Pharmacology Flashcards
What’s the MoA for metformin / biguanides? (2)
Reduce hepatic gluconeogenesis, increase peripheral blood glucose uptake.
What affect does metformin have on weight?
Weight neutral / may promote weight loss
Does metformin risk hypoglycaemia?
Not as a monotherapy
What are the adverse effects of metformin? (3)
GI upset, lactic acidosis, obstruction of B12/folate metabolism
What’s the MoA of SUR drugs? (3)
Binds to SUR1 subunit of Katp channel, closing it (depolarising), leading to opening of voltage-gated calcium channels and insulin release.
Do SUR drugs risk hypoglycaemia?
Yes
What effect do SUR drugs have on weight?
Weight gain
Side effects of SUR drugs?
Abnormal LFTs, renal failure, CHD risk
GLP-1 drugs are given orally or by injection?
Injection
What effect do GLP-1 drugs have on weight?
Weight loss
Are biguanides safe in pregnancy?
Yes
Maximum daily dose of metformin
2g (1g BD)
Example SUR drug
Gliclazide
Do SUR drugs prevent microvascular / macrovascular complications? (2)
Microvascular - Yes
Macrovascular - No
Side-effects of GLP-1 includes
Nausea, pancreatitis
Examples of GLP1 drugs
Exenatide, Liraglutide
DPP-4 drug example
Any -gliptin drugs (e.g. vildagliptin)
How do DPP-4 drugs work?
Reduce breakdown of GLP-1 (which itself promotes insulin secretion, lowers glucose absorption)
How do GLP-1 agonist drugs work? (4)
1) Promotes insulin secretion from pancreas
2) Lower glucose absorption in the gut
3) Suppress glucagon release
4) Delay gastric emptying & lower hunger
Are DPP-4 inhibitors weight-neutral?
Yes
Do DPP-4 inhibitors risk hypoglycaemia?
No
Do GLP-1 agonists protect against micro and macrovascular complications? (2)
Micro- assumed
Macro - unknown (but decreases SBP)
Do DPP-4 inhibitors protect against macrovascular progression?
No
Are DPP-4 inhibitors oral?
Yes (they block GLP-1 which is produced in the GI tract)
Glitazone/TZD drugs act how? Are they insulin dependent?
Through PPAR-gamma (induction of peripheral glucose uptake & fatty acid synthesis in adipocytes). No
Are glitazone/TZD drugs weight neutral?
No, they encourage production of fat.
What are the side-effects of glitazone drugs?
Fracture, hepatotoxic, fluid retention (can lead to heart failure)
SIGN 154 guidance of glycaemic control in T2DM: give the 1st line therapy (and alternative)
1st line = metformin
Alternative* = SUR
*if intolerant OR osmotic symptoms present.
Both are in addition to lifestyle measures.
SIGN 154 guidance of glycaemic control in T2DM: give the 2nd line therapy
Metformin / SUR + (one of) SUR / SGLT2/ DPP-4 / TZD
SIGN 154 guidance of glycaemic control in T2DM: give the third line therapy
Metformin / SUR + 2nd line therapy + addition of agent from another class (not used). If patient’s BMI is >30 substitute this new drug for GLP-1 injections (weight loss) OR insulin (if <30).
If patient’s have a history of CVD, what’s the standard 2 drugs used in T2DM control?
Metformin + SGLT2
DPP-4 drug naming convention….
-Gliptin
In T2DM, insulin therapy tends to be basal/bolus focused?
Basal (T1DM tends to be basal and bolus)
In T2DM, is the initial insulin therapy used as a monotherapy?
No, combined with metformin
Which tricyclic antidepressant is useful in neuropathic pain?
Amitriptyline (off-label)
If the patient cannot tolerate oral medication for neuropathic pain, which topical alternative is available?
Capsaicin cream
Metoclopramide and domiperidone are examples of what kind of drug?
Promotility agents
Ondansetron is an example of which type of drug?
Anti-emetic
What’s the standard therapy for hypothyroidism & starting dose for young patients?
Levothyroxine (T4) 50-100micrograms per day
In elderly, the dosage of levothyroxine is higher/lower than youth?
Lower (25-50micrograms per day versus 50-100 in youth)
In pregnancy, how should levothyroxine dose be adjusted in hypothyroidism?
Increase by 25-50%
How often should TSH be checked in hypothyroidism if the dosage is changed?
Every 2 months (versus 12-18 months once stabilised)
In secondary hypothyroidism, TSH is unreliable and treatment should be titrated to what?
Free T4 level
Levothyroxine should be taken at what time & how?
Before breakfast without other tablets
T4 is much more potent than T3, true or false?
False - T3 is more potent
Carbimazole represents the 1st/2nd line therapy in hyper/hypothyroidism?
1st in hyperthyroidism
Why is carbimazole not used in the 1st trimester of pregnancy?
Risk of aplasia cutis
What drug is used in the 1st trimester of pregnancy in hyperthyroidism?
PTU
PTU is how much less potent than carbimazole?
10x
How does PTU work?
Inhibits DIO1 (conversion of T4 to T3) rather than production of T4
What’s the major risk associated with ATDs?
Agranulocytosis
Once agranulocytosis has been treated, ATDs can be resumed. True/false?
False
How should suspected agranulocytosis be managed in hyperthyroid patients? (2)
1) Cease ATD immediately
2) Refer for immediate FBC
How do beta-blockers work in hyperthyroid disease?
These work on beta-adrenoceptors which reduce sympathetic nervous activity (excessive in hyperthyroid disease)
What’s the beta-blocker of choice in hyperthyroidism?
Propanolol
The immediate symptoms of thyrotoxicosis can be managed with which drug?
Beta-blocker
If a hyperthyroid patient is also asthmatic, how are cardiac symptoms managed?
Use calcium-channel blocker instead
