U.S. Department of Health & Human Services Divider Arrow National Institutes of Health Divider Arrow NCATS

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Rizatriptan (trade name Maxalt) is a 5-HT1 receptor agonist of the triptan class of drugs developed by Merck & Co. for the treatment of migraine headaches. Rizatriptan (trade name Maxalt) is a 5-HT1 receptor agonist of the triptan class of drugs developed by Merck & Co. for the treatment of migraine headaches. Rizatriptan acts as an agonist at serotonin 5-HT1B and 5-HT1D receptors. Rizatriptan binds with high affinity to human cloned 5-HT1B/1D receptors. Rizatriptan benzoate presumably exerts its therapeutic effects in the treatment of a migraine headache by binding to 5-HT1B/1D receptors located on intracranial blood vessels and sensory nerves of the trigeminal system. Rizatriptan is completely absorbed following oral administration. The mean oral absolute bioavailability of the rizatriptan benzoate tablet is about 45%, and mean peak plasma concentrations are reached in approximately 1-1.5 hours. The presence of a migraine headache did not appear to affect the absorption or pharmacokinetics of rizatriptan. Food has no significant effect on the bioavailability of rizatriptan but delays the time to reach peak concentration by an hour. The primary route of rizatriptan metabolism is via oxidative deamination by monoamine oxidase-A (MAO-A) to the indole acetic acid metabolite, which is not active at the 5-HT1B/1D receptor. N-mono-desmethyl-rizatriptan, a metabolite with activity similar to that of parent compound at the 5-HT1B/1D receptor, is formed to a minor degree. Plasma concentrations of N-mono-desmethyl-rizatriptan are approximately 14% of those of parent compound, and it is eliminated at a similar rate. Other minor metabolites, the N-oxide, the 6-hydroxy compound, and the sulfate conjugate of the 6-hydroxy metabolite are not active at the 5-HT1B/1D receptor.
Trandolapril is a non-sulhydryl prodrug that belongs to the angiotensin-converting enzyme (ACE) inhibitor class of medications. It is metabolized to its biologically active diacid form, trandolaprilat, in the liver. Trandolaprilat inhibits ACE, the enzyme responsible for the conversion of angiotensin I (ATI) to angiotensin II (ATII). ATII regulates blood pressure and is a key component of the renin-angiotensin-aldosterone system (RAAS). Trandolapril may be used to treat mild to moderate hypertension, to improve survival following myocardial infarction in clinically stable patients with left ventricular dysfunction, as an adjunct treatment for congestive heart failure, and to slow the rate of progression of renal disease in hypertensive individuals with diabetes mellitus and microalbuminuria or overt nephropathy. Trandolapril is marketed by Abbott Laboratories under the brand name Mavik.
Dexlansoprazole (trade names Kapidex, Dexilant) is a proton pump inhibitor (PPI) that is marketed by Takeda Pharmaceuticals for the treatment of erosive esophagitis and gastro-oesophageal reflux disease. Dexlansoprazole is used to heal and maintain healing of erosive esophagitis and to treat heartburn associated with gastroesophageal reflux disease (GERD). It lasts longer than lansoprazole, to which it is chemically related, and needs to be taken less often. Dexlansoprazole is supplied for oral administration as a dual delayed-release formulation in capsules and orally disintegrating tablets. The capsules and tablets contain dexlansoprazole in a mixture of two types of enteric-coated granules with different pH-dependent dissolution profiles. The most significant adverse reactions (≥2%) reported in clinical trials were diarrhea, abdominal pain, nausea, upper respiratory tract infection, vomiting, and flatulence.
Rifabutin is an antibiotic that inhibits DNA-dependent RNA polymerase activity in susceptible cells. Specifically, it interacts with bacterial RNA polymerase but does not inhibit the mammalian enzyme. It is bactericidal and has a very broad spectrum of activity against most gram-positive and gram-negative organisms (including Pseudomonas aeruginosa) and specifically Mycobacterium tuberculosis. It is FDA approved for the prophylaxis of disseminated Mycobacterium avium complex (MAC) disease in patients with advanced HIV infection. Multiple dosing of rifabutin has been associated with induction of hepatic metabolic enzymes of the CYP3A subfamily. Rifabutin’s predominant metabolite (25-desacetyl rifabutin: LM565), may also contribute to this effect. Similarly, concomitant medications that competitively inhibit the CYP3A activity may increase plasma concentrations of rifabutin. Common adverse reactions include discoloration of skin, rash, diarrhea, disorder of taste, indigestion, loss of appetite, nausea, vomiting, increased liver aminotransferase level (mild), ocular discoloration, uveitis, abnormal color of body fluid.
Status:
First approved in 1992

Class (Stereo):
CHEMICAL (ACHIRAL)


Conditions:

