- CONDITION CENTERS
Ms. Terrie is a clinical pharmacy writer based in Haymarket, Virginia.
Many ophthalmic disorders that are amenable to self-treatment are those involving the eyelids and adjacent areas, such as contact dermatitis and blepharitis.1 Some disorders that affect the eye surface can be self-treated as well, including dry eye, allergic conjunctivitis, viral conjunctivitis, diagnosed corneal edema, minor ocular irritation, as well as cleaning or lubricating of artificial eyes.1
Episodes of dry eye and allergic conjunctivitis are the most common ophthalmic conditions for which patients elect to use OTC ophthalmic products for prevention and treatment. Although some ophthalmic conditions are amenable to self-treatment, it is important for pharmacists to encourage patients with more serious conditions to seek immediate medical attention to prevent further complications.
A variety of OTC ophthalmic products are currently on the market, including ocular lubricants (artificial tear solutions and nonmedicated ointments), ocular decongestants, an ocular antihistamine/mast cell stabilizer, and products containing a combination of decongestants and antihistamines for the management and treatment of minor and self-limiting ophthalmic conditions, such as dry eye and allergic conjunctivitis. Eyelid scrubs for treating blepharitis, ophthalmic irrigant solutions for removing loose foreign substances from the eye (eg, lint and dust), and hyperosmotics for diagnosed corneal edema are also available.1
The primary ingredients in OTC ophthalmic ointments are white petrolatum, which acts as a lubricant and an ointment base; mineral oil, which assists the ointment in melting at body temperature; and lanolin, which aids in the absorption of water-soluble medications and also inhibits evaporation.1
Nonmedicated ointments are considered to be the mainstay of treating minor ophthalmic disorders, such as dry eye and minor eye irritation.1 In general, these products are to be used twice daily but can be administered more often, depending on the patient’s needs.1 Patients may complain about blurred vision when using ophthalmic ointments; therefore, many patients prefer to administer these ocular lubricants at bedtime to assist in keeping the ocular area moist during sleep and improve the symptoms associated with dry eye upon waking.1
Ocular lubricants, such as artificial tear solutions, contain preservatives and inorganic electrolytes to achieve tonicity and sustain pH, as well as water-soluble polymeric systems.1 Preservative-free products are available as well. These products typically contain enhancing agents, such as carboxymethylcellulose, glycerin, hydroxyethyl cellulose, hydroxypropyl methylcellulose, methylcellulose, polycarbophil, polyethylene glycol 400, polysorbate 80, or polyvinyl alcohol.1
Artificial tear substitutes provide a barrier function and help to improve the first-line defense at the level of conjunctival mucosa.1 These products help to dilute various allergens and inflammatory mediators that may be present on the ocular surface and assist in flushing the ocular surface of these agents.1 In general, artificial tears are instilled once or twice daily, typically in the morning and again at bedtime. Patients should be reminded that artificial tear products containing preservatives may cause allergic reactions and should be immediately discontinued if a reaction occurs.1 Artificial tear products can be refrigerated to provide additional soothing comfort upon instillation, are considered very safe, and can be used as often as needed.
Examples of OTC topical ophthalmic decongestants currently on the market include phenylephrine, naphazoline, tetrahydrolazine, and oxymetazoline. Naphazoline, tetrahydrolazine, and oxymetazoline are classified as imidazoles. Phenylephrine acts primarily on alpha adrenergic receptors of the ophthalmic vasculature to constrict conjunctival vessels, therefore decreasing eye redness.1 Like phenylephrine, the imidazole decongestants are used to constrict conjunctival blood vessels. Naphazoline has demonstrated efficacy in decreasing tearing and pain associated with superficial inflammation of the ocular area.1 Topical use of oxymetazoline has been shown to improve the symptoms of burning, itching, and tearing associated with allergic conjunctivitis.1
Decongestants are usually applied 1 or 2 drops up to 4 times a day, but are often overused by many patients. Oxymetazoline is a longer acting agent that is generally administered twice daily. Eye irritation and loss of efficacy is fairly common with the overuse of topical decongestants. Adverse effects of topical vasoconstrictors include burning and stinging after administration. The primary contraindication is narrow-angle glaucoma, as these agents produce a mild papillary dilation.1 Commonly used OTC decongestant ophthalmic drops include naphazoline hydrochloride 0.012%, 0.02%, and 0.03%; tetrahydrozaline 0.05%; phenylephrine hydrochloride 0.12%; and oxymetazoline hydrochloride 0.025%.
