Drugs - CNS Flashcards
Diazepam/Lorazepam
Benzodiazepine (Anxiolytic)
Allosteric modulator of GABA-A receptors
Increased inhibitory effect of GABA, acts on limbic system, thalamus, hypothalamus and cortex, calming effect
Uses: Anxiety, Alcohol withdrawal, muscle spasms, seizures/epilepsy
ADRs: Sleepiness, loss of co-ordination, tolerance, depression
Haloperidol
Typical antipsychotic
High Dopamine D2 receptor antagonism
Uses: Schizophrenia, tourettes
ADRs: Tardive dyskinesia (possibly permanent), Neuroleptic malignant syndrome (muscle rigidity, fever, delerium, autonomic instability), Long Q-T
Chlorpromazine
Typical antipsychotic
D1, 2, 3, 5 receptor antagonist 5HT-1/2 receptor antagonist H1 Histamine receptor antagonist Alpha 1/2 receptor antagonist M1/2 muscarinic antagonist
Treats: Schizophrenia, Bipolar, ADHD, nausea, vomiting
ADRs: Movement problems (e.g. tardive), sleepiness, dry mouth, orthostatic hypertension, neuroleptic malignant syndrome
Olanzapine
Atypical antipsychotic
5HT2A + D2 receptor antagonist
Uses: Schizophrenia, Bipolar, Anxiety, PTSD
ADRs: Weight gain, Extrapyramidal (tremors, muscle rigidity), paradoxical reactions
Risperidone
Atypical antipsychotic
5HT2A, 5HT7, D2, Alpha 1/2 antagonist
Uses: Schizophrenia, bipolar, irritability in autism
ADRs: Movement problems (e.g. tardive, less likely than typicals), neuroleptic malignant syndrome, sleepiness, constipation, weight gain
Quetiapine
Atypical antipsychotic
Dopamine, serotonin and andrenergic antagonist
Uses: Schizophrenia, Bipolar, Major depressive disorder
ADRs: Dry mouth, Dizziness, Headaches, Hypertension, Orthostatic hypotension, Weight gain, Movement issues (tardive, tremor), NMS
Clozapine
Atypical antipsychotic
Dopamine, serotonin, histamine, adrenergic, muscarinic antagonist
Uses: Schizophrenia, bipolar etc. Those intolerant to other anti-psychotics
ADRs: Constipation, muscle stiffness, sedation, tremores, hypotension, weight gain, Extrapyramidal: tardive
Agranulocytosis, leukopenia, neutropenia, seizures, dementia
Valproic acid
Anti-mania
Not fully understood, reduces seizure induced reduction in PIP3, blockage of voltage gated sodium channels and increased GABA levels
Treats: Epilepsy, Mania (bipolar), Migranes
ADRs: Nausea, Drowsiness, Dizziness, Vomiting, Weakness, Bleeding, Encephalopathy, Suicidal ideation
Lithium salts
Anti-mania
Unknown, increased serotonin? Interactions with NO and hence neuronal plasticity?
