McKenna's Pharmacology for Nursing, 2e

D

Appendix

Ophthalmic agents

O phthalmic agents are drugs that are intended for direct administration into the conjunctiva of the eye. These drugs are used to treat glaucoma (miotics constrict the pupil and decrease the resistance to aqueous flow); to aid in the diagnosis of eye problems (mydri- atics dilate the pupil for examination of the retina; cycloplegics paralyse the muscles that control the lens to aid refraction); to treat local ophthal- mic infections or inflammation; and to provide relief from the signs and symptoms of allergic reactions. These drugs are not generally

Care considerations

Assessment

■ ■ Screen for the following: allergy to the specific drug or components of the preparation; underlying medical conditions that would be affected if the drug were absorbed systemically . ■ ■ Evaluate eye, conjunctival colour; note any lesions. A vision examination may be appropriate. Implementation ■ ■ Assess the person’s general physical condition before beginning the test to decrease the potential for adverse effects . ■ ■ Follow these administration guidelines to provide the most therapeutic use of the drug with the fewest adverse effects : –– Solution or drops: Wash hands thoroughly before administering; do not touch the dropper to the person’s eye or to any other surface. Have the person tilt the head backwards or lie down, and have the person stare upwards. Gently grasp the lower eyelid and pull the eyelid away from the eyeball; instil drops into the pouch formed by the eyelid. Release the lid slowly; have the person close the eye and look downwards. Apply gentle pressure to the inside corner of the eye for 3 to 5 minutes to retard drainage. Do not rub the eyes; do not rinse the eyedropper. Do not use eye drops that have changed colour; if more than one type of eye drop is used, wait at least 5 minutes between administrations. Refer to Figure D.1. –– Ointment: Wash hands thoroughly before administering; hold the tube between the hands for several minutes to warm the ointment; discard the first centimetre of ointment when opening the tube for the first time. Tilt the person’s head backwards or have the person lie down and stare upwards. Gently pull out the lower lid to form a pouch; place 1–1.5 cm of ointment inside the lower lid. Have the person close the eye for 1 to 2 minutes and roll the eyeball in all directions; remove any excess ointment from around the eye. If using more than one kind of ointment, wait at least 10 minutes between administrations. Refer to Figure D.2.

absorbed systemically because of their method of administration. Caution should always be used when giving drugs during pregnancy or breastfeeding. Contraindications and cautions These drugs are contraindicated in the presence of allergy to the specific drug or to any component of the product being used. Although they are seldom absorbed systemically, caution should be used in any person who would have problems with the systemic effects of the drugs if they were absorbed systemically. Adverse effects Adverse effects of these drugs include local irritation, stinging, burning, blurring of vision (prolonged when using ointments), tearing and headache. Clinically important drug–drug interactions Because of their actions on the eye or because of the components of the drug, many of these drugs cannot be given at the same time but should be spaced 1 to 2 hours apart. Check the specific drug being used for details. Dosage The usual dosage for any of these drugs is one to two drops in each eye or in the affected eye two to four times daily, or 0.5–1 cm in the affected eye or eyes.