CPT to learn Flashcards
general treatment for sickness
ondasteron (5HT3 inhibitor)
Cylizine (H2 receptor antagonist)
dexamethasone (corticosteroid)
general treatment for sickness in pregnancy caused by hCG (hyperemesis gravidarum)
promethazine
metoclopramide
ondansetron
patients who use metformin need
good renal function
DDI
- ACEi (drugs which impair renal function)
- Diuretics (drugs which impair renal function)
- NSAIDs (drugs which impair renal function)
- Loop and thiazide like diuretics which increase glucose so can reduce metformin action
types of B cell lymphoma
Diffuse large B-cell lymphoma (DLBCL)
Follicular lymphoma
difference between X-rays in RA and OA
RA
- reduced joint space
- juxta artciular osteolytic lesions
- soft tissue damage
- deformity
OA
- osteophytes
- reduced joint space
- sclerotic lesions
- bony spurs
how to diagnose lupus with acronymn
A RASH POINTS
name the antiplatelet classes
Cyclo-oxygenase inhibitors
ADP receptor antagonists
Phosphodiesterase inhibitors
glycoprotein IIb/IIIa inhibitors
active form of aspirin
hepatic hydrolysis to salicylic acid (active form)
MOA of ADP receptor antagonist prasrugel
- ADP receptor antagonist- inhibits binding of ADP to P2Y12 receptor
- Inhibiting activation of GPIIb/IIIa receptors (independent of COX pathway)
CYP inhibitors
omeprazole (PPI)
ciprofloxacin (abx)
erythromycin (abx)
some SSRIs e.g. fluoxetine
grapefruit juie
amiodarone
disulfarim
CYP inducers
phenytoin
carbamazepine
rifampicin
smoking
barbituates
sulphyureas
Mode of action: Dipyridamole
- Inhibits cellular reuptake of adenosine–> increased plasma [adenosine] –> inhibits platelet aggregation via adenosine (A2) receptors
- Also acts as a phosphodiesterase inhibitor which prevents cAMP degradation –> inhibits expression of GP IIb/IIIa
- inhibits activation of platelets
abcximab MOA
- Blocks binding of fibrinogen and von Willebrand factor (vWF)Abciximab= antibody- blocks GPIIb/IIIa receptors >80% reduction in aggregation – bleeding risk
- IV admin
- Target final common pathway- more complete platelet aggregation
classes of lipid lowering drugs
statins
fibric acid derivatives (fibrates)
cholesterol absorption inhibitors
PCSK9 inhibitors
Drug-drug interaction: Fenofibrate
warfarin- can increase the effects - bleeding
Mode of action: Fenofibrate (fibric acid dervivative)
Activation of nuclear TF such as PPARα (peroxisome proliferation-activated receptor)
PPARα regulates expression of genes that control lipoprotein metabolism- increase production of lipoprotein lipase
- increase TAG from lipoprotein in plasma (lipolysis)
- increase fatty acid uptake by the liver
- increase HDL levels
- increase LDL affinity for receptor
mode of action of cholesterol absoprtion inhibitors (Ezetimibe)
- inhibits NPC1L1 transporter at brush border
- reducing absorption of cholesterol by gut by 50%
- hepatic LDL receptor expression increase
- decrease in total cholesterol
PCSK9 inhibitors mode of action
- LDLR on the liver cell surface binds to LDL and the LDLR–LDL complex is then internalized, after which the LDLR is normally recycled back to the cell surface
- PCSK9 binds to the LDLR on the surface of the hepatocyte, leading to the internalization and degradation of the LDLR in the lysosomes, and reducing the number of LDLRs on the cell surface.
- Inhibition of secreted PCSK9 by PCSK9 inhibitors therefore increases the number of available LDLRs on the cell surface and increase uptake of LDL‐C into the cell.
- lowering LDL in plasma
main hypertension medication with example drug
ACEi (ramipril)
ARB (losartan and candesartan)
CCB
- dihydropyridine (nifedipine and amlodopine
-
non dihydropyridine
- phenylalkaline (veramapil)
- benzothiazepine (diltiazem)
Thiazide (bendroflumethiazide)and thiazide like diuretics (indapamide)
which antihypertensives should never be prescribed together
B blocker and Non-dihydropyridine CCBs
(verapamil and diltiazem- asystole!!)
name a drug under the drug class CA inhibitors
Acetazolamide
Diuretic delivery to renal tubule and disease: liver disease
- Gut oedema- reduces absorption or oral diuretic
- Reduced albumin- furosemide needs to be bound to albumin to be delivered to the kidneys
- Bound to albumin so not filtered
- Actively transported into PCT lumen via Organic Anion Transporter with albumin
Bartter’s syndrome
- Genetic defects which cause cotransporter not to work
- 100% blockage of the Na+/K+/2Cl- channel
- Like giving someone extreme furosemide
- Common symptoms include:
- muscle weakness, cramping and spasms
- fatigue
- excessive thirst (polydipsia)
- excessive urination (polyuria)
- nocturia
Gitelmans syndrome
- Genetic defects which cause cotransporter not to work
- 100% blockage of Sodium chloride channel
- Like giving extreme thiazide
- Symptoms
- painful muscle spasms (tetany), muscle weakness or cramping,
- dizziness, and
- salt craving
Liddles sydrome
-
eNac channels permanently turned on (dont need aldosterone) therefore excessive excretion of potassium and excessive reabsorption of sodium
- hypernatremia
- hypertension
- symptoms
- weakness
- fatigue
- palpitations
- muscular weakness
- shortness of breath
- constipation/abdominal distention
- exercise intolerance
- long-standing hypertension could become symptomatic.
