articles on crop stasis/sour crop:
http://dlhunicorn.conforums.com/index.cgi?board=emergencies&action=display&num=1161893898
Antifungal Drugs
- Polyenes -- Amphotericin B, nystatin
- Imidazoles - ketoconazole, fluconazole, itraconazole
- 5-fluorocytosine
- Griseofulvin
- In general, treatment is prolonged, cost is high, side-effects can be significant
Polyenes - Amphotericin B
- Macrolide ring - series of double bonds
- Mechanisms - bind to ergosterol in the fungal cell membrane
- Administration - poorly soluble , prepare suspension, no electrolytes, slowly infuse iv
- Toxicity -- absorbs to renal tissues, causes necrosis, loss of renal function
Imidazole Drugs
- Related family of drugs - all contain an imidazole, or triazole, ring structure
- Ketoconazole, fluconazole, clotrimazole
- Pharmacokinetics vary - in general easier to give, less toxic, sometimes less effective, Inhibit ergosterol synthesis
- Use for combined therapy with amphotericin
5-Fluorocytosine
- Converted to 5-fluoropyrimidine by fungal cells -- inhibits nucleic acid synthesis
- Chief use -- cryptococcal meningitis
- Crosses blood-brain barrier
- Resistance can develop
Iodides
- KI -- given orally or by injection
- Seems effective for various types of chronic granulomatous infections
- Mechanism unknown -- not anti-fungal in vitro
- Causes iodide toxicity -- but is reversible
- Low cost
Griseofulvin
- Dermatophyte infection
- Give with fatty meal (increases absorption)
- Concentrates in keratinized epithelium
- Inhibits fungal cell wall metabolism
- Usually non-toxic
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An here is the relevant MERCK page on some antifungal drugs:
http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/191302.htm
http://www.cliniciansbrief.com/cms/portals/_default/pdfs/2006/06NOV_Cap1.pdf
Mycotic Infections in Psittacines: Some
Treatment Evidence
Mycotic infections are common in psittacines, yet safe and effective dose regimens for most antifungal agents have not been established.The synthetic,water-soluble antifungal agent fluconazole is well-absorbed from the gastrointestinal tract in the mammals in which it has been studied, with a reported oral bioavailability of 90% to 100%.Adverse effects are uncommon; gastrointestinal upset is the most common symptom in humans. In this study, the pharmacokinetics and effects of orally administered fluconazole in African grey parrots were investigated....... It was concluded that oral administration of fluconazole at 10 to 20 mg/kg every 24 to 48 hours will maintain plasma concentrations above the minimum inhibitory concentration for several common yeast species, including Candida albicans and C. tropicalis.The authors note that these results are promising, but further studies are needed to prove that this dose regimen is safe and effective in ill parrots and in other psittacine species.
COMMENTARY:With so many drug doses in avian medicine being based on empirical knowledge or data extrapolated from other species, this study provides valuable information for practitioners who work with birds.The study has the following limitations, as noted by the authors:
Only healthy African grey parrots were included, studies of IV administration to calculate bioavailability and volume of distribution were not performed, and pooled samples from several birds were used for calculating pharmacokinetic parameters.This, however, reflects the inherent difficulties in performing these studies in birds:They are often small, expensive, and difficult to handle, and there are a wide variety of species. Still, the data are useful. Fluconazole is now available to U.S. practitioners in generic form, making it a more practical and attractive option for
treating mycotic infectionsespecially when supported by scientific data that include the option of using a prolonged dosing interval in a species that is complicated to treat.Jennifer Schori,VMD
Pharmacokinetics of fluconazole after oral administration of single and multiple doses in African grey parrots. Flammer K, Papich M.AM J VET RES 67:417-422, 2006.