Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Potassium replacement Pregnancy: §8.1 Pregnancy Risk Summary, verbatim: 'There are no human data related to use of potassium chloride extended-release tablets during pregnancy, and animal reproduction studies have not been conducted. Potassium supplementation that does not lead to hyperkalemia is not expected to cause fetal harm. The background risk for major birth defects and miscarriage in the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.' No lactation statement was present in the fetched sections.

Potassium chloride

Brand names: Sando-K, Slow-K, Kay-Cee-L

Potassium chloride is a potassium supplement used to prevent or treat hypokalaemia; oral modified-release formulations and carefully controlled intravenous infusions are both available.

Adult dose

Dose: Treatment of hypokalaemia: 40 to 100 mEq per day, in divided doses. Prevention / maintenance: 20 mEq per day. §2.2 verbatim: 'Treatment of Hypokalemia: Typical dose range is 40 to 100 mEq per day. Maintenance or Prophylaxis: Typical dose range is 20 mEq per day.' Highlights (2.2): 'Treatment of hypokalemia : Doses range from 40 to 100 mEq/day in divided doses. Limit doses to 40 mEq per dose.' §2.2 also states: 'Dosage must be adjusted to the individual needs of each patient.'
Route: Oral — extended-release tablets. §2.1 verbatim: 'Take potassium chloride extended-release tablets with meals and with a glass of water or other liquid. Do not take potassium chloride extended-release tablets on an empty stomach because of its potential for gastric irritation. Swallow tablets whole without crushing, chewing or sucking.' ⚠️ SCOPE: this page also lists the INTRAVENOUS route, but the fetched label covers the ORAL extended-release tablet ONLY — it contains no IV regimen, no infusion rate and no infusion concentration. Nothing below may be used for IV potassium.
Frequency: Daily, in divided doses when the daily total exceeds 40 mEq — §2.2: 'Dosages greater than 40 mEq per day should be divided such that no more than 40 mEq is given in a single dose.' Each dose is taken with meals (§2.1).
Max: Maximum 40 mEq in any single dose — Highlights (2.2) verbatim: 'Limit doses to 40 mEq per dose.' §2.2 verbatim: 'Dosages greater than 40 mEq per day should be divided such that no more than 40 mEq is given in a single dose.' (The 100 mEq/day upper figure in the dose field is the top of a stated typical RANGE, not a labelled ceiling, so it is not reproduced here as a maximum.)
INDICATION: treatment and prevention of hypokalaemia (potassium replacement) — this page's primary indication, and the only indication the fetched label doses. || ⚠️ ORAL vs IV THRESHOLD, §2.1 verbatim: 'If serum potassium concentration is less than 2.5 mEq/L, use intravenous potassium instead of oral supplementation.' The label states the threshold but gives no IV regimen. || §2.1 verbatim: 'The treatment of potassium depletion, particularly in the presence of cardiac disease, renal disease, or acidosis, requires careful attention to acid-base balance, volume status, electrolytes, including magnesium, sodium, chloride, phosphate, and calcium, electrocardiograms, and the clinical status of the patient. Correct volume status, acid-base balance, and electrolyte deficits as appropriate.' || STRENGTHS (§3 verbatim): 'Tablets: 600 mg (8 mEq) and 750 mg (10 mEq)'. || LIQUID ALTERNATIVE (§5.1 verbatim): 'Consider the use of liquid potassium in patients with dysphagia, swallowing disorders, or severe gastrointestinal motility disorders.' || PAEDIATRICS (§8.4 verbatim): 'Safety and effectiveness in the pediatric population have not been established.' — hence paedDose is null. || ELDERLY (§8.5 verbatim): 'In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.' || The brand names on the page (Sando-K, Slow-K, Kay-Cee-L) are UK oral products and none of them is the product labelled in this bundle. A UK SPC fetch is needed before any IV regimen, any mmol figure or any UK brand-specific dose is published.

Dose adjustments

Renal

No numeric dose adjustment or eGFR threshold is given in the fetched label. §8.5 verbatim: 'This drug is known to be substantially excreted by the kidney, and the risk of toxic reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.' §2.1 verbatim: 'The treatment of potassium depletion, particularly in the presence of cardiac disease, renal disease, or acidosis, requires careful attention to acid-base balance, volume status, electrolytes... and the clinical status of the patient.' §5.1 / §7 additionally require close potassium monitoring with RAAS inhibitors and NSAIDs, which are commonly co-prescribed in renal disease.

