Why this topic matters in emergency medical care
The kidneys regulate fluid, electrolytes, acid–base balance, blood pressure and drug elimination. Urinary medicines can relieve obstruction, treat infection, alter blood pressure, remove fluid, correct electrolyte emergencies or replace renal function. However, the same medicines can worsen acute kidney injury (AKI), accumulate to toxic levels or hide a life-threatening obstructed infection.
This lesson is for EMT and nursing education. Use current Uganda Ministry of Health guidance, local antimicrobial policies, prescriber orders, renal dosing references and age-specific protocols in practice.
Learning outcomes
- Explain renal filtration, tubular handling, urine concentration and the renin–angiotensin–aldosterone system.
- Classify urinary antimicrobials, diuretics, analgesics for renal colic, alpha blockers, medicines for overactive bladder and renal-protective therapies.
- Recognise cystitis, pyelonephritis, urosepsis, obstructed infected kidney, AKI, chronic kidney disease, renal colic and electrolyte emergencies.
- Apply safe renal dose and route principles, fluid assessment, urine monitoring and medicine reconciliation.
- Identify nephrotoxins, interactions, pregnancy considerations, dialysis issues and escalation triggers.
1. Renal physiology and medicine targets
Each nephron filters plasma at the glomerulus, reabsorbs and secretes solutes through the tubules, and concentrates urine through the loop of Henle and collecting duct. The kidneys activate vitamin D, release erythropoietin and regulate renin. Reduced renal function changes drug clearance, fluid balance, potassium, acid–base status and blood pressure.
| Target | Physiological role | Medicine examples | Emergency relevance |
|---|---|---|---|
| Renin–angiotensin–aldosterone system | Maintains vascular tone and sodium retention | ACE inhibitors, ARBs, mineralocorticoid antagonists | Protective in selected CKD but can worsen AKI or hyperkalaemia during dehydration. |
| Loop sodium–potassium–chloride cotransporter | Concentrates urine and reabsorbs sodium | Furosemide | Rapid diuresis for pulmonary oedema; electrolyte depletion and ototoxicity risk. |
| Distal sodium–chloride transporter | Regulates sodium and calcium handling | Thiazide diuretics | Hypertension and stone prevention; hyponatraemia, hypokalaemia and hyperglycaemia. |
| Collecting duct epithelial sodium channel/aldosterone receptor | Sodium retention and potassium excretion | Amiloride, spironolactone | Useful in selected heart failure/aldosterone excess; hyperkalaemia can be fatal. |
| Vasopressin V2 receptor | Water reabsorption via aquaporins | Desmopressin, vasopressin antagonists | Controls diabetes insipidus or selected hyponatraemia; rapid sodium shifts are dangerous. |
| Ureteric smooth muscle/alpha-1 receptor | Peristalsis and outlet tone | Tamsulosin and other alpha blockers | May help selected distal stones; dizziness and hypotension risk. |
2. Practical classification of urinary medicines
| Group | Examples | Main role | Major concern |
|---|---|---|---|
| UTI antibiotics | Nitrofurantoin, trimethoprim, fosfomycin, beta-lactams, fluoroquinolones | Cystitis, pyelonephritis or complicated infection | Resistance, renal dosing, allergy and tissue penetration |
| Loop diuretics | Furosemide | Oedema, pulmonary oedema, fluid overload | Hypovolaemia, hypokalaemia, hyponatraemia and ototoxicity |
| Thiazide diuretics | Hydrochlorothiazide, bendroflumethiazide | Hypertension, mild oedema, calcium stone prevention | Hyponatraemia, hypokalaemia, gout and hyperglycaemia |
| Potassium-sparing/aldosterone blockers | Spironolactone, eplerenone, amiloride | Heart failure, hyperaldosteronism, selected hypertension | Hyperkalaemia and renal accumulation |
| Renal colic medicines | NSAIDs, paracetamol, opioids | Acute stone pain | NSAID kidney injury/bleeding; opioid sedation and ileus |
| Alpha blockers | Tamsulosin, doxazosin | Selected distal ureteric stone passage or outlet symptoms | Postural hypotension and syncope |
| Bladder medicines | Oxybutynin, solifenacin, mirabegron | Overactive bladder | Anticholinergic delirium/retention or hypertension |
| Electrolyte/acid-base therapy | Calcium, bicarbonate, potassium binders | Selected renal/metabolic emergencies | Arrhythmia, alkalosis and rapid electrolyte shifts |
3. Urinary tract infection medicines
UTI treatment depends on site, severity, pregnancy, age, renal function, catheter status and local resistance. Lower UTI (cystitis) usually causes dysuria, frequency and urgency without systemic illness. Pyelonephritis causes fever, flank pain, nausea, vomiting and systemic features. An obstructed infected kidney is a urological emergency requiring drainage as well as antibiotics.
