Pharmacology Flashcards
Name the SSRIs.
Fluoxetine Setraline Citalopram Escitalopram Paroxetine
What is the mechanism of action of the SSRIs?
Specifically inhibit serotonin reuptake at the pre-synaptic membrane, increasing the serotonin concentration in the synaptic cleft.
What are some advantages of using an SSRI over other types of anti-depressants?
Less sedating
Fewer anti-muscarinic effects
Lower risk of cardiotoxicity
Safer in overdose
What are some ADRs of SSRIs?
GI disturbances (nausea, vomiting, dyspepsia, diarrhoea, constipation, abdominal pain)
Altered appetite
Drowsiness OR insomnia
Sexual dysfunction
Name the TCAs.
Amitryptilline
Imipramine
Lofepramine
Nortryptilline
What is the mechanism of action of the TCAs?
Inhibit reuptake of serotonin and NA at the pre-synaptic membrane, increasing their concentrations in the synaptic cleft.
Also block serotonergic, alpha-adrenergicm histaminic and muscarinic receptors.
What are some ADRs of TCAs?
Sedation, weight gain, dry mouth, constipation, urinary retention, blurred vision, tachycardia, arrythmias, nausea, drowsiness.
What are the PK of TCAs? (absorption/metabolism)
Absorbed by the gut
Lipid soluble
Metabolised by the liver
What are the PK of SSRIs? (absorption/metabolism)
Almost completely absorbed from gut and metabolised by liver
Give an example of a NaSSA.
Mirtazapine
What is the mechanism of action of mirtazapine?
Enhances serotonin and NA neurotranmission.
Also classed as a TCA as well as a NaSSA
What are the indications for mirtazapine?
Severe depression, PTSD
What are some contra-indications for mirtazapine?
Renal impairment
Pregnancy
Hepatic impairment
Jaundice
What are the ADRs of mirtazapine?
Weight gain Sedation Hallucinations Confusion Mania Postural hypotension
Name the SNRIs.
Venlafaxine
Duloxetine
What is the mechanism of action of SNRIs?
Inhibit the re-uptake of serotonin and noradrenaline at the pre-synaptic membrane, increasing their concentration at the synaptic cleft.
What are the ADRs of SNRIs?
Same as SSRIs (GI disturbances, appetite changes, sleep disturbances)
PLUS increased BP, dry mouth, hyponatraemia
Name the MAOIs.
Isocarboxacid
Phenelzine
What is the mechanism of action of the MAOIs?
Inhibit the enzyme monoamine oxidase.
Prevents inactivation of monoamines (serotonin, NA, dopamine) within the neurone, causing excess neurotransmitter to diffuse into the synaptic cleft.
Why are MAOIs not often used?
Drug-food interactions -
MAOIs also inhibit the breakdown of tyramine, a chemical found in cheese. In excess, tyramine causes the release of large amounts of catecholamines, resulting in a hypertensive crisis.
What are the signs/symptoms of a hypertensive crisis?
HYPERTENSION Occipital headache Stiff neck Tachycardia Nausea Cardiac arrythmias Seizures Stroke
Name the typical antipsychotics.
Haloperidol
Chlorpromazine
Name the atypical antipsychotics.
Olanzapine Risperidone Clozapine Quetiapine Aripiprazole Paliperidone
What is the mechanism of action of antipsychotics?
Inhibition of the dopamine D2 receptors in the CNS (some have actions at other receptors as well)
What is the difference between the atypical and typical antipsychotics?
Atypical antipsychotics produce fewer EP signs and are more effective at treating the negative symptoms of schizophrenia.
What are the indications for clozapine?
Treatment resistant schizophrenia
- Failure of 2 antipsychotics
- One of which should be an atypical antipsychotic
- Over 6-8 weeks each
What are the side effects of clozapine?
AGRANULOCYTOSIS
(Requires regular haemotological monitoring)
Myocarditis
What are the side effects of typical antipsychotics?
Extrapyramidal signs:
dystonia, akathisia, Parkinson like symptoms (tremor, muscular rigidity, bradykinesia), tardive dyskinesia
What are the side effects of atypical antipsychotics?
Excessive weight gain (esp. olanzapine)
Increased prolactin secretion (risperidone)
EPSE (less common)
Postural hypotension
Cardiac toxicity (long QT syndrome and therefore increased risk of Torsades de Pointes)
What is the mechanism of action of the benzodiazepines?
