RENAL U5 Flashcards
By what three routes organisms might reach the urinary tract?
- The ascending (most freq. route)
- Blood-borne (spread to the kidney can occur in bacteraemic diseases)
- Lymphatic routes (little evidence for this route)
why are UTIs more common in females?
urethra is shorter and the urethral meatus is closer to the anus ALSO sexual intercourse is important in forcing bacteria into the female bladder
what virulence factors of organisms cause an individual to become susceptible to UTIs?
P fimbrae (attach to cells) , K antigens (resistant to phagocytosis) , iron scavenging aerobactin system
symptoms of UTIs in babies and infants?
- Failure to thrive
- Vomiting and diarrhoea
- Fever and apathy
what does the national guidance published in UKs say about children with unexplained fever?
they should have thier urine tested within 24h and attention is given to avoid over/under diagnosis and prompt start of A/B.
what is urethral syndrome?
women with dysuria the urine sample contains less than 100,000 bacteria/ml
how would you investigate for UTIs in Uncircumcised men?
retract foreskin followed by controlled micturition in which 20ml of urine from only the midportion of the stream is collected (initial and final components being voided)
what is the griess test?
Nitrate test - detects urinary nitrite made by bacteria that can convert dietary nitrate used to nitrite also, the test depends on enough nitrate in the diet and on allowing at least 4h for conversion
Criteria for diagnosing UTIs in different groups
Even though the criteria is >100,000 in some groups it is less for example;
• Men >1000ml
• Women with symptoms of UTI >100/ml
when is nitrofurantoin active?
only at acidic pH
what are the agents of choice in the presence of renal failure?
cephlasporins and penicillins
what is fosfomycin?
broad spectrum A/B that favours its use for treatment of cystitis with a single oral dose
why are quinolones contraindicated in children?
risk of causing joint problems
what is first line treatment for acute pyelonephritis?
cefuroxime, gentamicin or ciprofloxacin. for 10-14 days
which drugs have been implicated with clostridium difficile?
cephlasporins and quinolones
what is recurrent cystitis defined as?
defined as 3 episodes in past 12 months or 2 episodes in the past 6 months
when is nitrofurantoin contraindicated?
<45ml
what is prophylaxis for recurrent UTI management?
Trimethoprim 200mg single dose when exposed to a trigger or 100mg at night
Nitrofurantoin 100mg single dose when exposed or 50mg-100mg at night
what is the most likely cause of urethritis?
STD
Management for urethritis if referral to GUM clinic is denied?
- Doxycycline 100mg BD for 7 days or
- Azithromycin 1g, single dose for 1 day then 500mg for 2 days or
- Ofloxacin 200mg BD or 400mg daily for 7 days
what are risk factors for prostatitis?
- STIs and UTIs
- Indwelling catheters
- Acute bacterial prostatitis
- Increases with age
- Following manipulation of the gland – e.g. post-biopsy
symptoms of prostatitis?
- Fever, malaise, myalgia
- Urinary frequency, urgency, dysuria and nocturia
- Low back pain, low abdominal pain
- Pain on ejaculation is commonly reported
- Urethral discharge
treatment for acute prostatitis?
1st line – fluoroquinolones (e.g. ciprofloxacin or ofloxacin) for 4 weeks for 14 days then review
when should you not prescribe an alpha blocker?
if the person has postural hypotension, bladder stones
which alpha blockers should you avoid in severe hepatic impairment?
tamsulosin and MR alfuzosin
what drug would you use for nocturnal polyuria?
furosemide 40mg OD, demsopressin
what drug interactions increase the levels of demsopressin?
loperamide, NSAIDs, TCAs, SSRI, chlorpromazine
how long do alpha-reductase inhibitors need to be taken for effect?
6 months
common side effects of dutasteride?
sexual problems, depression, mood alterations, breast tenderness/enlargement
how does dutasteride treat voiding symptoms?
inhibits conversion of testosterone to dihydrotestosterone (DHT) and DHT is what causes the enlargement of the prostate gland and improved urinary flow
who are anti-muscuranics contraindicated in?
Myasthenia Gravis, severe UC, toxic megacolon, GI obstruction, uncontrolled angle-closure glaucoma, intestinal atony, sever liver disease
what is the supply criteria for tamsulosin?
- Male between 45-75 years
- Symptoms of BPH for a minimum of 3 months
- 2 weeks supply of tamsulosin can be given initially – if there has been an improvement a further supply of 2 weeks can be made
- After 6 weeks, a further supply can be made when the patient confirms a clinical assessment has been carried out
which drugs can alter haemodynamics?
