Cyclosporine and tacrolimus

Life-long diseases need life-long treatment: long-term safety of ciclosporin in canine atopic dermatitis

Ciclosporin (Atopica; Novartis Animal Health) has been licensed for canine atopic dermatitis (AD) since 2002. Adverse events (AEs) have been reported in 55 per cent of 759 dogs in 15 clinical trials, but are rare in pharmacovigilance data (71.81 AEs/million capsules sold). Gastrointestinal reactions were most common, but were mild and rarely required intervention. Other AEs were rare (≤1 per cent in clinical trials; <10/million capsules sold). Hirsutism, gingival hyperplasia and hyperplastic dermatitis were rarely significant and resolved on dose reduction. Ciclosporin decreases staphylococcal and Malassezia infections in AD, and at the recommended dose is not a risk factor for other infections, neoplasia, renal failure or hypertension. The impact on glucose and calcium metabolism is not clinically significant for normal dogs. Concomitant treatment with most drugs is safe. Effects on cytochrome P450 and MDR1 P-glycoprotein activity may elevate plasma ciclosporin concentrations, but short-term changes are not clinically significant. Monitoring of complete blood counts, urinalysis or ciclosporin levels is not justified except with higher than recommended doses and/or long-term concurrent immunosuppressive drugs. Ciclosporin is not a contraindication for killed (including rabies) vaccines, but the licensed recommendation is that live vaccination is avoided during treatment. In conclusion, ciclosporin has a positive risk-benefit profile for the long-term management of canine AD.

Safety, tolerability, and pharmacokinetics of 6-month daily dosing of an oral formulation of cyclosporine (ATOPICA for cats®) in cats

Cyclosporine was proven efficacious in the treatment of feline hypersensitivity dermatitis. This target animal study was conducted to evaluate the safety, tolerability, and pharmacokinetics of ATOPICA for Cats® (cyclosporine oral solution, USP) MODIFIED following 6-month daily dosing in cats. Forty healthy cats (four cats/sex/group) received 0, 8 (1×), 16 (2×), 24 (3×), or 40 (5×) mg/kg cyclosporine once daily for 6 months (183 days). Body weight, food consumption, ophthalmoscopic, physical examinations including neurological assessments, blood pressure, electrocardiography, clinical pathology (hematology, coagulation, clinical chemistry, urinalysis), organ weights, and macroscopic and microscopic examinations were performed and assessed. In addition, blood concentrations of cyclosporine were measured at the pretreatment trough on Days 1, 2, 7, 14, 31, 91, 154, and 182, and post-treatment on Days 1, 31, and 182. Adverse effects possibly related to treatment included prolonged APTT and one report each of bone marrow hypocellularity and lymphoma; all occurred in cats treated with doses more than 16 mg/kg. There was no significant accumulation of cyclosporine beyond the first week of treatment. Results confirm that ATOPICA for Cats is safe and well tolerated in cats without unexpected accumulation beyond the first week of treatment when administered as directed.

The use of ciclosporin A in veterinary dermatology

Ciclosporin A (CsA) has potent immunosuppressive and immunomodulatory activity that has been exploited in human medicine to prevent the rejection of transplanted organs and to manage atopic dermatitis and psoriasis. Over the past decade, CsA has been employed more frequently in veterinary dermatology and its value in the management of several canine and feline dermatoses is now well established. CsA inhibits calcineurin phosphatase, suppressing T cell activation and the synthesis of T cell cytokines consequently impairing the activity of B cells, antigen-presenting cells, mast cells, basophils and eosinophils. The pharmacokinetics of CsA are similar in humans, dogs and cats and the drug has a wide safety margin in dogs, cats and rabbits. Adverse effects, principally transient vomiting and soft faeces/diarrhoea, may be seen shortly after instituting treatment but often resolve despite continuing treatment. Gingival hyperplasia and cutaneous effects such as hirsutism may occur after prolonged treatment.

Cyclosporin A reduces airway mucus secretion and mucociliary clearance in rats

PURPOSE

To assay the effects of cyclosporin A on mucus secretion from goblet cells and on mucociliary transport in situ in rats.

METHODS

Twenty-one male Wistar rats were assigned to 3 groups: control (n = 5), saline (n = 8), and cyclosporin A (n = 8). After 30 days of drug therapy, the rats were killed, and the lungs were removed from the thoracic cavity. Mucus samples were collected, and the transport rate was evaluated in vitro using a bullfrog palate model. Mucociliary transport was timed in situ by direct view of particles trapped on the mucus moving across the respiratory tract. Finally, the amount of stored mucins in the goblet cells of the respiratory epithelium was measured.

