Candidiasis drug-resistant

Flucytosine is used in combination with amphotericin B or fluconazole in the treatment of cryptococcosis or (less commonly) candidiasis. The rapid development of resistance to flucytosine, however, precludes its use as single-agent therapy. Mechanisms for drug resistance may include loss of deaminase and decreased permeability to the drug. ... 

If immunocompromised patients experience frequent or severe recurrences, particularly of esophageal candidiasis, chronic maintenance therapy with fluconazole 100 to 200 mg daily should be considered. In patients with infrequent or mild cases, secondary prophylaxis is not recommended. The rationale for not giving prophylaxis includes availability of effective treatments for acute episodes, risk of developing resistant organisms, potential for drug interactions, and the cost of therapy. 

Flucytosine is an oral antifungal pro-drug. It has to be enzymatically deaminated by the fungi to the active metabolite, fluorouracil. Fluorouracil inhibits thymidylate synthetase and DNA synthesis. Its indications are treatment of cryptococcal meningitis and serious systemic candidiasis. Resistance develops rapidly, due to altered drug-permeability. For this reason Amphotericin B and flucytosine are often given in combination as they have synergistic effects. 

Nystatin [nye STAT in] is a polyene antibiotic its structure, chemistry, mode of action, and resistance resemble those of amphotericin B. Its use is restricted to topical treatment of Candida infections because of its systemic toxicity. The drug is negligibly absorbed from the gastrointestinal tract, and it is never used par-enterally. It is administered as an oral agent ( swish and swallow ) for the treatment of oral candidiasis. Excretion in the feces is nearly quantitative. Adverse effects are rare because of its lack of absorption, but occasionally nausea and vomiting occur. 

Oral candidiasis - besides other predisposing factors - is a common disease in the immunocompromised patient and should remind clinicians of the possibility of HIV infection. It is often associated with esophageal manifestations. Relapsing or chronic persistent vulvovaginal candidiasis has been reported in up to 50% of HIV-infected women, therefore some authors recommend HIV testing in this condition too [58]. Resistance to antifungal drugs is a common problem... 

Adverse effects of tetracyclines include resistant bacteria, folliculitis, candidiasis, gastrointestinal upset, and phototoxic effects. Tetracyclines must not be combined with systemic retinoids because of the increased probability for development of intracranial hypertension. Tetracycline is used in the treatment of moderate to severe acne vulgaris. It is the least expensive of the tetracyclines and therefore often prescribed for initial therapy. A common initial approach includes tetracycline 1 g daily (500 mg twice daily), 1 hour before meals after 1 or 2 months, when marked improvement of inflammatory lesions is observed, the dose may be decreased to 500 mg every day, for another 1 or 2 months. Drawbacks to the use of tetracycline include also a drug-food interaction with dairy prodncts. 

Public Flealth Service and the Infectious Diseases Society of America, as well as other experts in the area, do not recommend routine primary prophylaxis for OPC. The rationale includes effectiveness of therapy for acute episodes of OPC, low incidence of serious invasive fungal disease, low mortality associated with mucosal candidiasis, the potential development of resistant candidiasis, the possibility of drug interactions, and the prohibitive long-term cost of prophylaxis. For the same reasons, chronic suppressive therapy (i.e., secondary prophylaxis of recurrent OPC) is also not recommended routinely, but rather clinicians should treat each acute episode as it occurs. ... 

Resistance has not been described widely with itraconazole. This may be partly related to the fact that the drug has been used primarily for the treatment of endemic mycoses and not candidiasis. Even in patients never treated with itraconazole, however, C. albicans strains that are resistant to fluconazole also show decreased susceptibility to itraconazole. 

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