(Adapted from Omnipaquetm package insert)

Background:

Iohexol is a non-ionic, water-soluble contrast agent with 46.36% iodine content. It is excreted renally.

Available concentrations include: 140, 180, 240, 300 and 350 milligrams of iodine per milliliter.

Omnipaque 180, 240 and 300 are indicated for intrathecal use in adults. DO NOT ADMINISTER OMNIPAQUE 140 OR 350 INTRATHECALLY.

Contraindications: known hypersensitivity to iohexol; active local/systemic infection; co-administration of intra-thecal corticosteroids; overdose; significant intra-cranial entry; use in patient with epilepsy; grossly bloody CSF; co-administration with: phenothiazines, MAOI, TCA, CNS stimulants, antipsychotics.

Adverse occurrences: headache, meningismus, nausea, seizure, anaphylaxis. With inadvertent administration of Omnipaque not indicated for intrathecal use: death, seizure, cerebral hemorrhage, arachnoiditis, renal failure, rhabdomyolysis, hyperthermia, cerebral edema.

Technique:

A total of 3,060 milligrams of iodine should not be exceeded in one study in an adult patient.

For total columnar myelography, instill 6-12.5 mL of Omnipaque 240, or 6-10 mL of Omnipaque 300, via standard lumbar puncture over 1-2 minutes. To allow time for complete opacification of the subarachnoid space, obtain CT roughly 15-30 minutes, but not more than 1 hour, after contrast injection.

The patient should remain hydrated and observed for at least 12 hours post myelogram. Avoid excessive entry of contrast intracranially and maintain elevated head-of-bed once the study is complete.

Full details can be viewed in the OmnipaqueTM (iohexol) package insert, freely available at:

https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018956s099lbl.pdf