NEPHROSCAN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for NEPHROSCAN (NEPHROSCAN).
Calcium trisodium pentetate (NEPHROSCAN) chelates gadolinium ions by forming a stable complex with the metal, thereby reducing the toxicity and enhancing elimination of gadolinium from the body. It acts as a decorporation agent for gadolinium.
| Metabolism | Calcium trisodium pentetate is not metabolized; it is excreted unchanged primarily via renal glomerular filtration. |
| Excretion | Renal: 95% as unchanged drug via glomerular filtration; no biliary/fecal excretion. |
| Half-life | Terminal elimination half-life: 1.6 hours in normal renal function; prolonged to >20 hours in severe renal impairment (CrCl <30 mL/min). |
| Protein binding | Approximately 80% bound primarily to serum albumin. |
| Volume of Distribution | 0.2-0.3 L/kg, indicating distribution primarily in extracellular fluid; minimal tissue binding. |
| Bioavailability | Intravenous: 100%; no oral bioavailability as it is not absorbed orally. |
| Onset of Action | IV injection: immediate visualization of renal parenchyma within 1-2 minutes; diuretic effect if used for renography within 5-10 minutes. |
| Duration of Action | Renal imaging: up to 1 hour post-injection; diuretic effect: 20-30 minutes. Duration extended in renal impairment. |
1 to 5 mCi (37 to 185 MBq) as a single intravenous injection for renal imaging.
| Dosage form | POWDER |
| Renal impairment | No dose adjustment required based on GFR as the drug is used for functional imaging and not therapeutically active. |
| Liver impairment | No dose adjustment required based on Child-Pugh score for this diagnostic radiopharmaceutical. |
| Pediatric use | Dosing based on body weight: 0.05 mCi/kg (minimum 0.1 mCi) intravenous single dose; maximum 5 mCi. |
| Geriatric use | No specific dose adjustment recommended; use same adult dose with caution for renal function decline associated with aging. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for NEPHROSCAN (NEPHROSCAN).
| Breastfeeding | Technetium Tc-99m is excreted into breast milk. The M/P ratio is not established for this compound but for similar agents it is low. The effective half-life in breast milk is about 4-6 hours. Guidelines recommend interrupting breastfeeding for at least 4-6 hours (or longer) after administration to minimize infant exposure. Because of the short physical half-life (6 hours), most activity decays rapidly. Pump and discard milk for one half-life cycle. |
| Teratogenic Risk | NEPHROSCAN (technetium Tc-99m pentetate) is a radiopharmaceutical. In pregnancy, ionizing radiation exposure carries potential fetal risks, especially during organogenesis (first trimester) where the risk of teratogenesis is highest. However, diagnostic procedures using low-dose radionuclides generally result in fetal radiation exposure below 50 mGy, which is considered to have negligible risk. The agent crosses the placenta; second and third trimester risks are related to potential carcinogenesis and stochastic effects. The benefit of definitive diagnosis should outweigh theoretical risks. |
■ FDA Black Box Warning
None listed in current FDA labeling for NEPHROSCAN as a decorporation agent for gadolinium. However, calcium trisodium pentetate has boxed warnings for other indications (e.g., heavy metal chelation) including renal toxicity and depletion of essential metals; consult specific product labeling.
| Serious Effects |
["Absolute: Known hypersensitivity to calcium trisodium pentetate or any component.","Relative: Renal failure (risk of reduced efficacy and increased toxicity); caution in patients with hypocalcemia or electrolyte imbalances."]
| Precautions | ["Renal impairment: May reduce gadolinium elimination; monitor renal function.","Hypocalcemia: Calcium trisodium pentetate can bind calcium, leading to decreased serum calcium; monitor calcium levels.","Essential metal depletion: Long-term use may chelate zinc, manganese, and other essential metals.","Hypersensitivity reactions: Allergic reactions including anaphylaxis have been reported."] |
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| Fetal Monitoring | No specific monitoring required beyond standard precautions for radiopharmaceutical administration. Ensure adequate maternal hydration to promote renal clearance. If administered during pregnancy, document fetal radiation dose estimates. No specific fetal monitoring indicated. |
| Fertility Effects | No known effects on human fertility. Radiopharmaceuticals at diagnostic doses are not associated with impaired fertility. |