Ascor Drug Information

1. INDICATIONS AND USAGE ASCOR is vitamin C indicated for the short term (up to 1 week) treatment of scurvy in adult and pediatric patients age 5 months and older for whom oral administration is not possible, insufficient or contraindicated. Limitations of Use ASCOR is not indicated for treatment of vitamin C deficiency that is not associated with signs and symptoms of scurvy. ASCOR is vitamin C indicated for the short term (up to 1 week) treatment of scurvy in adult and pediatric patients age 5 months and older for whom oral administration is not possible, insufficient or contraindicated.

Limitations of Use ASCOR is not indicated for treatment of vitamin C deficiency that is not associated with signs and symptoms of scurvy.

6. ADVERSE REACTIONS The following adverse reactions are discussed in greater detail in other sections of the labeling: Oxalate nephropathy and Nephrolithiasis Hemolysis in patients with glucose-6-phosphate dehydrogenase deficiency The following adverse reactions associated with the use of ascorbic acid were identified in the literature. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate their frequency reliably or to establish a causal relationship to drug exposure: Administration site reactions: pain and swelling. ASCOR should not be rapidly administered.

Rapid intravenous administration (>250 mg/minute) of ASCOR may cause temporary faintness or nausea, lethargy, flushing, dizziness, and headache (the recommended infusion rates of diluted ASCOR solution are 1.3 mg/minute (Pediatric Patients age 5 months to less than 12 months), 3.3 mg/minute (Pediatric Patients age 1 year to less than 11 years) and 33 mg/minute (Adults and Pediatric Patients 11 years and older) ). Acute and chronic oxalate nephropathy have occurred with prolonged administration of high doses of ascorbic acid. In patients with glucose-6-phosphate dehydrogenase deficiency severe hemolysis has occurred. Most common adverse reactions are pain and swelling at the site of infusion ​To report SUSPECTED ADVERSE REACTIONS, contact McGuff Pharmaceuticals, Inc., toll free at 1-800-603-4795 or FDA at 1-800-FDA-1088 or ​www.fda.gov/medwatch.

Antibiotics 7.1 Antibiotics Ascorbic acid may decrease activities of erythromycin, kanamycin, streptomycin

doxycycline, and lincomycin. Bleomycin is inactivated in vitro by ascorbic acid. If the antibiotic efficacy is suspected to be decreased by concomitant administration of ASCOR, discontinue ASCOR administration.

Antibiotics Ascorbic acid may decrease activities of erythromycin, kanamycin, streptomycin, doxycycline, and

lincomycin. Bleomycin is inactivated in vitro by ascorbic acid. If the antibiotic efficacy is suspected to be decreased by concomitant administration of ASCOR, discontinue ASCOR administration.

Amphetamine & Other Drugs Affected by Urine Acidification 7.2 Amphetamine & Other

Drugs Affected by Urine Acidification Ascorbic acid may acidify the urine and lower serum concentrations of amphetamine by increasing renal excretion (as reflected by changes in amphetamine urine recovery rates). In case of decreased amphetamine efficacy discontinue ASCOR administration. Standard monitoring of therapy is warranted. In addition, acidification of urine by ascorbic acid will alter the excretion of certain drugs affected by the pH of the urine (e.g., fluphenazine) when administered concurrently.

It has been reported that concurrent administration of ascorbic acid and fluphenazine has resulted in decreased fluphenazine plasma concentrations. Standard monitoring of therapy is warranted.

Amphetamine & Other Drugs Affected by Urine Acidification Ascorbic acid may acidify

the urine and lower serum concentrations of amphetamine by increasing renal excretion (as reflected by changes in amphetamine urine recovery rates). In case of decreased amphetamine efficacy discontinue ASCOR administration. Standard monitoring of therapy is warranted. In addition, acidification of urine by ascorbic acid will alter the excretion of certain drugs affected by the pH of the urine (e.g., fluphenazine) when administered concurrently.

It has been reported that concurrent administration of ascorbic acid and fluphenazine has resulted in decreased fluphenazine plasma concentrations. Standard monitoring of therapy is warranted.

Warfarin 7.3 Warfarin Limited case reports have suggested interference of ascorbic acid

with the anticoagulation effects of warfarin, however, patients on warfarin therapy treated with ascorbic acid doses up to 1000 mg/day (5 times the largest recommended single dose) for 2 weeks (twice the maximum recommended duration), no effect was observed. Standard monitoring for anti-coagulation therapy should continue during ascorbic acid treatment, as per standard of care.

Warfarin Limited case reports have suggested interference of ascorbic acid with the

anticoagulation effects of warfarin, however, patients on warfarin therapy treated with ascorbic acid doses up to 1000 mg/day (5 times the largest recommended single dose) for 2 weeks (twice the maximum recommended duration), no effect was observed. Standard monitoring for anti-coagulation therapy should continue during ascorbic acid treatment, as per standard of care.

Laboratory Test Interference 7.4 Laboratory Test Interference

Because ascorbic acid is a strong reducing agent, it can interfere with numerous laboratory tests based on oxidation-reduction reactions (e.g., glucose, nitrite and bilirubin levels, leukocyte count, etc.). Chemical detecting methods based on colorimetric reactions are generally those tests affected. Ascorbic acid may lead to inaccurate results (false negatives) obtained for checking blood or urinary glucose levels, nitrite, bilirubin, and leukocytes if tested during or within 24 hours after infusion .

Laboratory Test Interference

Because ascorbic acid is a strong reducing agent, it can interfere with numerous laboratory tests based on oxidation-reduction reactions (e.g., glucose, nitrite and bilirubin levels, leukocyte count, etc.). Chemical detecting methods based on colorimetric reactions are generally those tests affected. Ascorbic acid may lead to inaccurate results (false negatives) obtained for checking blood or urinary glucose levels, nitrite, bilirubin, and leukocytes if tested during or within 24 hours after infusion .

4. CONTRAINDICATIONS None. None.

10. OVERDOSAGE Overdose with ascorbic acid may cause nausea, vomiting, diarrhea, facial flushing, rash, headache, fatigue or disturbed sleep. If overdose of ASCOR occurs, immediately discontinue administration and treat symptoms and signs of overdose, avoiding additional intake of ascorbic acid.