Drugs list

Question 1

What is the action and some features of amitriptyline?

Answer 1

• Tricyclic antidepressant.
• Nonspecific monoamine reuptake inhibitor, most importantly SERT and NET.
• Rarely used nowadays as severe side-effects due to nonspecificity. H1 - sedation M3 - dry mouth, constipation.
• Cardiotoxic. Previous MCI or history of arrhythmia is major contraindiction.

Question 2

What is the action and some features of aspirin?

Answer 2

• In the context of neuroscience, involved in pain relief
• Cyclooxygenase I and II non-competitive, irreversible inhibitor, acetylates them.
• Reduces synthesis of prostaglandins, reduces inflammation.
  
  • Prostaglandins sensitise C-fibre pain neurons so aspirin reduces inflammatory pain. NSAID.
• As a NSAID, used in chronic inflammatory diseases such as rheumatoid arthritis.
• Causes ototoxicity at high doses.
• Low doses: mild indigestion, risk of bleeding

Bold are related to neuro

Question 3

What is the action and some features of buspirone?

Answer 3

• 5-HT1A receptor agonist. Used as an anxiolytic.
• Agonist of the 5-HT1 receptor on the pre-synaptic membrane, leading to decreased 5-HT release

Question 4

What is the action and some features of carbamazepine?

Answer 4

• Inhibitor of VGNaC.
• Preferentially binds to inactive form so inhibits repetitive and sustained firing. Used in epilepsy as an anticonvulsant.
• [EXTRA] Used to treat trigeminal neuralgia.
• Side-effects: nausea, drowsiness.

Question 5

What is the action and some features of chlorpromazine?

Answer 5

• 1st gen/typical antipsychotic, also known as a neuroleptic.
• D2 antagonist. Used as an antipsychotic in psychoses such as schizophrenia.
• Only treats positive symptoms.
• Side-effects: movement problems ( tardive dyskinesia is severe, rare example, also acute muscle stiffness and Parkinsonism), sleepiness, considerable weight gain, hypotension & dizziness

Question 6

What is the action and some features of clozapine?

Answer 6

• Atypical antipsychotic. Works as a D2 antagonist but is also pretty non-specific, acts at many other receptors.
• Very effective, works in 1/3 of patients non-responsive to other treatments.
• Fewer extrapyramidal movmenet disorder side-effects than typical antipsychotics. But limited by non-specificity and toxicity eg. bone marrow toxicity

Question 7

What is the action and some features of codeine?

Answer 7

• Opioid used as an analgesic.
• Acts centrally at the µ opioid receptor, inhibits transmission of nociceptive information in the spinal cord as well as causing analgesia by acting directly on the brain eg. PAG.
• Causes constipation, itchiness and nausea. Addictive - dependence issues.

Question 8

What is the action and some features of cyclopentolate?

Answer 8

• Muscarinic antagonist.
• Used in paediatric eye examination as eyedrop to dilate the pupil and prevent accommodation.

Question 9

What is the action and some features of diazepam?

Answer 9

• Benzodiazepine
• Binds to specific binding site on GABA_A channel. Increases open probability when GABA bound, so potentiates GABA transmission - positive allosteric modulator.
• Used as an anxiolytic.
• Used acutely for status epilepticus (single seizure lasting more than five minutes or two or more seizures within a five-minute period without the person returning to normal between them).
• Used as a sedative and to reduce anxiety before surgery, and as a sedative in ICUs

Question 10

What is the action and some features of fluoxetine (Prozac)?

Answer 10

• Antidepressant of the SSRI class.
• Used to treat major depressive disorder, OCD and panic disorder.
• Can lead to dependence, withdrawal.
• Side effects:
  
  • Insomnia
  • GI disturbance
  • Sexual dysfunction
  • Withdrawal effects (emerging evidence)
• [EXTRA] -> Paradoxically increase the concentration of 5-HT in the synapse, which should be anxiogenic, but they are also proposed to decrease the sensitivity of 5-HT2C receptors on the post-synaptic membrane of certain synapses. Thus, they have anxiolytic effects in some parts of the brain, despite increasing 5-HT

Question 11

What is the action and some features of furosemide relevant to neuroscience?

