Iothalamate Sodium I 125

# Disclaimer
WikiDoc MAKES NO GUARANTEE OF VALIDITY. WikiDoc is not a professional health care provider, nor is it a suitable replacement for a licensed healthcare provider.  WikiDoc is intended to be an educational tool, not a tool for any form of healthcare delivery.  The educational content on WikiDoc drug pages is based upon the FDA package insert, National Library of Medicine content and practice guidelines / consensus statements.  WikiDoc does not promote the administration of any medication or device that is not consistent with its labeling. Please read our full disclaimer here.

# Overview
Iothalamate Sodium I 125 is a Diagnostic Agent that is FDA approved for the diagnosis of renal disease by evaluation of glomerular filtration.   Common adverse reactions include Hyperpyrexia.

# Adult Indications and Dosage

## FDA-Labeled Indications and Dosage (Adult)

### Indications
- GLOFIL-125 (Sodium Iothalamate I-125 Injection) is indicated for evaluation of glomerular filtration in the diagnosis or monitoring of patients with renal disease.

### Dosage
- The suggested dose range employed in the average patient (70 kg) is as follows:
Technique
Continuous intravenous infusion
Sigman (1) method
I. Preparation:
- Adequate diuresis (a urine flow exceeding 3 mL/min.) is established, preferably by an oral water load of 1,500 mL two hours prior to the beginning of the clearance study.
It is not necessary to withhold breakfast or admit the patient the night before.
II. Procedure:
- After the establishment of adequate diuresis, a number 14 or 16 French Foley catheter is aseptically inserted into the bladder.
An intravenous infusion of Lactated Ringers (Hartmanns) solution is started in each arm, one to maintain a site for injection of the GLOFIL-125, the other to serve as a site for serial withdrawal of blood. A two-way stopcock connects the needle and intravenous tubing of each arm.
- The dose is equally divided into (1) an intravenous priming dose to be injected as is and (2) a sustaining dose to be diluted in 30 to 60 mL of isotonic sodium chloride, depending on how many collection periods are anticipated.
- The priming dose is slowly injected into one arm. This is immediately followed by infusion of the sustaining solution through the same site, usually at the rate of 0.5 mL/min., by means of an automatic pump. During this infusion, the Lactated Ringers solution in the same arm is discontinued, and 40 to 45 minutes are allowed for equilibration in order to reach a state of constant plasma concentration of radioactivity.
- After attaining equilibrium, consecutive 15 minute collection periods are started. From the arm opposite the injection site, 5 mL of blood (allowing duplicate plasma counting volumes) is drawn six minutes prior to the midpoint of each collection period, placed in heparinized tubes, mixed, and centrifuged. The blood samples may be obtained through the two-way stopcock after discarding the first 30 mL aspirated into the syringe. This 30 mL contains the contents of the tubing, including infusion fluid, and must be cleared in order to obtain an undiluted blood sample. If desired, this step may be eliminated and blood samples obtained by direct venipuncture.
- During each collection period, total urine must be accurately collected and the volume accurately measured. Three such consecutive collection periods are sufficient for most clinical studies.
III. Clearance Calculations:
- Aliquots (1 mL each) of plasma and urine from each collection period are counted in a standard gamma-ray scintillation well detector.
- All counts are corrected for background activity.
- Glomerular filtration rate is calculated by the formula C=UV/P, in which:
- Average glomerular filtration rate (GFR) is calculated from the rates for the individual collection periods. GFR can be expressed in terms of body weight (mL/min/kg) or body surface area (mL/min/m2).
- Unilateral glomerular filtration rates can be determined by the same technique by utilizing ureteral catheterization.
Single intravenous injection
Cohen (2) method:
- The method of Cohen, et al (2) requires little preparation, few and small blood samples, no bladder catheterization, and no constant intravenous infusion. It is simple to perform, rapid, and utilizes equipment which is readily available in most modern laboratories.
I. Preparation:
- Lugol's solution, 3 drops orally, three times a day, is administered for one or two days prior to the test.
- No diet or water restriction is necessary.
- Oral water load is begun one hour before starting the test. Start with 20 mL/kg and force any clear liquids (unless contraindicated) until the test is complete.
II. Procedure: Record actual times for the collection of the blood and urine samples.
- Empty the bladder and label the urine Urine control.
- Inject 10-30 Ci GLOFIL-125 intravenously; wait 30 to 60 minutes.
- Collect the entire urine and label Urine discard.
- Draw 4 to 5 mL of blood into a heparinized syringe. Label Plasma #1.
- After another 30 to 60 minutes, collect the entire urine and label Urine #1.
- Immediately draw another blood specimen. Label Plasma #2.
- After final 30 to 60 minute wait, collect the urine. Label Urine #2.
- Draw the last blood specimen immediately. Label Plasma #3.
III. Clearance Calculations:
- Radioactivity of one mL aliquots of both urine and plasma are determined using a well-scintillation detector with a single channel pulse-height analyzer. Sufficiently reproducible counts are usually obtained with time settings of 2 minutes for urine samples and 20 minutes for the plasma samples. Calculations of the clearance rates are made by using the formula:(1)
C = glomerular filtration rate in mL/min/1.73 m2 
U = urine radioactivity in counts/min/mL 
V = urine flow rate in mL/min 
P= mean plasma radioactivity in counts/min/mL 
SA= body surface area in m2 
Radiation Dosimetry
- The estimated absorbed radiation doses to an average (70 kg) patient from an intravenous dose of 100 Ci (3.7 megabecquerels) of GLOFIL-125 are shown in Table 4. Calculations assume that there is 1% free iodide in the preparation and that the thyroid uptake of the iodine is 25%.
Visual Inspection
- Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

