Ophthalmic antibiotics

Neomycin 0.35% Triple Antibiotic Ophthalmic Ointment (Various)... 

The client diagnosed with bilateral conjunctivitis is prescribed antibiotic ophthalmic ointment. Which interventions should the nurse implement when discussing the medication with the client Select all that apply. 

The principal OTC pharmaceutical products include cold remedies, vitamins and mineral preparations, antacids, analgesics, topical antibiotics, antiftingals and antiseptics, and laxatives. Others include suntan products, ophthalmic solutions, hemorrhoidal products, sleep aids, and dermatological products for treatment of acne, dandmff, insect parasites, bums, dry skin, warts, and foot care products (11). More recent prescription-to-OTC switches have included hydrocortisone, antihistamine and decongestant products, antiftingal agents, and, as of 1995, several histamine H2-receptor antagonists. 

Bacitracin given parenteraHy is sufftciendy nephrotoxic that it is rarely used in human medicine for other than topical indications (80). Thus safe and effective use, especially as the zinc salt, is limited almost completely to ointments, sprays, and solutions for skin and ophthalmic use in concentrations of 250 to 1000 units per milliliter. Bacitracin is only rarely skin sensitizing. As in the case of polymyxin, bacitracin is usually combined with other antibiotics to enlarge its spectmm of activity, or with corticoids or analgesics to reUeve pain or itching. 

Antibiotics possess antibacterial activity and are used in the treatment of eye infections. Sulfonamides possess a bacteriostatic effect against a wide range of gram-positive and gram-negative microorganisms. They are used in the treatment of conjunctivitis, comeal ulcer, and other superficial infections of the eye. See the Summary Drug Table Select Ophthalmic Preparations and Chapter 6 for additional information on the sulfonamides. 

The antibiotic and sulfonamide ophthalmics are usually well tolerated, and few adverse reactions are seen. Occasional transient irritation, burning, itching, stinging, inflammation, or blurring of vision may occur. With prolonged or repeated use, a superinfection may occur. 

The antibiotic and sulfonamide ophthalmics are contraindicated in patients with a hypersensitivity to the drug or any component of the drug. These dru are also contraindicated in patients with epithelial herpes simplex keratitis, varicella, mycobacterial infection of the eye, and fungal diseases of the eye There are no significant precautions or interactions when the dru are administered as directed by the primary health care provider. 

Co-administration of ofloxacin and chitosan in eyedrops increased the bioavailabUity of the antibiotic [290]. Trimethyl chitosan was more effective because of its solubility (plain chitosan precipitates at the pH of the tear fluid). On the other hand, N-carboxymethyl chitosan did not enhance the corneal permeability nevertheless it mediated zero-order ofloxacin absorption, leading to a time-constant effective antibiotic concentration [291]. Also W,0-carboxymethyl chitosan is suitable as an excipient in ophthalmic formulations to improve the retention and the bioavailability of drugs such as pilocarpine, timolol maleate, neomycin sulfate, and ephedrine. Most of the drugs are sensitive to pH, and the composition should have an acidic pH, to enhance stability of the drug. The delivery should be made through an anion exchange resin that adjusts the pH at around 7 [292]. Chitosan solutions do not lend themselves to thermal sterilization. A chitosan suspension, however. 

In contrast, parenteral suspensions have relatively low solids contents, usually between 0.5 and 5%, with the exception of insoluble forms of penicillin in which concentrations of the antibiotic may exceed 30%. These sterile preparations are designed for intramuscular, intradermal, intralesional, intraarticular, or subcutaneous injection. Syringeability is an important factor to be taken into consideration with injectable dosage forms. The viscosity of a parenteral suspension should be sufficiently low to facilitate injection. Common suspending vehicles include preserved isotonic saline solution or a parenterally acceptable vegetable oil. Ophthalmic and optic suspensions that are instilled into the eye/ear must also be prepared in a sterile manner. The vehicles are essentially isotonic and aqueous in composition. The reader should refer to Chapter 12 for further discussion on parenteral products. 

Oils have been used as vehicles for several topical eyedrop products that are extremely sensitive to moisture. Tetracycline HC1 is an antibiotic that is stable for only a few days in aqueous solution. It is supplied as a 1% sterile suspension with Plastibase 50W and light liquid petrolatum. White petrolatum and its combination with liquid petrolatum to obtain a proper consistency is routinely used as the vehicle for ophthalmic ointments. 

For prophylaxis of ophthalmia neonatorum, various groups have proposed the use of erythromycin (0.5%) or tetracycline (1%) ophthalmic ointment in lieu of silver nitrate. Although silver nitrate and antibiotic ointments are effective against gonococcal ophthalmia neonatorum, silver nitrate is not effective for chlamydial disease and may cause a chemical conjunctivitis. 

Erythromycin, Ophthalmic (llotycin Ophthalmic) [Anti infective, Macrolioe, Opthalmic agent] U e Conjunctival/comeal Infxns Action Macrolide antibiotic Dose 1/2 in 2-6 x /d Caution [B, +] Contra Erythromycin hyp sensitivity Disp Oint SE Local irritation EMS See Erythromycin may cause burning, stinging, blurred vision... 

Chloramphenicol also is widely used for the topical treatment of eye infections. It is a very effective agent because of its extremely broad spectrum of activity and its ability to penetrate ocular tissue. The availability of safer, less irritating instilled ophthalmic antibiotics and the increase in fatal aplastic anemia associated with the use of this dosage form suggest that this agent might best be withdrawn. 

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