Drug Synergy Flashcards
What are the benefits of drug synergy?
enhanced benefit, minimise toxicity, minimise chance of resistance
What is selective toxicity?
maximise toxicity for other and minimise toxicity for host
What is the mechanism of action of maraviroc?
allosteric modulator of CCR5 receptor to prevent fusion
What is the mechanism of action of enfuvirtide?
peptide agonist of Gp41 - prevents fusion
What is the mechanism of action of zidovudine?
nucleoside reverse transcriptase inhibitor
What is the mechanism of action of nevirapine?
allosteric modulator of reverse transcriptase
What is the mechanism of action of raltegravir?
integrase inhibitor
What is the mechanism of action of saquinavir?
protease inhibitor
In HAART are the three drugs used always from different classes?
no - may be from the same class
What is the benefit of combining the protease inhibitor ritonavir with another protease inhibitor?
ritonavir is a potent inhibitor of Cyp3A4 which prevents the metabolism of the other protease inhibitor so the effect is increased
What is the mechanism of action of sofosbuvir?
a nucleotide inhibitor of NS5B - the RNA dependent RNA polymerase in HCV
Why are some bacteriocidal and bacteriostatic combinations of antibiotics antagonistic?
if the bacterostatic drug requires active bacteria
Why is penicillin and aminoglycosides synergistic?
because penicillins allow entry of the aminoglycoside into the cell
Why is flucytosine and amphotericin synergistic? (anti-fungals)
amphotericin breaks down the cell wall by targeting ergosterol so flucytosine can get in and inhibit DNA synthesis
Why is sulfonamide and trimethoprim synergistic? (anti-fungals used for pneumocystis jiroveci)
sulfonamide inhibits conversion of PABA to folate and trimethoprim inhibits conversion of folate to tetrahydrofolate - both act on the same pathway for DNA synthesis
Why are cisplatin/bleomycin and etoposide (drugs used for prostate cancer treatment) synergistic?
cisplatin/bleomycin damage the DNA and etoposide inhibits the repair of the DNA
What is the mechanism of action of glucocorticoids for immunosupression for organ transplant?
negative regulator of cytokine production
What is the mechanism of action of azathioprine for immunosupression for organ transplant?
it is a cytotoxic drug that blocks DNA synthesis of cell division so prevents the T cell proliferating
What is the mechanism of action of cyclosporin for immunosupression for organ transplant?
inhibits calcineurin which results in a lack of transcription of IL-2 so the T cell cant be activated by antigen presentation
What is the mechanism of action daclizumab for immunospuression for organ transplant?
it is an IL2 receptor antagonist - it prevents the T cell from recieving the signal it is to be divide
What is the mechanism of action of anti-thymocyte globulin for immunosupression for organ transplant?
lyses T cells
What is the mechanism of action of abatacept?
binds to CD80/86 to prevent the second signal for T cell activation
What is the mechanism of action of targin?
targin is made up of oxycodone and naloxone. oxycodone is a mu receptor agonist and naloxone is a mu receptor antagonist. the naloxone has poor oral bioavailability so remains in the gut where it can target the side effect of constipation caused by the oxocodone.