RESULTS

Drug dosage measurements showed that cyclosporine blood concentration at the moment the rats were killed was 1246.57 +/- 563.88 ng/mL. The in vitro transport rate was significantly lower (P < .001) in the cyclosporin A-treated group. Also, the in-situ mucociliary transport rate was decreased in all cyclosporin A-treated animals when compared to the saline group (P = .02). Mucus quantity measurements showed a significant decrease on both acid (P = .01) and neutral (P = .02) mucus production from goblet cells in the animals submitted to cyclosporin A therapy. The correlation between the percentage of total mucus and in vitro transport rate was positive and significant (r = 0.706, P < .001), as was the correlation between the percentage of total mucus and the in situ mucociliary transport rate (r = 0.688, P = .001).

CONCLUSION

This study shows that cyclosporin A plays an important role in the impairment of the mucociliary clearance in rats by reducing both acid and neutral mucus production from goblet cells and causing a decrease in the mucociliary transport velocity.

Practical Applications of Topical Therapy for Allergic, Infectious, and Seborrheic Disorders

Topical therapy is extremely important in the management of allergic, infectious, and seborrheic disorders. It can be used as a sole therapy or adjunctive therapy for these disorders, often minimizing the need for systemic therapy. In allergic diseases, pruritus can be decreased by removing allergen, desensitizing the skin or other antipruritic effects. Many agents can also maintain or replace moisture to the skin and have emollient effects. When used for infectious conditions, topical therapy can decrease microbial counts and reduce surface colonization of microbes and help to prevent relapses. Antiseborrheic products function by normalizing keratinocyte turnover rates by reducing epidermal division (keratoplastic), normalizing keratinization, and increasing desquamation (keratolytic). There are many different topical vehicles and modes of application: shampoos, whirlpools, soaks, rinses, sprays, lotions, gels, creams, and ointments. Shampoos are often the most practical and effective. The practitioner needs to become familiar with many active ingredients to learn what products are indicated for specific diseases.

Systemic treatment of sterile panniculitis with tacrolimus and prednisolone in dogs

This report deals with three additional canine cases of sterile panniculitis treated by oral administration of tacrolimus and prednisolone. The oral tacrolimus treatment was proved to be an affordable medical protocol for canine sterile panniculitis with good efficacy and without adverse effects.

Evaluation of prognostic factors, survival rates, and treatment protocols for immune-mediated hemolytic anemia in dogs: 151 cases (1993-2002)

OBJECTIVE

To evaluate prognostic factors, survival, and treatment protocols for immune-mediated hemolytic anemia (IMHA) in dogs.

DESIGN

Retrospective study.

ANIMALS

151 dogs with IMHA not associated with underlying infectious or neoplastic disease.

PROCEDURE

lnformation recorded from review of medical records included signalment at the time of initial evaluation; vaccination history; 30-, 60-, and 365-day follow-up outcomes; laboratory data; results of imaging studies; and necropsy findings. Dogs were grouped according to the presence of spherocytes, autoagglutination, a regenerative erythrocyte response, and treatments received (azathioprine, azathioprine plus ultralow-dose aspirin, azathioprine plus mixed-molecular-weight heparin [mHEP], or azathioprine plus ultralow-dose aspirin plus mHEP) for comparisons. All dogs received glucocorticoids.

RESULTS

Cocker Spaniels, Miniature Schnauzers, neutered dogs, and female dogs were overrepresented. Alterations in certain clinicopathologic variables were associated with increased mortality rate. Rates of survival following treatment with azathioprine, azathioprine plus ultralow-dose aspirin, azathioprine plus mHEP, and azathioprine plus ultralow-dose aspirin plus mHEP were 74%, 88%, 23%, and 70%, respectively, at hospital discharge; 57%, 82%, 17%, and 67%, respectively, at 30 days; and 45%, 69%, 17%, and 64%, respectively, at 1 year. In comparison, mean survival rates at discharge and at 30 days and 1 year after evaluation collated from 7 published reviews of canine IMHA were 57%, 58%, and 34%, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Treatment with a combination of glucocorticoids, azathioprine, and ultralow-dose aspirin significantly improved short- and long-term survival in dogs with IMHA.

