Pemetrexed disodium is available in single-dose vials containing 100 or 500 mg of pemetrexed as the disodium salt.3396 Vials also contain mannitol 106 or 500 mg, respectively.3396 Hydrochloric acid and/or sodium hydroxide may have been added to adjust pH.3396
Each 100- or 500-mg vial of pemetrexed should be reconstituted with 4.2 or 20 mL, respectively, of sodium chloride 0.9% (without preservatives) and swirled gently until the powder is completely dissolved to yield a 25-mg/mL solution.3396 Calcium-containing solutions should not be used for reconstitution.3396 The reconstituted solution should be visually inspected for particulate matter and discoloration prior to dilution; if particulate matter is present, the vial should be discarded.3396 The appropriate dose of the reconstituted solution must be diluted with additional sodium chloride 0.9% (without preservatives) to achieve a total volume of 100 mL.3396
Equivalency
Pemetrexed disodium 139.8 mg as the heptahydrate is equivalent to 100 mg of pemetrexed.3396 Pemetrexed disodium 699 mg as the heptahydrate is equivalent to 500 mg of pemetrexed.3396
Trade Name(s)
Alimta
Pemetrexed disodium diluted for infusion should be administered by intravenous infusion over 10 minutes.3396
As with other toxic drugs, caution should be exercised in the handling and preparation of pemetrexed and applicable special handling and disposal procedures should be followed.3396
Pemetrexed disodium is a white to light-yellow or green-yellow powder that forms a clear, colorless to yellow or green-yellow solution upon reconstitution.3396 Intact vials of pemetrexed disodium should be stored at controlled room temperature.3396 The reconstituted solution and the diluted solution for infusion may be stored for up to 24 hours after reconstitution at 2 to 8°C.3396 Any unused portions should be discarded.3396
Pemetrexed (Lilly) 9 mg/mL in sodium chloride 0.9% did not result in the loss of viability of Pseudomonas aeruginosa within 120 hours at room temperature of 22°C. A slight antimicrobial effect against Staphylococcus aureus was reported after 120 hours at room temperature; this slight effect cannot be regarded as sufficient for patient protection from growth of this microorganism. Diluted solutions should be stored under refrigeration whenever possible, and the potential for microbiological growth should be considered when assigning expiration periods.2740
Pemetrexed (Lilly) 25 mg/mL reconstituted with sodium chloride 0.9% was reported to be stable for 48 hours at 23°C exposed to or protected from light and for 31 days at 4°C exhibiting little or no drug loss when packaged in polypropylene syringes (Becton Dickinson) with Red Cap tip seals (Burron).2676
Freezing Solutions
Pemetrexed (Lilly) 2 to 20 mg/mL in dextrose 5% and also in sodium chloride 0.9% frozen at -20°C in polyvinyl chloride (PVC) bags developed substantial amounts of microparticulates, up to 30,000/mL, at all time points in the study up to 90 days. Especially concerning was the presence of hundreds of particles of 10 µm and larger, which may adversely impact patient safety. Although little loss of the drug occurred, the formation of such large quantities of microparticulates made the solutions unacceptable for use. The microparticulates that formed appeared to be related to the PVC containers because upon repeating the study in glass laboratory vessels, few microparticulates appeared.2693
For a list of references cited in the text of this monograph, search the monograph titled References.