DDI of loop diuretic
aminglycosides
- ototoxicity
- nephrotoxicity
NSAIDs and protein binding
NSAIDs displace other protein bound drugs- increasing free drug conc of other drugsParticularly high protein bound drugs
- MOA= competitive displacement
- Likely dose adjustment needed and increase monitoring
e.g.
- sulfonylureas- hypoglycaemia
- methotrexate – accumulation and hepatotoxicity
- warfarin- increased risk of bleeding
why does paracetamol have very little anti-inflammatory action
Related to peroxidases
Peroxide is important for the activity of paracetamol
In peripheral inflammation there is high levels of peroxidases which break down peroxide- therefore cant help with inflammation in peripheral tissue
renal considerations and NSAIDS
general MOA of corticosteroids
reduce transcription of IL-1 and IL-6
MOA of azathioprine
- Azathiprine is cleaved to 6-MP
- 6-MP is metabolised by TPMT to various molecules e.g. TIMP
- TIMP further metapolises to 6-MeMPN (antimetabolite)
- which inhibits purine synthesis
- DNA and RNA need purines to be made
Mode of action Mycophenolate mofetil
Inhibits inosine monophosphate dehydrogenase (required for guanosine synthesis)
Impairs B and T cell proliferation
Spares other rapidly dividing cells (due to guanosine salvage pathways in other cells)
what to remember with methotrexate
GIVEN WEEKLY
Methotrexate competitively and reversibly inhibits dihydrofolate reductase (DHFR)
adverse drug response Anti-TNFa
TB reactivation is a risk
TNFa released by macrophages in response to M TB infection
TNFa is essential for development and maintenance of granulomata
Need to screen for latent TB before anti-TNF treatment
rituximab depletes
B cells by bidning to CD20 receptor on B cells
Q
How is acid produced by parietal cells
- Carbonic anhydrase produces H2CO3 from water and carbon dioxide
- This dissociates to form HCO3- and H+
- H+ is pumped out of the cell on the apical membrane in exchange for potassium which comes into the cell
- Potassium conc of the lumen is replenished by the K+ transporter
- The chloride channel allows Cl- to move out of the cell into the lumen and combine with H+ à HCL
- Meanwhile the Cl- conc of the cell is maintained by the HCO3-/Cl- antiport on the basal membrane
- Influx of HCO3- into bloodstream= ALKALINE TIDE
confirmation of H.pylori infection
- Urea breath test
- Gastric urea= C12 isotopes (99%) and C13 isotopes= 1%
- Pts ingest urea with enriched C13
- H. pyrloi should convert this to ammonia and CO2
- Can detect C13 in exhaled CO2
- Stool antigen test
- Endoscopy with biopsy
H. pylori treatment
One week triple therapy
PPI + two antibacterial agents
- Lansoprazole + clarithromycin + amoxicillin OR
- Lansoprazole + clarithromycin + metronidazole (where allergic to amoxicillin )
Some evidence of local metronidazole resistance
Compliance with full course important for effectiveness and minimise risk of bacterial resistance
mesalazine first line treatment for
UC
Release of 5-aminosalsylic acid
Topical anti-inflammatory action at the colon (enteric coated tablets limit gastric breakdown)
Mesalazine has no role in rheumatoid arthritis (no systemic effect)
Sulfasalazine has more side effects so used infrequently for UC but sulfa group good for rheumatoid arthritis
Adverse drug response ICS
If taken correctly very few significant ADRS
Local immunosuppressive action e.g. candidiasis, horse voice (in pharynx)
Wash mouth out after
Pneumonia risk at high doses
Mode of action B agonists
- Bind to B2 receptors (GPCR)
- Increase cAMP
- Increase PKA
- Cause airway smooth muscle to relax
- Also increase mucus clearance by action of cilia
B agonist should alwyas be prescribed with
ICS
MOA of LTRA
Inhibit leukotrienes released by mast cells/eosinophils by blocking CysLT1 receptor
Reducing bronchoconstriction
Reducing mucus
Reducing oedema
define features of acute severe asthma
Unable to complete sentences
Peak flow 33-50% best or predicted
Respiratory rate ≥ 25/min
Heart rate ≥ 110/min
Plus any of the following considered life-threatening:
Peak flow < 33% best or predicted (if recordable)
Arterial oxygen saturation (SpO2) < 92%
Partial arterial pressure of oxygen (PaO2) < 8 kPa
Normal partial arterial pressure of carbon dioxide (PaCO2) (4.6–6.0 kPa)
Silent chest, Cyanosis, Poor respiratory effort, Arrhythmia, Exhaustion, Altered conscious level, Hypotension
treatment
Q
treatment of acute severe and life threatening asthma
A
Oxygen!!
Increase to 94-98%
High dose (nebulised) B2 agonist- continuous if necessary
Driven in with oxygen
Oral steroid (prednisolone) should be prescribed for minimum 5 days (IV if not oral- preferably oral)
Continuous IC alongside
Nebulised ipratropium bromide (ipratropium) – short acting muscarinic antagonist (SAMA) alongside b2 agonist if poor response alone
Ipratropium less selective for M3 receptors compared to tiotropium, M2 activity too
Consider IV aminophylline if life threatening/near fatal and no success with above
Caution with taking PO theophylline