Effect of topical 0.02% tacrolimus aqueous suspension on tear production in dogs with keratoconjunctivitis sicca

OBJECTIVE

To investigate the effect of 0.02% tacrolimus in aqueous suspension on tear production in dogs with keratoconjunctivitis sicca (KCS). Animals studied One hundred five dogs diagnosed with KCS [Schirmer tear test (STT) < or = 10 mm/min and clinical signs of dry eye]. Eyes with marginally decreased STT (11 < or = 15 mm/min) and clinical signs of dry eye were also evaluated.

PROCEDURE

The investigation was conducted in two parts: an initial efficacy study and a subsequent double blinded controlled study. In the efficacy study, the effect of topical tacrolimus (formerly FK-506) on tear production in dogs with primary KCS was evaluated. Dogs were divided into four categories: 1) 59 eyes (38 dogs) naïve to tear stimulation therapy with initial STT < or = 10 mm/min; 2) 28 eyes (21 dogs) naïve to tear stimulation therapy with initial STT 11 < or = 15 mm/min; 3) 30 eyes (15 dogs) maintained successfully on CsA therapy; 4) 47 eyes (24 dogs) unresponsive to CsA therapy. STT and clinical signs were evaluated prior to and after 6 to 8 weeks of twice daily tacrolimus administration. Tacrolimus was substituted for CsA therapy in categories 3 and 4. The controlled study compared the effect of topical tacrolimus in aqueous suspension to administration of the aqueous carrier alone on tear production in 20 dogs with primary KCS.

RESULTS

In the efficacy study, STT increased by 5 mm/min in 84.7%, 25.0%, 26.7% and 51.1% of eyes in categories 1, 2, 3 and 4 respectively after tacrolimus administration. Eighty-three percent of eyes with extremely low initial STT (< or = 2 mm/min), increased 5 mm/min after tacrolimus. In the controlled study, STT increased by 5 mm/min in 7/10 dogs (14/20 eyes) that received tacrolimus and in none of the 10 dogs that received aqueous carrier alone. Dogs receiving just the aqueous carrier were subsequently treated with tacrolimus, and STT increased 5 mm/min in 9 dogs (18/20 eyes) after administration.

CONCLUSIONS

Twice daily administration of 0.02% tacrolimus in aqueous suspension effectively increased tear production in dogs with KCS. Topical tacrolimus is a promising alternative to topical CsA for treatment of KCS and may be beneficial in patients with less than optimal response to topical CsA.

Gingivostomatitis

Gingivostomatitis (GS) with various patterns of disease may require antiviral therapy, steroids, laser fulguration, immunomodulation drugs, or nonsteroidal anti-inflammatory drugs. The use of cyclosporine as an immunomodulation drug has long-term benefits in reduction of the immunologic events that contribute to GS. Whole-mouth extraction or partial extraction (premolars and molars), with radiographic conformation that all root remnants have been removed, may be the most viable option in nonresponsive and or intractably painful stomatitis in noncompliant cats or dogs. Oral inflammation subsided after extraction without the need for further medication in approximately 70% of the cats from two studies with previous chronic unrelenting oral disease. The combination of immunomodulation with cyclosporine together with laser resection of proliferative tissue should be recommended if extraction of teeth is not desired. Removal of proliferative oral tissues by lasing (carbon dioxide laser) removes the tissue that maybe producing tissue antigens and the area where bacteria are sequestered. The use of anti-inflammatory medications is recommended in the management of GS. Therapeutic success is achieved when there is elimination of proliferative tissue and inflammation.

Histopathologic findings and classification of feline renal transplants

Seventy-seven feline transplant kidney specimens, obtained from 1 to 3,183 days (9 years) after transplantation, were reevaluated histologically and classified on the basis of the Banff '97 guidelines for human renal transplant kidneys. Overall, this classification system appeared useful in detecting rejection reactions and confirmed the finding in humans that biopsies can diagnose subclinical rejection and therefore are an important diagnostic tool for the follow up of renal transplants. However, on the basis of serum creatinine values, the severity of the acute or active and chronic lesions was not accurately reflected by this scoring system. This is thought to be due to the significant differences in histologic rejection patterns, especially in acute or active rejection, in cats when compared with humans. Tubulitis, lymphocytic glomerulitis, and vasculitis, which are the main pillars of the Banff '97 acute or active rejection scoring system, are either rare or not found in cats. The presence of significant necrotizing glomerulitis and vasculitis in feline renal transplants might imply that the rejection is complicated by acute antibody-mediated rejection. Alternatively, cyclosporine toxicity also should be considered because some of these kidneys show other signs of cyclosporine toxicity. Finally, the significance of subcapsular and interlobular phlebitis, rarely described in human rejection reactions but a distinct entity in cats, is unknown. From this study, it is clear that there are significant differences in the histology of acute or active rejection between humans and cats and that a better understanding of the histologic appearance of renal allografts will be especially beneficial for treatment and prognostic purposes.