## Off-Label Use and Dosage (Adult)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Iothalamate Sodium I 125 in adult patients.

### NonGuideline-Supported Use
There is limited information regarding Off-Label NonGuideline-Supported Use of Iothalamate Sodium I 125 in adult patients.

# Pediatric Indications and Dosage

## FDA-Labeled Indications and Dosage (Pediatric)
- Safety and efficacy not established in pediatrics patients.

## Off-Label Use and Dosage (Pediatric)

### Guideline-Supported Use
There is limited information regarding Off-Label Guideline-Supported Use of Iothalamate Sodium I 125 in pediatric patients.

### NonGuideline-Supported Use
There is limited information regarding Off-Label NonGuideline-Supported Use of Iothalamate Sodium I 125 in pediatric patients.

# Contraindications
- GLOFIL-125 should not be administered via a central venous line.

# Warnings
- None known

### Precautions
- As in the use of any radioactive material, care should be taken to minimize radiation exposure to the patient, consistent with proper patient management, and to insure minimum radiation exposure to occupational workers.
- Radiopharmaceuticals should be used only by physicians who are qualified by training and experience in the safe use and handling of radionuclides.
- Rapid or bolus-like injections should be avoided.

# Adverse Reactions

## Clinical Trials Experience
There is limited information regarding Clinical Trial Experience of Iothalamate Sodium I 125 in the drug label.

## Postmarketing Experience
- Hyperpyrexia

# Drug Interactions
There is limited information regarding Iothalamate Sodium I 125 Drug Interactions in the drug label.

# Use in Specific Populations

### Pregnancy
Pregnancy Category (FDA): C
- Animal reproduction studies have not been conducted with GLOFIL-125. It is also not known whether GLOFIL-125 can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. GLOFIL-125 should be given to a pregnant woman only if clearly needed.
Pregnancy Category (AUS):
- Australian Drug Evaluation Committee (ADEC) Pregnancy Category
There is no Australian Drug Evaluation Committee (ADEC) guidance on usage of Iothalamate Sodium I 125 in women who are pregnant.

### Labor and Delivery
There is no FDA guidance on use of Iothalamate Sodium I 125 during labor and delivery.

### Nursing Mothers
Radioiodine is excreted in human milk during lactation. It is not known whether GLOFIL-125 is excreted in human milk. Therefore, formula feedings should be substituted for breast feedings.

