Apraclonidine is a relatively selective alpha2 adrenergic receptor agonist that stimulates alpha1 receptors to a lesser extent. It has a peak ocular hypotensive effect occurring at two hours post-dosing. The exact mechanism of action is unknown, but fluorophotometric studies in animals and humans suggest that Apraclonidine has a dual mechanism of action by reducing aqueous humor production through the constriction of afferent ciliary process vessels, and increasing uveoscleral outflow.
Apraclonidine is indicated for the short-term adjunctive treatment of glaucoma for patients on maximally tolerated medical therapy who require additional reduction of IOP. These patients, who are treated with apraclonidine to delay surgery, should have frequent follow-up examinations and treatment should be discontinued if the intraocular pressure rises significantly.
Apraclonidine may be useful in the diagnosis of Horner's syndrome. In Horner's syndrome, the sympathetic innervation to the pupillary dilator muscle is lost. The affected pupil is thus miotic and the pupillary dilator responds to denervation by increasing α1 receptors. Apraclonidine is useful in this case due to its weak α1-adrenergic properties. When applied to the denervated (and thus hyper-sensitive) pupillary dilator muscle, a super-normal dilatory response is generated in which the pupil dilates to a degree greater than that which would be seen in a non-denervated muscle. This causes the reversal of anisocoria that is characteristic of Horner's.
Topical apraclonidine can also decrease IOP in glaucoma patients by increasing trabecular outflow, in a similar way to clonidine, but without the cardiovascular side effects. Apraclonidine has been compared with other treatments such as brimonidine and pilocarpine in preventing IOP spikes after laser trabeculoplasty. The results did not show significant differences in the reduction of IOP for apraclonidine, when compared to brimonidine or pilocarpine.
Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.
One drop of IOPIDINE 1% Ophthalmic Solution should be instilled in the scheduled operative eye one hour before initiating anterior segment laser surgery and a second drop should be instilled to the same eye immediately upon completion of the laser surgical procedure. Use a separate container for each single-drop dose and discard each container after use.
What drugs may interact with Apraclonidine?
Apraclonidine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.
Does food or alcohol interact with Apraclonidine?
Apraclonidine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.
What health conditions may interact with Apraclonidine?
Apraclonidine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.
IOPIDINE 1% Ophthalmic Solution is indicated to control or prevent post-surgical elevations in intraocular pressure that occur in patients after argon laser trabeculoplasty, argon laser iridotomy or Nd:YAG posterior capsulotomy.
Before using this drug, tell your doctor if:
Tell all of your health care providers that you take this medicine. This includes your doctors, nurses, pharmacists, and dentists.
Avoid driving and doing other tasks or actions that call for you to be alert or have clear eyesight until you see how apraclonidine affects you.
Do not use longer than you have been told by the doctor.
Have your eye pressure and eyesight checked as you have been told by the doctor.
Talk with your doctor before you drink alcohol or use other drugs and natural products that slow your actions.
Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine while you are pregnant.
Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
Is it safe during pregnancy or breastfeeding?
There are no adequate studies in women for determining risk when using Apraclonidine during pregnancy or while breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking Apraclonidine. Apraclonidine is pregnancy risk category C, according to the US Food and Drug Administration (FDA).
FDA pregnancy risk category reference below: