Ophthalmic pharmacology

Local and Systemic Ophthalmic Pharmacology and Toxicology of Organophosphate and Carbamate Antichol 1 nesterases... 

Ophthalmic pharmaceutical dosage forms serve as delivery vehicles for a wide range of drugs with pharmacological activity in the eye. The most commonly... 

Pharmacology Direct-acting miotics are parasympathomimetic (cholinergic) drugs which duplicate the muscarinic effects of acetylcholine. When applied topically, these drugs produce pupillary constriction, stimulate ciliary muscles, and increase aqueous humor outflow facility. With the increase in outflow facility, there is a decrease in lOP. Topical ophthalmic instillation of acetylcholine causes no discernible P.1248... 

Pharmacology Brinzolamide and dorzolamide are carbonic anhydrase inhibitors formulated for topical ophthalmic use. 

Phenylephrine is an effective mydriatic agent frequently used to facilitate examination of the retina. It is also a useful decongestant for minor allergic hyperemia and itching of the conjunctival membranes. Sympathomimetics administered as ophthalmic drops are also useful in localizing the lesion in Horner s syndrome. (See An Application of Basic Pharmacology to a Clinical Problem.)... 

The medical devices for category 2 in Table 1 are composed in batch. Process validation should be a key factor in manufacturing uniform products. In this category, sterile products, such as central venous catheters and ophthalmic viscosurgical solution without pharmacological and metabolic action, are involved. In vitro diagnostic products are also involved in this category. 

The therapeutic use of botulinum toxin for ophthalmic purposes and for local muscle spasm was mentioned in Chapter 6 Introduction to Autonomic Pharmacology. Local injection of botulinum toxin has become popular for the treatment of generalized spastic disorders (eg, cerebral palsy). Most clinical studies to date have involved administration in one or two limbs, and the benefits appear to persist for weeks to several months after a single treatment. Most studies to date have utilized type A botulinum toxin, but type B is also available. 

Lanolin has been used for many years as a vehicle for pharmacologically active substances in ophthalmic ointments and topical formulations.55-60 In addition to being a vehicle for penicillin and other antimicrobial substances, lanolin contains lipids such as 10-methyldodecanoic acid and 12-methyltridecanoic acid, which have antimicrobial activity.61,62... 

The kinetics of the hydroxide ion-catalyzed epimerization of pilocarpine to isopilocarpine and of its hydrolysis to pilocarpic acid have been studied (56). Both forms of degradation lead to loss of pharmacological activity. The importance of possible inactivation by epimerization during thermal sterilization of ophthalmic preparations of pilocarpine was pointed out. It was also considered that some epimerization would always occur during the extraction of pilocarpine from Jaborandi leaves, and that isopilocarpine might, therefore, be an artifact and not a genuine plant alkaloid (55). 

FisceUa R, Burstein NL. Ophthalmic drug formulations. In Bartlett JD, Jaanus SD, eds. CUmcal ocular pharmacology, ed. 4. Boston Butterworth Heinemann, 2001. 

Local anesthetics are drugs that produce reversible conduction blockage of nerve impulses. Autonomic system blockade followed by sensory anesthesia and skeletal muscle paralysis occur when local anesthetic concentration is increased. The effects of local anesthetics are completely reversible, with no evidence of structural damage to the nerve fibers. Another prominent clinical feature of local anesthesia is that loss of sensation occurs without loss of consciousness. This property makes local anesthetics highly useful for many office procedures and for eye surgery. This chapter considers the pharmacologic properties of anesthetics cmrently used for ophthalmic procedures. 

Adapted from Raj PP Handbook of regional anesthesia. New York Churchill Livingstone, 1985 Bartlett JD, Fiscella R, Jaanus SD, et al., eds. Ophthalmic drug facts. St. Louis Facts and Comparisons, 2005 Crandall DG. Pharmacology of ocular anesthetics. In Duane TD, Jaeger EA, eds. Biomedical foundations of ophthalmology. Philadelphia J.B. Lippincott, 1994 and Sobol WM, McCrary JA. Ocular anesthetic properties and adverse reactions, hit Ophthalmol Chn 1989 29 195-199. 

Clinicians often encounter patients with ophthalmic manifestations of neurologic impairment. Patients with anisocoria, neuromuscular abnormalities, and optic neuropathies can be challenging.This chapter describes the diagnostic and therapeutic uses of various pharmacologic agents in the management of these conditions. 

Avunduk AM, Avunduk MC, Dayanir y et al. Pharmacological mechanism of topical lodoxamide treatment in vernal keratoconjunctivitis a flow-cytometric smdy Ophthalmic Res 1998 30 37-43. 

An excipient is defined as a material that is deliberately incorporated into the formulation to aid some physicochemical process, for example for a tablet, integrity, dissolution, bioavailability or taste excipients are typically chosen from among many compounds without pharmacological properties (e.g. lactose), although there are examples where pharmacokinetics change with the excipient used. There are specialized examples of excipients, for example propellants are excipients that assist in the delivery of inhaled drugs to the respiratory tract. For intravenous infusions or ophthalmic products, the excipients are usually pH buffers or... 

Smolen VF. 1971. Quantitative determination of drug bioavailability and biokinetic behavior from pharmacological data for ophthalmic and oral administration of a mydriatic drug . J. Pharm. Sci. 60 354. 

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