Answer 11

• Loop diuretic. Inhibits NKCC.
• Ototoxic in high doses.
• Treat hypertension but thiazide diuretics are more commonly used.
  
  • May be used when tolerance is mounted against thiazides so a stronger diuresis is needed.
• Treatment of congestive heart failure - relief of oedema by fluid loss and vasodilation. However, reducing circulating volume activates SNS and RAAS, increasing myocardial O2 demand and worsening problem.
• Electrolyte disturbances also increase risk of MCI.
• Now rarely used, apart from one-off injection for acute pulmonary oedema after MCI.
• Side-effects: hypokalcaemia, metabolic alkalosis, hypocalcaemia, hyperuricaemia

Question 12

What is the action and some features of gentamicin relevant to neuroscience?

Answer 12

• Antibiotic of the aminoglycoside class.
• Acts at 30s subunit to inhibit translation initiation.
• Like all aminoglycosides, is ototoxic.

Question 13

What is the action and some features of haloperidol?

Answer 13

• 1st gen/typical antipsychotic, also known as a neuroleptic.
• D2 antagonist. Used as an antipsychotic in psychoses such as schizophrenia, and to treat tics in Tourette’s.
• Also used in Huntington’s (improves chorea symptoms)
• Side-effects: movement problems ( tardive dyskinesia is severe, rare example, also acute muscle stiffness and Parkinsonism), sleepiness, considerable weight gain, hypotension & dizziness

Question 14

What is the action and some features of ibuprofen?

Answer 14

• Cyclooxygenase I and II reversible, competitive inhibitor.
• Reduces synthesis of prostaglandins, reduces inflammation. Prostaglandins sensitise C-fibre pain neurons so aspirin reduces inflammatory pain. NSAID.
• Given after surgical procedures or even preemptively to reduce pain.
• Side-effects: risk of GI bleeding, rash, gastric reflux

Question 15

What is the action and some features of isoflurane?

Answer 15

• Inhaled general anaesthetic. Lipophilic.
• Hypothesised to act by altering membrane fluidity, and binding to and affecting intramembranous portions of ion channels.
• Mostly used for maintenance of anaesthesia.
• Side-effects:
  
  • Sensitises heart to adrenaline - arrhythmia
  • Respiratory depressant
  • Reduces MAP

Question 16

What is the action and some features of L-DOPA?

Answer 16

• Used to treat Parkinson’s disease. Can cross BBB and is converted into dopamine there.
• Given with carbidopa (peripheral DOPA decarboxylase inhibitor) to prevent excessive adrenaline and noradrenaline production in the periphery.
• After about 5 years:
  
  • Sudden on/off effects, gait freezing
  • Dyskinesias (intense whole-body writhing)

Question 17

What is the action and some features of lamotrigine?

Answer 17

*Used to manage chronic epilepsy.
* Inhibits the release of glutamate, and inhibits voltage-sensitive Na+ channels to stabilise neuronal membranes.

Question 18

What is the action and some features of lithium?

Answer 18

• Used as a mood stabiliser. Used for bipolar disorder, or major depressive disorder that does not respond to other treatments.
• Inhibits inositol monophosphatase - overactive phosphatidylinositol cycle thought to at least partially underlie bipolar disorder
• Narrow therapeutic index
• Common side-effects:
  • Nausea, vomiting
  • Headache
  • Dry mouth/metallic taste in mouth
  • Hand tremors
  • Hypothyroidism
  • Increased thirst and urination
  • Renal damage

Question 19

What is the action and some features of NSAIDs?

Answer 19

• Class of drugs which inhibit COX. Inhibit synthesis of lipid mediators of inflammation - prostaglandins, leukotrienes, PAF. Reduce inflammation and oedema.
• Prostaglandins sensitise C-fibre pain neurons, so NSAIDs reduce inflammatory pain.
  
