Reduce the insulin infusion rate by 50% if tube feeding or TPN is stopped abruptly ... (Use 0.9% sodium chloride injection if the patient is not receiving maintenance i.v. fluids.) ...

TPN: usual range: 1–3g (8–24mEq) daily. Severe renal impairment: max 20g in 48 hours. Renal impairment. Monitor serum magnesium levels; if repeated doses are given, test knee jerk reflexes ...