A distinct mechanism
of action¹

Phenylephrine works by binding to the alpha-1 adrenergic receptors on the iris dilator muscle, causing the muscle to contract and pupil to dilate. This duration of activity may last approximately 3-8 hours.³
RYZUMVI, on the other hand, reverses pupil dilation by binding to the alpha-1 adrenergic receptors, preventing phenylephrine from binding, and returns the pupil to its baseline size.¹

Tropicamide is a muscarinic antagonist that blocks the responses of the iris sphincter and ciliary muscles to cholinergic stimulation, dilating the pupil and paralysis of the ciliary muscle. The stronger preparation (1%) also paralyzes accommodation. This duration of activity can last ~3-8 hours, and complete recovery may require 24 hours.^4-6
RYZUMVI indirectly reverses mydriasis induced by muscarinic antagonist effects on the iris sphincter muscle.¹

Paremyd is a combination eye drop containing hydroxyamphetamine hydrobromide (1%) and tropicamide (0.25%). Hydroxyamphetamine is an indirectly-acting adrenergic agent that works by causing the release of norepinephrine resulting in dilation. Tropicamide is a muscarinic antagonist that blocks the response of the iris sphincter and ciliary muscles to cholinergic stimulation, dilating the pupil and paralysis of the ciliary muscle. Duration of activity may last 6 to 8 hours. In some cases, complete recovery may take up to 24 hours.^6-7
RYZUMVI indirectly reverses mydriasis induced by muscarinic antagonist effects on the iris sphincter muscle.¹