CPT Flashcards
if 2.5mg ramipril produces the same BP lowering affect as 10mg lisinopril, which is correct?
- ramipril is more efficacious than lisinopril
- ramipril is more potent than lisinopril
or
- ramipril is a full agonist an lisinopril is a partial agonist
- ramipril is more potent than lisinopril
a drug that causes the same affect at lower doses is more potent
a new antibiotic produces toxic effects at a dose of 120 mg TDS in 50% of patients and a clinically desired response at 100 mg TDS in half of the population. what is the therapeutic index of this new antibiotic?
1.2
ratio of the dose that produces toxicity to the dose that produces a clinically desired or effective response.
therefore, 120/100
T/F : buprenorphine is a partial agonist for opioid receptors. it can have an affinity for these receptors that is greater than a full agonist such as codeine.
true
- partial agonists can have greater, the same or lower affinity for the same receptor as a full agonist but will have lower efficacy than the full response
T/F : plasma steady state is reached quicker if the rate of infusion of an IV drug is doubled
false
- plasma steady state will increase (will double), but will take just as long ot be reached as if the rate was halved
the P450 enzyme CYP3A4 is inhibited by grapefruit juice. how would this affect the plasma conc of simvastatin if a patient were to drink grapefruit juice alongside taking this daily statin?
- could increase plasma conc of simvastatin
metabolised in part due to CYP3A4.
steady state plasma conc will be reached in how mant half lives?
5
T/F: lipophilic drugs will readily cross through cell membranes
true
- lipophilic drugs dissolve in the lipid membrane and penetrate the cell surface
a patient is taking 80mg atorvastatin for secondary CVD prevention. only 11.2mg is absorbed unchanged due to incomplete gut absorption and gut wall excretion. what is the oral bioavailability of atorvastatin?
14%
- bioavailability is the rate and extent at which drug reacts the systemic circulation
- total drug given orally / drug given IV (100% bioavailability) x 100%
(11. 2/80) x100%
a 46y/o female patient (70kg) is prescribed ramipril to manage essential hypertension. her dose has been increased to 5mg OD. the peak plasma conc of ramipril was 0.06mg/L. the apparent volume of distribution is:
17L/kg
Vd= dose / plasma conc
5 / 0.06= 83.3L
patient is 70kg, so 84/70 = 1.2 L/Kg
which of the following reactions is likely to occur during Phase II drug metabolism: - reduction - oxidation or - Glucuronidation
- Glucuronidation
- Phase II metabolism involves conjugation reactions. Sulfation and glucuronidation are the most common
- oxidation and reduction occur in Phase I
which of the following is not a known reaction between beta blockers and thiazide diuretics? - hyperglycaemia - hyperlipidaemia or - hyperkalaemia
hyperkalaemia
- thiazides are likely to cause hypokalaemia and beta blockers don’t directly affect this action
which of the below is a common ADR of furosemide? - increased LDL cholesterol - hyperkalaemia or - impotence
- increased LDL cholesterol
- hyperkalaemia and impotence are common ADRs associated with spirolactone
T/F: labetalol can be used to treat hypertension during pregnancy
true
- oral labetalol can be used to treat gestational hypertension when other agents (ACEi and ARBs, CCBs) are contraindicated
NICE guidelines define hypertension as:
> 140/90
- 120/80 deemed ‘normal’ ideal for reducing risk of CVD
- 130/90 is designated prehypertension, which should be targeted with lifestyle interventions
resistance to blood flow is affected most by:
- length of the vessel
- class of vessel (names artery, arteriole, capillary etc)
or
- radius of the vessel ?
- radius of the vessel
Part of Poiseuille’s law demonstrates that resistance to flow is inversely proportional to the radius of the vessel to the fourth power
smaller changes in radius result in big differences in resistance to flow
T/F: beta blockers are used in treating left ventricular heart failure by increasing HR?
false
- beta blockers slow the heart, allowing more time for filling and increasing cardiac output
spironolactone affords its initial BP lowering action by:
- causing hyperkalaemia
- blocking calcium entry into vascular smooth muscle cells
or
- inhibition of aldosterone activity?
