neuropharmacology

Question 1

what is depression caused by

Answer 1

• Chronic stress
• Sleep deprivation
• Alcohol
• Illicit drugs
• Beta blockers- common - side effect of this drug
• Relationship difficulties or loss of significant other
• Work or financial worries
• Aging
• Illness

Question 2

what are the 5 groups of antidepressants and their mechanism of action

Answer 2

!! 1. Selective serotonin reuptake inhibitors SSRIs e.g fluoxetine
- Block the reuptake of serotonin from the synapse
- Less CV effects and less problem with weight gain, no food reactions, less acute toxicity
- Causes nausea, anorexia, tremors and insomnia which will reduce over time, ‘washout period’ required, may cause inappropriate ADH secretion, can result in serotonin syndrome when combined with MAOIs

2. serotonin/ norepinephrine reuptake inhibitors SNRIs
3. Tricyclic antidepressants TCAs
   - Act by inhibiting the reuptake of noradrenaline into nerve terminals. This makes more of the neurotransmitter available in the synaptic cleft and it makes people feel better
   - Side effects are dry mouth, urinary retention, constipation, sedation, postural hypotension
   - Dangerous in acute overdose and can cause cardiac dysrythmias, confusion and mania
4. Monomine oxidase inhibitors MAOIs
   - In neurons MAO they inactivate any excess neurotransmitters that may have leaked out of the neuron. This stops the mopping up of neurotransmitters and causes them to hang around in the synapse which makes people feel better
   - Very food limiting
   - Side effects are hypotension, mania, tremors, antimuscarinic
5. Atypical antidepressants

Question 3

lithium

Answer 3

• Used for bipolar disorder and its action is to keep moods stable
• Causes nausea, anorexia, vomiting, diarrhoea, thirst, weakness, mental confusion
• it increased glutamene in the postsynaptic neuron

Question 4

!! benzodiazepines

Answer 4

• Most important class of anxiolytic e.g diazepam
• They bind to a specific site on GABA receptors in the brain and this enhances their response to the inhibitor transmitter GABA- makes more hang around in the synapse
• It effectively inhibit the transmission of nerve impulses in the CNS

Clinical uses of BZDs
- reduction in anxiety and aggression
- Sedation
- Muscle relaxation
- Alcohol withdrawal

• main disadvantage are the long lasting hangover effects