Amoxicillin sodium is available as a powder in vials containing the equivalent of amoxicillin 250 mg, 500 mg, and 1 g.3553; 3554; 3555
For intravenous injection, the 250-mg, 500-mg, and 1-g vials may be reconstituted with 5, 10, and 20 mL, respectively, of sterile water for injection when the dose reflects the entire contents of a vial and the entire vial contents are subsequently withdrawn.3553; 3554; 3555 One manufacturer states that 500-mg and 1-g vials also may be reconstituted with 5 mL of sterile water for injection when the dose reflects the entire contents of the vial and the entire vial contents are subsequently withdrawn.3555
Alternatively, the 250-mg vials may be reconstituted with 4.8 mL of sterile water for injection to yield a 50-mg/mL solution, the 500-mg vials may be reconstituted with 4.6 mL of sterile water for injection to yield a 100-mg/mL solution, and the 1-g vials may be reconstituted with 4.2 mL of sterile water for injection to yield a 200-mg/mL solution.3555 This allows for calculation of the volume required for a dose when only the partial contents of the vial are intended.3555
For intravenous infusion, the reconstituted drug should be added to a compatible intravenous infusion solution (e.g., using a minibag or an in-line burette).3553; 3554; 3555 (See Solution Compatibility.)
For intramuscular injection, 250-mg vials should be reconstituted with 2 mL of sterile water for injection3555 and 500-mg vials should be reconstituted with 23555 or 2.5 mL of sterile water for injection.3553 Lidocaine hydrochloride (e.g., 1%) or procaine hydrochloride 0.5% injection solution (no longer commercially available in the US) may be used in place of sterile water for injection for reconstitution of the drug for intramuscular administration.3553; 3555 Vials containing 1 g of amoxicillin should be reconstituted with 4 mL of sterile water for injection3555 or 2.5 mL of lidocaine hydrochloride injection solution for administration by intramuscular injection.3554
Final Volumes of Reconstituted Amoxicillin Sodium for Intramuscular Injection
| Vial Size | Volume of Diluent | Final Volume |
|---|---|---|
| 250 mg | 2 mL | 2.2 mL |
| 500 mg | 2 mL | 2.4 mL |
| 500 mg | 2.5 mL | 2.9 mL |
| 1 g | 2.5 mL | 3.3 mL |
| 1 g | 4 mL | 4.8 mL |
Sodium Content
Sodium content in amoxicillin sodium vials varies;3553; 3554; 3555 specific product labeling should be consulted for additional formulation details.
Trade Name(s)
Amoxil, Clamoxyl, Ibiamox
Amoxicillin sodium may be administered by slow direct intravenous injection over 3 to 4 minutes, intermittent intravenous infusion over 20 to 30 or 30 to 60 minutes, or intramuscular injection.3553; 3554; 3555 Intramuscular administration should be considered only when the intravenous route is not possible or is less appropriate for the patient.3553; 3554
Intact vials of amoxicillin sodium should be stored at or below 25°C;3553; 3554; 3555 at least one manufacturer states the vials should be protected from light.3555 After reconstitution with sterile water for injection, a transient pink color or slight opalescence may appear.3553; 3554; 3555 Reconstituted solutions are normally colorless or a pale straw color.3553; 3554; 3555 The reconstituted solution for intramuscular administration should be administered immediately3553; 3554 or within 1 hour3555 after reconstitution. The reconstituted solution for direct intravenous injection should be administered within 20 minutes3553; 3554 or 1 hour3555 after reconstitution. For intravenous infusion, the reconstituted solution should be added to the infusion solution without delay3553; 3554 and should be used immediately3553; 3554 (e.g., within 1 hour3555), though manufacturers provide stability data for the drug in various infusion solutions.3553; 3554; 3555 (See Solution Compatibility.)