When used as directed, ocular decongestants typically do not produce either ocular or systemic adverse effects.1 These products are indicated for use up to 4 times a day, and their therapeutic effects last approximately 2 hours. In order to obtain relief throughout the day, some patients tend to use drops more often than recommended, which can lead to adverse effects. The most common adverse effects associated with the use of ocular decongestants are rebound erythema and congestion of the conjunctiva, in which the conjunctival vessels become increasingly more dilated with continued use of these agents.1 Manufacturers recommend that these products be used for no more than 72 hours.
Patients with narrow-anterior chamber or narrow-angle glaucoma should not use ophthalmic decongestants because of the risk of angle closure glaucoma, and these patients should be referred to their ophthalmic health care provider.1 Ocular decongestants should be used cautiously in individuals with hypertension, arteriosclerosis, other cardiovascular diseases, and diabetes. In addition, cardiovascular adverse effects also are possible if ocular decongestants are used in individuals with hyperthyroidism.1 Women who are pregnant should avoid using ocular decongestants when possible.
In 2006, the FDA approved ketotifen 0.025% ophthalmic solution from prescription to OTC status, and it became available to patients in 2007. Ketotifen is the only OTC ophthalmic antihistamine product that relieves ocular itching without the use of a decongestant. Ketotifen is a benzocycloheptathiophene derivative that has been used for many years. It is classified as a noncompetitive H1-receptor-antagonist and mast cell stabilizer that inhibits release of mediators from cells involved in hypersensitivity reactions.2-4
Ketotifen is approved for use in individuals 3 years of age and older and is classified as pregnancy Category C. This agent is indicated for the temporary relief of itchy eyes from exposure to ragweed, pollen, grass, animal hair, and dander.2-4 The recommended dosage is 1 drop to the affected eye(s) every 8 to 12 hours but no more than twice daily. Common adverse reactions include headache, dry eyes, and rhinitis. Ketotifen is not indicated for treatment of contact lens–related inflammation. Patients should be instructed to wait at least 10 minutes before inserting their contact lenses after instillation of ketotifen.2-4
Other OTC ocular antihistamines include pheniramine maleate and antazoline phosphate available in combination with a decongestant. Pheniramine has been shown to have little effect on intraocular pressure, whereas antazoline can increase ocular pressure slightly.1
Pharmacists can assist patients in the proper selection of OTC ophthalmic products (Tables 1 and 2), as well as ensure that patients clearly understand how to administer these medications properly. Prior to recommending any of these products, pharmacists should determine if self-treatment is appropriate and refer patients to seek medical care when warranted.
Patients who elect to use ophthalmic decongestants should be reminded that excessive use can cause rebound congestion of the conjunctiva. Patients who are also using prescription ophthalmic medications should always consult their ophthalmologist prior to using OTC ophthalmic products.
In addition, patients should be counseled thoroughly on the appropriate use and duration of these products and the adverse effects associated with their use. They should be reminded to wash their hands prior to administration, as well as avoid touching the applicator to prevent contamination. Individuals who wear contact lenses should be advised not to wear their lenses until the ophthalmic condition improves. Patients with severe eye pain, those exhibiting signs and symptoms of ophthalmic infections, those with blurred vision, those with exposure of eyes to chemicals, and those who have had blunt trauma to the eye should seek immediate medical care.