ACEI, ARBs, NSAIDs
which drugs can cause crystal nephropathy?
methotrexate, ciprofloxacin, sulphonamides, aciclovir, ampicillin
what can aminoglycosides and zoledronate cause?
tubular toxicity
how would you detect AKI?
A rise in serum creatinine of 26micromol or greater within 48 hours
50% or greater rise in serum creatinine known or presumed to have occurred within past 7 days
Fall in urine output less than 0.5ml for more than 6 hours and more than 8 in children
what are clinical manifestations of CKD?
anaemia, uraemia, bone disease, neurological changes, HTN, proteinuria, haematuria, urinary tract features
what would you ideal drug have in renal failure?
- <25% excreted unchanged in urine
- No active/toxic renally cleared metabolites
- Levels minimally affected by fluid balance or protein-binding
- Wide therapeutic margin and low adverse effect profile
- Not nephrotoxic, able to reach the site of action in high enough concentration
what is the most common disease that leads to CKD?
DM
how would you optimised volume status in AKI?
Sodium and volume restriction are generally required along with limiting potassium and phosphorus intake.
what is first line treatment for UTIs in pregnancy?
nitrofurantoin - but avoid close to delivery time as causes haemolysis in baby
amoxicillin/cefalexin - 2nd line
why is trimethoprim contraindicated in pregnancy?
causes folate anatagonism - causes NTDs
what is second line treatment for UTIs in females?
use trimethoprim 200mg BD IF NOT used before or nitrfurantoin 50mg QDS - if not then use pivmecillinam 400mg initially then 200mg TDS for 3 days
what is the dosage for anti-muscuranics in overactive bladder?
oxybutynin - 5mg
solifenacin - 5mg
tolterodine - 2mg
when should you avoid tolteradine?
ventricular arrythmias
what is the recommended BP target goal for patients with CKD?
140/90
what is first line in patients without proteinuria in CKD?
CCB
what is metolazone?
thiazide-like diuretic - used as 2nd line if loop diuretic is ineffective treating fluid overload in CKD
if your ACR is 30mg/mmol or more in CKD/HTN what is the antihypertensive of choice?
ACEI/ARBs
when are ACEI the antihypertensive of choice in HTN/CKD?
- DM and an ACR of 3 mg/mmol or more (ACR category A2 or A3)
- HTN and an ACR of 30 mg/mmol or more (ACR category A3)
- ACR of 70 mg/mmol or more (irrespective of hypertension or cardiovascular disease)
where is erythropoetin mainly produced?
by the fibroblastoid cells in the cortex and the outer medulla of the kidney
treatment of renal anaemia?
ESAs e.g. darbepoetin alfa or a longer acting form which is methoxy polyethylene glycol-epoetin beta)
iron/folate deficiency must be corrected before therapy is initiated
pathophysiology of CKD-MBD
cholecalciferol needs to be hydroxylated and at position 1a occurs in kidney but this is impaired with renal failure - results in vit D deficiency leading to defective bone mineralisation
what stimulates secretion of PTH leading to hyperparathyroidism?
serum phosphate
treatment of hyperphosphataemia?
phosphate binding agents - calcium acetate, sevelamer, lanthanum
treatment for vitamin D deficiency?
alfacalcidol OR if ineffective paricalcitol
treatment for nausea and vomitting?
metclopramide, cyclizine, prochlorperazine,
what is ondansentron indicated for?
treatment of nausea and vomitting in post op, 5HT3-receptor antagonist
why should you avoid ispaghula in treatment of constipation?
due to high K+ content
treatment of acidosis?
oral doses of sodium bicarbonate
dose for toleteradine
2mg BD - not to be used with pts on anti-arrhythmic drugs
dose for tamsulosin
400mcg
dose for finasteride
5mg
dose for dutasteride
10mg
dose for desmopressin
50mcg - CI in over 65, alcohol abuse, hx of hyponatraemia, taking duiretics, HF
dose for oxybutynin
5mg gradually increasing by 5mg/weekly to max 20mg
which alpha blockers should be avoided in hepatic imapairment?
MR alfuzosin and tamsulosin
which alpha blockers do not need dose adjustment in hepatic impairment?
terazocin and doxazcosin
which patients should not be prescribed alpha blockers?
bladder stones, chronic UTIs, BPH with concomitant congestion of upper urinary tract