| Medicine/group | Typical role | Important safety points |
|---|---|---|
| Nitrofurantoin | Lower UTI when renal function and site are appropriate | Does not achieve adequate tissue levels for pyelonephritis; check renal function and pulmonary/hepatic toxicity with prolonged use. |
| Trimethoprim | Selected uncomplicated lower UTI | Hyperkalaemia, renal impairment, interactions with ACE inhibitors/ARBs/spironolactone and pregnancy considerations. |
| Fosfomycin | Selected resistant or uncomplicated lower UTI | Use local availability/resistance guidance; not a universal treatment for upper UTI. |
| Beta-lactams | Selected cystitis or pyelonephritis regimens | Check allergy, renal adjustment and culture results. |
| Fluoroquinolones | Selected complicated/upper UTI under local specialist guidance | Tendon, neurological, QT and aortic risks; reserve for appropriate indications. |
| Aminoglycosides | Severe resistant infection in monitored hospital care | Nephrotoxic and ototoxic; therapeutic drug monitoring is essential. |
3.1 Antibiotic safety
- Obtain urine culture before antibiotics when indicated and when this does not delay treatment in sepsis.
- Review previous cultures, recent antibiotics, catheter history, allergies and renal function.
- Complete the prescribed course; do not share leftover antibiotics or stop when symptoms first improve.
- Escalate for fever with flank pain, rigors, hypotension, vomiting, pregnancy, male UTI, child UTI, catheter-associated infection or immunosuppression.
4. Pyelonephritis, urosepsis and infected obstruction
Pyelonephritis can progress to sepsis, AKI and shock. A ureteric stone or stricture can block infected urine, preventing antibiotics alone from controlling the source. Red flags include severe colic with fever, anuria/oliguria, rigors, hypotension, confusion, rising creatinine or a single functioning kidney.
- Perform ABCDE, check glucose, temperature, perfusion, urine output and mental status.
- Establish IV/IO access where trained, obtain cultures and lactate when available, and begin sepsis resuscitation under protocol.
- Give timely broad-spectrum antibiotics authorised by the local guideline, adjusted for renal function.
- Use cautious crystalloid boluses with frequent reassessment, especially in heart or kidney failure.
- Arrange urgent imaging and urology review for obstruction; source control may require stent or nephrostomy.
5. Diuretics
| Class | Mechanism | Uses | Adverse effects |
|---|---|---|---|
| Loop diuretic | Blocks Na-K-2Cl transport in thick ascending limb | Pulmonary oedema, heart failure, severe oedema | Hypokalaemia, hyponatraemia, hypomagnesaemia, dehydration, hypotension and ototoxicity. |
| Thiazide | Blocks Na-Cl transport in distal convoluted tubule | Hypertension, mild oedema and selected calcium stones | Hyponatraemia, hypokalaemia, hypercalcaemia, hyperuricaemia and glucose intolerance. |
| Potassium-sparing | Blocks ENaC or aldosterone receptor | Heart failure, hyperaldosteronism, resistant hypertension | Hyperkalaemia, renal impairment, endocrine adverse effects with spironolactone. |
| Osmotic | Raises tubular osmotic load | Specialist intracranial-pressure or renal indications | Fluid shifts, pulmonary oedema and electrolyte disturbance. |
5.1 Furosemide safety
- Assess blood pressure, perfusion, fluid status, lung findings, renal function, electrolytes and recent dose before giving.
- In acute pulmonary oedema, nitrates and positive-pressure ventilation may be more immediately important than diuresis.
- Rapid IV administration can cause ototoxicity; use the prescribed rate and monitor hearing/neurological symptoms.
- Over-diuresis can precipitate AKI, hypotension and electrolyte-driven arrhythmia.
