Drugs list Flashcards
What is the action and some features of aciclovir?
- Guanosine analogue. Converted by viral thymidine kinase (but not human thymidine kinase) to aciclovir triphosphate, which inhibits DNA polymerase in infected cells.
- During DNA synthesis mediated by the infection, the acyclovir triphosphate is incorporated into the chain
- This terminates synthesis because there is no 3’ carbon on the acyclovir, so no more nucleotides can be added to the chain
- This prevents the virus from completing the cycle
- This is selectively toxic to the virus because the human cell can differentiate between the guanosine and the acyclovir
- Used against HSV-1 and HHV-3 (varicella zoster) herpesviruses.
What is the action and some features of adrenaline in reference to immunopathology?
- Strong β-adrenoreceptor agonist
- Immediate treatment for type 1 hypersensitivity reactions
- Asthma, acutely - acts at β2, bronchodilatory.
- Anaphylaxis - strong vasoconstrictor, counters the systemic vasodilation to prevent vasodilatory shock
What is the action and some features of amoxicillin?
- Type of penicillin
- β-lactam antibiotic.
- Binds to and inhibits penicillin-binding proteins (PBP) - transpeptidases involved in peptidoglycan synthesis.
- They are structural analogues of the peptide cross-bridges in peptidoglycan
- Therefore, they can preferentially bind to the transpeptidase enzymes (one of the penicillin binding proteins PBPs)
- This stops transpeptidation, so the peptidoglycan cannot form
- BACTERICIDAL
- More effective against Gram +ve bacteria as target more accessible
- Resistance seen in some bacteria through beta-lactamases
What is the action and some features of aspirin?
- Cyclooxygenase I and II non-competitive, irreversible inhibitor, acetylates them.
- Reduces synthesis of prostaglandins, reduces inflammation. Prostaglandins sensitise C-fibre pain neurons so aspirin reduces inflammatory pain. NSAID.
- As a NSAID, used in chronic inflammatory diseases such as rheumatoid arthritis.
- Causes ototoxicity at high doses.
- Low doses: mild indigestion, risk of bleeding
- Reduces synthesis of thromboxane A2, a major platelet activator and stimulator of aggregation. Of the antiplatelet agent class of anticoagulants as platelets have no nucleus so cannot synthesise more COX once inhibited.
- Given long-term for prophylactic prevention of clotting for those at risk, or acutely after MI to reduce risk of clots.
- Problems of long-term aspirin:
- Liver/kidney disease
- Uncontrolled bleeding
- GI problems
- Aspirin allergies
- Doesn’t mix well with alcohol
What is the action and some features of benzylpenicillin?
- Type of penicillin
- β-lactam antibiotic.
- Binds to and inhibits penicillin-binding proteins (PBP) - transpeptidases involved in peptidoglycan synthesis.
- They are structural analogues of the peptide cross-bridges in peptidoglycan
- Therefore, they can preferentially bind to the transpeptidase enzymes (one of the penicillin binding proteins PBPs)
- This stops transpeptidation, so the peptidoglycan cannot form
- BACTERICIDAL
- More effective against Gram +ve bacteria as target more accessible
- Resistance seen in some bacteria through beta-lactamases
What is the action and some features of chloroquine?
- Antimalarial, both prophylactic and therapeutic.
- In schizogony in erythrocytes, Plasmodium must degrade haemoglobin for its own use, in an acid vesicle.
- Chloroquine concentrates in this vesicle and prevents crystallisation of toxic haem to nontoxic haemozoin; also binds to haem to form highly toxic FP-chloroquine.
- Causes cell lysis and parasite autodigestion.
What is the action and some features of chloramphenicol?
It is an antibiotic that inhibits bacterial protein synthesis by binding to bacterial ribosomes.
It is a potent, broad-spectrum antibiotic used for eye, ear, and life-threatening infections.
*It binds to the 23 S rRNA on the 50S subunit.
What is the action and some features of chlorpheniramine?
- First-generation antihistamine, H1 antagonist. Aka chlorphenamine.
- Inhibits type I hypersensitivity reactions. Usually used for mild allergic conditions such as allergic rhinitis (hayfever).
