Drugs Flashcards
Gold risk in rheumatology
- myelosupression
- renal toxicity
- mouth ulcer
- photosensitivity
MAO inhibitors side effects
Hypertensive reaction to foods high in tyramine (cheese, processed meats…)
Drugs cause delirium
Labetalol risks
- hypoglycaemia
- bradycardia
Mechanism of ACE inhibitors
inhibits the conversion angiotensin I to angiotensin II
→ decrease in angiotensin II levels → to vasodilation and reduced blood pressure
→ decrease in angiotensin II levels → reduced stimulation for aldosterone release → decrease in sodium and water retention by the kidneys
renoprotective mechanism ACE inhibitors
angiotensin II constricts the efferent glomerular arterioles
ACE inhibitors therefore lead to dilation of the efferent arterioles → reduced glomerular capillary pressure → decreased mechanical stress on the delicate filtration barriers of the glomeruli
this is particularly important in diabetic nephropathy
How are ACE inhibitors are activated
phase 1 metabolism in the liver
Side effects of ACE inhibitors
- cough
- angioedema
- hyperkalmeia
- first dose hypotension
ACE inhibitors cautions and contradictions
pregnancy and breastfeeding - avoid
renovascular disease - may result in renal impairment
aortic stenosis - may result in hypotension
hereditary of idiopathic angioedema
specialist advice should be sought before starting ACE inhibitors in patients with a potassium >= 5.0 mmol/L
Interactions of ACE inhibitors
patients receiving high-dose diuretic therapy (more than 80 mg of furosemide a day)
significantly increases the risk of hypotension
Mechanism of Adenosine
causes transient heart block in the AV node
agonist of the A1 receptor in the atrioventricular node, which inhibits adenylyl cyclase thus reducing cAMP and causing hyperpolarization by increasing outward potassium flux
adenosine has a very short half-life of about 8-10 seconds
Adverse effects adenosine
chest pain
bronchospasm
transient flushing
can enhance conduction down accessory pathways, resulting in increased ventricular rate (e.g. WPW syndrome)
Contradictions of Adenosine
Asthmatics
Causes bronchospasm
Adenosine should ideally be infused
large-calibre cannula due to it’s short half-life,
Interactions of adenosine
dipyridamole (antiplatelet agent) and blocked by theophyllines.
Noticible adverse effects ADP receptor inhibitors
ticagrelor may cause dyspnoea
due to the impaired clearance of adenosine
Clopidogrel drug contradictions
clopidogrel and proton pump inhibitors, particularly omeprazole and esomeprazole, leading to reducing antiplatelet effects.
contraindications to prasugrel use.
prior stroke or transient ischaemic attack, high risk of bleeding, and prasugrel hypersensitivity are absolute contraindication
Salbutamol
- beta receptor agonist
- short-acting bronchodilator
- Relaxes bronchial smooth muscles through beta 2 receptors
Corticosteroids
- Anti-inflammatory
- used as maintenance therapy
Ipratropium
- Blocks the muscarinic acetylcholine receptors
- Short-acting inhaled bronchodilator. Relaxes bronchial smooth muscle
• Used primarily in COPD
• Tiotropium has similar effects but is long-acting
Methylxanthines (e.g. theophylline)
- Non-specific inhibitor of phosphodiesterase resulting in an increase in cAMP
- Given orally or intravenously
• Has a narrow therapeutic index
Monteleukast, zafirlukast
- Blocks leukotriene receptors
- Usually taken orally
• Useful in aspirin-induced asthma
Oxygen saturation targets
acutely ill patients
94-98%
Oxygen saturation targets patients at risk of hypercapnia (e.g. COPD patients)
88-92%
COPD management O2
prior to availability of blood gases, use a 28% Venturi mask at 4 l/min and aim for an oxygen saturation of 88-92% for patients with risk factors for hypercapnia but no prior history of respiratory acidosis
adjust target range to 94-98% if the pCO2 is normal
When not to use O2 therapy (no hypoxia present, but conditions diagnoses)
myocardial infarction and acute coronary syndromes
stroke
obstetric emergencies
anxiety-related hyperventilation
Theophylline poisoning
acidosis, hypokalaemia
vomiting
tachycardia, arrhythmias
seizures
Management of theophylline poisoning
- consider gastric lavage if <1 hour prior to ingestion
activated charcoal - whole-bowel irrigation can be performed if theophylline is sustained release form
charcoal haemoperfusion is preferable to haemodialysis
Potential mechanism of theophylline
theophyllines may be a non-specific inhibitor of phosphodiesterase resulting in an increase in cAMP. Other proposed mechanisms include antagonism of adenosine and prostaglandin inhibition
canakinumab
- monoclonal antibody targeted at IL-1 beta
- used systemic juvenile idiopathic arthritis and adult-onset Still’s disease
anakinra
- IL-1 receptor antagonist
- used in the management of rheumatoid arthritis
What are antipsychotics used for?