Agonist at GABA-A receptors
GABA is the major inhibitory neurotransmitter in the CNS
What are the indications of benzos?
SHORT TERM use for anxiety disorders
Alcohol detoxification
What are the ADRs of benzos?
Drowsiness Light headedness Ataxia Confusion Amnesia
What are the indications for beta-blockers (in a psychiatric setting)?
Patients who have predominantly the somatic, autonomic symptoms of an anxiety disorder, e.g. tachycardia, tremor.
What is buspirone and what is it indicated for?
5-HT 1A agonist
Generalsed anxiety disorder (short term use only)
What are the contraindications of buspirone?
Epilepsy
Acute porphyria
What are the side effects of buspirone?
Light headedness
Dizziness
Nausea
What is the mechanism of the barbiturates?
Agonist of the GABA-A receptors (distinct binding site from the benzos)
What is the mechanism of action of pregabalin?
Inhibits glutamate, noradrenaline and substance P
What is pregabalin indicated in?
Generalised anxiety disorder
Neuropathic pain
What are some side effects of pregabalin?
Dizziness, drowsiness, blurred vision, diplopia, confusion, vivid dreams
Name the benzodiazepine antagonist.
Flumazenil
IV only
Name the hypnotic agents.
Zopiclone
Zolpidem
Zalepon
What is the mechanism of action of the hypnotic agents?
Act on the GABA-A complex
Name the acetylcholinesterase inhibitors.
Donepezil
Galantamine
Rivastigmine
What are the indications for acetylcholinesterase inhibitors?
Mild to moderate dementia related to Alzheimer’s disease
What are the side effects of acetylcholinesterase inhibitors?
Nausea, vomiting
Gastric and duodenal ulcers
Syncope
Bradycardia, AV block, MI
What are the contra-indications for acetylcholinesterase inhibitors?
Renal impairment (galantamine)
Cardiac disease
Peptic ulcer disease
Name the NMDA antagonist.
Memantine
What are the indications for memantine?
Moderate to severe dementia related to Alzheimer’s disease
What are the side effects of memantine?
Constipation Hypertension Seizures Dizziness Depression
What are the contra-indications of memantine?
Renal impairment
Seizure history
What is the mechanism of action of disulfiram?
Inhibition of acetaldehyde dehydrogenase.
If taken with alcohol, causes facial flushing, headache, palpitations, nausea and vomiting, etc.
What are the side effects of disulfiram?
Fatigue
Reduced libido
What are the contra-indications of disulfiram?
CVS disease
Hypertension
Previous CVA
Psychosis
What is the mechanism of acamprosate?
Reduces the conditioned aspects of drinking
Prevents craving induced relapses
What are the side effects of acamprosate?
GI disturbance
Rash
What are the contra-indications of acamprosate?
Severe hepatic/renal failure
Name the mood stabilisers.
Lithium, sodium valproate, lamotrigine, carbamazepine
What monitoring is required with sodium valproate?
Serum levels when indicated
Annual TFT
6 monthly LFT and FBC
What are some side effects of sodium valproate?
Tremor, sedation, GI disturbances, headache, thrombocytopenia, hair loss
What monitoring is required with carbamazepine?
6 monthly serum levels
LFTs, U&Es, FBCs and annual TFTs
What are some side effects of carbamazepine?
Dizziness, visual disturbances, hyponatremia, oedema, GI disturbances, rashes
What are some contra-indications of carbamazepine?
AV node abnormalities
History of bone marrow suppression
Acute porphyria
What monitoring is required with lithium?
Serum concentration after one week, then one week after every change in dose
(Serum level is aimed at 0.4-0.8 mmol/L)
6 monthly TFT and U&E
What are the indications for lithium?
Prophylaxis and treatment of mania, hypomania and depression in bipolar disorder
Prophylaxis and treatment of recurrent unipolar depression
What are the side effects of lithium?
Diabetes insipidus like syndrome, nausea/GI disturbances, weight gain, FINE tremor, leukocytosis, ECG changes, metallic taste in mouth.
What ECG changes may be seen with lithium?
Flattened T waves
Wide QRS complexes
What are some contra-indications for lithium?
Low sodium diet
Addison’s disease
Untreated hypothyroidism
Cardiac rhythm disorder
What are some signs of lithium toxicity?
COARSE tremor Ataxia Dysarthria Reduced level of consciousness Convulsions Coma
