TABLE 1

Medications That Affect 123I-MIBG Imaging (13)

Drug or classExamplesMechanism of interference (known or expected)Discontinuation before 123I-MIBG scan (d)
OpioidUptake inhibition7–14
CocaineUptake inhibition7–14
TramadolUptake inhibition7–14
Tricyclic antidepressantsAmitriptyline and derivatives, imipramine and derivatives, amoxapine, doxepin, othersUptake inhibition7–21
Sympathicomimetics * Phenylpropanolamine, ephedrine, pseudoephedrine, phenylephrine, amphetamine, dopamine, isoproterenol, salbutamol, terbutaline, fenoterol, xylometazolineDepletion of granules7–14
Antihypertensive or cardiovascular agentsLabetalolInhibition of uptake and depletion21
ReserpineDepletion and transport inhibition14
Bretylium, guanethidineDepletion and transport inhibition14
Calcium channel blockers (nifedipine, nicardipine, amlodipine)Increased uptake and retention14
AntipsychoticsPhenothiazines † (chlorpromazine, promethazine, fluphenazine, others)Uptake inhibition21–28
Thioxanthenes (maprotiline, trazodone)Uptake inhibition21–28
Butyrophenones (droperidol, haloperidol)Uptake inhibition21–28
LoxapineUptake inhibition7–21

  • ↵ * Components of bronchodilators, decongestants, and diet aids.

  • ↵ † Frequent components of antiemetic and antiallergic agents.