- inhibition of aldosterone activity
- not first line therapy,
- inhibits aldosterone activity at its receptor leading to diuresis
- long term it is suggested that it many ahem direct effect on the vasculature
T/F: ACEi can lower BP by inhibiting the breakdown of bradykinin?
true
- can lower BP by inhibiting breakdown of bradykinin as well as their action through ACEi
which class of drugs does losartan belong to?
angiotensin receptor blocker (ARB)
which of the following CCB shows the greatest selectivity for vascular smooth muscle? - amlodopine - verapamil or - diltiazem
Amlodopine
- dihydropyridine like calcium channel blocker
- shows little to no activist in the cardiac tissue
- verapamil shows selectivity for cardiac tissue with some VSM action
- Diltiazem sits between them
Oestriodiol’s major effects do not include:
-stimulation of growth of the endometrium
- stimulates production of progesterone receptor
or
- inhibition of oestrogen receptor production
- inhibition oestrogen receptor production
progesterone acts to inhibit producing of the oestrogen receptor
testosterone: - increases HDL: LDL ratio - decreases HLD: LDL ratio or - has no effect on cholesterol profile
increases HLD: LDL ratio
- less HDL to other cholesterol increases the risk of atherosclerotic disease in males
Combined oral and progesterone only contraceptive efficacy is increased/decreased/no change by anti epileptic drugs including phenytoin
decreased
- phenytoin among other drugs increases CYP450 activity which increases metabolism of COCP and POP resulting in reduced efficacy
T/F: hormone replacement therapy can decrease the risk of venous thromboembolism
false
- increased risk through effects on a number of proteins in the clotting cascade including increased thrombin activity
a type A adverse drug reaction is not: - rare - predictable or - dose dependent?
is not rare
- usually a consequence of the drug’s primary pharmacological effect (e.g. bleeding when using the anticoagulant warfarin) or a low therapeutic index of the drug (e.g. nausea from digoxin), and they are therefore predictable.
T/F: the yellow card system is the responsibility of healthcare professionals only
false
tamoxifen is:
- a pure agonist of the oestrogen receptors
- pure oestrogen receptor antagonist
or
- selective oestrogen receptor modulator?
- selective oestrogen receptor modulator (SERM)
- depending on the tissue, tamoxifen acts as an antagonist (breast tissue) or an agonist (endometrium)
T/F: oestrogen and their synthetic analogues are not well absorbed in the GI tract?
false
- well absorbed in the GI tract and undergo significant first pass metabolism in the liver
A patient from Ethiopia has the common deficiency in CYP2D6. what effect if any would you expect to see with therapeutic effect and dosing if he was using codeine as an analgesic?
- decreased therapeutic effect
- increased dose may be considered
the active metabolite of codeine requires CYP2D6 oxidation activity. a deficiency would result in less active metabolite being produced and less analgesia
increased/ decreased:
in a patient with hepatic disease, what effect will this have on the therapeutic action of tamoxifen?
decreased
- tamoxifen is a prodrug that relies on hepatic metabolism to produce active metabolites
GLP-1 agonists like exenatide have shown promising weight reduction effects during long term use. their actions include: - decreased insulin secretion - decreased gastric emptying or - increased glucagon production?
- decreased gastric emptying
T/F: Glucagon raises blood glucose levels in patients who have severe insulin induced hypoglycaemia
true
- Glucagon can be administered im, sc, or iv
- glycogen synthesis is reduced blocking the effects of insulin in the liver
Gliclazide is a sulfonylurea. which of the following is not a primary concern when prescribing it for diabetic management? - causes hypoglycaemia - contradicted in renal impairment or - cause weight gain
- contraindicated in renal impairment
- Gliclazide is metabolised hepatically so can be used in renal compromised patients with care.
- sulfonylureas cause weight gain and relatively more likely to cause hypoglycaemia than metformin.
why are insulins made as soluble preparations:
- to delay absorption from injection site
- to shorten their half life
or
- to prevent hexamers being formed
- to delay absorption from injection site
- soluble preparation delays absorption and overcomes the short plasma half life
- soluble insulins form hexameters at site of injection contributing to the delay in absorption
metformin is likely to be your first choice oral agent in conjunction with insulin in diabetic patients. which best describes anti diabetic action of this biguanide? - increase insulin secretion - reduce of hepatic glucose production or - inhibit fatty acid oxidation
- reduce hepatic glucose production
- metformin does not affect insulin secretion.
