Nephrology · Clinical Calculator · Pharmacology

Renal Medication Safety Index Dosing · Dialyzability · Toxicity · Hyperkalemia · Sick-Day Holds

A bedside review tool for polypharmacy in CKD and dialysis. Enter the patient's creatinine clearance and dialysis status, pick the drugs they're taking from a library of 46 commonly prescribed agents in Philippine practice, and get a single aggregate readout: renal doses, dialyzability, nephrotoxicity, hyperkalemia risk, and the SADMANS sick-day hold list — plus per-drug monitoring and cautions. Built to operationalize a two-minute medication review at each CKD visit.

Published: References: 4 Last reviewed: 2026 Read time:

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Instructions
  1. Enter the patient's creatinine clearance (CrCl) in mL/min. Choose whether the value is uncorrected mL/min (Cockcroft–Gault) or eGFR-style mL/min/1.73 m². For patients on dialysis, this field can be left blank — the dialysis dose column will drive dosing.
  2. Set the dialysis status (Not on dialysis / Hemodialysis / Peritoneal dialysis / CRRT). This selects the correct dose band for every drug you pick.
  3. Pick every drug the patient is taking from the checkbox library below. Use the filter box to search by generic name, Philippine brand (Lasix, Losec, Micardis, Ponstan, etc.), or drug class.
  4. Review the aggregate warning banners first (Avoid, Nephrotoxic, SADMANS sick-day hold, Hyperkalemia, Dose adjustment), then expand each drug card for the renal dose at this CrCl, monitoring plan, and cautions. Use this at every CKD visit and before writing any sick-day plan.

All computation runs in your browser; no values are stored or transmitted. Library covers 46 common drugs; not a substitute for a full pharmacist review in complex polypharmacy.

When to Use

Use this tool at every CKD or dialysis visit where you are starting, stopping, or reviewing medications. It is especially high-yield when a patient's medication list has grown across several prescribers, when a sick-day plan needs to be written, or when a hospital discharge summary has changed the regimen.

Highest yield populations

Polypharmacy in the elderly (≥5 chronic medications), CKD G3b–G5 with any RAAS blocker, patients on hemodialysis or peritoneal dialysis at every prescription change, patients presenting with unexplained AKI (screen for triple-whammy or nephrotoxin exposure), and any patient before a sick-day counseling session for SGLT2i, metformin, or diuretic + ACEi/ARB regimens.

⚠️

What this tool does NOT do

It does not check drug–drug interactions — use the companion Drug Interaction Checker for that. It does not cover every drug on the market: the library is 46 of the most common outpatient nephrology-relevant agents in Philippine practice. It cannot replace a full clinical pharmacist review in complex regimens (e.g., transplant, oncology, TB therapy, HIV/HCV protease inhibitors). Doses shown are typical adult ranges; individualize for weight, indication, and target level for narrow-therapeutic-index drugs.

Pearls & Pitfalls
💡

SADMANS — the sick-day hold mnemonic

Sulfonylureas · ACE inhibitors · Diuretics · Metformin · Angiotensin receptor blockers · NSAIDs · SGLT2 inhibitors. Hold these during any acute illness with vomiting, diarrhea, dehydration, or reduced oral intake — a 24–48 h pause prevents dehydration-driven AKI, lactic acidosis, hypoglycemia, and euglycemic DKA. Restart when the patient is eating and drinking normally for at least 24 hours. Handing patients a written sick-day plan at diagnosis is one of the highest-value interventions in outpatient CKD.

🚫

Triple-whammy — the classic preventable AKI

NSAID + ACEi/ARB + diuretic in the same regimen roughly triples the risk of AKI (Lapi et al., BMJ 2013). The combination collapses glomerular perfusion at the moment volume depletion strikes. Screen for it at every visit and every hospital discharge. When any two of the three are non-negotiable, the third must go — usually the NSAID, always the NSAID if there is a paracetamol-appropriate indication.

⚕️

Mefenamic acid — the Philippine OTC problem

Ponstan and Dolfenal (mefenamic acid) are widely sold without prescription in Mercury Drug and Watsons, most commonly for dysmenorrhea. Case series have documented dose-related AKI in young women with previously normal kidneys after only a few days of use. Counsel every young woman with CKD, a single kidney, or a history of AKI to avoid it entirely; offer paracetamol ± hyoscine for dysmenorrhea instead. Ibuprofen and naproxen (Advil, Flanax) carry the same class risk and are equally freely sold.

💊

Morphine and codeine — do not use in advanced CKD

Morphine's active metabolites M6G (analgesic, sedating) and M3G (neuroexcitatory, myoclonic) accumulate when CrCl <30, causing prolonged sedation, respiratory depression, myoclonus, and hyperalgesia — and neither is meaningfully dialyzed. Codeine is similar (its active metabolite is morphine). Preferred analgesics in advanced CKD: paracetamol first, then fentanyl, hydromorphone, methadone, or buprenorphine — none rely on renally-cleared active metabolites.

