Dosing & Uses
Dosage Forms & Strengths
1-2 gtt in the conjunctival sac
Repeat in 5 minutes, if necessary
For cycloplegia and to break posterior synechiae in iritis
Postoperatively instill 1-2 gtt into eye(s) TID-QID when desirable to maintain dilation and rest ciliary body
Combinations induce mydriasis that is considerably greater than that of either drug alone
<18 safety and efficacy not established
Serious - Use Alternative
Significant - Monitor Closely
Frequency Not Defined
Headache or browache
Sensitivity to light
Transient burning or stinging
Hypersensitivity reactions such as allergic conjunctivitis or dermatitis
Pallor or blanching
Trembling or tremors
Premature ventricular contractions
Hypersensitivity to either component
Known or suspected angle-closure glaucoma
Soft contact lenses
Reduce dose if used within 21 d of MAO inhibitors or TCAs
Wait 5 minutes between multiple drops (no >3 drops needed)
May cause false-normal tonometry readings, tonometry should be performed before phenylephrine is administered
Pregnancy & Lactation
Pregnancy Category: C
Lactation: unknown if excreted in breast milk, use caution
A:Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B:May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C:Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D:Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X:Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA:Information not available.
Onset: 15 min
Absorption: some systemic
Maximum effect: 60 min
Duration: 3 hr
Recovery (usual): 3-7 hr
Mechanism of Action
Phenylephrine acts directly on alpha-adrenergic receptors in eye producing contraction of dilator muscle of pupil and constriction of arterioles in conjunctiva
Ophthalmic scopolamine blocks the responses of iris sphincter muscle and the accommodative muscle of the ciliary body to cholinergic stimulation, thereby producing mydriasis and cycloplegia