The FDA has approved rezafungin (Rezzayo – Cidara/Melinta), an intravenous echinocandin antifungal, for once-weekly treatment of candidemia and invasive candidiasis (IC) in adults with limited or no alternative options. It is the first new drug to become available in the US in more than 15 years for treatment of systemic Candida infections.

The FDA has approved oteseconazole (Vivjoa – Mycovia), a new oral azole antifungal, to reduce the incidence of recurrent vulvovaginal candidiasis (RVVC) in females with a history of RVVC. Oteseconazole is the first drug to be approved in the US specifically for treatment of RVVC.

Onychomycosis is caused most commonly by Trichophyton rubrum or T. mentagrophytes. About 10% of all persons worldwide and 40% of those ≥60 years old are believed to have the disease. Risk factors include older age, diabetes, poor peripheral circulation, smoking, HIV infection, psoriasis, and immunosuppression. Left untreated, onychomycosis can cause nail plate destruction, ingrown nails, and (particularly in patients with diabetes) secondary infections. Guidelines on treatment of onychomycosis have been published.

The FDA has approved ibrexafungerp (Brexafemme – Scynexis), a first-in-class triterpenoid antifungal ("fungerp"), for oral treatment of vulvovaginal candidiasis in postmenarchal females.

The text and tables that follow include recommendations for management of sexually transmitted infections (STIs) other than HIV and viral hepatitis. Some of the indications and dosages recommended here have not been approved by the FDA.

The treatment of atrial fibrillation includes anticoagulation, rate control, and rhythm control. New US guidelines for the management of atrial fibrillation have recently been published.

Many infections can be transmitted during sexual contact. The text and tables that follow include recommendations for management of sexually transmitted infections (STIs) other than HIV, viral hepatitis, and enteric infections. Some of the indications and dosages recommended here have not been approved by the FDA.

The drugs of choice for treatment of fungal infections are listed in the table that begins on page 62. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines for some of these infections are available online from the Infectious Diseases Society of America (www.idsociety.org).

The FDA has approved a buccal tablet formulation of miconazole (Oravig – Strativa) for local treatment of oropharyngeal candidiasis in adults. Miconazole has been available for many years in topical formulations for treatment of superficial fungal infections and vulvovaginal candidiasis.

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. The drugs of choice, their dosages and alternatives are listed in a table that begins on page 54. A table listing the adverse effects of some of these antimicrobials begins on page 58.

The drugs of choice for treatment of some fungal infections are listed. Some of the indications and dosages recommended here have not been approved by the FDA. More detailed guidelines are available online from the Infectious Diseases Society of America (www.idsociety.org).

The FDA has approved the marketing of tolvaptan (Samsca - Otsuka), an oral vasopressin receptor antagonist, for treatment of hypervolemic or euvolemic hyponatremia due to congestive heart failure (CHF), cirrhosis or the syndrome of inappropriate antidiuretic hormone secretion (SIADH). A similar drug, conivaptan (Vaprisol) is already available for intravenous (IV) treatment of euvolemic hyponatremia in hospitalized patients. Tolvaptan was approved by the FDA for both inpatient and outpatient use, but it should be started in a hospital.

Inflammatory bowel disease (IBD) is either Crohn's disease or ulcerative colitis. Drug selection is guided by disease type (Crohn's versus ulcerative colitis), severity and location and whether the goal is induction or maintenance of remission. Table 1 on page 66 lists the drugs used to treat IBD with their formulations and cost. Table 2 on page 68 lists the drugs of choice and their doses for different indications. Table 3 on page 71 lists the drugs' adverse effects and recommendations for monitoring. More detailed guidelines are available from the American College of Gastroenterology.

A recent letter to the editor of the Annals of Internal Medicine documented a single case of myopathy apparently due to an interaction between simvastatin (Zocor, and others) and green tea. Since it became available generically, simvastatin has surpassed atorvastatin (Lipitor) as the best selling statin. As such, it is probably the most common cause of statin-induced myopathy, which is often a result of drug interactions.

A reader expressed disappointment that our recent listing of “Some Warfarin Drug Interactions”1 did not include acetaminophen. Perhaps it should have. Acetaminophen can increase the anticoagulant effect of warfarin, particularly with continued use, but it does so inconsistently. The mechanism of this interaction has not been established, but may be related to an acetaminophen metabolite inhibiting vitamin K-epoxide reductase, the target for warfarin’s anticoagulant effect.2

Patient susceptibility varies, possibly on a genetic basis; occasional use of acetaminophen generally has little or no effect on the international normalized ratio (INR) in patients on chronic warfarin therapy, but in some, even a few grams of the drug may cause a dramatic increase in INR. One study in healthy subjects found no effect of acetaminophen 4 g per day for 2 weeks, while another study in patients with the same acetaminophen dose for the same period of time found a moderate increase in INR.3,4 It might be prudent to monitor INR in patients on chronic warfarin therapy more closely than usual when they take more than 2 g per day of acetaminophen for more than a few days.

