Joflupaan (123i) Rotop (Ioflupane (123i))

Ioflupane is used in SPECT imaging of the dopaminergic system to evaluate several movement‑related disorders.

• Parkinsonian syndromes: provides quantitative assessment of striatal dopamine transporter availability, supporting diagnosis and disease staging.
• Differential diagnosis of movement disorders: differentiates idiopathic Parkinson's disease from atypical parkinsonian disorders such as multiple system atrophy and progressive supranuclear palsy.
• Dementia with Lewy bodies: reveals characteristic reduction in dopamine transporter binding, aiding distinction from Alzheimer's disease and other dementias.

• Ioflupane is a radiolabeled analogue of the neurotransmitter dopamine that binds with high affinity to presynaptic dopamine transporters (DAT) located on nigrostriatal neurons. After intravenous injection, the compound crosses the blood‑brain barrier and accumulates in regions with intact DAT. The attached iodine‑123 isotope emits gamma photons detectable by single‑photon emission computed tomography (SPECT), producing a visual map of dopaminergic neuronal integrity.

Ioflupane may be associated with adverse reactions related to the radiopharmaceutical itself or the injection procedure.

Common Side Effects

• Nausea: mild to moderate nausea occurring shortly after injection.
• Headache: transient headache reported by some patients.
• Injection site pain: brief discomfort at the venous access point.
• Dizziness: temporary light‑headedness during or after the procedure.
• Fatigue: mild tiredness that resolves without intervention.

Serious or Rare Side Effects

• Allergic reaction: urticaria, rash, or anaphylaxis requiring immediate medical attention.
• Severe hypotension: marked drop in blood pressure following injection.
• Radiation‑induced tissue injury: rare localized tissue damage at high cumulative doses.
• Pulmonary embolism: extremely rare but possible if particulate matter is introduced.
• Nephrotoxicity: rare kidney function impairment in susceptible individuals.

Before using Ioflupane, clinicians should observe several precautionary measures to ensure patient safety and product integrity.

• Pregnancy: avoid use unless the potential diagnostic benefit outweighs unknown fetal risk.
• Breastfeeding: discontinue breastfeeding or consider alternative imaging, as iodine‑123 may be excreted in milk.
• Renal impairment: assess kidney function; reduced clearance may increase radiation exposure.
• Thyroid disorders: evaluate thyroid status because iodine‑123 can affect thyroid hormone balance.
• Concomitant medications: review drugs that may interfere with dopamine transporter binding, such as certain antidepressants or stimulants.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake the vial.

Ioflupane can interact with other substances that affect dopamine transporter binding or alter iodine metabolism.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAO‑I): may significantly alter DAT binding and confound imaging results.
• Certain antidepressants (e.g., bupropion, sertraline): can competitively inhibit DAT, leading to false‑negative scans.
• Iodine‑containing contrast agents: excess iodine may compete with iodine‑123, reducing image quality.

Moderate Interactions (Monitor Closely)

• Antipsychotics (e.g., haloperidol, risperidone): may affect DAT availability; timing of medication should be considered.
• Stimulants (e.g., methylphenidate, amphetamines): can modify DAT occupancy, requiring dose adjustment or washout period.
• Thyroid medications (levothyroxine): monitor thyroid function as iodine load may influence radiotracer distribution.