部份中文甲硝唑处方资料（仅供参考） 药物名称: 甲硝唑 药物别名: 甲硝基羟乙唑，灭滴灵，灭滴唑，FLAGYL 英文名称: Metronidazole 药理毒理　　 本品为硝基咪唑衍生物，可抑制阿米巴原虫的氧化还原反应，使原虫氮链发生断裂。体外试验证明，药物浓度为1～2mg/L时，溶组织阿米巴于6～20小时即可发生形态改变，24小时内全部被杀灭，浓度为0.2mg/L时，72小时内可杀死溶组织阿米巴。本品有强大的杀灭滴虫的作用，其机理未明。 甲硝唑对厌氧微生物有杀灭作用，它在人体中还原时生成的代谢物也具有抗厌氧菌作用，抑制细菌的脱氧核糖核酸的合成，从而干扰细菌的生长、繁殖，最终致细菌死亡。 对某些动物有致癌作用。 药代动力学　　 口服或直肠给药后能迅速而完全吸收，蛋白结合率＜5%，吸收后广泛分布于各组织和体液中，且能通过血脑屏障，药物有效浓度能够出现在唾液、胎盘、胆汁、乳汁、羊水、精液、尿液、脓液和脑脊液中。有报道，药物在胎盘、乳汁、胆汁的浓度与血药浓度相似。健康人脑脊液中血药浓度为同期血药浓度的43%。少数脑脓肿患者，每日服用1.2～1.8g后，脓液的药浓度（34～45mg/L）高于同期的血药浓度（11～35mg/L）。耳内感染后其脓液内的药物浓度在8.5mg/L以上。口服后1～2小时血药浓度达高峰，有效浓度能维持12小时。口服0.25g、0.4g、0.5g 、2g后的血药浓度分别为6 mg/L、9mg/L、12mg/L、40mg/L。本品经肾排出60%～80%，约20%的原形药从尿中排出，其余以代谢产物（25%为葡萄糖醛酸结合物，14%为其他代谢结合物）形式由尿排出，10%随粪便排出，14%从皮肤排泄。 适应症 本品有强大的杀灭滴虫作用，为治疗阴道滴虫病的首选药物。此外对肠道及组织内阿米巴原虫也有杀灭作用，可用于治疗阿米巴痢和阿米巴肝脓肿，疗效与依米丁相仿。其优点是毒性小、疗效高、口服方便、适应范围广。 本品有抗厌氧菌作用，可用于治疗厌氧杆菌引起的产后盆腔炎、败血症、牙周炎等。还可用于治疗贾第氏鞭毛虫病、酒糟鼻。用于阑尾、结肠手术、妇产科手术，可降低或避免手术感染。 本品口服吸收良好，生物利用度可达90％～100％，Cmax为1～2小时，Vd为0.6～0.7L／kg，血浆蛋白结合率约为10％～20％。有效血浓度可维持12小时，药物可以原形由尿排出，亦由阴道分泌液、乳汁、唾液中排出。t1/2为8～14小时。 用法用量 （1）治滴虫病: 成人1日3次，每次服200mg，另每晚以200mg栓剂放入阴道内，连用7～10日。为保证疗效，须男女同治。 （2）治阿米巴病：成人1日3次，每次400～800mg（大剂量宜慎用），5～7日为1疗程。 （3）治贾第氏鞭毛虫病: 常用量每次400～300mg，1日3次口服，疗程5日。 （4）治疗由厌氧菌引起的产后盆腔感染、败血症、骨髓炎等：一般口服200～400mg，1日600～1200mg。也可静脉滴注。 （5）治酒糟鼻: 口服200mg，1日2～3次。配合2％灭滴灵霜外搽，1日3次。1疗程3周。 任何疑问，请遵医嘱！ 不良反应　　 15%～30%病例出现不良反应，以消化道反应最为常见，包括恶心、呕吐、食欲不振、腹部绞痛，一般不影响治疗；神经系统症状有头痛、眩晕，偶有感觉异常、肢体麻木、共济失调、多发性神经炎等，大剂量可致抽搐。少数病例发生荨麻疹、潮红、瘙痒、膀胱炎、排尿困难、口中金属味及白细胞减少等，均属可逆性，停药后自行恢复。 禁忌　　 有活动性中枢神经系统疾患和血液病者禁用。 注意事项 （1）可有食欲不振、恶心、呕吐等反应，少数有腹泻，此外可偶见头痛、失眠、皮疹、白细胞减少等。少数病例有膀胱炎、排尿困难、肢体麻木及感觉异常，停药后可迅速恢复。 （2）哺乳期妇女及妊娠3个月以内的妇女、中枢神经疾病和血液病患者禁用。 （3）出现运动失调及其他中枢神经症状时应停药。 （4）服药期间应每日更换内裤，注意洗涤用具的消毒，防止重复感染。 （5）对某些细菌有诱变性，但一般认为对人的致癌、致畸的危险很小。 药物相互作用　　 本品能增强华法林等抗凝药物的作用。与土霉素合用可干扰甲硝唑清除阴道滴虫的作用。 包装规格 FLAGYL TAB 500MG 50  METRONIDAZOLE     00025-1821-50 FLAGYL TAB 250MG 50  METRONIDAZOLE     00025-1831-50    FLAGYL ER TAB 750MG 30  METRONIDAZOLE     00025-1961-30 生产厂家：美国辉瑞公司 FLAGYL - metronidazole tablet, film coated  G.D. Searle LLC FLAGYL® metronidazole tablets To reduce the development of drug-resistant bacteria and maintain the effectiveness of FLAGYL® and other antibacterial drugs, FLAGYL® should be used only to treat or prevent infections that are proven or strongly suspected to be caused by bacteria. WARNING Metronidazole has been shown to be carcinogenic in mice and rats. (See PRECAUTIONS.) Unnecessary use of the drug should be avoided. Its use should be reserved for the conditions described in the INDICATIONS AND USAGE section below. DESCRIPTION FLAGYL (metronidazole) is an oral synthetic antiprotozoal and antibacterial agent, 1-(β-hydroxyethyl)-2-methyl-5-nitroimidazole, which has the following structural formula: FLAGYL tablets contain 250 mg or 500 mg of metronidazole USP. Inactive ingredients include cellulose, FD&C Blue No. 2 Lake, hydroxypropyl cellulose, hypromellose, polyethylene glycol, stearic acid, and titanium dioxide. CLINICAL PHARMACOLOGY Disposition of metronidazole in the body is similar for both oral and intravenous dosage forms, with an average elimination half-life in healthy humans of eight hours. The major route of elimination of metronidazole and its metabolites is via the urine (60 to 80% of the dose), with fecal excretion accounting for 6 to 15% of the dose. The metabolites that appear in the urine result primarily from side-chain oxidation [1-(β-hydroxyethyl)-2-hydroxymethyl-5-nitroimidazole and 2-methyl-5-nitroimidazole-1-yl-acetic acid] and glucuronide conjugation, with unchanged metronidazole accounting for approximately 20% of the total. Renal clearance of metronidazole is approximately 10 mL/min/1.73 m2. Metronidazole is the major component appearing in the plasma, with lesser quantities of the 2-hydroxymethyl metabolite also being present. Less than 20% of the circulating metronidazole is bound to plasma proteins. Both the parent compound and the metabolite possess in vitro bactericidal activity against most strains of anaerobic bacteria and in vitro trichomonacidal activity. Metronidazole appears in cerebrospinal fluid, saliva, and human milk in concentrations similar to those found in plasma. Bactericidal concentrations of metronidazole have also been detected in pus from hepatic abscesses. Following oral administration, metronidazole is well absorbed, with peak plasma concentrations