🩺

Colchicine — a narrow window and no antidote

Colchicine has a very narrow therapeutic index and no antidote for overdose. Toxicity risk rises sharply in CKD and skyrockets when a strong CYP3A4/P-gp inhibitor is co-prescribed (clarithromycin, azole antifungals, verapamil, diltiazem, cyclosporine) — fatal outcomes have been reported. Hold colchicine during any acute AKI or sepsis. Diarrhea is the classic first sign of toxicity — stop the drug immediately. Adjust doses strictly to eGFR bands and to dialysis status.

Why Use It

Medications are the third-most-common driver of acute kidney injury in Philippine wards, after sepsis and volume depletion — and in outpatient CKD they may be the leading modifiable factor. Community series have attributed roughly 30% of acute kidney injury episodes in Filipino patients to medications, with NSAIDs (especially mefenamic acid, freely available OTC), aminoglycosides, and contrast leading the list. Every CKD visit is a chance to intervene: renally dose-adjust, drop a triple-whammy, deprescribe a legacy drug that no longer fits the current kidney function, or hand the patient a written SADMANS sick-day plan. This tool operationalizes that two-minute review — CrCl, dialysis status, drug picks, aggregate warnings — so the safety check happens at every encounter rather than only when an AKI has already landed the patient in the emergency department.

Renal Medication Safety Index

Enter the patient's creatinine clearance and dialysis status, then pick every drug in the current regimen. The tool aggregates renal doses, dialyzability, nephrotoxicity, hyperkalemia risk, and SADMANS sick-day holds across the whole list.

Enter Cockcroft–Gault CrCl or eGFR in mL/min. Leave blank for dialysis patients.
Cockcroft–Gault is preferred for drug dosing; eGFR values are treated as approximately equivalent.
Selects the correct dose band. CRRT uses the HD band as a conservative proxy.
Optional. Used for weight-based agents (aminoglycosides, insulin, colchicine reference).

⚕ Renal doses summarize KDIGO 2024, Diabetes Canada CPG 2018 (Ch. 15), Whittaker et al. (CJASN 2018), and FDA/EMA product labels for 46 commonly prescribed agents in Philippine outpatient nephrology practice. Doses are typical adult ranges; individualize for weight, indication, and target level for narrow-therapeutic-index drugs. This tool does not check drug–drug interactions — use the companion Drug Interaction Checker. For licensed clinicians; not a substitute for individualized assessment or a full clinical pharmacist review in complex polypharmacy.

Next Steps

Translate the aggregate warnings into a concrete, patient-facing plan.

1. Dose-adjust or discontinue

  • For every drug flagged Avoid, substitute an equivalent non-renally-cleared agent (e.g., paracetamol for NSAID, gliclazide/DPP-4 for glibenclamide, hepatically-cleared β-blocker for atenolol at low CrCl, fentanyl or hydromorphone for morphine).
  • For every drug flagged Dose adjustment, write the new dose in the prescription clearly and add "CKD dose — do not resume prior dose without repeat CrCl."
  • Drop any triple-whammy: if the patient is on NSAID + ACEi/ARB + diuretic, the NSAID must go.

2. Write a SADMANS sick-day plan

  • Hand the patient a written note listing which of their drugs to hold during acute illness (fever, vomiting, diarrhea, poor oral intake): Sulfonylureas, ACEi, Diuretics, Metformin, ARBs, NSAIDs, SGLT2i.
  • Include the resume rule: "restart when you are eating and drinking normally for 24 hours."
  • Confirm the patient can identify each drug on their pillbox by generic + Filipino brand name.

3. Set the monitoring schedule

  • New RAAS blocker, MRA, or diuretic: creatinine and potassium at 1–2 weeks, then at 1 month.
  • New SGLT2i: eGFR at baseline and 3 months (expect an initial dip of 3–5 mL/min — reassure, do not stop).
  • Digoxin, aminoglycoside, or vancomycin: trough level and creatinine.
  • Statin: LFTs at baseline; CK only if muscle symptoms.

