YorkieTalk.com Forums - Yorkshire Terrier Community - View Single Post - RABIES VACCINE--Skin Pigmentation Reaction

Kris Christine · 02-25-2008, 05:41 AM

This is a continuation of the previous post which was too long.

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Pentoxifylline (Trental)

Pentoxifylline, sold by Hoechst-Roussel under the trade name Trental®, is a methylxanthine derivative that decreases platelet activation, inhibits T- and B-lymphocyte activation, and decreases natural killer cell activity. In humans, it is used for down-regulating inflammatory conditions, such as granuloma anulare, scleroderma, and even spider bites. In veterinary medicine, it is most useful in cases involving some degree of vasculopathy, such as dermatomyositis, vasculitis, rabies vaccine-induced alopecia, and mucinosis. Since it may decease scarring, it is sometimes even used long term in cases of acral lick dermatitis. It is also sometimes used for the treatment of inhalant allergies, allergic bronchitis, and pattern alopecias.

With pentoxifylline, it may take 1-3 months before the benefits of treatment are evident. Gastrointestinal upset, either vomiting, diarrhea (or both) is the most likely adverse effect, although thrombocytopenia has also been reported. There have actually been relatively few side effects reported with the drug.

Tacrolimus (Protopic)

Tacrolimus is an inhibitor of T-lymphocyte activation. It is at least 10 times as potent as cyclosporine, yet is minimally absorbed through the skin. Tacrolimus is available commercially as a 0.1% topical, and as a 0.03% pediatric formulation (Protopic: Fugisawa), in 30 g and 60 g tubes. It is licensed for the treatment of eczematous dermatitis in people.

Tacrolimus has been used for the treatment of cutaneous lupus erythematosus, and also for the eczematous manifestations of inhalant allergies. It is typically applied twice daily for a trial period of 6-8 weeks. Once remission is achieved, it may be possible to taper to once daily, and sometimes even alternate-day therapy.

There are a few cautions to use, even though major side effects have not been reported. There is some mild to moderate burning at the site of application, at least reported in people. It is important that only a thin film be applied to the skin, and that the product is not ingested. Sun exposure is typically restricted for the first hour or two after application.

PENTOXIFYLLINE

Pentoxifylline is a methylxanthine derivative first used and marketed in the United States for intermittent claudication in humans. Hypercoagulable states and blood flow abnormalities improve through decreased platelet aggregation and adhesion, increased red cell deformability, decreased vasoconstriction, increased plasminogen activator, increased plasmin, increased antithrombin III, decreased fibrinogen, decreased alpha2-antiplasmin, decreased alpha1-antitrypsin, and decreased alpha2-macroglobulin. Results of subsequent studies revealed that the drug results in a variety of physiologic changes at the cellular level. Immune modulation includes increased leukocyte deformability, decreased leukocyte adhesion and aggregation, decreased neutrophil superoxide release, decreased neutrophil degranulation, increased leukocyte chemotaxis, decreased monocyte TNF-alpha production, decreased leukocyte response to TNF-alpha, decreased production and leukocyte response to IL-1 and IL-12, increased production of IL-10 and PGE2, and decreased natural killer cell activity. Many of these effects result in inhibition of T- and B-cell activation. Wound healing and connective tissue disorders are improved by increased fibroblast collagenases, decreased fibroblast collagen, decreased fibroblast fibronectin, decreased fibroblast glycosaminoglycans, and decreased response to TNF-alpha. Based on these experimental findings, pentoxifylline has been used for a wide variety of diseases in humans. Adverse effects are rare over a wide dosage range, up to 2200 mg/day, and are minimized using sustained-release tablets. Adverse effects include nausea, vomiting, dizziness, and headache, all seen in less than 3% of human patients. Drug interactions have been reported with cisplatin, alkylating agents, and amphotericin B. Cimetidine increases the level of pentoxifylline by decreasing its clearance. Synergistic activity has been reported between pentoxifylline and ciprofloxacin in the inhibition of TNF-alpha.

Recent pharmacokinetic studies suggest that pentoxifylline should be administered every 8 hours in dogs and that administration with food does not affect absorption into the systemic circulation. Pentoxifylline has been used for a wide variety of cutaneous disorders in dogs. They include dermatomyositis, vasculitis, rabies vaccine induced vasculitis, vascular thrombosis leading to ear margin necrosis, wounds, acral lick dermatitis, and diseases resulting in severe fibrosis such as deep scarring pyoderma. Variable efficacy has been anecdotally reported for these diseases but no specific cases or controlled studies have been published. Efficacy has been well-documented for the ability of pentoxifylline (Trental, Hoechst Marion Roussel, 10 mg/kg, q12h, PO) to prevent allergic contact reactions to plants of the Commelinceae family in three dogs. Response was seen after only 2 days of treatment with relapse occurring upon discontinuation of the drug in one dog. No adverse effects were observed in the three dogs. A double-blind placebo-controlled study was conducted to evaluate pentoxifylline for the treatment of canine atopic dermatitis. Ten dogs were administered the drug at 10 mg/kg, q12h, PO for 4 weeks. Pruritus and erythema significantly decreased in the dogs administered the test drug versus those on placebo. However, most of the dogs still had residual pruritus at 4 weeks. Increasing the dosage and frequency may increase efficacy. Pentoxifylline is available in 400 mg controlled-release tablets. The optimal dosage and duration of pentoxifylline administration are not known for all of the various indications in dogs. For small dogs, the large tablets are reformulated into capsules. Pentoxifylline causes GI irritancy so should not be reformulated as a liquid and should be administered with a small amount of food.