6. Acute kidney injury and nephrotoxic medicines
AKI is a sudden reduction in kidney function, often recognised by rising creatinine or reduced urine output. Causes include dehydration/low perfusion (pre-renal), obstruction (post-renal), infection, toxins, inflammation and intrinsic renal disease. Medicine management requires identifying and stopping avoidable nephrotoxins, correcting perfusion and treating the cause—not simply giving a diuretic.
| Nephrotoxin/risk | Potential injury | Safety response |
|---|---|---|
| NSAIDs | Reduce renal prostaglandin-mediated perfusion | Avoid in dehydration, shock, CKD or AKI; use safer analgesic plan. |
| ACE inhibitor/ARB | Reduces intraglomerular pressure; can worsen AKI during hypovolaemia | Medication reconciliation and clinician review during acute illness. |
| Aminoglycosides/vancomycin | Tubular injury and accumulation | Culture-directed use, renal dosing and drug-level monitoring. |
| Contrast media | Risk in vulnerable patients | Assess AKI/CKD, dehydration and nephrotoxins; follow imaging protocol. |
| Herbal/traditional remedies | Unknown nephrotoxic ingredients or contamination | Ask non-judgementally and document all products. |
7. Chronic kidney disease and renal dose adjustment
CKD changes clearance, protein binding, acid–base balance, erythropoiesis, bone-mineral metabolism and cardiovascular risk. A “normal” creatinine can be misleading in a small or frail person with low muscle mass. Dose decisions should use the prescribed renal function estimate and specialist guidance.
- Renally cleared antibiotics, opioids, gabapentinoids, insulin, anticoagulants and sedatives may need lower doses or longer intervals.
- Accumulation can present as confusion, excessive sleepiness, ataxia, respiratory depression, bleeding or severe nausea.
- Ask whether the patient receives haemodialysis, peritoneal dialysis or a transplant; timing around dialysis changes medicine removal.
- Avoid abrupt fluid loading in anuric patients; pulmonary oedema can develop rapidly.
8. Electrolyte and acid–base emergencies
| Emergency | Clinical clues | Medicine/support principle |
|---|---|---|
| Hyperkalaemia | Weakness, paraesthesia, bradycardia, peaked T waves, widened QRS | Cardiac monitoring; IV calcium stabilises myocardium, while insulin/glucose and other therapies shift or remove potassium under protocol. |
| Hypokalaemia | Weakness, cramps, ileus, U waves and arrhythmia | Replace potassium carefully with ECG/renal monitoring; treat magnesium deficiency and cause. |
| Hyponatraemia | Headache, confusion, seizures, nausea | Identify acute/severe symptoms; hypertonic saline is specialist-controlled because rapid correction can injure the brain. |
| Metabolic acidosis | Deep breathing, confusion, hypotension | Treat cause such as sepsis, DKA or renal failure; bicarbonate is selective, not routine. |
| Uraemia | Confusion, pericarditis, pruritus, nausea, bleeding tendency | Urgent renal review; dialysis may be required for refractory complications. |
9. Alpha blockers and renal colic
NICE recommends an NSAID as first-line analgesia for suspected renal colic when not contraindicated; IV paracetamol is an alternative when NSAIDs are unsuitable or insufficient, with opioids considered when necessary. Alpha blockers may be considered for selected distal ureteric stones under clinician direction.
- Check pregnancy, renal function, GI bleeding, anticoagulants, asthma and allergy before NSAIDs.
- Alpha blockers may cause postural hypotension, dizziness and syncope; counsel the patient to rise slowly.
- Unrelenting pain, fever, anuria, solitary kidney or rising creatinine requires urgent urological review—not repeated outpatient analgesia.
10. Bladder and urinary-symptom medicines
| Class | Examples | Role | Emergency precautions |
|---|---|---|---|
| Antimuscarinics | Oxybutynin, solifenacin, tolterodine | Overactive bladder and urgency | Dry mouth, constipation, blurred vision, delirium and urinary retention; avoid in obstruction or high anticholinergic burden. |
| β3 agonist | Mirabegron | Relaxes detrusor muscle | May raise BP; review severe hypertension and interactions. |
| Urinary analgesic | Phenazopyridine where available | Short-term dysuria symptom relief | Does not treat infection; urine discoloration and renal/hepatic cautions. |
| Desmopressin | V2 agonist reduces urine output | Diabetes insipidus, nocturnal enuresis and selected bleeding disorders | Water intoxication and hyponatraemia; fluid restriction and sodium monitoring matter. |
11. Dialysis and medicine considerations
- Ask the patient’s dialysis schedule, vascular access type and last session; missed dialysis can cause fluid overload, hyperkalaemia and uraemia.