occurring between one and two hours after administration. Plasma concentrations of metronidazole are proportional to the administered dose. Oral administration of 250 mg, 500 mg, or 2,000 mg produced peak plasma concentrations of 6 mcg/mL, 12 mcg/mL, and 40 mcg/mL, respectively. Studies reveal no significant bioavailability differences between males and females; however, because of weight differences, the resulting plasma levels in males are generally lower. Decreased renal function does not alter the single-dose pharmacokinetics of metronidazole. However, plasma clearance of metronidazole is decreased in patients with decreased liver function. Microbiology Trichomonas vaginalis, Entamoeba histolytica FLAGYL (metronidazole) possesses direct trichomonacidal and amebacidal activity against T. vaginalis and E. histolytica. The in vitro minimum inhibitory concentration (MIC) for most strains of these organisms is 1 mcg/mL or less. Anaerobic Bacteria Metronidazole is active in vitro against most obligate anaerobes but does not appear to possess any clinically relevant activity against facultative anaerobes or obligate aerobes. Against susceptible organisms, metronidazole is generally bactericidal at concentrations equal to or slightly higher than the minimum inhibitory concentrations. Metronidazole has been shown to have in vitro and clinical activity against the following organisms: Anaerobic gram-negative bacilli, including:     Bacteroides species including the Bacteroides fragilis group (B. fragilis, B.     distasonis, B. ovatus, B. thetaiotaomicron, B. vulgatus)     Fusobacterium species Anaerobic gram-positive bacilli, including:     Clostridium species and susceptible strains of Eubacterium Anaerobic gram-positive cocci, including:     Peptococcus niger     Peptostreptococcus species Susceptibility Tests Bacteriologic studies should be performed to determine the causative organisms and their susceptibility to metronidazole; however, the rapid, routine susceptibility testing of individual isolates of anaerobic bacteria is not always practical, and therapy may be started while awaiting these results. Quantitative methods give the most precise estimates of susceptibility to antibacterial drugs. A standardized agar dilution method and a broth microdilution method are recommended.1 Control strains are recommended for standardized susceptibility testing. Each time the test is performed, one or more of the following strains should be included: Clostridium perfringens ATCC 13124, Bacteroides fragilis ATCC 25285, and Bacteroides thetaiotaomicron ATCC 29741. The mode metronidazole MICs for those three strains are reported to be 0.25, 0.25, and 0.5 mcg/mL, respectively. A clinical laboratory is considered under acceptable control if the results of the control strains are within one doubling dilution of the mode MICs reported for metronidazole. A bacterial isolate may be considered susceptible if the MIC value for metronidazole is not more than 16 mcg/mL. An organism is considered resistant if the MIC is greater than 16 mcg/mL. A report of "Resistant" from the laboratory indicates that the infecting organism is not likely to respond to therapy. INDICATIONS AND USAGE Symptomatic Trichomoniasis FLAGYL is indicated for the treatment of symptomatic trichomoniasis in females and males when the presence of the trichomonad has been confirmed by appropriate laboratory procedures (wet smears and/or cultures). Asymptomatic Trichomoniasis FLAGYL is indicated in the treatment of asymptomatic females when the organism is associated with endocervicitis, cervicitis, or cervical erosion. Since there is evidence that presence of the trichomonad can interfere with accurate assessment of abnormal cytological smears, additional smears should be performed after eradication of the parasite. Treatment of Asymptomatic Consorts T. vaginalis infection is a venereal disease. Therefore, asymptomatic sexual partners of treated patients should be treated simultaneously if the organism has been found to be present, in order to prevent reinfection of the partner. The decision whether to treat an asymptomatic male partner who has a negative culture or one for whom no culture has been attempted is an individual one. In making this decision, it should be noted that there is evidence that a