Concentration Effects
Degradation of amoxicillin is concentration dependent; the higher the concentration, the less stable the drug.3556
Amoxicillin sodium prepared at an amoxicillin concentration of 50 mg/mL is substantially less stable in all infusion solutions than at lower concentrations of 10 or 20 mg/mL.1469
Amoxicillin sodium prepared at an amoxicillin concentration of 125 mg/mL in sterile water for injection in Infusor elastomeric pumps (Baxter) demonstrated greater than 10% loss within about 1 hour at 24 to 26°C.3556 Amoxicillin sodium prepared at an amoxicillin concentration of 50 mg/mL in sterile water for injection in FOLfusor elastomeric pumps (Baxter) demonstrated greater than 10% loss within about 5 hours at 24 to 26°C.3556
Temperature Effects
Degradation of amoxicillin also is temperature dependent; the higher the temperature, the less stable the drug.3556 The rate of degradation of amoxicillin sodium prepared at an amoxicillin concentration of 125 mg/mL in sterile water for injection in Infusor elastomeric pumps (Baxter) was 1.92 and 3.29% per hour at 5 and 37°C, respectively.3556
Freezing Solutions
Amoxicillin sodium prepared at an amoxicillin concentration of 10 mg/mL in sterile water for injection was unstable when stored frozen at 0 and -20°C but was stable for 13 days when stored below -30°C. Amoxicillin sodium prepared at an amoxicillin concentration of 10 mg/mL in sterile water for injection was stable for only 2 days at 0°C in the unfrozen state.1470
Amoxicillin sodium prepared at an amoxicillin concentration of 10 mg/mL in sodium chloride 0.9% was stable for 10.5 days at 0°C (unfrozen) and for 14 hours when frozen at -19°C; in dextrose 5%, the comparative times were 12.5 and 8.4 hours, respectively.1471
The processes of freezing and thawing increase the degradation rate of amoxicillin sodium prepared at an amoxicillin concentration of 10 mg/mL in sodium chloride 0.9% in polyvinyl chloride (PVC) bags (Travenol). Freezing and thawing (natural or microwave) could account for a 5 to 10% loss of amoxicillin; the losses will be affected by the time to reach the equilibrium frozen temperature.1472
Elastomeric Reservoir Pumps
Amoxicillin sodium (Panpharma) prepared at an amoxicillin concentration of 25 mg/mL in equal volumes of sterile water for injection and sodium chloride 0.9% (Braun) in Accufuser elastomeric pumps (Wym) was stable for 12 hours at 18 to 26°C and 24 hours at 4 to 8°C.3556
Sorption
Amoxicillin sodium was shown not to exhibit sorption to PVC bags and tubing, polyethylene tubing, Silastic tubing, polypropylene syringes, and trilayer bags of polyethylene, polyamide, and polypropylene.536; 606; 1918
Filtration
Amoxicillin sodium prepared at an amoxicillin concentration of 1.98 mg/mL in sodium chloride 0.9% did not exhibit significant drug loss due to sorption to a 0.22-µm cellulose ester membrane filter (Ivex-HP, Millipore).1034
Y-Site Injection Compatibility (1:1 Mixture)
Additional Compatibility Information
Infusion Solutions
One manufacturer states that satisfactory concentrations of the drug are retained when administration of amoxicillin sodium (Amoxil, GlaxoSmithKline) prepared at an amoxicillin concentration of 10 g/L in sterile water for injection and compound sodium chloride (Ringer’s solution) is completed within 6 and 2 hours, respectively, at 20°C.3553; 3554 Dilutions of the drug in compound sodium lactate (Hartmann’s solution) and in dextrose 4% in sodium chloride 0.18% are unstable after 30 minutes at 20°C.3553; 3554
One manufacturer states that a satisfactory degree of amoxicillin activity is retained when amoxicillin sodium (Ibiamox, Douglas) is diluted in compound sodium chloride (Ringer’s solution), sodium lactate (concentration not specified), compound sodium lactate (Hartmann’s solution), and dextrose 4% in sodium chloride (concentration not specified) for 6, 3, 3, and 1 hour, respectively, at room temperature.3555
Peritoneal Dialysis Solutions
The stability of amoxicillin (Aspen Pharmacare) 125 mg/L in pH-neutral Balance (Fresenius), icodextrin-based Extraneal (Baxter), and dextrose-based Dianeal PD-4 (Baxter) peritoneal dialysis solutions was evaluated.2984 At 4, 25, and 37°C, amoxicillin was stable in Balance for 336, 12, and 12 hours, respectively; in Extraneal for 336, 48, and 24 hours, respectively; and in Dianeal PD-4 for 336, 72, and 24 hours, respectively.2984
Amoxicillin (Fisamox, Aspen Pharmacare) 1 g in 2 L of Dianeal PD-4 with dextrose 2.5% (Baxter) exhibited 10% drug loss over 6 hours at 37°C.3108
For a list of references cited in the text of this monograph, search the monograph titled References.