Ophthalmic medications pharmacology - part 1 doc

[...]... has been a focus on the development of less irritating preservatives For instance, sodium perborate (Gen-aqua®) is used in Genteal® This agent is unique in that contact with the eye changes it into oxygen and water, producing minimally-lasting negative effects Purite (in Refresh®) and Polyquaternium -1 (in Systane®) are other new additions to the line of artificial tears preservatives Other common preservatives... increase contact time, certain ophthalmic preparations use special gel-forming vehicles One of these, Gelrite® (in Timoptic XE®), allows the medication to remain in solution until it contacts the precorneal tear film It then forms a more viscous gel, which is subsequently removed by the tears over time Finally, vehicles such as white petrolatum and lanolin are used in ophthalmic ointments Excipients... degraded by oxygen (oxidation) Medications should be stored in their opaque containers Certain additives, called antioxidants, can stabilize a solution by minimizing deterioration An example of an antioxidant is sodium bisulfate Sterility and Preservatives Once opened, solutions are not only exposed to degradation but also to microbial contamination Pseudomonas aeruginosa is a well-known contaminant of sodium...2 Chapter 1 Pharmaceutical agents are used daily for patient evaluation, diagnosis, and treatment Many patients are also using other drugs to treat various medical conditions A general understanding of pharmacology, therapeutics, drug administration, makeup, actions, interactions, and side effects is critical... the cap on a countertop 4 Chapter 1 Vehicles Vehicles are inert (nonactive) agents that either provide support for or are used to dissolve the active drug Though they may be used as a buffer, their major function is to control viscosity (thickness) of the solution Increasing the viscosity increases the contact time of the active drug Some commonly used vehicles in ophthalmic solutions are povidone... is no movement between them Most ophthalmic solutions are designed to be isotonic with human tears (0.9 sodium chloride equivalent) Tonicity agents, or buffers, are added to a preparation to keep it in this range Examples of tonicity agents include glycerin, sodium, potassium chloride, and other salts The eye can withstand solutions ranging in tonicity from 0.6 to 1. 8 Outside this range, irritation,... added to give form or consistency to the preparation Salts, sugars, fillers, binders, lubricants (as an additive), colors, and flavors fall into this group They have limited use and application in ophthalmic medications Drug Administration OphA There are several routes of drug administration, each suitable for given conditions Although different ocular conditions can be treated in a variety of ways,... the method that will be easiest for the patient to comply with, and c) the drug and route that has the least risk and the lowest possibility of side effects Topical Ophthalmic drugs must reach the eye in high concentrations Many systemic medications do not penetrate the anterior segment due to the blood aqueous barrier When the desired target is the cornea, conjunctiva, ciliary body, or other anterior... resolves itself, and no treatment is necessary Because these medications blur the vision, they are best instilled when visual difficulties are least likely to cause impairment (eg, at bedtime) What the Patient Needs to Know • • To instill ointment, gently pull your lower lid down to create a pocket Place a small ribbon of ointment (about one-fourth inch) into the pocket, and close your eyes for a minute,... time when the blurring will not be a problem OptA OptT Gels To improve patient compliance and to decrease the need for multiple drops, some drugs have been formulated as gels (such as Pilopine-HS® gel) or gel-forming sustained release preparations (such as Timoptic XE®) The active drug in these preparations is released more slowly, prolonging its effect Like ointments, they will blur the vision Other . Hypersensitivity 10 3 Chapter 13 . Retinal Therapies 10 9 Appendix A: Acute Drug Reactions and Emergencies 11 3 Appendix B: Vitamins 11 7 Appendix C: The Drug Approval Process 12 3 Index 12 7 Acknowledgments In. Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) 63 Chapter 9. Anesthetics 69 Chapter 10 . Anti-Infectives 75 Chapter 11 . Antiglaucoma Agents 89 Chapter 12 . Side Effects, Toxicity, and Hypersensitivity 10 3 Chapter. identify the appro- priate icon: paraoptometric paraoptometric assistant paraoptometric technician ophthalmic assistant ophthalmic technician ophthalmic medical technologist * ophthalmic surgical