- it inhibits gluconeogenesis in the ever resulting in less glucose production
- metformin also increases fatty acid oxidation and reduce plasma triglycerides
those that can only tolerate a low dose statin should be offered:
Fenofibrate/ evolocumab/ ezetimibe
in addition as secondary prevention
Ezetimibe - good first choice addition
- fenofibrate is offered in combination with a statin in specialist circumstances- typically in familial hypercholestrolaemias but has an increased risk of rhabdomyolysis
- evolocumab is not routinely prescribed with a statin
T/F: ezetimibe has a large ADR profile because of its systemic actions
false
- prodrug that undergoes hepatic metabolism to produce an active metabolite that undergoes significant enterohepatic circulation so the majority of the drug stays within the GI, therefore relatively few ADRs.
fibrates primary mechanism of action is:
- binding of bile acids
- inhibition of the NPC1L1 transporter in the small intestines
or
- activation of the nuclear transporter PPARalpha
- activation of the nuclear transporter PPARalpha
T/F: a high dose statin should be offered to all with a CVD risk of >10% as a primary prevention
false
- low dose statin is recommended
which of the below is not a known action of statins that contributes to reduction in CVD risk?
- improved haemostasis
- stabilisation of atherosclerotic plaque
or
- increased endothelin
- increase endothelin
- A and B both reduce the progression of atherosclerosis or reduce the likelihood of plaque rupture leading to thrombus formation and possible AMI or stroke.
- statins reduce enothelin which is an autocoid that causes vasoconstriction
T/F: Ivabradine reduces HR ( - chronotropy) but does not reduce BP
true
- the action on the iF changes in the SAN slows the heart but does not affect BP
- particularly useful in HF and managing angina
the class Ic antiarrhythmetic agent flecainide:
-decreases the AP duration
- speeds up tissue conduction during phase 0
or
- increases the PR interval
increase the PR interval
- increase AP duration, slows tissue conduction during phase 0 and as a result increases the PR interval
which of the following CCB is not a class IV antiarrhythmic agent? - diltiazem - verapamil or - amlodopine
amlodopine
- selective for vascular smooth muscle calcium channels and has little affect in the heart
- diltiazem shows the greatest selectivity for calcium channels in the heart
T/F: the predominant ion that governs depolarisation (phase 0) in the SAN is sodium
false
- sodium ions enter the cell through fast sodium channels in the ventricles in phase 0.
- in the SAN, phase 0 depends predominately on calcium influx
amiodarone is a class III antiarrhythmic that:
- only inhibits potassium channels
- only inhibits sodium and potassium channels
or
- can act as a beta receptor antagonist
can can as a beta receptor antagonist - is a class III antiarrhythmic but can act on sodium channels, potassium channels, calcium channels and as a non competitive beta blocker
clopidogrel is licensed and prescribed for up to 12 months following an acute myocardial infarction - in addition to aspirin - only if aspirin is contraindicated or - in addition to prasugrel
in addition to aspirin
- aspirin, if not contraindicated, is prescribed indefinitely following an AMI.
- Clopidogrel is recommended in addition to aspirin for up to 12 months in most patients
- you would not prescribe prasugrel in addition to Clopidogrel as they act at the same site on the P2Y12 receptor
which ADP receptor antagonist binds reversibly to the P2Y12 receptor? - Clopidogrel - prasugrel or - tricagrelor
Tricagrelor
- binds reversibly at a different location to the other agents
which of the below is not true about dipyridamole mechanism of action? - inhibits cellular uptake of adenosine - prevents cAMP degradation or - blocks fibrinogen binding
blocks fibrinogen binding
- part of the mechanism of GPIIb/ IIIa inhibitors
T/F: Naloxone is used to treat opioid addiction
false
- rapid acting opioid antagonist which can be used in opioid overdose but tiggers severe withdrawal effects in opioid addicted people
explain why docusate sodium may be prescribed alongside morphine
- side effect of opioid analgesics is contipation
- docusate sodium has faecal softening properties and is a stimulant of intestinal smooth muscle which aids peristalsis.
