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.