- Side-effects: sleepiness, weakness, dry mouth.
What is the action and some features of ciprofloxacin?
- Antibiotic of the fluoroquinolone class.
- Binds to DNA gyrase, causing introduction of double-strand breaks in DNA.
- They are BACTERICIDAL or BACTERIOSTATIC
What is the action and some features of cisplatin?
- Alkylating agent used in cytotoxic chemotherapy.
- Platinum bound to two NH3 and two Cl. Cl displaced by water, cross-links DNA bases.
- Remarkably effective in testicular cancer, even metastatic.
- Increased cure rate from 10% to 80%
- Displacement of the chlorine allows cross-linking of the DNA strands
- This leads to cytotoxicity
What is the action and some features of cromoglicate?
- Described as a mast cell stabiliser, inhibits degranulation.
- Used to prevent type I hypersensitivity reactions, as chronic prophylaxis in asthma.
- Long-term treatment
- Largely replaced by leukotriene receptor antagonists due to their convenience - cromoglicate must be taken 4 times a day.
What is the action and some features of cyclophosphamide?
- Alkylating agent used in cytotoxic chemotherapy.
- Chloride atoms displaced to crosslink nitrogens of guanine bases.
- In vivo it is oxidised to phosphoramide mustard
- The chlorines can take part in displacement reaction, which cross-link the DNA strands and can induce damage
- It is effective in treating cancer and other conditions (e.g. rheumatoid arthritis)
- Selectivity is determined by:
- The aldophosphamide intermediate is detoxified by aldehyde dehydrogenase (ALDH)
- This confers some selectivity for cells with low ALDH
What is the action and some features of dexamethasone?
- Steroid - synthetic glucocorticoid.
- Acts at nuclear glucocorticoid receptors, reduces phospholipase A2 synthesis. Reduces synthesis of lipid mediators of inflammation - prostaglandins, leukotrienes, platelet activating factor. Reduces inflammation and oedema.
- Prostaglandins sensitise C-fibre pain neurons, so reduces inflammatory pain. Analgesic.
- Side-effects:
- Immune depression, susceptibility to infection
- Hypertension - action at mineralocorticoid receptor, sodium/fluid retention
- Bone resorption, diabetes, peptic ulcers, impaired skin healing
What is the action and some features of doxorubicin?
- Aka Adriamycin
- Used as cytotoxic chemotherapy.
- Very planar and intercalates between base pairs.
- Stabilises DNA topoisomerase II at reaction intermediate with double-strand breaks.
- Prevents detangling of sister chromatids and induces double-strand breaks.
- Topoisomerase is expressed most during G2 of the cell cycle.
- This means that the cells in this phase are most susceptible to doxorubicin
What is the action and some features of erythromycin?
- Antibiotic of the macrolide class.
- Acts at ribosomal 50s subunit to inhibit translocation of tRNA, preventing protein synthesis
- They are BACTERICIDAL/BACTERIOSTATIC
What is the action and some features of flucloxacillin?
- Type of penicillin
- β-lactam antibiotic.
- Binds to and inhibits penicillin-binding proteins (PBP) - transpeptidases involved in peptidoglycan synthesis.
- They are structural analogues of the peptide cross-bridges in peptidoglycan
- Therefore, they can preferentially bind to the transpeptidase enzymes (one of the penicillin binding proteins PBPs)
- This stops transpeptidation, so the peptidoglycan cannot form
- BACTERICIDAL
- More effective against Gram +ve bacteria as target more accessible
- Resistance seen in some bacteria through beta-lactamases
What is the action and some features of gentamicin?
- Antibiotic of the aminoglycoside class.
- Acts at 30s subunit to inhibit translation initiation, therefore also inhibiting protein synthesis.
- Like all aminoglycosides, is ototoxic.
- They are BACTERICIDAL
What is the action and some features of heparin?
- Anticoagulant.
- A long, unbranched polysaccharide chain composed of repeating disaccharide units.
- Allosterically activates antithrombin-III; stabilises ATIII-thrombin interaction by 2000-4000x, promoting thrombin breakdown by this serpin.
