Hydroxyamphetamine / tropicamide
Dilation & diagnostic · Rx
Trade namesParemyd
Drug classCombination mydriatic (adrenergic releaser + anticholinergic)
StrengthHydroxyamphetamine 1% + tropicamide 0.25%
AvailabilityRx
Mechanism of actionHydroxyamphetamine releases endogenous norepinephrine onto the dilator muscle; tropicamide blocks the sphincter, rapid dilation with minimal cycloplegia and faster recovery than tropicamide + phenylephrine.
Indication / reason for useRoutine diagnostic mydriasis when quick recovery is desired.
Usual adult dosing1-2 drops; mydriasis within 15 min, recovery in a few hours.
PreservativeBAK
Contact lensesRemove lenses; reinsert after 15 minutes.
Common / important adverse effectsStinging, photophobia, mild transient blur; angle-closure risk in narrow angles.
Contraindications & cautionsNarrow angles; note hydroxyamphetamine invalidates a subsequent Horner localization test, don't use it if that work-up is planned.
Pregnancy / lactationLimited data.
Chair-side reference only. Dosing, contraindications and pregnancy guidance here are not exhaustive. Confirm against the current prescribing information and the patient’s full history before prescribing or advising.