Potassium chloride is available as a 2-mEq/mL concentrate for injection in 5-, 10-, 15, and 20-mL single-dose, preservative-free vials.3858 Each mL of the concentrate contains 149 mg of potassium chloride (2 mEq of potassium) in water for injection; hydrochloric acid may have been added for pH adjustment.3858 The concentrate must be diluted prior to administration.3858 Ensure complete mixing of the concentrate with the infusion solution, particularly if soft or bag type containers are used.3858
Potassium chloride also is available as a premixed, ready-to-use infusion solution in single-dose flexible plastic bags containing 10 or 20 mEq potassium in 50 or 100 mL, and 40 mEq potassium in 100 mL.3859 The premixed solutions have the following properties:3859
| Potassium Ion Concentration /Container Size | Potassium Chloride Concentration | Osmolarity | Potassium (and Chloride) Ion Concentration |
|---|---|---|---|
| 10 mEq/100 mL | 7.46 g/L | 200 mOsm/L | 100 mEq/L |
| 10 mEq/50 mL | 14.9 g/L | 400 mOsm/L | 200 mEq/L |
| 20 mEq/100 mL | 14.9 g/L | 400 mOsm/L | 200 mEq/L |
| 20 mEq/50 mL | 29.8 g/L | 799 mOsm/L | 400 mEq/L |
| 40 mEq/100 mL | 29.8 g/L | 799 mOsm/L | 400 mEq/L |
pH
Osmolarity
The 2-mEq/mL concentrate for injection has a calculated osmolarity of approximately 4000 mOsm/L.3858
Osmolality
The osmolality of potassium chloride (Abbott) 2 mEq/mL was determined to be 4355 mOsm/kg by freezing-point depression and 3440 mOsm/kg by vapor pressure.1071
The osmolality of a potassium chloride 7.5% solution was determined to be 1895 mOsm/kg.1233
Potassium chloride is administered by slow intravenous infusion, preferably through a central venous line to reduce the risk of extravasation, pain, and phlebitis associated with peripheral infusion.3858; 3859 Care must be taken to avoid paravenous administration or extravasation because such administration may result in tissue damage.3859 Concentrations of 400 mEq/L must be administered through a central venous line.3859
The concentrate must be diluted prior to administration; direct intravenous injection of undiluted potassium chloride concentrate may result in fatal cardiac arrhythmia and cardiac arrest.3858
Great care is required when adding potassium chloride to infusion solutions, whether in flexible plastic containers or in rigid bottles. Adding potassium chloride to running infusion solutions hanging in the use position, especially in flexible containers, has resulted in the pooling of potassium chloride and a resultant high-concentration bolus of the drug being administered to patients, with serious and even fatal consequences. Attempts to mix adequately the potassium chloride in flexible containers by squeezing the container in the hanging position were unsuccessful. It is recommended that drugs be admixed with solutions in flexible containers when positioned with the injection arm of the container uppermost. With both rigid bottles and flexible containers, subsequent repeated inversion and agitation to effect thorough mixture are necessary.85; 130; 454; 455; 456; 714; 715; 1127; 1778; 2151
Intact containers of the concentrate for injection and premixed solution should be stored at controlled room temperature.3858; 3859 Unused portions of single-dose vials should be discarded.3858
Potassium chloride injection 80 mEq/L added to dextrose 5% contained in glass bottles results in a leaching of precipitates consisting of silica and alumina.129
Drugs in Syringe Compatibility
Y-Site Injection Compatibility (1:1 Mixture)
Additional Compatibility Information
Methylprednisolone
The compatibility of methylprednisolone sodium succinate (Upjohn) with potassium chloride added to an auxiliary medication infusion unit has been studied. Primary admixtures were prepared by adding potassium chloride 40 mEq/L to dextrose 5%, dextrose 5% in sodium chloride 0.9%, and Ringer’s injection, lactated. The primary admixture was added along with methylprednisolone sodium succinate (Upjohn) to the auxiliary medication infusion unit with the following results:329
| Methylprednisolone Sodium Succinate | Potassium Chloride 40 mEq/L Primary Solution | Results |
|---|---|---|
| 500 mg | D5S, D5W, LR qs 100 mL | Clear solution for 24 hr |
| 1000 mg | D5W qs 100 mL | Clear solution for 24 hr |
| 1000 mg | D5S, LR qs 100 mL | Clear solution for 6 hr |
| 2000 mg | D5S, D5W, LR qs 100 mL | Clear solution for 24 hr |
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