In those that administered 0.8% terconazole, plasma concentrations of the drug remained quite low with the peak plasma concentration being 0.006 mcg at 6.6 hours. Those metabolism rates show similar results in pregnant vulvovaginal candidiasis, non-pregnant vulvovaginal candidiasis and healthy women. The half-life of terconazole in blood is recorded to be around 6.9 hours over a range of 4–11.3 hours). Radioactivity of plasma terconazole is low compared to terconazole at 0.6%. Excretion of radioactivity is via two routes, renal (32–53%) and fecal (47–52%). Metabolism is extensive and is highly protein bound (94.9%) with the degree of binding being independent of drug concentration. History
In 1940, the first commercial antifungal drug, called amphotericin B, was available on the market, replacing rare and expensive treatments. It was effective in its function but was very toxic and only used for serious infections. The drug was infused into the bloodstream and could cause kidney damage and other side effects. The first azole compounds to replace this treatment were synthesized in the late 1960s and early 1970s and administered to humans under strict care. These compounds were imidazoles, a molecule containing two non-adjacent nitrogen atoms in a 5 membered ring. The first oral antimycotic imidazole, called ketoconazole, was available on the market in 1981. Triazole based drugs came shortly after and quickly gained popularity due to its broader spectrum of antifungal activity and less toxicity. Terconazole was the first triazole-based antifungal drug synthesized for human use. Janssen Pharmaceutica developed it in 1983.
Though many travelers find a four-times-per-day regimen inconvenient, lower doses have not been shown to be effective. Potential side effects include black tongue, black stools, nausea, constipation, and ringing in the ears. Bismuth subsalicylate should not be taken by those with aspirin allergy, kidney disease, or gout, nor concurrently with certain antibiotics such as the quinolones, and should not be taken continuously for more than three weeks. Some countries do not recommend it due to the risk of rare but serious side effects.A hyperimmune bovine colostrum to be taken by mouth is marketed in Australia for prevention of ETEC-induced TD. As yet, no studies show efficacy under actual travel conditions.Though effective, antibiotics are not recommended for prevention of TD in most situations because of the risk of allergy or adverse reactions to the antibiotics, and because intake of preventive antibiotics may decrease effectiveness of such drugs should a serious infection develop subsequently. Antibiotics can also cause vaginal yeast infections, or overgrowth of the bacterium Clostridium difficile, leading to pseudomembranous colitis and its associated severe, unrelenting diarrhea.Antibiotics may be warranted in special situations where benefits outweigh the above risks, such as immunocompromised travelers, chronic intestinal disorders, prior history of repeated disabling bouts of TD, or scenarios in which the onset of diarrhea might prove particularly troublesome. Options for prophylactic treatment include the quinolone antibiotics (such as ciprofloxacin), azithromycin, and trimethoprim/sulfamethoxazole, though the latter has proved less effective in recent years. Rifaximin may also be useful.