1. Pharmacogenetic-based dosing of warfarin. Med Lett Drugs Ther 2008; 50:39.
2. HH Thijssen et al. Paracetamol (acetaminophen) warfarin interaction: NAPQI, the toxic metabolite of paracetamol, is an inhibitor of enzymes in the vitamin K cycle. Thromb Haemost 2004; 92:797.
3. D Kwan et al. The effects of acetaminophen on pharmacokinetics and pharmacodynamics of warfarin. J Clin Pharmacol 1999; 39:68.
4. I Mahe et al. Paracetamol: A haemorrhagic risk factor in patients on warfarin. Br J Clin Pharmacol 2005; 59:371.

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Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.

The drugs of choice for treatment of some fungal infections are listed in the tables. Some of the indications and dosages recommended here have not been approved by the FDA. Other guidelines are available from the Infectious Diseases Society of America (www.idsociety.org).

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. Guidelines are available from the US Centers for Disease Control and Prevention (CDC) with detailed recommendations for treatment of these diseases.

Serious adverse interactions between drugs continue to be reported. Many of these are due to inhibition or induction of cytochrome P450 (CYP) enzymes, particularly CYP3A4. CYP3A is thought to be involved in the metabolism of more than 50 percent of currently prescribed drugs.2 CYP3A4, which is more abundantly expressed than CYP3A5, accounts for most CYP3A activity in vivo.

Micafungin sodium (Mycamine - Astellas), the second echinocandin antifungal to become available in the US, has been approved by the FDA for intravenous treatment of esophageal candidiasis and prophylaxis of invasive Candida infections in patients undergoing hematopoietic stem cell transplantation (HSCT).

The drugs of choice for treatment of some fungal infections are listed in the table that begins on page 8. Some of the indications and dosages recommended here have not been approved by the FDA.

Tuberculosis (TB) is still a problem in the United States, even though the incidence continues to decline in most of the country (MMWR Morbid Mortal Wkly Rep 2004; 53:209). Treatment of TB can be divided into treatment of latent infection diagnosed by a positive PPD and treatment of active clinical TB. Guidelines with detailed management recommendations are available from the US Centers for Disease Control and Prevention (CDC) (MMWR Morbid Mortal Wkly Rep 2003; 52RR-11:1).

Many infections can be transmitted during sexual contact. The text and tables that follow are limited to management of sexually transmitted infections (STIs) other than HIV, viral hepatitis and enteric infections. Guidelines are available from the US Centers for Disease Control and Prevention (CDC) with detailed recommendations for treatment of these diseases (MMWR Recomm Rep 2002; 51, RR-6:1). New guidelines are expected soon.

Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table below lists first-choice and alternative drugs for most parasitic infections. The brand names and manufacturers of the drugs are listed in this article.

Changes caused by one drug in the absorption, distribution, metabolism or excretion of another may lead to a pharmacokinetic adverse drug interaction (DN Juurlink et al, JAMA 2003; 289:1652). Additive drug interactions, such as vasodilation caused by both sildenafil (Viagra) and nitrates, can also have adverse effects.

Voriconazole (Vfend -- Pfizer), an antifungal triazole structurally related to fluconazole (Diflucan) with a spectrum of action similar to that of itraconazole, has been approved by the FDA for primary treatment of invasive aspergillosis and for refractory infection with Scedosporium apiospermum (the asexual form of Pseudallescheria boydii) or Fusarium spp.

Superseded--purchase updated Parasitic Infections article
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites.

Note: Drugs for Parasitic Infections, revised and updated, is now available to both subscribers and nonsubscribers on our web site. This article, a bi-annual feature of The Medical Letter for many years, will not be published as a printed issue in 2002, but is included in the 16th edition of The Medical Letter Handbook of Antimicrobial Therapy. The handbook is now available and can be ordered by calling customer service at 1-800-211-2769.

Many drugs, mostly azole derivatives, are marketed in the USA for topical treatment of vulvovaginal candidiasis. A single-dose, sustained-release formulation of butoconazole nitrate 2% cream (Gynazole 1) is the newest addition. Fluconazole (Diflucan) is approved for single-dose oral treatment.

Many infections can be transmitted during sexual contact. The text and tables [in this article] are limited to treatment of non-HIV infections associated primarily with sexual transmission.

Reports of adverse interactions between drugs continue to accumulate. Recently, the FDA has expanded the recommendations on drug interactions found in the package inserts of new drugs.

Celecoxib, a selective COX-2 inhibitor, has been approved by the FDA for treatment of osteoarthritis and rheumatoid arthritis.

(Superseded by the 2013 version. Click here to purchase.)
Parasitic infections are found throughout the world. With increasing travel, immigration, use of immunosuppressive drugs and the spread of AIDS, physicians anywhere may see infections caused by previously unfamiliar parasites. The table lists first-choice and alternative drugs for most parasitic infections.