Immunomodulating agents

Inflammation involves a universally recognized, although incompletely understood, cascade of molecular events orchestrated by lymphokines and other innate biochemicals of immunity. Repeated or extended contact with immunogenic agents results in adaptive immunity involving antigen-induced events that stimulate down-stream immune cells and result in expansion of the inflammatory cascade. When immunogenic stimulation persists or autoregulatory immune mechanisms go awry, however, adaptive immunologic events can result in immune-mediated processes detrimental to systemic or organ-specific homeostasis. Because of the complexities of immunologic events, the potential side effects of long-term corticosteroid therapy, and the focused spectrum of most conventional nonsteroidal anti-inflammatory agents (centered on arachidonic acid-related mechanisms), a variety of other chemotherapeutic immunosuppressive agents have assumed an increasingly prominent therapeutic role in veterinary ophthalmology in the management of chronic ocular inflammatory diseases. In addition, nonimmunosuppressive immunomodulating agents (ie, immuno-stimulants or immunorestoratives) may be used as adjunctive therapies in the management of ocular or visual system diseases.

Review of the properties and mechanisms of action of cyclosporine with an emphasis on dermatological therapy in dogs, cats and people

Cyclosporine is being increasingly used in veterinary medicine. It is a potent suppressor of T cell induction and proliferation, and has a wide variety of anti-inflammatory and antiproliferative effects, downregulating effects on antigen presentation, and variable effects on parasites. This paper reviews its properties and mechanisms of action with particular reference to its use in the treatment of dermatological conditions in dogs, cats and people.

Review of the pharmacokinetics, interactions and adverse reactions of cyclosporine in people, dogs and cats

Cyclosporine is being increasingly used in veterinary medicine. Oral formulations of the drug have found many therapeutic uses, but topical formulations have met with only limited success, probably owing to their poor penetration through the stratum corneum. The concurrent use of ketoconazole to inhibit cyclosporine metabolism has been shown to reduce the required dose and hence the cost of cyclosporine therapy. In human medicine, adverse reactions to the drug, especially nephrotoxicity, are common but in dogs given the commonly used oral dose of 5 mg/kg per day there have been few adverse reactions. However, no toxicity studies lasting longer than 12 months have been carried out in this species. This paper reviews the pharmacokinetics, drug and procedural interactions, contraindications and the adverse reactions to cyclosporine, with particular reference to its use in the treatment of dermatological conditions in dogs, cats and people.

Cyclosporin: applications in small animal dermatology

Cyclosporin has been increasingly used for the treatment of skin diseases in small animals. Reported uses include the treatment of atopy, cutaneous lupus erythematosus, feline acquired alopecia resembling pseudopelade of humans, pemphigus erythematosus, pemphigus foliaceus, perianal fistulae and sebaceous adenitis. In addition, cyclosporin has been used anecdotally for several other skin diseases. Few side effects have been noted at doses therapeutic for dermatologic diseases. Current suggestions for monitoring, and the value of trough cyclosporin serum concentrations for prediction of toxicity and efficacy are discussed.

Influence of drug treatment on survival of dogs with immune-mediated hemolytic anemia: 88 cases (1989-1999)

OBJECTIVE

To evaluate association of various treatments for immune-mediated hemolytic anemia with survival to discharge in dogs.

DESIGN

Retrospective cross-sectional analysis.

ANIMALS

88 dogs with idiopathic immune-mediated hemolytic anemia.

PROCEDURE

Medical records of dogs with immune-mediated hemolytic anemia treated between August 1989 and August 1999 were examined. Survival to discharge, PCV at referral, autoagglutination, and drug treatment and dosage were recorded.

RESULTS

Treatments included administration of prednisone, dexamethasone, azathioprine, danazol, cyclosporine, cyclophosphamide, bovine hemoglobin solution, and human immunoglobulin. Overall mortality rate was 50.5%. Significant associations with death were not detected for use of azathioprine, cyclosporine, danazol, or human immunoglobulin. A significant difference in mortality rate was not detected between use of multiple immunosuppressive drug treatments and use of single immunosuppressive drugs. Use of cyclophosphamide and bovine hemoglobin solution were associated with significant increases in relative risk of death

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggest that use of cyclophosphamide and bovine hemoglobin solution in treatment of idiopathic immune-mediated hemolytic anemia may be associated with increased risk of death.