woman may become reinfected if her consort is not treated. Also, since there can be considerable difficulty in isolating the organism from the asymptomatic male carrier, negative smears and cultures cannot be relied upon in this regard. In any event, the consort should be treated with FLAGYL in cases of reinfection. Amebiasis FLAGYL is indicated in the treatment of acute intestinal amebiasis (amebic dysentery) and amebic liver abscess. In amebic liver abscess, FLAGYL therapy does not obviate the need for aspiration or drainage of pus. Anaerobic Bacterial Infections FLAGYL is indicated in the treatment of serious infections caused by susceptible anaerobic bacteria. Indicated surgical procedures should be performed in conjunction with FLAGYL therapy. In a mixed aerobic and anaerobic infection, antimicrobials appropriate for the treatment of the aerobic infection should be used in addition to FLAGYL. In the treatment of most serious anaerobic infections, FLAGYL I.V. (metronidazole hydrochloride) or FLAGYL I.V. RTU® (metronidazole) is usually administered initially. This may be followed by oral therapy with FLAGYL (metronidazole) at the discretion of the physician. INTRA-ABDOMINAL INFECTIONS, including peritonitis, intra-abdominal abscess, and liver abscess, caused by Bacteroides species including the B. fragilis group (B. fragilis, B. distasonis, B. ovatus, B. thetaiotaomicron, B. vulgatus), Clostridium species, Eubacterium species, Peptococcus niger, and Peptostreptococcus species. SKIN AND SKIN STRUCTURE INFECTIONS caused by Bacteroides species including the B. fragilis group, Clostridium species, Peptococcus niger, Peptostreptococcus species, and Fusobacterium species. GYNECOLOGIC INFECTIONS, including endometritis, endomyometritis, tubo-ovarian abscess, and postsurgical vaginal cuff infection, caused by Bacteroides species including the B. fragilis group, Clostridium species, Peptococcus niger, and Peptostreptococcus species. BACTERIAL SEPTICEMIA caused by Bacteroides species including the B. fragilis group and Clostridium species. BONE AND JOINT INFECTIONS, as adjunctive therapy, caused by Bacteroides species including the B. fragilis group. CENTRAL NERVOUS SYSTEM (CNS) INFECTIONS, including meningitis and brain abscess, caused by Bacteroides species including the B. fragilis group. LOWER RESPIRATORY TRACT INFECTIONS, including pneumonia, empyema, and lung abscess, caused by Bacteroides species including the B. fragilis group. ENDOCARDITIS caused by Bacteroides species including the B. fragilis group. To reduce the development of drug-resistant bacteria and maintain the effectiveness of FLAGYL and other antibacterial drugs, FLAGYL should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy. CONTRAINDICATIONS FLAGYL is contraindicated in patients with a prior history of hypersensitivity to metronidazole or other nitroimidazole derivatives. In patients with trichomoniasis, FLAGYL is contraindicated during the first trimester of pregnancy. (See WARNINGS.) WARNINGS Central and Peripheral Nervous System Effects Convulsive seizures, encephalopathy, aseptic meningitis, optic and peripheral neuropathy, the latter characterized mainly by numbness or paresthesia of an extremity, have been reported in patients treated with metronidazole. The appearance of abnormal neurologic signs demands the prompt discontinuation of FLAGYL (metronidazole) therapy. FLAGYL should be administered with caution to patients with central nervous system diseases. PRECAUTIONS General Patients with severe hepatic disease metabolize metronidazole slowly, with resultant accumulation of metronidazole and its metabolites in the plasma. Accordingly, for such patients, doses below those usually recommended should be administered cautiously. Known or previously unrecognized candidiasis may present more prominent symptoms during therapy with FLAGYL (metronidazole) and requires treatment with a candidacidal agent. Prescribing FLAGYL in the absence of a proven or strongly suspected bacterial infection or a prophylactic indication is unlikely to provide benefit to the patient and increases the risk of the development of drug-resistant bacteria. Information for patients Alcoholic beverages should be avoided while taking FLAGYL and for at least one day afterward. (See PRECAUTIONS-Drug