Mode Of Action Flashcards
Insulin
Stimulates glucose uptake from circulation into tissues, glycogen, lipid and protein synthesis. Inhibits gluconeogenesis and ketogenesis
Sulphonylureas (Gliclazide)
Stimulates pancreatic insulin secretion by blocking ATP-dependant K+ channels causing depolarisation and opening of voltage gated Ca2+ channels
Biguanides (Metformin)
Increases response to insulin - suppresses hepatic glucose production, increases uptake and utilisation and suppresses intestinal absorbtion
Thyroxine
Replace endogenous hormones
Anti-Thyroid (Carbimazole)
Pro-drug metabolised to thiamazole to inhibit organification of iodine and coupling of iodothyronine which suppresses synthesis of thyroid hormone
Bisphosphonates (Alendronate)
Reduce bone turnover by inhibiting osteoclasts
Mineralocorticoid (Fludrocortisone)
Activates mineralocorticoid receptor to increase ion and H2O transport to raise extracellular volume and BP - lowering K+ levels
NAIDs (Diclofenac)
Inhibit synthesis of prostaglandins from arachidonic acid by inhibiting COX enzyme
Opiates (Codeine)
Metabolised in the liver to produce morphine which agonises Opioid U-receptors
Morphine
Activates Opioid U-receptors in CNS to reduce neuronal excitability.
Blunts response to hypoxia and hypercapnia in the medulla.
Reduce cardiac work and O2 demand
Paracetamol
Not Understood - weak COX 1 inhibitor
Xanthine-Oxidase-Inhibitor (Allopurinol)
Inhibits X-O to reduce metabolism of Xanthine to uric acid
Alpha-Blockers (Doxazocin)
Selective for a-adrenoreceptors found in smooth muscle cells to cause vasodilation and fall in BP
5-alpha-reductase Inhibitors (Finasteride)
Reduce the size of the prostate by inhibiting intracellular 5a-reductase enzyme that converts testosterone into dihydrotestosterone which stimulates pancreatic growth
Penicillins (Amoxicillin)
Inhibit the enzymes responsible for cross linking peptidoglycan in bacterial cell wall
Cephalosporins (Cephradine)
Inhibit the enzymes responsible for cross linking peptidoglycan in bacterial cell wall
Trimethorpim
Inhibit bacterial folate production
Nitrofurantoin
Metabolised by nitrofuran reductase to active component that damages bacterial DNA
`Tetracyclines (Doxyclycline)
Bind to 30s ribosome to inhibit protein synthesis and tRNA unable to bind to mRNA
Aminoglycosides (Gentamicin)
Irreversibly bind to 30s ribosome to inhibit bacterial synthesis
Macrolides (Erythromycin)
Bind 50s ribosome to block translocation
Quinolones (Ciprofloxacin)
Inhibit bacterial DNA synthesis
Anaerobic - Metronidazole
Passive diffusion into cell, then reduced to produce nitroso free radical which bind to DNA and reduces synthesis. (Aerobic bacteria unable to reduce metronidazole)
Glycopeptides (Vancomycin)
Inhibits growth and cross linking of peptidoglycan chains
Antacids (Gaviscon)
Buffer the stomach