4. Counsel and document

  • Counsel every young Filipino woman with CKD or a single kidney to avoid Ponstan/Dolfenal (mefenamic acid); offer paracetamol ± hyoscine for dysmenorrhea.
  • Screen for HLA-B*58:01 before starting allopurinol in Filipino patients (allele frequency ~7–13%); febuxostat is an alternative in known carriers.
  • Document the reviewed medication list in the chart with dates and the reasons for each dose change — this closes the loop for the next visit.
  • Pair this review with the Drug Interaction Checker for CYP3A4/P-gp interactions.
Evidence & References

CrCl bands used in this tool

BandCrCl range (mL/min)Rationale
>60≥ 60Normal or CKD G1–G2 — usually no renal dose adjustment.
30–6030 to 59CKD G3a–G3b — moderate reduction for many agents.
15–3015 to 29CKD G4 — substantial reduction; several agents avoided.
<15< 15CKD G5, pre-dialysis — most renally-cleared agents contraindicated or minimal dose.
HDHemodialysisDose after HD session for dialyzable drugs; select agents avoided outright.
PDPeritoneal dialysisAdjusted for continuous low-clearance dialysis; PD-specific dose bands.
CRRTContinuous RRTUses the HD band as a conservative proxy pending drug-level monitoring.

Aggregate flags

FlagWhat it means
AvoidThe drug's dose band at this CrCl is "avoid" — substitute or discontinue.
NephrotoxicThe drug's nephrotox field is "high" — weigh benefit vs kidney injury risk; monitor Cr.
SADMANS sick-day holdHold during acute illness, vomiting/diarrhea, dehydration, or reduced oral intake.
HyperkalemiaDrug increases serum K+ — monitor closely, especially in CKD G3b–G5 and combinations.
Dose adjustmentThe dose at this CrCl differs from the >60 baseline — renally adjust.

The library covers 46 commonly prescribed agents in Philippine outpatient nephrology practice, curated from KDIGO 2024, Diabetes Canada CPG 2018 (Ch. 15), Whittaker et al. (CJASN 2018), and current FDA/EMA product labels. Doses are typical adult ranges; individualize for weight, indication, and target levels.

References

  1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2024). KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International Supplements, 115(4S), S117–S314. https://doi.org/10.1016/j.kisu.2024.01.001
  2. Whittaker, C. F., Miklich, M. A., Patel, R. S., & Fink, J. C. (2018). Medication safety principles and practice in CKD. Clinical Journal of the American Society of Nephrology, 13(11), 1738–1746. https://doi.org/10.2215/CJN.00580118
  3. Lapi, F., Azoulay, L., Yin, H., Nessim, S. J., & Suissa, S. (2013). Concurrent use of diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers with non-steroidal anti-inflammatory drugs and risk of acute kidney injury: Nested case-control study. BMJ, 346, e8525. https://doi.org/10.1136/bmj.e8525
  4. Diabetes Canada Clinical Practice Guidelines Expert Committee, McFarlane, P., Cherney, D., Gilbert, R. E., & Senior, P. (2018). Chronic kidney disease in diabetes (Chapter 15). Canadian Journal of Diabetes, 42(Suppl. 1), S201–S209. https://doi.org/10.1016/j.jcjd.2017.11.004
Important: This tool is an educational bedside aid for licensed clinicians and does not replace a full clinical pharmacist review, individualized dosing decisions, or drug–drug interaction checking. The library covers 46 commonly prescribed outpatient nephrology-relevant agents and is not exhaustive; doses shown are typical adult ranges. Always individualize for weight, indication, target level (for narrow-therapeutic-index drugs), pregnancy, transplant regimens, and current institutional protocols. Confirm every recommendation against the current FDA/EMA/PMDA product label and the latest KDIGO guidance before prescribing.
References 4 sources
  1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. (2024). KDIGO 2024 clinical practice guideline for the evaluation and management of chronic kidney disease. Kidney International Supplements, 115(4S), S117–S314. https://doi.org/10.1016/j.kisu.2024.01.001
  2. Whittaker, C. F., Miklich, M. A., Patel, R. S., & Fink, J. C. (2018). Medication safety principles and practice in CKD. Clinical Journal of the American Society of Nephrology, 13(11), 1738–1746. https://doi.org/10.2215/CJN.00580118
  3. Lapi, F., Azoulay, L., Yin, H., Nessim, S. J., & Suissa, S. (2013). Concurrent use of diuretics, angiotensin converting enzyme inhibitors, and angiotensin receptor blockers with non-steroidal anti-inflammatory drugs and risk of acute kidney injury: Nested case-control study. BMJ, 346, e8525. https://doi.org/10.1136/bmj.e8525
  4. Diabetes Canada Clinical Practice Guidelines Expert Committee, McFarlane, P., Cherney, D., Gilbert, R. E., & Senior, P. (2018). Chronic kidney disease in diabetes (Chapter 15). Canadian Journal of Diabetes, 42(Suppl. 1), S201–S209. https://doi.org/10.1016/j.jcjd.2017.11.004
Dr. W Rivero, MD

W Rivero, MD, FPCP, DPSN

Specialist in Internal Medicine, Nephrology, and Clinical Nutrition. Practicing integrative and evidence-based nephrology across Quezon City, Pampanga, and Bulacan.

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