- ATIII (anti-thrombin III) is an endogenous inhibitor of coagulation factors, especially Factor Xa and Thrombin (IIa)
- Heparin stabilises these interactions, slowing the clotting cascade
- Therefore, it is useful for prevention and treatment of thrombosis
- Active in minutes so given to reduce risk of clots in acute MI.
- Given as IV bolus then subcutaneous
- Can cause severe bleeding and Heparin-induced thrombocytopenia (low levels of platelets)
What is the action and some features of imatinib?
- Aka Glivec
- Targetted chemotherapy drug - small molecule inhibitors of cell cycle enzymes.
- Small-molecule inhibitor of the tyrosine kinase product of the BCR-ABL fusion gene on the Philadelphia chromosome.
- It is also effective against other tyrosine kinases, so it is effective against multiple types of cancer
- Used to treat Philadelphia +ve cancers; almost all chronic myelogenous leukaemias, some chronic lymphoblastic leukaemias.
What is the action and some features of isonizid?
- Antibiotic, specifically against mycobacteria.
- Works by inhibiting synthesis of long-chain mycolic acids.
- Bactericidal to growing organisms, otherwise bacteriostatic
What is the action and some features of maraviroc?
- Used to treat HIV.
- Prevents entry by binding and blocking CCR5.
- Fairly significant risk of hepatotoxicity.
What is the action and some features of methotrexate?
- Antimetabolite used as a cytotoxic chemotherapy agent.
- Close analogue of folic acid - competitive inhibitor of DHFR.
- This inhibits synthesis of purines and dTMP
- Thus, this inhibits RNA synthesis and DNA replication
- Also used as a first-line DMARD in rheumatoid arthritis.
What is the action and some features of NSAIDs?
- Class of drugs which inhibit COX. Inhibit synthesis of lipid mediators of inflammation - prostaglandins, leukotrienes, PAF. Reduce inflammation and oedema.
- Prostaglandins sensitise C-fibre pain neurons, so NSAIDs reduce inflammatory pain.
What is the action and some features of oseltamivir?
- Aka Tamiflu
- Antiviral used to treat influenza. Also can be preventative for those at high risk.
- Competitive inhibitor of neuraminidase. Prevents cleavage of sialic acid residues so release of new virions.
What is the action and some features of paracetamol?
- Analgesic but not considered an NSAID as it doesn’t reduce inflammation. Also has antipyretic properties.
- Appears to inhibit COX (according to spec, “a specific COX”) - action seems to come from inhibition of COX2 in the brain.
- Its metabolite AM404 is a weak cannabinoid receptor agonist, which may also contribute to analgesia.
What is the action and some features of penicillin?
- β-lactam antibiotic.
- Binds to and inhibits penicillin-binding proteins (PBP) - transpeptidases involved in peptidoglycan synthesis.
- They are structural analogues of the peptide cross-bridges in peptidoglycan
- Therefore, they can preferentially bind to the transpeptidase enzymes (one of the penicillin binding proteins PBPs)
- This stops transpeptidation, so the peptidoglycan cannot form
- BACTERICIDAL
- More effective against Gram +ve bacteria as target more accessible
- Resistance seen in some bacteria through beta-lactamases
What is the action and some features of raltegravir?
- Inhibits integrase. Used to treat HIV. May also be used as part of post-exposure prophylaxis.
- Prevents integration of viral DNA into the human genome so transcription of viral mRNA.
What is the action and some features of rifampicin?
- Of the rifamycin class of antibiotics.
- Inhibits bacterial RNA polymerase [DNA-dependent] so inhibits transcription.
- Used particularly for TB.
- They are BACTERICIDAL or BACTERIOSTATIC
What is the action and some features of saquinavir?
- HIV protease inhibitor, used to treat or prevent HIV.
- Protease required for cleavage of HIV polyproteins to release functional HIV proteins.
What is the action and some features of simvastatin?
- Statin, so is a HMG-CoA reductase inhibitor.
- Inhibits cholesterol biosynthesis, lowers plasma LDL.
- They also increases hepatic LDL receptor expression
- This leads to decreased plasma LDL and plasma triglycerides, as well as slightly increased plasma HDL
- Reduces risk/slows progression of atherosclerosis and thus coronary heart disease.
What is the action and some features of streptokinase?
