phenylephrine + atropine

Phenylephrine + atropine is a combination of two pharmacological agents commonly used in ophthalmology to achieve maximal pupil dilation (mydriasis) prior to intraocular surgery or for certain diagnostic procedures. Phenylephrine is an alpha-1 adrenergic receptor agonist that induces mydriasis by contracting the dilator muscle of the iris and causing vasoconstriction in ocular tissues. Atropine is an antimuscarinic agent that blocks muscarinic acetylcholine receptors, resulting in both mydriasis and cycloplegia (paralysis of accommodation). When used together, these drugs provide a synergistic effect for pupil dilation, which can be necessary for specific surgical or diagnostic needs. However, this combination can cause significant cardiovascular effects such as increased heart rate and blood pressure, especially when administered systemically or in susceptible patients[4][6][7]. The use of this combination should be carefully monitored due to potential adverse effects.