of cocaine use (5 points)
- High risk of addiction
- Irritability and mood disturbances
- Restlessness
- Paranoia
- Auditory hallucinations
Medical consequences of cocaine use (4 points)
- Cardiovascular (disturbances in heart rhythms, heart attacks)
- Respiratory (chest pain, respiratory failure)
- Neurological (strokes, seizures, headaches)
- Gastrointestinal (abdominal pain, nausea)
How does cocaine increase dopamine levels?
By inhibiting reuptake
What happens when cocaine blocks the transporter opening?
It closes the passage and prevents the transporter from doing its job so dopamine remains high in the synapse
What are amphetamine effects similar to?
Cocaine effects
Amphetamine effects at low doses (7 points)
- Energised and attentive
- Mood improvement
- Reduced appetite
- Increased wakefulness
- Improved reaction time
- Fatigue resistance
- Increased muscle strength
Amphetamine effects at higher doses (3 points)
- Risk of psychosis
- Addiction
- Risk of seizure, stroke, coma, heart attack
What are amphetamines prescribed for?
ADHD, narcolepsy, obesity, depression
Why are amphetamines rarely prescribed now?
As there is a high risk of harm
What do amphetamines cause the neuron to do?
Release more dopamine
What do amphetamines disrupt?
Storage of dopamine into vesicles
With amphetamines, dopamine is released without…
Triggering an action potential
What is the difference between amphetamines and cocaine?
Amphetamines are less euphoric but more stimulating than cocaine
How are amphetamines similar to cocaine? (2 points)
- Increased dopamine signalling in the mesolimbic pathway
- Increased dopamine in the nigrostriatal pathway leads to enhanced basal ganglia and thalamic activity
3 types of drugs that act on the serotonin system
- Selective serotonin reuptake inhibitors (SSRIs)
- MDMA (ectasy)
- Hallucinogens
Example of an SSRI
Prozac