Pharmacology Flashcards
What is an irreversible side effect of tetracyclines?
Teeth staining
How does montelukast work?
Blocks action of leukotriene D4 in the lungs which decreases inflammation and relaxes smooth muscle
How does rituximab work and what conditions is it used for?
Binds to CD20 on B cells
Used in Hodgkins lymphoma and some vasculitides
How does vigabatrin work?
Analogue of GABA which inhibits GABA aminotransferase (inhibits GABA breakdown)
Has a seizure suppression effect
How does cyclophosphamide work?
Chemotherapeutic agent which causes cell apoptosis when it breaks down to its metabolite phosphoralide mustard
Which chemotherapy agent has the side effect of haemorrhagic cyctitis?
Cyclophosphamide
How does vincristine work?
Vinca alkaloid chemotherapeutic agent which acts through inhibiting microtubule activity
Which chemotherapy drug causes peripheral neuropathy?
Vincristine
How does doxorubicin work?
Anthracycline chemotherapy drug which acts through inhibition of topoisomerase II (allows uncoiling of DNA in preparation for transcription)
Which chemotherapy agent is known to be cardiotoxic?
Doxorubicin
How does blinatumomab work and what is it used for?
Targets the CD19 antigen on B-cells
Used in treatment of refractory B cell leukaemia
Which biological agent works by inhibiting IgE?
Omalizumab
How does inflixamab work?
Inhibits TNF-alpha
Which type of antibiotic is known for its QTc prolongation?
Macrolides
How do PPIs work?
Inhibit the H+-K+-ATP pump in the gastric parietal cells
How does lamotrigine prevent seizures?
Prolongs sodium channel inactivation to prevent membrane depolarisation and subsequent seizure activity
How does metformin work to lower blood sugars?
Decreased gluconeogenesis and increase peripheral utilisation of glucose
How does insulin function to reduce blood sugar levels?
Enhances glucose uptake and cell metabolism
How does gliclazide work to lower blood sugar levels?
Augments insulin secretion from functioning B pancreatic cells
How does risperidone work?
It is a D2, 5-HT, alpha-1, histamine-1 antagonist
How does a n oculogyric crisis present?
Involuntary deviation upward of both eyes
Which type of drugs most commonly cause oculogyric crises?
Neuroleptic drugs
What is the mechanism of action of trimethoprim?
Inhibits an essential step in synthesis of bacterial nucleic acid synthesis
Is an antifolate antibiotic
What is the mechanism of action of gentamicin?
Inhibits bacterial synthesis by binding to 30s subunit of bacterial ribosomes
What is the mechanism of action of clarithromycin?
Inhibits bacterial synthesis by binding to 50s ribosomal subunit
What is the mechanism of action of cyclopentolate?
Muscarinic acetylcholine M1 receptor antagonist
What is the mechanism of action of azithromycin?
Binds to recombinant 23S rRNA of bacterial 50S ribosomal unit to inhibit bacterial synthesis
What is the mechanism of action of metronidazole?
Inhibits bacterial synthesis by causing loss of helical DNA structure and strand breakage
What is the mechanism of action of vancomycin?
Inhibits synthesis of bacterial cell wall via prevention of peptide incorporation into the peptidoglycan matrix
What is the mechanism of action of allopurinol?
Inhibits xanthine oxidase and its active metabolite
What is allopurinol used for in oncology patients?
Used to avoid TLS
What is the mechanism of action of amlodipine?
Inhibits calcium ion reflux at L-type calcium channels
What is the mechanism of action of hyoscine?
Antimuscarinic agent which competitively inhibits acetylcholine muscarinic receptors
What is the mechanism of action of isoprenaline?
Positive inotropic and chronotropic effects via B1 adrenergic stimulation
What is the mechanism of action of adrenaline?
Alpha and beta receptor agonist
B1 receptors - increases HR and myocardial contractility
A-adrenergic receptors - inhibits vasodilation
What is the mechanism of action of atenolol?
Selective B1 receptor antagonist - antagonist to sympathetic innervation
What is the mechanism of action of NAC?
Generates glutathione which in turn conjugates the NAPQI (paracetamol metabolite) into a harmless metabolite
Reduces the circulation of toxic metabolites
What is the mechanism of action of mycophenolate mofetil?
