Dexamethasone topical

Suspension. If the drug is not sufficiently soluble, it can be formulated as a suspension. A suspension may also be desired to improve stability, bioavailability, or efficacy. The major topical ophthalmic suspensions are the steroid anti-inflammatory agents prednisolone acetate, dexamethasone, fluorometholone, and rimex-olone. Water-soluble salts of prednisolone phosphate and dexamethasone phosphate are available however, they have a lower steroid potency and are poorly absorbed. 

A Kupferman, MV Pratt, K Suckewer, HM Leibowitz. (1974). Topically applied steroids in corneal disease. III. The role of drug derivative in stromal absorption of dexamethasone. Arch Ophthalmol 91 373-376. 

Solutions are used topieally as well as internally. Examples of eompounded liquids include topicals (wart solutions), oral syrups and elixirs, nasal solutions, otic solutions, iontophoretic solutions (dexamethasone sodium phosphate), and many others (Table 5). 

Dexamethasone and betamethasone are corticosteroids available for topical application in eye products. Docusate sodium is indicated for ear wax removal. 

Blepharitis is a topical inflammation of the eyelid margins that should be treated using topical antibacterial agents. Gentamicin eye ointment is preferred to the fusidic acid drops since the ointment is a better formulation to be used where the condition involves the eyelid margins. Chloramphenicol eye drops is the third option since it is an antibiotic with a wider spectrum of activity. A combination of corticosteroid and antibiotic is not recommended because of the side-effects associated with the steroid. The use of oral tablets is not usually recommended since blepharitis can easily be managed with topical drops. The use of dexamethasone eye drops, monotherapy steroid, could clear the inflammation but mask persistence of infection. 

Dexamethasone (DEXONA) 0.5-5 mg/day oral, 4-20 mg/day IM/IV, 0.1% topical (skin cream) as dexamethasone sodium phosphate and trimethyl acetate... 

Synthetic glucocorticoids are prednisolone, prednisone, methylprednisolone, dexamethasone, betamethasone and triamcinolone (Table 13.2). Hydrocortisone is available as either succinate or phosphate salts for oral and intravenous administration. It is the drug of choice when a rapid effect is required, e.g. acute adrenal insufficiency, or as peri-operative replacement therapy. Prednisolone can also be given intravenously. It has about 0.8 of the mineralocorticoid activity of hydrocortisone. Prednisone is a prodrug that is converted to prednisolone in the body. For chronic therapy, synthetic steroids without mineralocorticoid activity are preferred, such as dexamethasone, betamethasone or triamcinalone. Beclo-metasone passes membranes poorly and is more active topically than when given orally. It is used as an aerosol for chronic rhinitis and asthma, and topically in severe eczema. Fludrocortisone is a synthetic halogenated derivate of cortisol that is used for its mineralocorticoid effect. 

The effects of topical dexamethasone on intraocular pressure have been compared with those of fluorometho-lone (SEDA-22, 446 66). The ocular hypertensive response to topical dexamethasone in children occurs more often, more severely, and more rapidly than that reported in adults. It should be avoided in children if possible and it is desirable to monitor the intraocular pressure when it is being used. Fluorometholone may be more acceptable. 

Children have more frequent, more severe, and more rapid ocular hypertensive responses to topical dexamethasone than adults. In one case a systemic glucocorticoid caused significant but asymptomatic ocular hypertension in a child (67). 

Hwang, D.G., et al. 1989. Collagen shield enhancement of topical dexamethasone penetration. Arch Ophthalmol 107 1375. 

For ophthalmic disorders or for topical application in the treatment of various skin disorders, either dexamethasone or its esters may be used. 

Darunavir (TMC114) Prezista 300 mg tablet Dexamethasone, erythromycins, voriconazole, itrraconazole, ketoconazole, aspirin, fluconazole, NSAIDS, diclofenac topical... 

The human aqueous humor contains detectable levels of both dexamethasone alcohol and dexamethasone phosphate within 30 minutes of topical application. 

After topical application to the eye, fluorometholone alcohol penetrates and is rapidly metabolized within the aqueous humor. Comparative anti-inflammatory studies indicate that the efficacy of fluorometholone alcohol is somewhat less than dexamethasone alcohol and prednisolone acetate (see Table 12-1). Increasing the concentration of fluorometholone alcohol from 0.1% to 0.25% does not significantly increase its anti-inflammatory activity but does enhance its tendency to raise lOP. The 17-acetate derivative of fluorometholone has demonstrated greater anti-inflammatory activity in the experimental rabbit keratitis model than has fluorometholone alcohol. However, studies with fluorometholone acetate show that it is metabolized slowly as compared with the alcohol derivative (Figure 12-1). Thus it is possible that the 17-acetate substitution to the fluorometholone base not only enhances its anti-inflammatory effects, but also impedes its metabolism. 

Posterior subcapsular cataracts (PSCs) can occur with all routes of administration (Figure 12-2), including systemic, topical, cutaneous, nasal aerosols, and inhalation corticosteroids. In a study of 44 rheumatoid arthritis patients treated with various steroids, including prednisone and dexamethasone, 17 (39%) developed bilateral PSCs. Dosage and duration of therapy appeared to be correlated with the incidence of cataract development. Patients who received prednisone therapy for 1 to 4 years showed an 11% incidence if the dose range was less than 10 mg/day a 30% incidence if the dose was... 

Figure 12-3 Weekly intraocular pressure responses of eyes treated with medrysone 1%, fluorometholone 0.1%, and dexamethasone phosphate 0.1%. Each point represents a mean value (mm Hg) of 12 eyes. (Reprinted with permission from Mindel JS, Tovitian HO, Smith H, et al. Comparative ocular pressure elevations of topical corticosteroids. Arch Ophthalmol 1980 98 1578. Copyright 1980, American Medical Association.)...

Dilation of the pupil and ptosis can occur with topical steroid administration. Application of dexamethasone 0.1% in human volimteers produced mydriasis as early as 1 week after the drug s initial use.The average increase in pupillary diameter was approximately 1 mm. The effect disappears on cessation of drug therapy. 

The mydriatic effect of topically applied corticosteroids was investigated in living monkey eyes. Instillation of dexamethasone 0.1% (Decadron) produced pupillary dilation and ptosis as well as elevation of lOP. When the steroids were tested without their vehicles but in saline solntion, the effects on lOP, pupil size, and upper eyelid did not occnr.Thns it has been snggested that an excipient in the vehicle mixture causes the effects, possibly by altering cell membrane permeability to the steroid. 

Topical or periocular steroids cause few systemic effects. When topical dexamethasone sodium phosphate was administered four times daily for 6 weeks, subjects showed reduced plasma levels of cortisol. However, elevation of 11-deoxycortisol with the oral metyrapone tartrate test indicated that the pituitary-adrenal axis was intact. 

Intralesional injection of steroid can lead to adrenal suppression. Infents and small children are especially susceptible, because a given amoimt of steroid is distributed in a smaller volume of fluid and tissue compartments. Infents injected with mixtiu es of triamcinolone acetonide and betamethasone or dexamethasone fiar periocular hemangiomas exhibited depressed serum cortisol and adrenocorticotropic hormone levels. The adrenal suppression can last up to 5 months and can result in weight loss and growth retardation. It is not known whether other corticosteroid preparations would produce similar effects or which other fectors might influence these results. In general, topical and periocular use of steroids produces minimal systemic effects. Withdrawal of topical or periocular steroids does not generally cause adrenal crisis. 

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