64y/o male suffers from chronic OA in his L knee. he has managed the pain with paracetamol until recently. in a discussion with his GP it is decided that he should take naproxen. he currently takes no other medication. what should be co-prescribed alongside? - omeprazole - aspirin or - NSAID topical gel
omeprazole (PPI)
- patients prescribed an NSAID should be prescribed also with a PPI regardless of whether it is a COX-2 or non-selective NSAID
which of these opioids is a partial agonist at the μ-opioid receptor? - morphine - buprenorphine or - fentanyl
buprenorphine
- potent partial agonist which is associated with its lower abuse potential than morphine
which of the prostanoids below show apposing platelet aggregatory action? - PGE2 and TXA2 - PGI2 and PGE2 or - PGI2 and TXA2
PGI2 and TXA2
- PGI2 inhibits platelet aggregation
- TXA2 contributes to platelet aggregation
- inhibition of COX-1 in platelets by aspirin inhibits the synthesis of TXA2
which of the following drugs has least anti-inflammatory effects? - aspirin - paracetamol or - naproxen
paracetamol
- little to no anti-inflammatory effect, though in part due to peroxidase production at the site of inflammation
suggest two mechanisms by which NSAIDs can cause GI ADRs
- decreased mucus secretion
- decreased bicarbonate secretion
- reduced mucosal blood flow
- pH partitioning and accumulation of NSAIDs at gastric mucosa
- inhibition of PGE2 and PGI2 major factors in these ADRs
T/F: opioids inhibit pain in the dorsal horn of the spinal cord?
true
- in part they act at opioid receptors to block transmitter release and postsynaptic transmission in the dorsal horn
which of the following NSAIDs is least selective for COX-2? - aspirin - ibuprofen or - celecoxib
aspirin
T/F: NSAIDs reduce symptoms of rheumatoid arthritis and slow its progression
false
- symptomatic relief of symptoms but not to slow progression
which of the following is not true of the 6-mercaptopurine (6-MP) metabolite thiopurine methyltransferase (TMPT)
- the TMPT gene is highly polymorphic
- low TMPT increases risk of myelosuppression
or
- TMPT activity does not influence azathioprine treatment
TMPT activity does not influence azathioprine treatment
- TMPT activity varies across populations and low activity increases risk of toxicity due to prolonged activity of the active metabolites of azathioprine
T/F: Vinca alkaloids prevent spindle formation
true
- prevent spindle formation by binding to tubulin (and preventing polymerisation) resulting in M-phase arrest
disease modifying anti-rheumatic drugs should:
- never be used in combination
- only be given in combination with steroids
or
- be considered in combination in severe rheumatoid disease
be considered in combination in severe rheumatoid disease
- evidence suggests that combination methotrexate with ciclosporin, sulfasalazine or hydroxychlolquine affords significant benefit in disease management
methotrexate is used both as a chemo agent and as a DMARD. what is its chemotherapeutic action?
- guanine nucleotide cross linker
- dihydrofolate reductase inhibitor
or
- inhibition of receptor tyrosine kinases
dihydrofolate reductase inhibitor
- inhibition of dihydrofolate indirectly inhibits DNA synthesis
- platinum compounds = guanine nucleotide cross linker
methotrexate has a half life of circa 30 hours. with what frequency should it be taken?
once weekly
- methotrexate is metabolised to polyglutamates which have long half lives
following surgery to remove a cancerous breast lump, a patient is to commence chemotherapy with the hope of removing any malignant ells that may have been left behind. suggest two patient specific pieces of information you would need to calculate an appropriate regiment. why are they important?
- BMI
- liver function
- renal function
- performance status
- narrow therapeutic indices and significant side effect profile means that very specific and tailored doses are required.
- renal and hepatic function will dictate ADME.
before initiating anti-TNF therapy what should be screened for and why?
TB
- TNF is essential in granuloma formation so that TB bacilli are walled off.
- treatment for TB should be initiated prior therapy if latent or active TB is diagnosed
Tacrolimus is used in patients undergoing transplantation. how does it act?
- TNFα inhibition
- production of 6-thiosine monophosphate (TIMP)
or
- prevents IL-2 production by inhibition of calcineurin
prevents IL-2 production by inhibition of calcineurin
- TIMP production is part of MOA of anti proliferative agents such as azathioprine
- TNFα inhibitors are monoclonal antibodies such as infliximab
T/F: PPIs increase the metabolism of warfarin and phenytoin
false
- PPIs inhibit CYP2C decreasing the metabolism of drugs including warfarin and phenytoin
- important DDI considering the large number of people taking warfarin long term
evidence suggests that H.pylori eradication is best achieved with combination therapies. which regiment is recommended by the Leicestershire commissioning group?
PPI + Clarithromycin and Amoxicillin
- use triple therapy
describe the difference between lactulose and macrogols in their laxative effect in the large bowel
lactulose: draw fluid into the gut lumen
macrogol: retain the fluid they came with - better at limiting loss of fluid from the stood
they are both osmotic laxatives
PPIs are typically taken p.o. Which is not true of this class of drugs?