  • Sensitise the nociceptive nerves to excitation by increasing the likelihood of opening of voltage-gated sodium channels
• Cannot be used to treat neuropathic pain
• Downsides of NSAID use:
  
  • COX-1 is constitutively active (eg. produces prostaglandins to support the gastric mucosa) while COX-2 is activated by inflammation
  • Thus, COX-2 selective inhibitors (celecoxib) were developed as analgesics to avoid peptic ulcers associated with NSAID treatment
  • But there is current concern over cardiovascular harm associated with COX-2 inhibition (Vioxx controversy)
• Contraindicated in patients with peptic ulcers - if used for pain relief, can increase severity of peptic ulcers

Question 20

What is the action and some features of nicotine?

Answer 20

• Agonist of nicotinic acetylcholine receptors.
• Stimulant at low doses, sedative at increasing doses. Anxiolytic properties.
• Highly addictive (stimulates dopamine release)

Question 21

What is the action and some features of phenelzine?

Answer 21

• Monoamine oxidase inhibitor, irreversible.
• Used as an antidepressant, appears to work by increasing synaptic concentration of serotonin and noradrenaline.

Question 22

What is the action and some features of phenytoin?

Answer 22

• Voltage-dependent inhibition of VGNaC, preventing rapid, high-frequency firing.
• Used to treat status epilepticus acutely, or chronically to prevent seizures occurring.
• Side-effects include nausea, stomach pain and loss of coordination.

Question 23

What is the action and some features of propofol?

Answer 23

• Intravenous general anaesthetic.
• Acts by potentiating GABA_A receptors. Prinicpally works as a hypnotic, so requires analgesics (opoids) and muscle relaxants.
• Most commonly used induction agent by far.

Question 24

What is the action and some features of propranolol relevant to neuroscience?

Answer 24

• Nonspecific β-adrenergic antagonist.
• Used as an anxiolytic.
• Used in heart failure. This is to reduce sympathetic drive to reduce myocardial oxygen consumption.
  Also reduce RAAS activation - reduce peripheral vasoconstriction, reduce afterload.
• Contraindictions - asthma, as it is a β2-antagonist so exacerbates bronchoconstriction, but observations and studies have found that their use does not precipitate asthma attacks

Question 25

What is the action and some features of sumatriptan?

Answer 25

• 5-HT1 agonist. Inhibits release of CGRP, which sensitises trigeminal nociceptive neurons.
• Used to treat migraine.

Question 26

What is the action and some features of temazepam?

Answer 26

• Binds to specific binding site on GABA_A channel.
• Increases open probability when GABA bound, so potentiates GABA transmission - positive allosteric modulator.
• Used as a hypnotic to treat insomnia.
• Used as a sedative and to reduce anxiety before surgery, and as a sedative in ICUs.

Question 27

What is the action and some features of tetrabenazine?

Answer 27

*An anti-dopaminergic used in the treatment of Huntington’s Disease.
*It is a reversible human vesicular monoamine transporter type 2 inhibitor, acting w/in the basal ganglia.

Question 28

What is the action and some features of tramadol?

Answer 28

• Opioid used as an analgesic.
• Acts centrally at the µ opioid receptor, inhibits transmission of nociceptive information in the spinal cord as well as causing analgesia by acting directly on the brain eg. PAG.
• Causes constipation, itchiness and nausea. Addictive - dependence issues.

Question 29

What is the action and some features of valproate?

Answer 29

• Mechanism of action unclear - may be by blocking VGNaC and increasing brain GABA levels.
• Inhibits GABA breakdown
• Used for chronic management of epilepsy, and for treating manic episodes in bipolar disorder.
• Side-effects: nausea, drowsiness, dizziness, hepatotoxicity.
• Causes birth defects, particularly spina bifida; must not be taken in pregnancy.

Question 30

What is the action and some features of venlafaxine?

Answer 30

• Serotonin-noradrenaline reuptake inhibitor (SNRI).
• Increases synaptic serotonin and noradrenaline concentrations.
• Used to treat major depressive disorder and various anxiety disorders.