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Urinary alkalinisation Pregnancy: Patients should consult a doctor before taking Effercitrate Tablets in pregnancy or lactation.

Citric acid with potassium citrate

Brand names: Cymalon

Citric acid with potassium citrate is an oral urinary alkalinising preparation used to relieve discomfort in lower urinary tract infections and to raise urinary pH, for example to help prevent uric acid or cystine stones.

Adult dose

Dose: Two tablets dissolved in a glass of water, for cystitis and symptoms of cystitis (Effercitrate effervescent tablets)
Route: Oral (tablets dissolved in a glass of water)
Frequency: Up to three times daily
VERBATIM UK SPC §4.2 (Effercitrate Tablets): 'For oral administration. Adults and Children over 6 years: Two tablets to be dissolved in a glass of water up to three times daily. Children under 6 years: Not recommended. Elderly: As adult dose. See section 4.4 Sufficient should be given to render and maintain the urine alkaline'. §4.1: 'For the treatment of cystitis, symptoms of cystitis and as an initial therapy in mild symptomatic cystitis prior to an MSU result. Confirmed bacterial infections should then be treated with an appropriate course of an antibacterial agent.' STRENGTH, §2: 'Each tablet contains potassium bicarbonate and anhydrous citric acid. When dissolved in water, the solution will contain the equivalent of 1.5g potassium citrate and 0.25g citric acid.' §2 does not say whether the 1.5 g / 0.25 g figures are per tablet or per two-tablet dose, so no per-tablet strength is stated here. §4.4: 'If symptoms persist or worsen after 4 days, patients should seek medical advice.' The SPC prints no maximum duration or maximum daily total, so none is given. FORM FLAG: the SPC is for EFFERVESCENT TABLETS (potassium bicarbonate + citric acid forming potassium citrate in solution); this SPC gives no sachet dose - do not read the tablet dose as a sachet dose.

Paediatric dose

Dose: Two tablets dissolved in a glass of water (children over 6 years)
Route: Oral (tablets dissolved in a glass of water)
Frequency: Up to three times daily
THE LABEL'S OWN FIGURE, NOT SCALED. VERBATIM §4.2: 'Adults and Children over 6 years: Two tablets to be dissolved in a glass of water up to three times daily. Children under 6 years: Not recommended.' Same dose as adults; no weight-based figure is given. Verify any under-18 dose against a children's formulary before use.

Dose adjustments

Renal

Contraindicated in renal dysfunction, particularly with oliguria (§4.3); caution in patients with kidney disease (§4.4). No dose figure is given.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Hyperkalaemia from any cause
  • Renal dysfunction, particularly with oliguria
  • Ventricular arrhythmias
  • Untreated Addison's disease
  • Acute dehydration
  • Known hypersensitivity to potassium citrate, citric acid or any of the other ingredients

Side effects

  • Gastric irritation (tablets should always be well diluted with water; gastric effects may be minimised by taking with, or after, meals)

Interactions

  • Potassium-containing medicines, potassium-sparing diuretics (amiloride, triamterene), aldosterone antagonists (spironolactone) and other medicines that raise potassium (angiotensin-II receptor antagonists, ACE inhibitors, aliskiren, cyclosporine, tacrolimus): should not be co-administered
  • Cardiac glycosides: activity depends on serum potassium - possible interaction, caution advised
  • Citrates alkalinise the urine and may alter urinary excretion of salicylates, tetracyclines and barbiturates, and may prolong the half-life of basic drugs such as sympathomimetics and stimulants
  • Anti-bacterial activity of nitrofurantoin and methenamine is diminished

Monitoring

  • Caution in kidney disease, hypertension or heart disease
  • Use with caution in elderly patients: potassium excretion is reduced, increasing the risk of hyperkalaemia
  • In patients with acidosis, monitor acid-base balance
  • Patients should seek medical advice if symptoms persist or worsen after 4 days

Clinical monograph

How it works

Citrate is metabolised to bicarbonate, which is excreted in the urine to raise urinary pH; alkalinisation increases the solubility of uric acid and cystine, while citrate also inhibits calcium stone crystallisation.

Prescribing in practice

  • The potassium content can cause hyperkalaemia, so use with caution and monitor potassium in chronic kidney disease and in patients on potassium-sparing diuretics, ACE inhibitors or ARBs.
  • Avoid in significant renal impairment with hyperkalaemia and in conditions where a sodium or potassium load is hazardous; it is for short-term symptomatic relief unless used for stone prevention.
  • Urinary alkalinisation alters renal handling of some drugs and is not a substitute for antibiotics when an infection requires treatment.

Monitoring

Monitor serum potassium and, when used for stone prevention, urinary pH, particularly in renal impairment.

Counselling the patient

  • Dissolve or take as directed with plenty of water and keep well hydrated.
  • This eases urinary discomfort but does not replace antibiotics if you have an infection that needs them.
  • Tell your prescriber if you have kidney problems or take blood-pressure medicines that raise potassium.

Evidence & guidelines

Potassium citrate is an established urinary alkalinising agent used for symptomatic relief in lower urinary tract infection and as part of metabolic stone-prevention regimens.

Reference: 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.

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