lDIRECTIONS FOR ADMINISTRATION
▶With intravenous useIn severe hypomagnesaemia
administer initially via controlled infusion device
(preferably syringe pump).
Forintravenous infusion, in persistent pulmonary
hypertension of the newborn, dilute to a max.
concentration of 100 mg/mL ( 10 %) ( 0. 4 mmol/mL Mg^2 +)
magnesium sulfate heptahydrate ( 200 mg/mL
( 0. 8 mmol/mL Mg^2 +)iffluid restricted) with Glucose 5 %or
Sodium Chloride 0. 9 %.
For neonatal hypocalcaemia, hypomagnaesemia, and
torsade de pointes, dilute to 10 %( 100 mg magnesium
sulfate heptahydrate ( 0. 4 mmol Mg^2 +)in 1 mL) with
Glucose 5 %or 10 %, Sodium Chloride 0. 45 %or 0. 9 %or
Glucose and Sodium Chloride combinations. Up to 20 %
solution may be given influid restriction. Rate of
administration should not exceed 10 mg/kg/minute
( 0. 04 mmol/kg/minute Mg^2 +) of magnesium sulfate
heptahydrate.
lPRESCRIBING AND DISPENSING INFORMATIONThe BP
directs that the label states the strength as the % w/v of
magnesium sulfate heptahydrate and as the approximate
concentration of magnesium ions (Mg^2 +) in mmol/mL.
Magnesium Sulfate Injection BP is a sterile solution of
Magnesium Sulfate Heptahydrate.lMEDICINAL FORMS
There can be variation in the licensing of different medicines
containing the same drug. Forms available from special-order
manufacturers include: solution for injection, infusion,
solution for infusion
Solution for injection
▶Magnesium sulfate (Non-proprietary)
Magnesium sulfate heptahydrate 500 mg per 1 mlMagnesium
sulfate 50 % (magnesium 2 mmol/ml) solution for injection 10 ml
ampoules| 10 ampouleP£ 21. 70 – £ 21. 71 DT = £ 21. 63
Magnesium sulfate 50 % (magnesium 2 mmol/ml) solution for injection
20 ml vials| 10 vialP£ 49. 20
Magnesium sulfate 50 % (magnesium 2 mmol/ml) solution for injection
5 ml ampoules| 10 ampouleP£ 37. 80 – £ 61. 26
Magnesium sulfate 50 % (magnesium 2 mmol/ml) solution for injection
2 ml ampoules| 10 ampouleP£ 17. 30 – £ 17. 35 DT = £ 17. 35
Solution for infusion
▶Magnesium sulfate (Non-proprietary)
Magnesium sulfate heptahydrate 100 mg per 1 mlMagnesium
sulfate 10 % (magnesium 0. 4 mmol/ml) solution for injection 10 ml
ampoules| 10 ampouleP£ 66. 26 DT = £ 66. 26
Magnesium sulfate heptahydrate 500 mg per 1 mlMagnesium
sulfate 50 % (magnesium 2 mmol/ml) solution for infusion 50 ml vials|
10 vialP£ 73. 002.4 Phosphate imbalance
Phosphorus
Phosphate supplements
Oral phosphate supplements p. 600 may be required in
addition to vitamin D in children with hypophosphataemic
vitamin D-resistant rickets, see also Vitamin D, under
Vitamins p. 623.
Phosphate infusion is occasionally needed in phosphate
deficiency arising from use of parenteral nutrition deficient
in phosphate supplements; phosphate depletion also occurs
in severe diabetic ketoacidosis. It is difficult to provide
detailed guidelines for the treatment ofsevere
hypophosphatemiabecause the extent of total body deficits
and response to therapy are difficult to predict. High doses of
phosphate may result in a transient serum elevation
followed by redistribution into intracellular compartments
or bone tissue. It is recommended that severe
hypophosphataemia be treated intravenously as large dosesof oral phosphate may cause diarrhoea; intestinal absorption
may be unreliable and dose adjustment may be necessary.
Phosphate is not thefirst choice for the treatment of
hypercalcaemia because of the risk of precipitation of
calcium phosphate in the kidney and other tissues. If used,
the child should be well hydrated and electrolytes
monitored.Neonates
Phosphate deficiency may occur in very low-birthweight
infants and may compromise bone growth if not corrected.
Parenterally fed infants may be at risk of phosphate
deficiency due to the limited solubility of phosphate. Some
units routinely supplement expressed breast milk with
phosphate, although the effect on the osmolality of the milk
should be considered.Phosphate-binding agents
Calcium-containing preparations are used as phosphate-
binding agents in the management of hyperphosphataemia
complicating renal failure. Aluminium-containing
preparations are rarely used as phosphate-binding agents
and can cause aluminium accumulation.
Sevelamer hydrochloride is licensed for the treatment of
hyperphosphataemia in adults on haemodialysis or
peritoneal dialysis. Although experience is limited in
children sevelamer hydrochloride may be useful when
hypercalcaemia prevents the use of calcium carbonate
p. 592.2.4aHyperphosphataemia
ELECTROLYTES AND MINERALS›ALUMINIUM
Aluminium hydroxide
lINDICATIONS AND DOSE
Hyperphosphataemia in renal failure
▶BY MOUTH USING CAPSULES
▶Child 5–11 years: 1 – 2 capsules 3 – 4 times a day, dose
adjusted as necessary
▶Child 12–17 years: 1 – 5 capsules 3 – 4 times a day, dose
adjusted as necessarylCONTRA-INDICATIONSHypophosphataemia.infants.
neonates
CONTRA-INDICATIONS, FURTHER INFORMATION
▶Neonates and infantsAluminium-containing antacids
should not be used because accumulation may lead to
increased plasma-aluminium concentrations.
lINTERACTIONS→Appendix 1 : antacids
lSIDE-EFFECTSConstipation
lHEPATIC IMPAIRMENTAvoid; can cause constipation
which can precipitate coma.
lRENAL IMPAIRMENTThere is a risk of accumulation and
aluminium toxicity with antacids containing aluminium
salts. Absorption of aluminium from aluminium salts is
increased by citrates, which are contained in many
effervescent preparations (such as effervescent
analgesics).598 Fluid and electrolyte imbalances BNFC 2018 – 2019
Blood and nutrition9