Dosing and uses of Cyclomydril (cyclopentolate/phenylephrine)
Adult dosage forms and strengths
cyclopentolate/phenylephrine
ophthalmic solution
- 0.2%/1%
Mydriasis
1-2 gtt in the conjunctival sac q5-10 min, not to exceed 3 times
Other Information
Combinations induce mydriasis that is considerably greater than that of either drug alone
Pediatric dosage forms and strengths
<18 safety and efficacy not established
Cyclomydril (cyclopentolate/phenylephrine) adverse (side) effects
Frequency not defined
Blurred vision
Burning sensation in eye
Hypersensitivity reactions such as allergic conjunctivitis or dermatitis
Sensitivity to light
Headache or browache
Reactive hyperemia
Transient burning or stinging
Transient keratitis
Rare
- Hypertension, tachycardia, palpitation, premature ventricular contractions, tachyarrhythmia, vasodilatation
- Ataxia, confusion, occipital headache, psychotic disorder, raised intraocular pressure, seizure, trembling or tremors
- Increased perspiration
- Pallor or blanching
Warnings
Contraindications
Aneurysm
Hypersensitivity to either component
Known or suspected angle-closure glaucoma or increased intraocular pressure
Soft contact lenses
Cautions
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 and lactation
Pregnancy category: C
Lactation: unknown if excreted in breast milk, use caution
Pregnancy categories
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.
Pharmacology of Cyclomydril (cyclopentolate/phenylephrine)
Onset: rapid
Absorption: some systemic
Maximum effect: 30-60 min
Duration: 3 hr
Recovery (usual): 3-7 hr
Excretion: urine
Mechanism of action
Cyclopentolate blocks the action of acetylcholine resulting in relaxation of the cholinergically innervated sphincter muscle of the iris
Cholinergic stimulation of the accommodative ciliary muscle of the lens is also blocked
Anticholinergic effects of cyclopentolate in the eye produce dilation of the pupil (mydriasis) and paralysis of accommodation (cycloplegia)
Phenylephrine acts directly on alpha-adrenergic receptors in eye producing contraction of dilator muscle of pupil & constriction of arterioles in conjunctiva
