Topical therapy

Trifluridine, C2qH22F2N20, (5-trifluoromethyl-2 -deoxyuridine [70-00-8] F TdU, 14) was first prepared (30) in 1962. It is used for topical therapy of herpes vims-infected eyes. It is especially usefiil for treating infections that are resistant to IdU therapy. Like IdU, trifluridine is incorporated into DNA in place of thymidine in both infected and uninfected cells. But it is 10 times more potent than IdU against herpes keratitis in rabbits and 10 times more soluble in water. Trifluridine is also usefiil in treating human cytomegalovims (HCMV), but its toxicity to bone marrow may limit its clinical use. 

Ash K, Lord J, Zukowski M, McDaniel DH (1998) Comparison of topical therapy for striae alba (20% glycolic acid/ 0,05% tretinoin versus 20% glycolic acid/ 10% L-ascorbic acid). Dermatol Surg 24(8) 849-856... 

Topical therapy with 0.75 metronidazole or 1-2% salicylic acid... 

Topical mesalamine products provide a more rapid response than oral preparations. Improvement in symptoms may be seen in as little as 2 days, but 2 to 4 weeks of treatment may be necessary for maximal response. Response rates of up to 90% after 4 weeks of topical therapy have been reported, compared to 45% to 62% response rates with oral therapy.6,18 Oral and topical mesalamine preparations may be used together to provide maximal effect. Oral mesalamine may also be used for patients who are unwilling to use topical preparations. 

Maintenance of remission of ulcerative colitis may be achieved with oral or topical aminosalicylates. Mesalamine suppositories 1 g daily may prevent relapse in up to 90% of patients with proctitis.1 Mesalamine enemas are appropriate for left-sided disease and may often be dosed three times weekly. Oral mesalamine at lower doses (e.g., 1.6 g per day) may be combined with topical therapies to maintain remission. Topical or oral corticosteroids are not effective for maintaining remission of distal UC and should be avoided. 

Localized pain may be treated effectively with local topical therapy, whereas generalized pain may be treated best with systemic agents. 

Assess patient preference for systemic (oral) or local (topical) therapy. Would frequent application of topical medications be possible Would the patient accept topical medications with a medicinal odor ... 

Evaluate for adverse effects and drug interactions. For patients on topical therapy, evaluate for local adverse effects. For patients on acetaminophen or NSAIDs, inquire about alcohol use. 

Management of patients with psoriasis generally involves both nonpharmacologic and pharmacologic therapies. Pharmacologic alternatives for plaque psoriasis include topical treatments, phototherapy, photochemotherapy, and systemic therapies alone (orally or by injection). The choice of treatment is usually dictated by the severity of disease.15-17 In some cases, a combination of treatment options may be preferred. Topical therapies can be used in patients with limited or mild... 

Topical therapy is the initial drug treatment strategy for patients with mild to moderate psoriasis. It is estimated that approximately 70% to 80% of all patients with psoriasis can he treated adequately with use of topical therapy.1 Topical therapies include corticosteroids, coal tar products, anthralin, vitamin D3 analogues such as calcipotriol, retinoids such as tazarotene, and topical immunomodulators such as tacrolimus and pime-crolimus.18 Vitamin D3 analogues and topical retinoids all affect keratinocyte functions and the immune response. Currently, these are in wider use than is either anthralin or coal tar preparations. 

Lebwohl M, Ali S. Treatment of psoriasis. Part 1. Topical therapy and phototherapy. J Am Acad Dermatol 2001 45 487-498. 

Moderate to severe acne can be effectively treated with oral antibiotics, especially when treatment with topical therapy has failed. Because of their ability to decrease P. acnes colonization, oral antibiotics can prevent acne lesions from developing.8 Improvement of symptoms is generally evident at 6 to 10 weeks, with maximum benefits occurring after 6 months of therapy.23... 

The diagnosis of scabies is made by obtaining skin scrapings and detecting the mite in a wet mount. Topical therapy is 5% permethrin. 

Since dermatophyte hyphae seldom penetrate into the living layers of the skin, instead remaining in the stratum corneum, most infections can be treated with topical antifungals. Infections covering large areas of the body or infections involving nails or hair may require systemic therapy. Patients with chronic infections or infections that do not respond to topical therapy are also candidates for systemic therapy. 

Although more invasive, esophageal candidiasis does not typically evolve into a life-threatening infection. However, topical therapy is ineffective. Azoles (fluconazole, itraconazole solution, or voriconazole), echinocandins, or intravenous amphotericin B (in cases of unresponsive infections) are effective treatment options. Parenteral therapy should be used in patients who are unable to take oral medications.20... 

Systemic therapy with a variety of (3-lactams, macro-lides and lincosamides (clindamycin) has been the cornerstone of skin infection therapy for many years [17]. However, topical antibiotics can play an important role in both treatment and prevention of many primary cutaneous bacterial infections commonly seen in the dermatological practice [18], Indeed, while systemic antimicrobials are needed in the complicated infections of skin and skin structure, the milder forms can be successfully treated with topical therapy alone [18], The topical agents used most often in the treatment of superficial cutaneous bacterial infections are tetracyclines, mupirocin, bacitracin, polymyxin B, and neomycin. 

A 50- year-old male diabetic develops an external otitis from which Pseudomonas organisms are cultured. Topical therapy with polymyxin is effective. What is the mechanism of action of polymyxin ... 

Low-dose opioid analgesics (e.g., oxycodone) may be useful for patients who experience no relief with acetaminophen, NSAIDs, intraarticular injections, or topical therapy. 

Salicylic acid, sulfur, and resorcinol are second-line topical therapies. They are keratolytic and mildly antibacterial agents. Salicylic acid has comedolytic and antiinflammatory action. 

Topical therapy alone is inadequate and is unnecessary when systemic therapy is administered. 

Topical therapy with mupirocin is equivalent to oral therapy. 

Patients should be taught how to administer topical therapy. With a forefinger pulling down the lower eyelid to form a pocket, the patient should place the dropper over the eye, look at the tip of the bottle, and then look up and place a single drop in the eye. To maximize topical activity and minimize systemic absorption, the patient should close the lid for 1 to 3 minutes after instillation and place the index finger over the nasolacrimal drainage system in the inner corner of the eye. 

Potential therapeutic applications of host defense peptides also include the lantibiotic nisin. Indeed, nisin has had an impressive history as a food preservative with FDA approval in 1988 for use in pasteurized, processed cheese spreads. The attractiveness of nisin as a potential therapeutic is also enhanced due to its relative resistance to proteases and broad spectrum Gram-positive antimicrobial activity including multidrug-resistant strains. Biosynexus Inc. has licensed the use of nisin for human clinical applications and Immucell Corp. has licensed the use of Mast Out, an antimastitic nisin-containing product, to Pfizer Animal Health." Indeed, nisin formulations have been used as an active agent in the topical therapies Mast Out and Wipe-Out for bovine mastitis, an inflammatory disorder of the udder that is the most persistent disease in dairy cows." ... 

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