interactions.) Patients should be counseled that antibacterial drugs including FLAGYL should only be used to treat bacterial infections. They do not treat viral infections (e.g., the common cold). When FLAGYL is prescribed to treat a bacterial infection, patients should be told that although it is common to feel better early in the course of therapy, the medication should be taken exactly as directed. Skipping doses or not completing the full course of therapy may (1) decrease the effectiveness of the immediate treatment and (2) increase the likelihood that bacteria will develop resistance and will not be treatable by FLAGYL or other antibacterial drugs in the future. Laboratory tests FLAGYL (metronidazole) is a nitroimidazole and should be used with caution in patients with evidence of, or history of, blood dyscrasia. A mild leukopenia has been observed during its administration; however, no persistent hematologic abnormalities attributable to metronidazole have been observed in clinical studies. Total and differential leukocyte counts are recommended before and after therapy for trichomoniasis and amebiasis, especially if a second course of therapy is necessary, and before and after therapy for anaerobic infections. Drug interactions Metronidazole has been reported to potentiate the anticoagulant effect of warfarin and other oral coumarin anticoagulants, resulting in a prolongation of prothrombin time. This possible drug interaction should be considered when FLAGYL (metronidazole) is prescribed for patients on this type of anticoagulant therapy. The simultaneous administration of drugs that induce microsomal liver enzymes, such as phenytoin or phenobarbital, may accelerate the elimination of metronidazole, resulting in reduced plasma levels; impaired clearance of phenytoin has also been reported. The simultaneous administration of drugs that decrease microsomal liver enzyme activity, such as cimetidine, may prolong the half-life and decrease plasma clearance of metronidazole. In patients stabilized on relatively high doses of lithium, short-term FLAGYL therapy has been associated with elevation of serum lithium and, in a few cases, signs of lithium toxicity. Serum lithium and serum creatinine levels should be obtained several days after beginning metronidazole to detect any increase that may precede clinical symptoms of lithium intoxication. Alcoholic beverages should not be consumed during FLAGYL therapy and for at least one day afterward because abdominal cramps, nausea, vomiting, headaches, and flushing may occur. Psychotic reactions have been reported in alcoholic patients who are using metronidazole and disulfiram concurrently. Metronidazole should not be given to patients who have taken disulfiram within the last two weeks. Drug/Laboratory test interactions Metronidazole may interfere with certain types of determinations of serum chemistry values, such as aspartate aminotransferase (AST, SGOT), alanine aminotransferase (ALT, SGPT), lactate dehydrogenase (LDH), triglycerides, and hexokinase glucose. Values of zero may be observed. All of the assays in which interference has been reported involve enzymatic coupling of the assay to oxidation-reduction of nicotinamide adenine dinucleotide (NAD+ NADH). Interference is due to the similarity in absorbance peaks of NADH (340 nm) and metronidazole (322 nm) at pH 7. Carcinogenesis, mutagenesis, impairment of fertility Metronidazole has shown evidence of carcinogenic activity in a number of studies involving chronic, oral administration in mice and rats. Prominent among the effects in the mouse was the promotion of pulmonary tumorigenesis. This has been observed in all six reported studies in that species, including one study in which the animals were dosed on an intermittent schedule (administration during every fourth week only). At very high dose levels (approx. 