- Never take blood pressure or insert IV lines in a functioning arteriovenous fistula arm unless the renal team authorises it.
- Some medicines are removed by dialysis, some are not, and timing may be deliberately post-dialysis.
- Patients may be anticoagulated during dialysis; bleeding and access-site complications require careful pressure and documentation.
- Urgent transfer is required for pulmonary oedema, severe hyperkalaemia/ECG changes, pericarditis, severe acidosis or altered consciousness.
12. Clinical scenarios
Scenario 1: Pyelonephritis with sepsis
A febrile patient has flank pain, rigors, tachycardia and hypotension. Perform ABCDE, obtain access and cultures where feasible, start authorised sepsis fluids/antibiotics with renal adjustment and transfer urgently. Ask about stones because obstruction changes the required source control.
Scenario 2: Infected obstructed kidney
A patient with renal colic develops fever and anuria. Do not treat as simple pain. Give monitored support, avoid delaying antibiotics and arrange emergency urology assessment for drainage.
Scenario 3: AKI after vomiting
A dehydrated patient has taken ibuprofen and an ACE inhibitor during gastroenteritis. Review nephrotoxins, restore perfusion cautiously, monitor urine output/electrolytes and seek clinician review before further doses.
Scenario 4: Hyperkalaemia
A dialysis patient has weakness and a wide QRS. Place on ECG monitoring, call advanced help and follow the hyperkalaemia protocol. Calcium protects the myocardium but does not remove potassium; insulin/glucose and definitive dialysis may be required.
Scenario 5: Renal colic in pregnancy
A pregnant patient has flank pain and haematuria. Avoid casual NSAID use, assess for infection/obstruction and arrange obstetric/urological advice for analgesia and imaging.
Scenario 6: Diuretic-related collapse
A patient on high-dose furosemide is dizzy with low BP and cramps. Check fluid status, ECG and electrolytes; do not automatically give another diuretic for ankle swelling.
13. Monitoring and documentation
Record urine output, fluid intake/losses, weight when available, BP, pulse, perfusion, lung findings, mental status, medication/last dose, allergy, renal function and ECG. For antibiotics document culture, dose, time and response. For diuretics document urine response and electrolytes. Handover the last dialysis session, access site, obstruction risk and any nephrotoxins.
14. Revision questions
- Explain how the kidneys alter medicine clearance.
- Differentiate cystitis, pyelonephritis and urosepsis.
- Why is an infected obstructed kidney a source-control emergency?
- List the common nephrotoxic medicines and risk situations.
- Compare loop, thiazide and potassium-sparing diuretics.
- What are the danger signs of furosemide over-diuresis?
- Why can trimethoprim cause hyperkalaemia?
- Explain first-line pharmacological care of renal colic.
- When may alpha blockers be considered?
- How should dialysis access be protected?
- List signs of hyperkalaemia requiring ECG monitoring.
- Why is rapid correction of hyponatraemia dangerous?
- What are the major cautions for NSAIDs in renal patients?
- Compare antimuscarinic bladder medicines with mirabegron.
- Which findings suggest AKI?
- How does renal failure alter opioid and gabapentinoid safety?
- What information is essential in a urinary medicine handover?
- Write a safe plan for a patient with UTI, hypotension and reduced urine output.
15. Key takeaways
- Renal patients need medicine reconciliation, renal-dose review, electrolyte monitoring and careful fluid assessment.
- Fever plus obstruction, anuria or shock is an emergency; antibiotics alone may not control the source.
- NSAIDs help renal colic but can worsen AKI, bleeding and heart failure.
- Diuretics remove fluid but do not automatically improve kidney function; over-diuresis causes shock and electrolyte arrhythmia.
- Hyperkalaemia, severe acidosis, pulmonary oedema and uraemic complications require urgent monitored care and possible dialysis.
- Document urine output, last doses, last dialysis, access site, cultures and every medicine/fluid given.
