TELEPAQUE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TELEPAQUE (TELEPAQUE).
Telepaque (iopanoic acid) is an oral cholecystographic agent. It is absorbed from the gastrointestinal tract, conjugated in the liver, and excreted in bile. In the gallbladder, it concentrates and opacifies the bile, allowing radiographic visualization. It is also a non-competitive inhibitor of 5'-deiodinase, reducing conversion of T4 to T3.
| Metabolism | Hepatic; conjugated with glucuronic acid. Renal and fecal excretion of conjugated metabolites. The drug may undergo enterohepatic circulation. |
| Excretion | Primarily renal (90-95% within 24 hours, via glomerular filtration without significant tubular reabsorption); fecal excretion accounts for <5% as unchanged drug. |
| Half-life | Terminal elimination half-life is approximately 8-12 hours; may be prolonged in patients with renal impairment or biliary obstruction. |
| Protein binding | Approximately 90% bound to serum albumin. |
| Volume of Distribution | About 0.12-0.15 L/kg, indicating limited extravascular distribution and mainly confined to plasma and interstitial fluid. |
| Bioavailability | Oral absorption is complete (nearly 100%) after oral administration; not administered parenterally. |
| Onset of Action | Oral administration: radiopacity appears within 15-30 minutes; maximal opacification of gallbladder occurs 10-15 hours post-dose. |
| Duration of Action | Radiographic visualization persists for 12-24 hours; complete elimination typically within 2-3 days; residual contrast may obscure later studies. |
3 to 6 g orally as a single dose administered 10-14 hours before cholecystography, typically as 6 to 12 tablets (500 mg each).
| Dosage form | TABLET |
| Renal impairment | Contraindicated in patients with severe renal impairment (GFR <30 mL/min). For moderate impairment (GFR 30-59 mL/min), use with caution and consider dose reduction or alternative imaging. |
| Liver impairment | Contraindicated in severe hepatic impairment (Child-Pugh class C). For moderate impairment (Child-Pugh class B), use with caution and consider alternative diagnostic methods. |
| Pediatric use | Not recommended for use in children due to limited safety data. |
| Geriatric use | Use with caution in elderly patients due to increased risk of nephrotoxicity and dehydration; ensure adequate hydration and monitor renal function closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for TELEPAQUE (TELEPAQUE).
| Breastfeeding | Telepaque (iopanoic acid) is excreted into breast milk; M/P ratio unknown. Potential for infant thyroid suppression due to iodine content. Discontinue breastfeeding or avoid use; alternative imaging preferred. |
| Teratogenic Risk | FDA Pregnancy Category D. First trimester: increased risk of congenital anomalies based on animal studies, but human data limited. Second and third trimesters: potential fetal hypothyroidism due to iodine release; neonatal goiter and transient hypothyroidism reported. |
| Fetal Monitoring |
■ FDA Black Box Warning
None.
| Serious Effects |
["Hypersensitivity to iopanoic acid or iodine-containing compounds","Acute renal failure or severe renal impairment","Severe hepatic disease","Thyrotoxicosis (relative contraindication in hyperthyroid states)","Pregnancy and lactation (relative); avoid in nursing mothers"]
| Precautions | ["Severe hypersensitivity reactions including anaphylaxis","Renal impairment may increase risk of nephrotoxicity","Hepatotoxicity in patients with pre-existing liver disease","Prolonged use may cause hypothyroidism due to inhibition of T4-to-T3 conversion","Interference with thyroid function tests"] |
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| Monitor maternal thyroid function (TSH, free T4) before and after administration; fetal thyroid ultrasound if exposed in second or third trimester; neonatal TSH screening at birth. |
| Fertility Effects | No documented effects on human fertility. Animal studies have not revealed impaired fertility at clinically relevant doses. |