Author: Brian Holtry

Isoniazid – Antituberculosis Agent

Isoniazid usually is administered orally. The drug may be given by IM injection when oral therapy is not possible. The fixed-combination preparation containing isoniazid and rifampin (Rifamate®) and the fixed-combination preparation containing isoniazid, rifampin, and pyrazinamide (Rifater®) should be given either 1 hour before or 2 hours after a meal; the manufacturer states that Rifater® should be given with a full glass of water.

Isoniazid: Cautions

Peripheral neuritis, usually preceded by paresthesia of the feet and hands, is the most common adverse effect of isoniazid and occurs most frequently in malnourished patients and those predisposed to neuritis (e.g., alcoholics, diabetics). Rarely, other adverse nervous system effects have also occurred including seizures, toxic encephalopathy, muscle twitching, ataxia, stupor, tinnitus, euphoria, memory impairment, separation of ideas and reality, loss of self-control, dizziness, and toxic psychosis. Neurotoxic effects may be prevented or relieved by the administration of 10-50 mg of pyridoxine hydrochloride daily during isoniazid therapy, and pyridoxine should be administered in malnourished patients, pregnant women, and those predisposed to neuritis (e.g., HIV-infected individuals).

Capreomycin Sulfate

Capreomycin, a polypeptide antibiotic complex of 4 microbiologically active components, is an antituberculosis agent. Capreomycin is used in conjunction with other antituberculosis agents in the treatment of clinical tuberculosis.

Aminosalicylic Acid

Aminosalicylic acid is used in conjunction with other antituberculosis agents in the treatment of clinical tuberculosis. The drug is designated an orphan drug by the US Food and Drug Administration (FDA) for use in the treatment of tuberculosis. These regimens have a minimum duration of 6 months (26 weeks), and consist of an initial intensive phase (2 months) and a continuation phase (usually either 4 or 7 months). Aminosalicylic acid is considered a second-line antituberculosis agent for use in these regimens.

Antituberculosis Agents General Statement

Antituberculosis agents are antibiotics and synthetic anti-infectives used in the treatment of tuberculosis and other diseases caused by organisms of the genus Mycobacterium. Isoniazid, rifampin, ethambutol, and pyrazinamide are the drugs used most frequently in the treatment of tuberculosis and are considered first-line agents for use in antituberculosis regimens.

Flucytosine (Ancobon 250, 500mg)

While flucytosine may be effective when used alone for the treatment of some fungal infections (e.g., candidal cystitis, chromomycosis), the drug should not be used alone in the treatment of severe, life-threatening infections. In the treatment of serious candidal or cryptococcal infections, flucytosine generally has been used as an adjunct to IV amphotericin B or an azole antifungal agent (e.g., fluconazole, itraconazole). There is some evidence that combined use of flucytosine and amphotericin B may be associated with an increased risk of serious adverse effects, especially in immunocompromised patients including those with human immunodeficiency virus (HIV) infection.

Nystatin

Nystatin is used orally for the treatment of intestinal candidiasis. In patients with coexisting intestinal candidiasis and vulvovaginal candidiasis, nystatin has been administered orally in conjunction with intravaginal application of an antifungal agent. Nystatin has been administered orally as a suspension in conjunction with local application of the drug for the treatment of candidal diaper dermatitis. The majority of infants with candidal diaper dermatitis harbor C. albicans in their intestines, and infected feces appear to be an important source of the cutaneous infection.

Amphotericin B (Fungilin, Fungizone, Abelcet, Fungisome, Amphocil)

Systematic drug interaction studies have not been performed to date using amphotericin B cholesteryl sulfate complex, amphotericin B lipid complex, or amphotericin B liposomal. The fact that drug interactions reported with conventional IV amphotericin B could also occur with these lipid-based or liposomal formulations of the drug should be considered.