The drugs of choice for treatment of deep fungal infections are listed in the table below. Some of the indications and dosages recommended here have not been approved by the FDA.

Four new drugs have become available in the USA for HIV infection or its complications. Nevirapine (Viramune - Roxane), intravenous cidofovir (Vistide - Gilead), and amphotericin B oral suspension (Fungizone Oral Suspension - Bristol-Myers Squibb) have been approved by the US Food and Drug Administration; nelfinavir (Viracept - Agouron) is currently available only through an "Expanded Access Program."

Fexofenadine (fex oh fen' a deen) hydrochloride (Allegra - Hoechst Marion Roussel) has been approved by the US Food and Drug Administration for treatment of seasonal allergic rhinitis. An active metabolite of terfenadine, fexofenadine is being heavily advertised as "nonsedating...without 'black box' warnings."

Terbinafine (Lamisil - Sandoz), an allylamine synthetic antifungal, previously available in the USA in a topical formulation (Medical Letter, 35:76, 1993) has now been marketed for oral use in the treatment of fungal nail infections caused by dermatophytes. Oral terbinafine has been available in Europe since 1992.

The drugs of choice for treatment of deep fungal infections are listed in the table on page 101. Some of the indications and dosages recommended here have not been approved by the US Food and Drug Administration. More detailed guidelines are available from the Infectious Diseases Society of America (J Sobel et al, Clin Infect Dis, volume 30, April 2000).

Itraconazole (Sporanox - Janssen), an oral antifungal triazole that has been available in the USA since 1992 for treatment of deep fungal infections (Medical Letter, 35:7, 1993), is now being marketed for treatment of dermatophyte infections of the toenails, with or without fingernail involvement.

Results of recently completed clinical trials have led to some changes in recommendation for treatment of human immunodeficiency virus (HIV) and other infections associated with AIDS.

Tuberculosis (TB) continues to be a major problem in the United States, particularly in areas where drug resistance is common (Morbid Mortal Weekly Rep, 44:387, May 26, 1995). Since poor compliance is the most important cause of treatment failure and is associated with emergence of drug resistence, some experts now recommend that all patients take drugs for TB under direct observation (SE Weis et al, N Engl J Med, 330:1179, 1994; R Bayer and D Wilkinson, Lancet, 345:1545, June 17, 1995).

Influenza vaccine for the 2002-2003 season will include last year's A strains, A/New Caledonia/20/99 (H1N1)-like and A/Moscow/10/99 (H3N2)-like, and a new B strain, B/Hong- Kong/330/01-like (MMWR Morb Mortal Wkly Rep 2002; 51:503).

The rising incidence of tuberculosis (TB) has been accompanied by a dramatic increase in drug resistance in some areas of the USA (TR Frieden et al, N Engl J Med, 328:521, 1993). Since poor compliance is the most important cause of treatment failure and associated with emergence of drug resistance, some experts now recommend that patients with TB take their drugs under direct obeservation (MD Iseman et al, N Engl J Med, 329:576, 1993).

Results of recently completed clinical trials have led to some changes in recommendations for treatment of human immunodeficiency virus (HIV) and other infections associted with AIDS.

Rifabutin (formerly ansamycin; Mycobutin - Adria), a rifamycin antibiotic similar to rifampin (Rifadin, Rimactane) was recently approved by the US Food and Drug Administration for prevention of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection.

Itraconazole (Sporanox - Janssen), an antifungal triazole, has been approved by the US Food and Drug Administration (FDA) for oral treatment of histoplasmosis and blastomycosis. These two endemic mycoses occur both in normal hosts and in immunocompromised patients, such as those with AIDS (RW Bradsher, Clin Infect Dis, 14:S82, 1992; LJ Wheat, Clin Infect Dis, 14:S91, 1992).

The incidence of opportunistic fungal infections continues to increase, particularly in patients who have AIDS, are taking immunosuppressive drugs, or are in intensive care units. Intravenous (IV) amphotericin B (Fungizone, and others), sometimes given with flucytosine (Ancobon), is the drug of choice for initial treatment of most rapidly progressive, acutely life-threatening fungal infections; for less severe infections, fluconazole (Diflucan, ketoconazole (Nizoral), or itraconazole (Sporanox - an investigational drug in the (USA) may also be effective, can be taken orally, and are much better tolerated. The treatment of superficial fungal infections is not discussed here.

A growing number of clinical trials now permits some consensus on the treatment of human immunodeficiency virus (HIV) and other infections associated with acquired immune deficiency syndrome (AIDS) in adults.

Fluconazole (Diflucan - Roerig), an antifungal azole, was recently approved by the US Food and Drug Administration for oral and intravenous (IV) treatment of cryptococcal meningitis and various forms of candidiasis. Both cryptococcal meningitis and candidiasis occur frequently in patients with AIDS, organ transplants, or cancer.