Hepatic

Not stated. The fetched label contains no hepatic impairment section and no hepatic dose adjustment. The only mention of hepatic function is the generic elderly caution at §8.5: 'dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal or cardiac function'.

Dose independently re-sourced from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • §4 verbatim: 'Potassium chloride is contraindicated in patients on triamterene and amiloride.' Highlights (4): 'Concomitant use with triamterene and amiloride'. §7.1 adds: 'Use with triamterene or amiloride can produce severe hyperkalemia. Concomitant use is contraindicated.'
  • ⚠️ This is the ONLY contraindication in the fetched US label.

Side effects

  • §6 verbatim: 'The most common adverse reactions to oral potassium salts are nausea, vomiting, flatulence, abdominal pain/discomfort, and diarrhea.'
  • §6 verbatim: 'There have been reports hyperkalemia and of upper and lower gastrointestinal condition including obstruction, bleeding, ulceration, perforation.'
  • §6 verbatim: 'Skin rash has been reported rarely.'
  • §5.1 (Gastrointestinal Adverse Reactions) verbatim: 'Solid oral dosage forms of potassium chloride can produce ulcerative and/or stenotic lesions of the gastrointestinal tract, particularly if the drug maintains contact with the gastrointestinal mucosa for prolonged periods.' 'If severe vomiting, abdominal pain, distention, or gastrointestinal bleeding occurs, discontinue potassium chloride extended-release tablets and consider possibility of ulceration, obstruction or perforation.'

Monitoring

  • Serum potassium — §2.1 verbatim: 'Monitor serum potassium and adjust dosages accordingly. Monitor serum potassium periodically during maintenance therapy to ensure potassium remains in desired range.'
  • Acid-base balance, volume status and electrolytes — §2.1: '...electrolytes, including magnesium, sodium, chloride, phosphate, and calcium'.
  • Electrocardiograms and clinical status — §2.1 lists 'electrocardiograms, and the clinical status of the patient' as requiring careful attention when treating potassium depletion in cardiac disease, renal disease or acidosis.
  • Renal function in the elderly — §8.5: 'it may be useful to monitor renal function.'
  • Potassium when co-prescribed with RAAS inhibitors — §7.2 verbatim: 'Drugs that inhibit the renin-angiotensin-aldosterone system (RAAS) including angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), spironolactone, eplerenone, or aliskiren produce potassium retention by inhibiting aldosterone production. Closely monitor potassium in patients on concomitant RAAS inhibitors.'
  • Potassium when co-prescribed with NSAIDs — §7.3 verbatim: 'NSAIDS may produce potassium retention by reducing renal synthesis of prostaglandin E and imparing the renin-angiotensin system. Closely monitor potassium in patients on concomitant NSAIDs.'
  • Watch for GI symptoms that require discontinuation — §5.1: severe vomiting, abdominal pain, distention or gastrointestinal bleeding.

Clinical monograph

How it works

It replaces the potassium ion, the principal intracellular cation essential for nerve conduction, muscle contraction and cardiac rhythm, correcting a deficit and its associated effects.

Prescribing in practice

  • Intravenous potassium chloride must always be diluted and infused slowly with cardiac monitoring, as bolus or concentrated administration can cause fatal cardiac arrest; this is a recognised never-event hazard.
  • Use cautiously in renal impairment and with potassium-sparing diuretics, RAS inhibitors or aldosterone antagonists because of the risk of hyperkalaemia.
  • Oral modified-release tablets should be swallowed whole with plenty of fluid, ideally sitting or standing, to limit gastrointestinal ulceration.

Monitoring

Monitor serum potassium and renal function, with continuous ECG monitoring during intravenous replacement.

Counselling the patient

  • Swallow the tablets whole with a full glass of water and do not crush or chew them.
  • Report muscle weakness, palpitations or tingling, which may signal too much potassium.

Evidence & guidelines

Its role in correcting potassium deficits is well established, with current prescribing references and the SPC emphasising the dangers of inappropriate intravenous administration.

Reference: NICE NG29; UK guidelines; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways