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