Pharmacology - Examples Flashcards
How is Type 2 diabetes typically managed in adults?
Lifestyle modification
If HbA1c > 48 mmol/mol, standard dose metformin
If HbA1c > 58 mmol/mol, metformin with one of DD-4 inhibitor, pioglitazone, sulphonylurea or SGLT-2 inhibitor
If HbA1c > 58 mmol/mol (second intensification), consider insulin or triple therapy
How does metformin work?
Metformin is used to treat diabetes by activating 5’-AMP-activated protein kinase (AMPK) in hepatocyte mitochondria. This inhibits ATP production, blocks gluconeogenesis and HGO. It also blocks adenylate cyclase (promotes fat oxidation).
What are the side effects of metformin? How are they mitigated?
Abdominal pain, decreased appetite, diarrhoea, vomiting
Gradual introduction helps with tolerability
What is an example of a DPP-4 inhibitor?
Sitagliptin
How do DPP-4 inhibitors work?
Diabetes management:
They inhibit the action of DPP-4. This enzyme is present in vascular endothelium and can metabolise incretins in the plasma. Incretins help stimulate the production of insulin, reduce production of glucagon, slow down digestion and decrease appetite.
What are the side effects of DPP-4 inhibitors?
Upper respiratory tract infections (5% of patients)
Flu-like symptoms e.g. headache, runny nose, sore throat
Serious allergic reactions/ avoid in patients with pancreatitis
How do sulphonylurea work?
Diabetes management:
Inhibit the ATP-sensitive potassium (KATP) channel on the pancreatic beta cell. This channel controls beta cell membrane potential. Inhibition causes depolarisation which stimulates Ca2+ influx and subsequent insulin vesicle exocytosis.
What are the side effects of sulphonylurea?
Weight gain
Hypoglycaemia (should be discussed with patient)
What is an example of a SGLT2 inhibitor?
Dapagliflozin
How do SGLT2 inhibitors work?
Diabetes manegement:
Reversibly inhibits sodium-glucose co-transporter 2 (SGLT2) in the renal proximal convoluted tubule to reduce glucose reabsorption and increase urinary glucose excretion.
What are the side effects of SGLT2 inhibitors?
Uro-genital infections due to increased glucose load (5% of patients)
Slight decrease in bone formation
Can worsen diabetic ketoacidosis (stop immediately)
Weight loss
Reduction in BP
What are the different types of seizures?
Absence Focal Generalised tonic-clonic Myoclonic Tonic/atonic
What is the diagnostic approach to determining the type of seizure?
EEG
What is the most commonly prescribed drug for individuals without child-bearing potential suffering from seizures?
Sodium valproate
How does lamotrigine work?
Seizure management:
Blocks voltage gated Na+ channels preventing Na+ influx. Prevents depolarisation of glutamatergic neurones and reduces glutamate excitotoxicity.
What are the side effects of lamotrigine?
Rash (can be avoided by gradual administration)
Drowsiness
Steven-Johnson’s syndrome (less common)
Suicidal thoughts (less common)
How does sodium valproate work?
Seizure management:
Inhibition of GABA transaminase prevents the breakdown of GABA. This increases GABA concentrations directly in the synapse presynaptically and also indirectly prolongs GABA in the synapse due to the fact that extra neuronal metabolism of GABA is slowed.
What are the side effects of sodium valproate?
Stomach pain and diarrhoea Drowsiness Weight gain Hair loss Hepatotoxicity Teratogenicity Pancreatitis
Why is sodium valproate contraindicated for those with child-bearing potential?
Neural tube defects, decreased IQ and autism after in utero exposure
How do diazepams work?
Seizure management:
Increases chloride ion influx in response to GABA binding at the GABAA receptor. Increased chloride ion influx associated with hyperpolarization of excitatory neurons.
What are the side effects of diazepams?
Drowsiness
Respiratory depression (if I.V. or at high dose)
Haemolytic anaemia (uncommon)
Jaundice (uncommon)
Why are diazepams not used for long-term suppression?
Increased tolerance and high possibility of dependence
How does levetiracetam work?
Seizure management:
Inhibition of the synaptic vesicle protein SV2A. It inhibits this protein and prevents vesicle exocytosis. A reduction in glutamate secretion reduces glutamate excitotoxicity.
What are the side effects of levetiracetam?
Dizziness
Somnolence
Fatigue
Headache