Uses: Bipolar, MDD, Schizophrenia
ADRs: Confusion, constipation, Headache, Myoclonus, Hand tremor, Weight gain, Extrapyramidal (muscle rigidity, parkinsonism, dsytonia), Hypothyroidism
Imipramine
TCA
Serotonin reuptake inhibiton
Noradrenaline reuptake inhibition
Dopamine reuptake inhibition
Treats: MDD
ADRs: CNS (dizziness, drowsiness, seizures, extrapyramidal), CVS (orthostatic hypotension, tachycardia, dysrhythmia), GI (Dry mouth, paralytic ileus, increased appetite, hepatitis)
Citalopram/Fluoxetine/Sertraline
SSRI
Serotonin reuptake inhibitor
Uses: MDD, depression, Panic disorder, anxiety, OCD, Bulimia
ADRs: Sexual dysfunction (lack of arousal, erection, orgasm), drowsiness, insomnia, nausea, weight gain, sweating, BP changes
ADRs particularly prevalent with sertraline
Venlaxafine
SNRI
Serotonin noradrenaline reuptake inhibitor
Uses: MDD, Anxiety, Panic disorder, social phobia
ADRs: Suicide, Severe withdrawal, headache, nausea, insomnia, asthenia, dizziness, Sexual side effects (lack of arousal/orgasm)
Orlistat
Anti-obesity
Inhibitor of gastric and pancreatic lipases
Uses: Obesity
ADRs: Steatorrhoea, flatus excessivus, fecal incontinence, frequency
Cyclizine
H1 antagonist (anti-emetic)
May have effects on the labrynthine apparatus
Uses: Treat nuasea, vomiting, motion sickness, vertigo (post op following opiods and general anaesthesia)
ADRs: Drowsiness, xerostomia, headache, diplopia, dermatitis, urinary retention
Metoclopramide
D2 receptor antagonist
Inhibition of D2 receptors in the chemoreceptor trigger zone in the CNS
Uses: Nausea (post op and chemo related)
ADRs: Restlessness, focal dystonia, hypertension, hypotension, constipation, depression, headache, extrapyramidal, hyperprolactinaemia (male –> low libido, erectile dysfunction. Female –> mammoplasia, mastodynia, galactorrhoea, amenorrhoea)
Domperidone
D2/3 antagonist (peripherally selective)
Blocks actions of dopamine in the central nervous system’s chemoreceptor trigger zone
Uses: Nausea, gastroparesis (delayed stomach emptying (idiopathic))
ADRs: QT prolongation / sudden cardiac death, hyperprolactinaemia (male –> low libido, erectile dysfunction. Female –> mammoplasia, mastodynia, galactorrhoea, amenorrhoea)
Odansetron
5HT3 antagonist
Chemoreceptor trigger zone receptor inhibition, Enterochromaffin cells in the small intestine serotonin release inhibition (response to serotonin may be vomiting reflex)
Uses; Nausea (post-op, chemo), morning sickness
ADRs: Constipation, dizziness, headache, QT prolongation/SCD,
Paracetamol
NOAD (non-steroidal analgesic drug)
Not fully understood, assumed COX2 inhibitor without anti-inflammatory action
Uses: Pain, Fever
ADRs: Liver damage
Morphine/Codeine
Opiate
mu opioid receptor agonist, mimicking the action of endogenous endorphins, enkephalins and dynorphins (analgesia)
Uses: Pain killing (mild to moderate for codeine, moderate to sever for morphine)
ADRs: Respiratory depression, nausea, vomiting, habituation
Codeine = prodrug form of morphine, converted to morphine in first pass.
Tramadol
Opioid
mu-opioid receptor agonist, mimicking the action of endogenous endorphins, enkephalins and dynorphins
(analgesia)
Uses: Mild to severe pain (less effective for severe pain than morphine)
ADRs: Respiratory depression, nausea, vomiting, habituation
Carbamepazine
Anti-epileptic
Stabilises the inactivated state of voltage gated Na channels, affected cells are less excitable. Also a GABA agonist, enhancing the effects of inhibitory nerve impulses.
Uses: Epilepsy, neuropathic pain, (bipolar and schizophrenia (off label))
ADRs: Drowsiness,m dizziness, headaches, motor coordination impairment, CNS depression
Lamotrigine
Anti-epileptic/Anti-convulsant (Voltage gated sodium channel blocker)
Blocks Nav channels as well as L, N, P type Ca2+ channels. This is thought to reduce glutamatergic activity in projections to the ventral striatum and limbic areas
Uses: Epilepsy (focal, tonic clonic), bipolar
ADRs: Severe skin reactions (toxic epidermal necrosis), rash, aseptic meningitis, double vision, pupil constriction, lack of coordination, anxiety, cough, nausea
Phenytoin
Anti-seizure (Nav blocker)
Voltage dependent blocker of voltage gated sodium channels, enhancing the inactivation state stability
Uses: Seizures (tonic-clonic, focal, absence, status elepticus), VTach, ATach
ADRs: Severe hypotension, arrhythmias, nystagmus, double vision, sedation, reduction in folic acid in plasma, teratogenic
Apomorphine
Non-selective dopamine agonist
D1 and D2 agonist
Uses: Alcohol and morphine adiction, Parkinsons (induce ‘on periods’), ED
ADRs: Potent emetic
