pharmacology CKD Flashcards
What do you do for people under 135/85 mmHg bp?
Monitor at least every 5 years
When do you start drug treatment for people between 135/85 - 149/94 (stage 1) mmHg bp?
When they have any of these: target organ damage, CVD, renal disease, diabetes, 10 year CVD risk of 10% or more
what do you do for people with 150/95mmHg or more (stage 2 hypertension)?
start drug treatment
What are therapeutic objectives for someone with stage 2 hypertension and CKD?
Reduce hypertension to reduce CV risk & slow progression of CKD
For hypertension what treatment should you start if aged >55? What is the target bp and why, if they have CKD?
- Amlodipine (L-type calcium channel blocker).
- Target bp is less than normal due to CKD eg 130/70
For CKD what treatment should be offered?
Blood pressure management to slow progression of CKD regardless of cause
For CV risk what treatment should be offered?
Lifestyle modification: smoking, salt, exercise.
-If CV risk >10% atorvastatin (13%-31% depending on ethnicity). Statins reduce cholesterol
What is proteinuria a marker of?
glomerular dysfunction (leaking)
For significant proteinuria (ACR>30) what could be given? What considerations?
- ACE inhibitor or ARB. Or SGLT-2 inhibitor (dapaglifozin).
- Salt restriction to normal recommended levels.
- Stop amlodipine if ACE-inhibitor pushed blood pressure too low
Should you prescribe aspririn for CKD?
Consider in CKD in those with high risk of stoke or MI. but limited evidence of benefit even in those with many risk factors, and risk of harm. Generally avoid as primary prevention
What is the effect of trimethoprim on GFR ?
Invalidates GFR because inhibits active secretion of creatinine so equation is invalid (breaks link between creatinine and GFR)
How can ibuprofen and ACE inhibitors contribute to worsening GFR? What should be done to compensate?
- Ibuprofen inhibits PG synthesis and reduces renal blood flow.
- Ace inhibitors reduce perfusion pressure in glomerulus.
- NSAIDS not good if kidney damage. Stop NSAIDS, use paracetamol instead.
- Pause ACEi when acutely unwell.
What should we consider when prescribing drugs for someone with reduced renal function?
- might drug damage kidney and worsen kidney injury (ibuprofen)
- is drug eliminated by kidney so accumulates if kidney function impaired leading to side effects (eg. Morphine, metformin)
What are examples of statins?
Atorvastatin, simvastatin
What is mechanism of action of statins?
Competitive inhibitors of HMG-CoA reductase which is responsible for converting HMG-CoA to mevalonate in cholesterol synthesis. Statins reduce hepatic cholesterol synthesis, cause upregulation of LDL-receptors & increased hepatic uptake of LDL from circulation
What is drug target of statins?
HMG-CoA reductase
What are main side effects of statins?
Muscle toxicity (more likely with higher doses or in those with increased risk of muscle toxicity), constipation, diarrhoea, GI symptoms
What could potentially increase statin serum concentrations?
Co-administration with potent 3A4 inhibitors could increase statin serum concentrations
What is mechanism of aspirin?
Irreversibly inactivates COX enzyme, preventing conversion of arachidonic acid to produce prostaglandins. Reduction in thromboxane A2 in platelets reduces aggregation. Reduction of PGE2 at sensory pain neurones reduces pain and in brain decreases fever.
What is drug target of aspirin?
cyclo-oxygenase
What are side effects of aspirin?
Dyspepsia, haemorrhage.
What dose of aspirin should we avoid in elderly and why?
Avoid doses greater than 160mg daily because increased risk of bleeding
If history of peptic ulcer what could be do with aspirin?
co-administer PPI
How does aspirin contribute to peptic ulcer?
Blockade of COX1 in gastric mucosal cells reduces bicarbonate production exposing stomach lining to acid