- they reversibly inhibit the hydrogen/ potassium ATPase proton pump
- they inhibit around 90% acid secretion within 24-36 hours
or
- given as enteric-coated tablets as they are unstable in acid
they reversibly inhibit the hydrogen/ potassium ATPase proton pump
- PPIs irreversibly and covalently bind to the proton pump.
- acid secretion requires synthesis of new proton pumps
T/F: Metoclopramide decreases intestinal motility
false
- increases intestinal motility ( pro kinetic) which contributes to its anti-emetic effects
describe how hyoscine hydrobromide may be effective in managing motion sickness.
- muscarinic receptor antagonist, competitively blocks mAchR
- also some action through the CTZ
- sedation caused by these agents often contributes to their use for motion sickness
which of the following is not true of neurokinin 1 receptor antagonists?
- augment the effects of 5HT3 receptor antagonist
- prevent the action of substance P
or
- should not be used as an anti-emetic in patients undergoing chemotherapy
should not be used as an anti-emetic in patients undergoing chemotherapy
- particularly useful in chemo patients (cisplatin) because the argument the action of 5HT3 antagonists and corticosteroids
which receptor subtype does the commonly used antiemetic ondansetron inhibit? - histamine H1 - 5HT1 or -5HT3
5HT3
- particularly useful in vomiting induced by highly emetogenic chemo
Loperamide affords its action through targeting μ receptors in the mesenteric plexus. which of the following statements is not true?
- decreases tone of longitudinal and circular smooth muscle
- increases peristalsis but decreases segmental contractions
or
- decreases colonic mass movement by suppressing gastrocolic reflex
increases peristalsis but decreases segmental contractions
- loperamide decreases peristalsis but increases segmental contractions
- increasing transit time allowing more fluid to be removed from the faeces.
which of the below best describes the action of histamine antagonists in their anti secretory action
- competitively inhibit histamine action at H2 receptors in gastric parietal cells
- competitively inhibit histamine action at H1 receptors in gastric parietal cells
- non-competitively inhibit histamine action at H2 receptors in gastric parietal cells
or
- non-competitively inhibit histamine action at H1 receptors in gastric parietal cells
competitively inhibit histamine action at H2 receptors in gastric parietal cells
- Ranitidine and the other anti-secretory histamine antagonists competitively inhibit H2 receptor in the gastric parietal cells
T/F: sodium valproate can increase the plasma conc of lamotrigine when prescribed together
true
- inhibits hepatic enzymes including glucuronidation which contributes to lamotrigine metabolism
- caution when coprescribed
Carbamazepine increases, decreases or has no effect on CYP enzyme action on COCP?
increases
- among other AEDs increases the metabolism of both oestrogen and progesterone containing OC.
- higher doses of OC are likely to be needed if being coprescribed
describe how selegiline and rasagaline can be beneficial in the management of Parkinson’s disease?
- inhibit MAOB metabolism of dopamine.
- prolong action of L-DOPA reducing dose required
- have modest effects when used alone
which of the following is recommended as first line treatment in idiopathic Parkinson's disease? - Levodopa - Rotigotine or - Co-careldopa
- Co-careldopa
Levodopa with the DOPA decarboxylase inhibitor carbidopa is used
levodopa alone produces little increase in dopamine crossing the BBB
Rotigotine is formulated as a patch and is not typically used as first line treatment
list the 4 types of generalised seizures considered
absence
myoclonic
tonic-clonic
atonic
T/F: Anticholinergics have little effect on treating bradykinesia
true
- help restore balance between CNS cholinergic and dopamine activity
- produces the usual common anticholinergic side effects including confusion and drowsiness
which of the following is true of phenytoin?
- wide therapeutic window
- is used in status epilepticus
or
- requires very little therapeutic monitoring
is used in status epilepticus
- typically following a benzodiazepine if this has been unsuccessful
- has a narrow therapeutic window and exhibits zero order elimination kinetics
- therapeutic monitoring required to guide dosing in patients with large pharmacokinetic variability
which is not true of sodium valproate
- it inhibits CYP450 enzymes including 2C9
- causes weight loss
- teratogenic
causes weight loss
- sodium valproate causes weight gain which may be associated with polycystic ovary syndrome prevalence in women
- causes neural tube defects