### Pediatric Use
Safety and effectiveness in children have not been established.

### Geriatic Use
There is no FDA guidance on the use of Iothalamate Sodium I 125 with respect to geriatric patients.

### Gender
There is no FDA guidance on the use of Iothalamate Sodium I 125 with respect to specific gender populations.

### Race
There is no FDA guidance on the use of Iothalamate Sodium I 125 with respect to specific racial populations.

### Renal Impairment
There is no FDA guidance on the use of Iothalamate Sodium I 125 in patients with renal impairment.

### Hepatic Impairment
There is no FDA guidance on the use of Iothalamate Sodium I 125 in patients with hepatic impairment.

### Females of Reproductive Potential and Males
There is no FDA guidance on the use of Iothalamate Sodium I 125 in women of reproductive potentials and males.

### Immunocompromised Patients
There is no FDA guidance one the use of Iothalamate Sodium I 125 in patients who are immunocompromised.

# Administration and Monitoring

### Administration
- Intravenous

### Monitoring
There is limited information regarding Monitoring of Iothalamate Sodium I 125 in the drug label.

# IV Compatibility
There is limited information regarding IV Compatibility of Iothalamate Sodium I 125 in the drug label.

# Overdosage
There is limited information regarding Overdose of Iothalamate Sodium I 125 in the drug label.

# Pharmacology
There is limited information regarding Iothalamate Sodium I 125 Pharmacology in the drug label.

## Mechanism of Action
There is limited information regarding Iothalamate Sodium I 125 Mechanism of Action in the drug label.

## Structure
- GLOFIL-125 (Sodium Iothalamate I-125 Injection) is a sterile, nonpyrogenic aqueous injection containing approximately 1 mg sodium iothalamate per mL, and 0.9 percent benzyl alcohol as a preservative. The radioactive concentration of the material is 250-300 Ci/mL as of the calibration date. Sodium bicarbonate and hydrochloric acid are present for pH adjustment.
Physical Characteristics
- Iodine-125 decays by electron capture with a physical half-life of 60.14 days. Photons that are useful for detection are listed in Table 1.

## Pharmacodynamics
There is limited information regarding Pharmacodynamics of Iothalamate Sodium I 125 in the drug label.

## Pharmacokinetics
- The renal clearance of sodium iothalamate in man closely approximates that of inulin. The compound is cleared by glomerular filtration without tubular secretion or reabsorption. Following infusion administration of I-125 iothalamate, the effective half-life is about 0.07 days.

## Nonclinical Toxicology
- No long-term animal studies have been performed to evaluate carcinogenic potential, mutagenic potential, or whether this drug affects fertility in males or females.

# Clinical Studies
There is limited information regarding Clinical Studies of Iothalamate Sodium I 125 in the drug label.

# How Supplied
- Identity
No. 1000, GLOFIL-125 is a clear, colorless, sterile, and nonpyrogenic solution available as a 4 mL vial. It is supplied in a concentration of approximately 1 mg/mL sodium iothalamate (range is 0.52.0 mg sodium iothalamate per mL), with a radioactivity concentration of 250 to 300 Ci/mL at the time of calibration. Benzyl alcohol 0.9%, is added as a preservative. Sodium bicarbonate and hydrochloric acid are added for pH adjustment. The calibration and expiration dates are shown on the label.

## Storage
- Refrigerate the product upon receipt at 2C to 8C.

# Images

## Drug Images

## Package and Label Display Panel

### INGREDIENTS AND APPEARANCE

# Patient Counseling Information
There is limited information regarding Patient Counseling Information of Iothalamate Sodium I 125 in the drug label.

# Precautions with Alcohol
- Alcohol-Iothalamate Sodium I 125 interaction has not been established. Talk to your doctor about the effects of taking alcohol with this medication.

# Brand Names
- GLOFIL-125

# Look-Alike Drug Names
There is limited information regarding the look alike drug names.

# Drug Shortage Status

# Price