Overview
DESCRIPTION Chemical Characteristics MEGATOPE (iodinated I 131 albumin) injection is a sterile, nonpyrogenic, radioactive diagnostic agent for intravenous use. Each mL contains albumin human (approximately 10 mg), dibasic sodium phosphate (16 mg), guanidine hydrochloride (not more than 0.4 mg), monobasic sodium phosphate (1.
Mechanism of Action
CLINICAL PHARMACOLOGY Following intravenous injection, iodinated I 131 albumin is distributed throughout the intravascular pool within 10 minutes; extravascular distribution takes place more slowly. Iodinated I 131 albumin also can be detected in the lymph and in certain body tissues within 10 minutes after injection, but maximum distribution of radioactivity throughout the extravascular space does not occur until two to four days after administration. The time at which extravascular activity is maximal has been designated as the “equilibrium time.” When this point has been reached, the radioactivity remaining in the intravascular and extravascular spaces decreases slowly and exponentially in parallel fashion.
Indications
- INDICATIONS AND USAGE MEGATOPE is indicated in adults for use in determinations of total blood and plasma volumes.
Common Doses
- 1 mL
- 360 mL
Dosage
DOSAGE AND ADMINISTRATION Premedication Administer 10 drops of Strong Iodine Solution, USP (e.g., Lugol’s Solution) three times daily, beginning at least 24 hours before administration of MEGATOPE and continue for 1 week or 2 weeks thereafter to minimize the uptake of iodine-131. Recommended Dosage The recommended dose of MEGATOPE for total blood or plasma volume determination in adult patients is from 0.185 MBq to 1.85 MBq (5 microCi to 50 microCi) administered intravenously. When a procedure such as a blood volume is to be repeated, do not exceed 7.4 MBq (200 microCi) in any 1 week.
Contraindications
- CONTRAINDICATIONS None Known.
Side Effects
- ADVERSE REACTIONS The following adverse reactions have been identified with the use of radioiodinated albumin products. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Immune System Disorders: Hypersensitivity
Interactions
- No major interactions listed on the FDA label. Always consult a healthcare professional.