ascorbic acid (Rx, OTC)

Frequency Not Defined

Flushing

Flank pain

Faintness, headache

Diarrhea, dyspepsia, nausea, vomiting

Hyperoxaluria (large doses)

Contraindications

Hypersensitivity

Cautions

Hemolysis has been reported with ascorbic acid in patients with glucose-6-phosphate dehydrogenase deficiency; discontinue treatment if hemolysis is suspected and treat as needed

Ascorbic acid may interfere with laboratory tests based on oxidation-reduction reactions (eg, blood and urine glucose testing, nitrite and bilirubin levels, and leucocyte count testing); delay laboratory tests until 24 hours after ascorbic acid infusion if possible

Oxalate nephropathy and nephrolithiasis

• Acute and chronic oxalate nephropathy reported with prolonged administration of high doses of ascorbic acid
• Increased risk for oxalate nephropathy in patients with renal disease, renal impairment, history of oxalate kidney stones, and geriatric patients
• Monitor renal function; discontinue treatment if oxalate nephropathy develops and treat any suspected oxalate nephropathy accordingly

Drug interactions overview

• Ascorbic acid may decrease effects of erythromycin, kanamycin, streptomycin, doxycycline, and lincomycin; if antibiotic efficacy is suspected, discontinue ascorbic acid
• Limited case reports have suggested interference of ascorbic acid with anticoagulation effects of warfarin; monitor

• Amphetamine and other drugs affected by urine pH

  • Ascorbic acid may acidify urine
  • Lowers amphetamines levels by increasing renal excretion
  • May alter excretion of certain drugs affected by urine pH (eg, fluphenazine)

Pregnancy

No adverse developmental outcomes are reported in the published literature

There are no available data on use of Ascor in pregnant women to inform a drug-associated risk of adverse developmental outcomes

Lactation

There are no data on the presence of ascorbic acid in human milk following IV dosing in lactating women

Ascorbic acid is present in human milk after maternal oral intake

Pregnancy Categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

Sources: Citrus fruits, peppers, cabbage, papaya, orange juice, broccoli, guava, carambola, radishes

Function: Required for collagen biosythesis

Deficiency: Scurvy; fatigue, depression, easy bruising & bleeding, weakened cartilage, coiled hairs, difficulty wound healing, thickened skin, abnormal bone growth in infants

Toxicity: Potential for kidney stones, withdrawal from high doses can lead to scurvy, even with "normal" intake

Mechanism of Action

Necessary for collagen formation and tissue repair; plays a role in oxidation/reduction reactions as well as other metabolic pathways including synthesis of catecholamines, carnitine, and steroids; also plays a role in conversion of folic acid to folinic acid

Pharmacokinetics

Distribution: Large

Metabolism: Liver

Absorption: Rapidly absorbed

Excretion: Urine

IV Compatibility

Compatible w/ most common diluents (eg, dextrose solns, NS, LR, Ringer's, ½NS, dextrose-saline, dextrose-LR)

IV Preparation

Dilute with large volume of compatible fluid to minimize adverse reactions

IV ascorbic acid (Ascor) is supplied as a pharmacy bulk package (PBP)

Intended for dispensing of single doses to multiple patients in a pharmacy admixture program and is restricted to the preparation of admixtures for infusion

Use only in a suitable ISO Class 5 work area such as a laminar flow hood (or an equivalent clean air compounding area)

Open vials are to be used within 4 hr

Prior to administration, the final diluted solution for infusion must be isotonic (undiluted the osmolarity is ~5,900 mOsmol/L)

Calculate the osmolarity of the intended admixture for infusion

Add daily dose directly to an appropriate volume of a suitable infusion solution (eg, 5% Dextrose Injection)

Do not mix with solutions containing elemental compounds that cause reduction (eg, copper)

Final concentration of ascorbic acid admixture solution for infusion: 1-25 mg/mL

Visually inspect for particulate matter and discoloration prior to administration; solution should appear colorless to pale yellow

Immediately use as a slow IV infusion

IV Administration

Consider IV or IM administration when PO is not feasible

Avoid rapid infusion

Infusion rate of diluted Ascor solution

• 5 months-12 months: 1.3 mg/minute
• 1-11 years: 3.3 mg/minute
• >11 years: 33 mg/minute

Oral Administration

Take with or without meals

Storage

Unopened IV vials: Store in refrigerator at 2-8°C (36-46°F); protect from light; contains no preservatives

Opened IV vials: Use within 4 hr of vial entry; discard remaining portion

Tablets: Store at room temperature at 15-30°C (59-86°F)