16. Recommended references for further study
- Pharmacology of the Urinary System – SlideShare teaching resource
- NICE: Lower UTI antimicrobial prescribing
- NICE: Acute pyelonephritis antimicrobial prescribing
- NICE: Renal and ureteric stones
- NICE: Acute kidney injury
- WHO: Kidney disease fact sheet
Clinical note: This page supports EMT learning and revision. It does not replace an authorised prescription, local emergency protocol, senior supervision or patient-specific advice. In a deteriorating patient, stabilise ABCDE, call for advanced help and transfer urgently.
Complete Urinary and Renal Pharmacology Tables
Dosage and stewardship note: Adult doses below are common teaching examples. Confirm urine culture guidance, pregnancy, allergy, severity, current weight, renal function, obstruction and the Uganda/facility antimicrobial protocol. Adjust renally cleared medicines and never delay drainage or referral when obstruction, sepsis or infected stones are suspected.
Medicines for Urinary Tract Infection
| Medicine | Pharmacodynamics and pharmacokinetics | Indications and common adult dosage examples | Contraindications/precautions | Interactions | Side effects and serious adverse effects | Monitoring and nursing responsibilities |
|---|---|---|---|---|---|---|
| Nitrofurantoin | Reduced inside bacteria to reactive intermediates that damage DNA/proteins. Rapid oral absorption and renal secretion produces high urine but poor renal-tissue/serum levels. | Uncomplicated lower UTI when susceptible. Common regimen 100 mg orally twice daily for 5 days, formulation/protocol dependent. | Not for pyelonephritis, prostatitis or urosepsis. Avoid significant renal impairment according to current eGFR threshold; avoid at term pregnancy and in G6PD deficiency where haemolysis risk matters. | Magnesium antacids reduce absorption; probenecid reduces urinary secretion and raises toxicity. | Nausea, headache and brown urine. Serious: pulmonary reaction/fibrosis, hepatitis, neuropathy and haemolysis. | Confirm lower-tract infection and renal function. Give with food. Escalate fever/flank pain/sepsis. Report cough, dyspnoea, jaundice or neuropathy, especially with prolonged use. |
| Trimethoprim–sulfamethoxazole | Sequentially blocks bacterial folate synthesis; good oral absorption and renal elimination. | Susceptible uncomplicated UTI and selected complicated infections. Double-strength tablet 160/800 mg twice daily; duration commonly 3 days for uncomplicated cystitis and longer for complicated disease, guided by culture/resistance. | Severe sulfonamide allergy, marked liver disease, severe renal failure without monitoring and late pregnancy/young infants. Caution G6PD deficiency and folate deficiency. | Raises warfarin effect, potassium with ACEI/ARB/spironolactone, methotrexate toxicity and sulfonylurea hypoglycaemia. | Rash, nausea and photosensitivity. Serious: Stevens–Johnson syndrome, marrow suppression, hyperkalaemia, AKI/interstitial nephritis and haemolysis. | Culture when indicated; check renal function, potassium, CBC for prolonged therapy and interactions. Stop/escalate rash with mucosal lesions, jaundice or cytopenia signs. |
| Fosfomycin trometamol | Blocks early peptidoglycan synthesis; single oral dose produces high urine concentrations and is excreted unchanged. | Selected uncomplicated lower UTI: 3 g orally once. Not appropriate for pyelonephritis or sepsis. | Severe renal impairment and complicated upper infection require review. | Metoclopramide can lower urinary concentrations. | Diarrhoea, nausea, headache and vaginitis; rare severe allergy or C. difficile infection. | Dissolve sachet correctly; verify lower UTI and follow culture/local resistance. Reassess non-response or systemic symptoms. |
| Ciprofloxacin | Fluoroquinolone inhibits DNA gyrase/topoisomerase IV; good oral bioavailability, tissue penetration and renal clearance. | Selected pyelonephritis/complicated UTI when benefits and susceptibility justify use. Common adult example 500 mg orally twice daily for 7 days; regimen varies and resistance may limit use. | Avoid routine uncomplicated cystitis when safer options work. Caution pregnancy, seizure, QT prolongation, aortic disease, myasthenia and renal impairment. | Calcium/iron/antacids reduce absorption; raises theophylline/tizanidine toxicity; QT drugs and warfarin interact. | Nausea and diarrhoea. Serious: tendon rupture, neuropathy, CNS effects, dysglycaemia, QT arrhythmia, aortic events and C. difficile. | Obtain culture for complicated disease. Separate cations. Stop for tendon pain, neuropathy or severe CNS symptoms. Adjust renal dose and reinforce stewardship. |
