BNF for Children 2011-2012

BNFC 2011–2012 9.2.1 Oral preparations for fluid and electrolyte imbalance 457Electrolyte content—gastro-intestinalsecretionsType ofMillimoles per litrefluidH + Na + K + HCO 3 ClGastric 40–60 20–80 5–20 — 100–150Biliary — 120–140 5–15 30–50 80–120Pancreatic — 120–140 5–15 70–110 40–80Smallbowel— 120–140 5–15 20–40 90–130Faeces, vomit, or aspiration should be saved and analysedwhere possible if abnormal losses are suspected; where thisis impracticable the approximations above may be helpful inplanning replacement therapy9.2.1 Oral preparations for fluidand electrolyte imbalance9.2.1.1 Oral potassium9.2.1.2 Oral sodium and water9.2.1.3 Oral bicarbonateSodium and potassium salts, which may be given bymouth to prevent deficiencies or to treat establisheddeficiencies of mild or moderate degree, are discussedin this section. Oral preparations for removing excesspotassium and preparations for oral rehydration therapyare also included here. Oral bicarbonate, for metabolicacidosis, is also described in this section.For reference to calcium, magnesium, and phosphate,see section 9.5.9.2.1.1 Oral potassiumCompensation for potassium loss is especially necessary:. in children in whom secondary hyperaldosteronismoccurs, e.g. renal artery stenosis, renal tubule disorder,the nephrotic syndrome, and severe heartfailure;. in children with excessive losses of potassium in thefaeces, e.g. chronic diarrhoea associated with intestinalmalabsorption or laxative abuse;. in those taking digoxin or anti-arrhythmic drugs,where potassium depletion may induce arrhythmias.Measures to compensate for potassium loss may berequired during long-term administration of drugsknown to induce potassium loss (e.g. corticosteroids).Potassium supplements are seldom required with thesmall doses of diuretics given to treat hypertension;potassium-sparing diuretics (rather than potassiumsupplements) are recommended for prevention of hypokalaemiadue to diuretics such as furosemide or thethiazides when these are given to eliminate oedema.Dosage If potassium salts are used for the preventionof hypokalaemia, then doses of potassium chloride 1–2 mmol/kg (usual max. 50 mmol potassium) daily bymouth are suitable in patients taking a normal diet.Smaller doses must be used if there is renal insufficiencyto reduce the risk of hyperkalaemia. Potassium saltscause nausea and vomiting and poor compliance is amajor limitation to their effectiveness (small divideddoses may minimise gastric irritation); when appropriate,potassium-sparing diuretics are preferable (see alsoabove). Regular monitoring of plasma-potassium concentrationis essential in those taking potassium supplements.When there is established potassium depletionlarger doses may be necessary, the quantity dependingon the severity of any continuing potassium loss (monitoringof plasma-potassium concentration and specialistadvice would be required). Potassium depletion isfrequently associated with chloride depletion and withmetabolic alkalosis, and these disorders require correction.Administration Potassium salts are preferably givenas a liquid (or effervescent) preparation, rather thanmodified-release tablets; they should be given as thechloride (the use of effervescent potassium tablets BPC1968 should be restricted to hyperchloraemic states,section 9.2.1.3). Potassium chloride solutions suitablefor use by mouth in neonates are available from ‘specialorder’manufacturers or specialist importing companies,see p. 809; they should be used with care because theyare hypertonic and can damage the gastric mucosa.Salt substitutes A number of salt substitutes which containsignificant amounts of potassium chloride are readily availableas health food products (e.g. LoSalt c and Ruthmol c ). Theseshould not be used by patients with renal failure as potassiumintoxication may result.POTASSIUM CHLORIDECautions see notes above; cardiac disease; withmodified-release preparations, intestinal stricture,history of peptic ulcer, hiatus hernia; interactions:Appendix 1 (potassium salts)Contra-indications plasma-potassium concentrationabove 5 mmol/litreRenal impairment close monitoring required— risk ofhyperkalaemia; avoid in severe impairmentSide-effects nausea, vomiting, abdominal pain, diarrhoea,flatulence; with modified-release preparations,gastro-intestinal obstruction, ulceration, and bleedingalso reportedIndication and dosePotassium depletion. By mouthNeonate 0.5–1 mmol/kg K + twice daily (total dailydose may alternatively be given in 3 divideddoses), adjusted according to plasma-potassiumconcentrationChild 1 month–18 years 0.5–1 mmol/kg K +twice daily (total daily dose may alternatively begiven in 3 divided doses), adjusted according toplasma-potassium concentrationNote Do not confuse Effervescent Potassium Tablets BPC1968 (section 9.2.1.3) with effervescent potassium chloridetablets. Effervescent Potassium Tablets BPC 1968 do notcontain chloride ions and their use should be restricted tohyperchloraemic states (section 9.2.1.3).Kay-Cee-L c (Geistlich)Syrup, sugar-free, red, potassium chloride 7.5%(1 mmol/mL each of K + and Cl ), net price 500 mL =£4.07. Label: 219 Nutrition and blood