Management of schizophrenia, psychosis, mania, and agitation
How are antipsychotics categorized?
Typical and atypical antipsychotics
What is a key reason for the development of atypical antipsychotics?
To reduce extrapyramidal side effects associated with typical antipsychotics
What is the mechanism of action of typical antipsychotics?
Dopamine D2 receptor antagonists, blocking dopaminergic transmission
List common adverse effects of typical antipsychotics.
- Extrapyramidal side effects
- Hyperprolactinaemia
What are common examples of typical antipsychotics?
- Haloperidol
- Chlorpromazine
What are the common extrapyramidal side effects (EPSEs)?
- Parkinsonism
- Acute dystonia
- Akathisia
- Tardive dyskinesia
What is tardive dyskinesia?
Late onset of choreoathetoid movements, may occur in 40% of patients
What are the specific warnings for antipsychotics in elderly patients?
- Increased risk of stroke
- Increased risk of venous thromboembolism
What are common side effects of atypical antipsychotics?
- Weight gain
- Hyperprolactinaemia
- Agranulocytosis (in clozapine)
What is the first-line treatment for schizophrenia according to 2005 NICE guidelines?
Atypical antipsychotics
What is the primary action of benzodiazepines?
Enhance the effect of GABA by increasing the frequency of chloride channels
List the uses of benzodiazepines.
- Sedation
- Hypnotic
- Anxiolytic
- Anticonvulsant
- Muscle relaxant
What is the recommended duration for prescribing benzodiazepines?
Short period of time (2-4 weeks)
What is benzodiazepine withdrawal syndrome?
Condition similar to alcohol withdrawal syndrome with symptoms like insomnia and anxiety
What are common adverse effects of clozapine?
- Agranulocytosis
- Neutropaenia
- Seizures
- Constipation
- Myocarditis
What is the therapeutic range for lithium?
0.4-1.0 mmol/L
What are common adverse effects of lithium?
- Nausea/vomiting
- Fine tremor
- Nephrotoxicity
- Thyroid enlargement
- Weight gain
What should be monitored in patients on lithium therapy?
- Lithium levels
- Thyroid function
- Renal function
What are SSRIs primarily used for?
First-line treatment for depression
Name two preferred SSRIs.
- Citalopram
- Fluoxetine
What are common adverse effects of SSRIs?
- Gastrointestinal symptoms
- Increased risk of gastrointestinal bleeding
What are the risks associated with citalopram?
Dose-dependent QT interval prolongation
What is the mechanism of action for SNRIs?
Inhibit the reuptake of serotonin and noradrenaline
What are tricyclic antidepressants (TCAs) primarily used for?
Depression and neuropathic pain
What is a common low-dose TCA used for neuropathic pain?
Amitriptyline
What are Z drugs?
Drugs that have similar effects to benzodiazepines but act on the α2-subunit of the GABA receptor
List the groups of Z drugs.
- Imidazopyridines (e.g., zolpidem)
- Cyclopyrrolones (e.g., zopiclone)
- Pyrazolopyrimidines (e.g., zaleplon)
What are common adverse effects of Z drugs?
- Similar to benzodiazepines
- Increased risk of falls in the elderly
