Furosemide is available in 2-, 4-, and 10-mL amber single-dose or single-use vials and 4- and 10-mL single-dose prefilled syringes.3645; 3646; 3647 Each mL of solution contains furosemide 10 mg in water for injection, with sodium chloride for isotonicity, sodium hydroxide, and, if necessary, hydrochloric acid to adjust pH.3645; 3646; 3647
pH
The pH of furosemide injection ranges from 8 to 9.3.3645; 3646; 3647
Osmolality
Furosemide (Hoechst-Roussel) 10 mg/mL has an osmolality of 287 mOsm/kg.50 The osmolality of the Elkins-Sinn product has been determined to be 289 mOsm/kg by freezing-point depression.1071
In another study, the osmolality of furosemide injection (manufacturer unspecified) was determined to be 291 mOsm/kg.1233
Trade Name(s)
Lasix
Furosemide may be administered by intramuscular injection, by slow, direct intravenous injection over 1 to 2 minutes, and by intravenous infusion at a rate not exceeding 4 mg/min following dilution of the drug in a compatible diluent.3645; 3646; 3647 (See pH Effects.)
Intact vials and syringes should be stored at controlled room temperature and protected from light.3645; 3646; 3647 Prefilled syringes should not be removed from the carton until ready to use.3646 Furosemide injection solutions should not be used if they are discolored or contain particulate.3645; 3646; 3647
Furosemide (Hospira) 1 mg/mL diluted in dextrose 5% and packaged as 10 mL in 15-mL polypropylene tubes (BD Biosciences) was physically compatible with less than 4% loss of furosemide in 96 hours at 25°C in the dark.3568
pH Effects
Furosemide injection is a buffered alkaline solution.3645; 3646; 3647 The drug may precipitate at pH values less than 7; care must be taken to ensure that the pH of a prepared infusion solution is in the weakly alkaline to neutral range.3645; 3646; 3647 Furosemide must not be mixed with or added to a running intravenous line containing acidic solutions, including other parenteral drugs (e.g., ciprofloxacin, labetalol, milrinone).3645; 3646; 3647 Manufacturers state that furosemide may be added to sodium chloride 0.9%, Ringer’s injection, lactated, or dextrose 5% after the pH of the solution has been adjusted to greater than 5.5.3645; 3646; 3647 In addition, furosemide has been found to be unstable in acidic media,96; 664 but very stable in basic media.664
A 2-mL fluid barrier of dextrose 5% in a microbore retrograde infusion set failed to prevent precipitation when used between gentamicin sulfate 5 mg/0.5 mL and furosemide 2 mg/0.2 mL.1385
Temperature Effects
Intact vials and syringes should be stored at controlled room temperature.3645; 3646; 3647 Refrigeration of the drug may result in precipitation or crystallization; however, resolubilization at room temperature or on warming may be performed without affecting the drug’s stability.593
Furosemide under simulated summer conditions in paramedic vehicles was exposed to temperatures from 26 to 38°C over 4 weeks. Analysis found no loss of drug under these conditions.2562
Autoclaving
Autoclaving of furosemide 1 mg/mL in sodium chloride 0.9% in glass bottles at 115°C for 34 minutes resulted in no loss of furosemide. Storage of the solution for 70 days at room temperature with protection from light also showed no detectable change in furosemide content. However, storage at room temperature with exposure to light for 70 days resulted in about a 60% loss of furosemide and the formation of a yellow-orange precipitate.1108
Light Effects
Furosemide is subject to photodegradation by several mechanisms.358; 400; 2067 Photodegradation is minimized at pH 7; rates of decomposition increase as the pH becomes more acidic or basic.400; 2067 Photodegradation is unaffected by ionic strength and initial concentration (in the range of 10 mcg/mL to 1 mg/mL), but the rate of loss may decrease at the higher concentration due to a light-filtering effect of the yellow discoloration. In pH 7 phosphate buffer, more than 60% furosemide loss occurred in transparent glass vials exposed to fluorescent light for 90 hours; little or no loss occurred if the transparent vials were covered with aluminum foil or if amber glass containers were used.2067
Syringes
Furosemide (Hoechst) 10 mg/mL was filled into 25-mL polypropylene syringes (Becton Dickinson) and stored at 25°C while exposed to normal room light or in the dark for 24 hours. There was no detectable change in furosemide content in either light-exposed or light-protected syringes.1108
Furosemide (Abbott) 1, 2, 4, and 8 mg/mL diluted in sodium chloride 0.9% was packaged in polypropylene syringes. Samples were stored for 84 days at 22°C and also at 4°C protected from light for 84 days. This was followed by an additional 7 days of storage at 22°C exposed to fluorescent light. No visible changes occurred and little or no loss of furosemide occurred in any of the samples.2389
Furosemide 5 mg/mL packaged as 8 mL in 12-mL transparent polypropylene syringes (Terumo) and 50 mL in 60-mL transparent polypropylene syringes (Becton Dickinson) was physically stable and exhibited little to no loss in 35 days stored at 4°C protected from light followed by 24 hours at 20°C exposed to light.3569
Filtration
Furosemide (Hoechst) 0.04 mg/mL in dextrose 5% and sodium chloride 0.9% was filtered through a 0.22-µm cellulose ester membrane filter (Ivex-HP, Millipore) over 6 hours. No significant drug loss due to binding to the filter was noted.1034
Central Venous Catheter
Furosemide (American Regent) 1 mg/mL in dextrose 5% was found to be compatible with the ARROWg+ard Blue Plus (Arrow International) chlorhexidine-bearing triple-lumen central catheter. Essentially complete delivery of the drug was found with little or no drug loss occurring. Furthermore, chlorhexidine delivered from the catheter remained at trace amounts with no substantial increase due to the delivery of the drug through the catheter.2335
Standardize 4 Safety
One or more standardized concentrations for this drug have been established through Standardize 4 Safety (S4S), a national patient safety initiative to reduce medication errors, especially during transitions of care. (See Standardize 4 Safety in Users Guide.) Recommendations developed to date through this initiative are available at www.ashp.org/pharmacy-practice/standardize-4-safety-initiative.
Table 1. Standardize 4 Safety Continuous IV Infusion Standard Concentrations for Furosemide3635; 3636
| Patient Population | Concentration Standards | Dosing Units |
|---|---|---|
| Adults | 2 mg/mL 10 mg/mL | mg/hour |
| Pediatric patients (50 kg) | 2 mg/mL 10 mg/mL | mg/kg/hour |
For a list of references cited in the text of this monograph, search the monograph titled References.