| Ceftriaxone | Third-generation cephalosporin inhibits cell-wall synthesis; long half-life permits daily dosing, biliary/renal elimination. | Severe pyelonephritis/urosepsis and initial empiric therapy per local protocol. Common adult 1–2 g IV once daily, severity-dependent. | Severe immediate beta-lactam allergy; hyperbilirubinaemic neonates. Do not mix with calcium-containing IV solutions in neonates. | Warfarin effect may rise; IV calcium compatibility rules. | Diarrhoea, rash and injection pain. Serious: anaphylaxis, C. difficile, biliary sludging and cytopenias. | Obtain cultures before antibiotics when possible without delaying sepsis therapy. Check allergy, observe first doses, review culture for narrowing and monitor response/renal-liver status. |
Diuretics and Medicines Affecting Urine Flow
| Medicine/class | PD/PK | Indications and dose | Contraindications/interactions | Side/adverse effects | Nursing care | |
|---|---|---|---|---|---|---|
| Furosemide | Blocks Na-K-2Cl cotransporter in thick ascending limb, producing potent natriuresis; rapid IV and renal elimination. | Pulmonary/peripheral oedema and selected hyperkalaemia with urine production. Acute adult 20–40 mg IV slowly, higher if chronic exposure/renal dysfunction. | Severe volume/electrolyte depletion and anuria. NSAIDs reduce effect; aminoglycosides increase ototoxicity; digoxin risk rises with low K. | Hypotension, dehydration, low Na/K/Mg, AKI and gout; rapid high dose causes ototoxicity. | Weight, strict balance, BP, oedema/lungs, creatinine and electrolytes. Confirm obstruction is not causing anuria; do not use merely to force urine in established AKI. | |
| Spironolactone | Blocks aldosterone receptor in collecting duct, sparing potassium; hepatic active metabolites. | Ascites, HFrEF, hyperaldosteronism and resistant hypertension. Common 25–100 mg/day depending indication. | Hyperkalaemia, Addison disease and severe renal impairment. ACEI/ARB, trimethoprim and potassium increase hyperkalaemia. | Hyperkalaemia, gynaecomastia, menstrual disturbance; serious arrhythmia. | Baseline/serial K and renal function, BP and weight. Teach avoidance of potassium supplements/salt substitutes unless prescribed. | |
| Mannitol | Filtered but not reabsorbed; increases plasma osmolality and osmotic diuresis. | Selected raised intracranial/intraocular pressure—not routine AKI. Dose is weight-based, commonly 0.25–1 g/kg IV by specialist protocol. | Anuria, pulmonary oedema, severe dehydration and active intracranial bleeding except selected surgery. | Other nephrotoxic agents and diuretics intensify fluid/electrolyte problems. | Initial volume expansion, pulmonary oedema, dehydration, sodium disturbance and AKI. | Use filter set, inspect for crystals, warm/dissolve per product instructions, strict balance, osmolality/electrolytes and respiratory monitoring. |
| Tamsulosin | Selectively blocks alpha-1A receptors in prostate/ureter, relaxing smooth muscle; hepatic CYP metabolism. | BPH urinary symptoms and selected medical expulsive therapy for ureteric stones. Common 0.4 mg once daily after the same meal. | Severe orthostatic hypotension; caution cataract surgery, hepatic/renal impairment. | PDE5 inhibitors and antihypertensives increase hypotension; strong CYP3A4 inhibitors raise levels. | Dizziness, orthostasis, ejaculatory disorder and headache; rare priapism. | Check lying/standing BP and falls risk. Teach first-dose dizziness and to tell ophthalmic surgeon about current/past use. |
| Potassium citrate | Alkalinises urine and raises urinary citrate, binding calcium and reducing selected stone formation; renal elimination. | Hypocitraturia, uric-acid and cystine stones under metabolic evaluation. Dose is based on urine citrate/pH, often divided with meals. | Hyperkalaemia, severe renal failure, delayed GI transit and active untreated UTI with urease organisms. | ACEI/ARB/MRA/trimethoprim increase potassium; anticholinergics slow transit. | GI irritation, nausea and hyperkalaemia; serious arrhythmia or GI ulceration. | Monitor K, renal function and urine pH/citrate. Give with food/water, swallow extended-release tablets whole and avoid empiric use without stone evaluation. |