Prevents DNA synthesis and proliferation by inhibiting inosine monophosphate
What is the mechanism of action of flecainide?
Blocks sodium channels which reduce the rate of depolarisation of phase 0 without changing the overall AP duration.
What class of anti-arrythmic is flecainide?
Class Ic
Give an example of a class III antiarrhythmic drug?
Amiodarone
What is the mechanism of action of amiodarone?
Block potassium channels that increase the action potential duration by increasing length of repolarisation in phase 3.
What is an example of a class Ia anti-arrhythmic drug?
Disopyramide
What is the mechanism of action of disopyramide?
Block sodium channels that increase AP duration by increasing length of depolarisation during phase 0
What is the mechanism of action of Ivabradine?
Blocks the If channel in the SAN, reducing rate of pacemaker potential depolarisation, increasing refractory period and slowing the heart rate
What is an example of a class Ib anti-arrhythmic drug?
Mexiletine
What is the mechanism of action of melixetine?
Block sodium channels that shorten the AP duration by reducing the length of plateau in phase 2.
What is the most common side effect of IV quinine?
Tinnitus
What are the major side effects of ciclosporin?
Chronic interstitial nephritis
Hypertrichosis
Periodontal destruction
Which commonly used drug in TB management can reduce the effectiveness of warfarin?
Rifampicin - potent enzyme inducer
Which antibiotic can cause cholestatic jaundice?
Co-amoxiclav
Which chemotherapy agent can cause haemorrhagic cystitis?
Cyclophosphamide
What is the mechanism of action of fexofenadine?
H1 antagonist
What is the mechanism of action of fomepizole?
Competitive inhibitor of alcohol dehydrogenase
What is the mechanism of action of milrinone?
Positive inotrope - competitive phosphodiesterase-3-inhibitor that inhibits degradation of cAMP.
What is the mechanism of action of domperidone?
Dopamine-receptor antagonist
Which antiepileptic medication is associated with visual field defects?
Vigabatrin
What is the mechanism of action of aminophylline?
Inhibits phosphodiesterase type III and IV which breakdown cAMP in smooth muscle cells. Allows bronchodilation.
What is the mechanism of action of chloramphenicol?
Inhibits intracellular protein production
Binds to 50S subunit of 70S ribosome inhibiting action of peptidyl transferase
What is the mechanism of action for ondansetron?
Selective serotonin 5-HT3 receptor antagonist
What is the mechanism of action of verapamil?
Non-dihydropyridine CCB
What is the most common side effect of verapamil?
Constipation
What is the mechanism of action of infliximab?
IgG monoclonal ab which binds to TNF-alpha with high affinity
Which chemotherapeutic agent causes peripheral neuropathy?
Vincristine
Which drug causes “grey baby syndrome”?
Chloramphenicol
What is “grey baby syndrome”?
Cardiovascular collapse in infants due to immature hepatic glucuronidation meaning they are unable to excrete the drug.
Which corticosteroid has the highest mineralocorticoid activity?
Fludrocortisone
What is the mechanism of action of levetiracetam?
Binds to SV2A which regulates release of neurotransmitters into vesicles
What is a type A drug reaction?
“Augmented”
Exaggeration of a drugs normal pharmacological actions
Normally dose dependent
What is a type B drug reaction?
“Bizarre”
Novel response not expected from the known pharmacological actions of teh drug
What is a type C drug reaction?
“Continuing”
Persist for a very long time
What is a type D drug reaction?
“Delayed”
Become apparent sometime after the use of a medicine
What is a type E drug reaction?
“End-of-use”
Associated with medication withdrawal.
What is the mechanism of action of ondansteron?
Serotonin receptor antagonist - selectively blocks 5-HT3 serotonin receptor
What are the common side effects of ondansetron?
Dry mouth
Drowsiness
Constipation
Which antibiotic can cause red man syndrome if it is infused too quickly?
Vancomycin
How does red man syndrome present?
Pruritic erythematous rash over face, neck and upper torso
What is one of the main significant side effects of ethambutol?
Visual disturbances
What is the antidote for benzodiazepine overdose?
Flumazenil