- Thrombolytic agent.
- The enzyme of beta-haemolytic Streptococci - dissolves blood clots by converting plasminogen to plasmin.
- Used in treatment of acute MI with aspirin.
- However most individuals have anti-streptokinase antibodies. Not recommended to be used twice in a person’s lifetime.
- Administration: IV infusion or via catheter at site of arterial blockage
- Side-effects: increased risk of bleeding, nausea.
- Contraindictions:
- Recent Strep infection
- Stroke
- Pregnancy
What is the action and some features of streptomycin?
- Antibiotic of the aminoglycoside class.
- Acts at 30s subunit to inhibit translation initiation and therefore prevents protein synthesis.
- Like all aminoglycosides, is ototoxic.
- BACTERICIDAL
What is the action and some features of tamoxifen?
- Hormonal therapy for breast cancer
- Oestrogen receptor modulator.
- In breast tissue, acts as an ER antagonist. Used to treat ER-positive breast cancer.
- Thus, it stops the growth of breast cells
- It is metabolised to hydroxytamoxifen
- It may also have other unknown mechanisms of action
What is the action and some features of tetracycline?
- Antibiotic of the tetracycline class.
- Acts at ribosomal 30s subunit to inhibit tRNA binding.
- Inhibits protein synthesis
- BACTERICIDAL
- Can be exported by membrane pumps
- [[spec incorrectly classifies this as an aminoglycoside, it acts at the same ribosomal subunit but is its own class]]
What is the action and some features of trastuzumab?
- Aka Herceptin
- Anti-HER2/Neu monoclonal antibody.
- Blocks the growth factor receptor HER2, inhibits neoplasia where growth is driven by its overexpression.
- This down-regulates the growth factor signals that are mediated by the HER2 receptors and it also induces antibody-dependent cellular cytotoxicity (ADCC)
- HER2+ breast cancer and HER2+ stomach cancer
What is the action and some features of trimethoprim?
- Antibiotic of the 2,4-diaminopyridine class.
- Dihydrofolate reductase (DHFR) inhibitor - this converts dihydrofolate to tetrahydrofolate so inhibits nucleotide synthesis.
- They are BACTERIOSTATIC (but bactericidal when combined with sulfonamides)
What is the action and some features of vincristine?
- Vinca alkaloid
- Used as a cytotoxic chemotherapy agent.
- Binds to tubulin and prevents polymerisation into microtubules, so prevents movement and separation of chromatids in metaphase and leads to apoptosis.
- Side-effects: hair loss, change in sensation/neuropathic pain, difficulty walking, headaches.
- Dangers of vinca alkaloids such as vincristine:
- They are severely neurotoxic, since they inhibit microtubules, which are essential in neurons for neurotransmitter transport.
- Therefore they cannot be administered into the CSF, but must be administered via IV
What is the action and some features of warfarin?
- Vitamin K epoxide reductase inhibitor.
- This re-reduces oxidised vitamin K to reduced vitamin K. Requires oxidation of NADH.
- In coagulation factors, the glutamic acid residues must be gamma carboxylated into order to bind calcium, which is necessary for formation of complexes with platelet surfaces.
- This gamma carboxylation is dependent on vitamin K.
- Reduced Vitamin K is a cofactor for factors 2, 7, 9 and 10 (2 is thrombin) - anticoagulant.
- Used for prophylaxis/treatment of:
- DVT, pulmonary embolism
- Thrombosis after heart valve replacement or MI/AF
- Problems:
- Narrow therapeutic window
- Risk of haemorrhage
- Many drug-drug interactions as it binds to albumin in plasma
- Contraindictions - pregnancy, alcoholism
What is the action and some features of zanamivir?
- Aka Relenza
- Antiviral used to treat influenza. Also can be preventative for those at high risk.
- Competitive inhibitor of neuraminidase. Prevents cleavage of sialic acid residues so release of new virions.
What is the action and some features of zidovudine?
- Aka Azidothymidine/AZT
- Of the chain terminator class of RT inibitors. Also known as nucleoside RT inhibitors.
- Thymidine analogue that prevents DNA chain extension.
- Used for treatment and prevention of HIV, prevents viral replication.