Acute Kidney Injury and Electrolyte Emergency Medicines
| Medicine | Mechanism | Indication/dose principle | Major risks/interactions | Nursing responsibilities | |
|---|---|---|---|---|---|
| Calcium gluconate | Stabilises myocardial membrane; does not remove potassium. | Hyperkalaemia with ECG changes: common adult 10 mL of 10% IV slowly, repeat if ECG changes persist. | Extravasation, bradyarrhythmia and digoxin toxicity caution; incompatible with bicarbonate/phosphate in same line. | Continuous ECG, secure IV, confirm concentration and follow with potassium-shifting/removing therapy. | |
| Insulin plus glucose | Insulin activates Na/K ATPase and shifts potassium intracellularly; glucose prevents hypoglycaemia. | Severe hyperkalaemia: common adult 10 units regular insulin IV with 25 g glucose, protocol-dependent; dose reduction may be needed in renal failure/high hypoglycaemia risk. | Severe/prolonged hypoglycaemia and hypokalaemia. Beta-blockers mask symptoms. | Independent dose check, baseline and frequent glucose for at least several hours, repeat potassium/ECG and ensure definitive removal plan. | |
| Nebulised salbutamol | Beta-2 stimulation shifts potassium into cells. | Adjunct in hyperkalaemia; high-dose nebulised regimens are protocol-directed and not monotherapy. | Tachyarrhythmia/ischaemia; beta-blockers reduce response. | Monitor ECG, pulse and potassium; do not rely on it alone. | |
| Sodium bicarbonate | Raises extracellular bicarbonate/pH and may shift potassium when metabolic acidosis is present. | Selected severe metabolic acidosis, sodium-channel blocker toxicity and hyperkalaemia with acidosis. Dose based on blood gas and cause—not routine for every AKI. | Volume/sodium overload, hypocalcaemia, alkalosis and paradoxical intracellular acidosis; incompatible with calcium in same line. | Blood gas, sodium, calcium, fluid status and ventilation; use infusion pump and reassess cause. | |
| Sodium polystyrene sulfonate | GI cation-exchange resin removes potassium slowly. | Selected non-immediate potassium removal; onset is delayed and effect unpredictable. Not emergency monotherapy. | Bowel obstruction/ileus and postoperative bowel; sorbitol increases intestinal necrosis risk. | Constipation, electrolyte disturbance; serious colonic necrosis. | Assess bowel function, avoid when ileus suspected, monitor electrolytes and arrange dialysis when indicated. |
Renal Dose Adjustment and Nephrotoxicity
- Estimate current renal function: acute creatinine changes make equations unreliable; use trends, urine output and clinical context.
- Review high-risk medicines: NSAIDs, aminoglycosides, iodinated contrast, ACEI/ARB during shock/dehydration, metformin during severe AKI/hypoxia, lithium, digoxin, gabapentin and many antimicrobials.
- Do not under-treat sepsis: give an appropriate initial antibiotic dose promptly, then adjust maintenance as renal data and drug levels become available.
- Dialysis is definitive for selected emergencies: refractory hyperkalaemia/acidosis, severe overload, uraemic complications and dialysable poisoning require urgent referral; medicines must not delay it.
Urinary/Renal Nursing Care Plan
| Nursing problem | Outcome | Interventions and rationales | Evaluation |
|---|---|---|---|
| Impaired urinary elimination | Relief of retention/dysuria and measurable output. | Assess bladder, pain, voiding pattern and obstruction; measure output; obtain clean specimen before antibiotics when appropriate; catheterise only when indicated with asepsis. | Improved voiding/output and symptoms. |
| Risk for electrolyte imbalance | K/Na/acid-base remain within safe range. | Serial electrolytes/ECG, strict balance, medication review, monitor neuromuscular/cardiac signs and escalate thresholds promptly. | Stable rhythm, labs and mental state. |
| Acute pain from renal colic | Pain controlled without masking sepsis/obstruction. | Assess pain/fever/solitary kidney/anuria, prescribed analgesia/antiemetic, strain urine when ordered, hydrate appropriately but do not force fluids into obstruction. | Pain reduced; red flags referred. |
| Knowledge deficit | Patient explains medicine course, hydration and return signs. | Teach adherence, culture review, renal dosing, avoidance of OTC NSAIDs/herbals, and urgent return for fever, flank pain, vomiting, anuria or confusion. | Correct teach-back and follow-up. |