Terbinafine (brand name Lamisil, Terbisil, Terboderm and others) is an antifungal medication used to treat ringworm and fungal nail infections. Terbinafine inhibits ergosterol synthesis by inhibiting squalene epoxidase, an enzyme that is part of the fungal cell membrane synthesis pathway. Because terbinafine prevents the conversion of squalene to lanosterol, ergosterol cannot be synthesized. This is thought to change cell membrane permeability, causing fungal cell lysis. Many side effects and adverse drug reactions have been reported with oral terbinafine hydrochloride possibly due to its extensive biodistribution and the often extended durations involved in antifungal treatment (longer than two months).
Famotidine, a competitive histamine H2-receptor antagonist, is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Famotidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Famotidine include an increase in gastric bacterial flora such as nitrate-reducing organisms. Famotidine binds competitively to H2-receptors located on the basolateral membrane of the parietal cell, blocking histamine affects. This competitive inhibition results in reduced basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin.
Ceftazidime is a semisynthetic, broad-spectrum, beta-lactam antibiotic, used especially for Pseudomonas and other gram-negative infections in debilitated patients. Ceftazidime is used to treat lower respiratory tract, skin, urinary tract, blood-stream, joint, and abdominal infections, and meningitis. The drug is given intravenously (IV) or intramuscularly (IM) every 8–12 hours (two or three times a day), with dose and frequency varying by the type of infection, severity, and/or renal function of the patient. Injectable formulations of ceftazidime are currently nebulized "off-label" to manage Cystic Fibrosis, non-Cystic Fibrosis bronchiectasis, drug-resistant nontuberculous mycobacterial infections, ventilator-associated pneumonia, and post-transplant airway infections. Ceftazidime is generally well-tolerated. When side effects do occur, they are most commonly local effects from the intravenous line site, allergic reactions, and gastrointestinal symptoms. According to one manufacturer, in clinical trials, allergic reactions including itching, rash, and fever, happened in fewer than 2% of patients. Rare but more serious allergic reactions, such as toxic epidermal necrolysis, Stevens-Johnson syndrome, and erythema multiforme, have been reported with this class of antibiotics, including ceftazidime. Gastrointestinal symptoms, including diarrhea, nausea, vomiting, and abdominal pain, were reported in fewer than 2% of patients.
Atenolol is a Beta-1 cardio-selective adreno-receptor blocking agent discovered and developed by ICI in 1976. Atenolol was launched in the market under the trade name Tenormin in 1976, and became the best-selling Beta-blocker in the world in the 1980s and 1990s. TENORMIN is indicated for the treatment of hypertension, to lower blood pressure; also for the long-term management of patients with angina pectoris and also is indicated in the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality. Like metoprolol, atenolol competes with sympathomimetic neurotransmitters such as catecholamines for binding at beta(1)-adrenergic receptors in the heart and vascular smooth muscle, inhibiting sympathetic stimulation. This results in a reduction in resting heart rate, cardiac output, systolic and diastolic blood pressure, and reflex orthostatic hypotension. Higher doses of atenolol also competitively block beta(2)-adrenergic responses in the bronchial and vascular smooth muscles. Hypotensive mechanism of atenolol is very complex. Decrease in CO and inhibition of renin-angiotensin-aldosterone system may mainly be responsible for hypotension. It is likely that potassium retaining action of atenolol partly contributes to its hypotensive action. It is also hypothetized that renal kallikrein-kinin system may play a role in modulating the hypotensive action of atenolol.
Ketoconazole is an azole antifungal. Ketoconazole was the first broad-spectrum oral antifungal agent available to treat systemic and superficial mycoses. Evidence of hepatotoxicity associated with its use emerged within the first few years of its approval. Due to its hepatotoxic side effects, oral ketoconazole was withdrawn from the European and Australian markets in 2013. The United States imposed strict relabeling requirements and restrictions for prescription, with Canada issuing a risk communication echoing these concerns. Today, oral ketoconazole is only indicated for endemic mycoses, where alternatives are not available or feasible. Meanwhile, topical ketoconazole is effective, safe, and widely prescribed for superficial mycoses, particularly as the first-line treatment for tinea versicolor. Topically administered ketoconazole is usually prescribed for fungal infections of the skin and mucous membranes, such as athlete's foot, ringworm, candidiasis (yeast infection or thrush), jock itch, and tinea versicolor. Topical ketoconazole is also used as a treatment for dandruff (seborrheic dermatitis of the scalp) and for seborrheic dermatitis on other areas of the body, perhaps acting in these conditions by suppressing levels of the fungus Malassezia furfur on the skin. Ketoconazole interacts with 14-α demethylase, a cytochrome P-450 enzyme necessary for the conversion of lanosterol to ergosterol. This results in inhibition of ergosterol synthesis and increased fungal cellular permeability. Other mechanisms may involve the inhibition of endogenous respiration, interaction with membrane phospholipids, inhibition of yeast transformation to mycelial forms, inhibition of purine uptake, and impairment of triglyceride and/or phospholipid biosynthesis. Ketoconazole can also inhibit the synthesis of thromboxane and sterols such as aldosterone, cortisol, and testosterone. Ketoconazole is active against clinical infections with Blastomyces dermatitidis, Coccidioides immitis, Histoplasma capsulatum, Paracoccidioides brasiliensis.
Cefoxitin is a cephamycin antibiotic often grouped with the second-generation cephalosporins. It is active against a broad range of gram-negative bacteria including anaerobes. The methoxy group in the 7a position provides cefoxitin with a high degree of stability in the presence of beta-lactamases, both penicillinases and cephalosporinases, of gram-negative bacteria. The bactericidal action of cefoxitin results from inhibition of cell wall synthesis.