02-25-2008, 05:41 AM	#2
Kris Christine YT Addict Join Date: Jan 2008 Location: THE RABIES CHALLENGE FUND Posts: 434	RABIES VACCINE-Skin Pigmentation Reaction Continued This is a continuation of the previous post which was too long. -------------------------------------------------------------------------------- Pentoxifylline (Trental) Pentoxifylline, sold by Hoechst-Roussel under the trade name Trental®, is a methylxanthine derivative that decreases platelet activation, inhibits T- and B-lymphocyte activation, and decreases natural killer cell activity. In humans, it is used for down-regulating inflammatory conditions, such as granuloma anulare, scleroderma, and even spider bites. In veterinary medicine, it is most useful in cases involving some degree of vasculopathy, such as dermatomyositis, vasculitis, rabies vaccine-induced alopecia, and mucinosis. Since it may decease scarring, it is sometimes even used long term in cases of acral lick dermatitis. It is also sometimes used for the treatment of inhalant allergies, allergic bronchitis, and pattern alopecias. With pentoxifylline, it may take 1-3 months before the benefits of treatment are evident. Gastrointestinal upset, either vomiting, diarrhea (or both) is the most likely adverse effect, although thrombocytopenia has also been reported. There have actually been relatively few side effects reported with the drug. Tacrolimus (Protopic) Tacrolimus is an inhibitor of T-lymphocyte activation. It is at least 10 times as potent as cyclosporine, yet is minimally absorbed through the skin. Tacrolimus is available commercially as a 0.1% topical, and as a 0.03% pediatric formulation (Protopic: Fugisawa), in 30 g and 60 g tubes. It is licensed for the treatment of eczematous dermatitis in people. Tacrolimus has been used for the treatment of cutaneous lupus erythematosus, and also for the eczematous manifestations of inhalant allergies. It is typically applied twice daily for a trial period of 6-8 weeks. Once remission is achieved, it may be possible to taper to once daily, and sometimes even alternate-day therapy. There are a few cautions to use, even though major side effects have not been reported. There is some mild to moderate burning at the site of application, at least reported in people. It is important that only a thin film be applied to the skin, and that the product is not ingested. Sun exposure is typically restricted for the first hour or two after application. PENTOXIFYLLINE Pentoxifylline is a methylxanthine derivative first used and marketed in the United States for intermittent claudication in humans. Hypercoagulable states and blood flow abnormalities improve through decreased platelet aggregation and adhesion, increased red cell deformability, decreased vasoconstriction, increased plasminogen activator, increased plasmin, increased antithrombin III, decreased fibrinogen, decreased alpha2-antiplasmin, decreased alpha1-antitrypsin, and decreased alpha2-macroglobulin. Results of subsequent studies revealed that the drug results in a variety of physiologic changes at the cellular level. Immune modulation includes increased leukocyte deformability, decreased leukocyte adhesion and aggregation, decreased neutrophil superoxide release, decreased neutrophil degranulation, increased leukocyte chemotaxis, decreased monocyte TNF-alpha production, decreased leukocyte response to TNF-alpha, decreased production and leukocyte response to IL-1 and IL-12, increased production of IL-10 and PGE2, and decreased natural killer cell activity. Many of these effects result in inhibition of T- and B-cell activation. Wound healing and connective tissue disorders are improved by increased fibroblast collagenases, decreased fibroblast collagen, decreased fibroblast fibronectin, decreased fibroblast glycosaminoglycans, and decreased response to TNF-alpha. Based on these experimental findings, pentoxifylline has been used for a wide variety of diseases in humans. Adverse effects are rare over a wide dosage range, up to 2200 mg/day, and are minimized using sustained-release tablets. Adverse effects include nausea, vomiting, dizziness, and headache, all seen in less than 3% of human patients. Drug interactions have been reported with cisplatin, alkylating agents, and amphotericin B. Cimetidine increases the level of pentoxifylline by decreasing its clearance. Synergistic activity has been reported between pentoxifylline and ciprofloxacin in the inhibition of TNF-alpha. Recent pharmacokinetic studies suggest that pentoxifylline should be administered every 8 hours in dogs and that administration with food does not affect absorption into the systemic circulation. Pentoxifylline has been used for a wide variety of cutaneous disorders in dogs. They include dermatomyositis, vasculitis, rabies vaccine induced vasculitis, vascular thrombosis leading to ear margin necrosis, wounds, acral lick dermatitis, and diseases resulting in severe fibrosis such as deep scarring pyoderma. Variable efficacy has been anecdotally reported for these diseases but no specific cases or controlled studies have been published. Efficacy has been well-documented for the ability of pentoxifylline (Trental, Hoechst Marion Roussel, 10 mg/kg, q12h, PO) to prevent allergic contact reactions to plants of the Commelinceae family in three dogs. Response was seen after only 2 days of treatment with relapse occurring upon discontinuation of the drug in one dog. No adverse effects were observed in the three dogs. A double-blind placebo-controlled study was conducted to evaluate pentoxifylline for the treatment of canine atopic dermatitis. Ten dogs were administered the drug at 10 mg/kg, q12h, PO for 4 weeks. Pruritus and erythema significantly decreased in the dogs administered the test drug versus those on placebo. However, most of the dogs still had residual pruritus at 4 weeks. Increasing the dosage and frequency may increase efficacy. Pentoxifylline is available in 400 mg controlled-release tablets. The optimal dosage and duration of pentoxifylline administration are not known for all of the various indications in dogs. For small dogs, the large tablets are reformulated into capsules. Pentoxifylline causes GI irritancy so should not be reformulated as a liquid and should be administered with a small amount of food.