500 mg/kg/day, which is approximately 33 times the most frequently recommended human dose for a 50 kg adult based on mg/kg body weight), there was a statistically significant increase in the incidence of malignant liver tumors in males. Also, the published results of one of the mouse studies indicate an increase in the incidence of malignant lymphomas as well as pulmonary neoplasms associated with lifetime feeding of the drug. All these effects are statistically significant. Several long-term, oral-dosing studies in the rat have been completed. There were statistically significant increases in the incidence of various neoplasms, particularly in mammary and hepatic tumors, among female rats administered metronidazole over those noted in the concurrent female control groups. Two lifetime tumorigenicity studies in hamsters have been performed and reported to be negative. Although metronidazole has shown mutagenic activity in a number of in vitro assay systems, studies in mammals (in vivo) have failed to demonstrate a potential for genetic damage. Fertility studies have been performed in mice at doses up to six times the maximum recommended human dose based on mg/m2 and have revealed no evidence of impaired fertility. Pregnancy Teratogenic Effects Pregnancy Category B Metronidazole crosses the placental barrier and enters the fetal circulation rapidly. Reproduction studies have been performed in rats at doses up to five times the human dose and have revealed no evidence of impaired fertility or harm to the fetus due to metronidazole. No fetotoxicity was observed when metronidazole was administered orally to pregnant mice at 20 mg/kg/day, approximately one and a half times the most frequently recommended human dose (750 mg/day) based on mg/kg body weight; however, in a single small study where the drug was administered intraperitoneally, some intrauterine deaths were observed. The relationship of these findings to the drug is unknown. There are, however, no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, and because metronidazole is a carcinogen in rodents, this drug should be used during pregnancy only if clearly needed. Use of FLAGYL for trichomoniasis during pregnancy should be restricted to those for whom alternative treatment has been inadequate. Use of FLAGYL (metronidazole) for trichomoniasis in pregnancy should be carefully evaluated because metronidazole crosses the placental barrier and its effects on the human fetal organogenesis are not known (see above). Nursing mothers Because of the potential for tumorigenicity, shown for metronidazole in mouse and rat studies, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother. Metronidazole is secreted in human milk in concentrations similar to those found in plasma. Geriatric use Decreased renal function does not alter the single-dose pharmacokinetics of metronidazole. However, plasma clearance of metronidazole is decreased in patients with decreased liver function. Therefore, in elderly patients, monitoring of serum levels may be necessary to adjust the metronidazole dosage accordingly. Pediatric use Safety and effectiveness in pediatric patients have not been established, except for the treatment of amebiasis. ADVERSE REACTIONS The most serious adverse reactions reported in patients treated with FLAGYL (metronidazole) have been convulsive seizures, encephalopathy, aseptic meningitis, optic and peripheral neuropathy, the latter characterized mainly by numbness or paresthesia of an extremity. Since persistent peripheral neuropathy has been reported in some patients receiving prolonged administration of FLAGYL, patients should be specifically warned about these reactions and should be told to stop the drug and report immediately to their physicians if any neurologic symptoms occur. The most common adverse reactions reported have been referable to the gastrointestinal tract, particularly nausea reported by about 12% of patients, sometimes accompanied by headache, anorexia, and occasionally vomiting; diarrhea; epigastric distress; and abdominal cramping. Constipation has also been reported. The following reactions have also been reported during treatment with FLAGYL (metronidazole): Mouth: A sharp, unpleasant metallic taste is not unusual. Furry tongue, glossitis, and stomatitis have occurred; these may be associated with a sudden overgrowth of Candida which may occur during therapy. Hematopoietic: Reversible neutropenia (leukopenia); rarely, reversible thrombocytopenia. Cardiovascular: Flattening of the T-wave may be seen in electrocardiographic tracings. Central Nervous System: Encephalopathy, aseptic meningitis, convulsive seizures, optic neuropathy, peripheral neuropathy, dizziness, vertigo, incoordination, ataxia, confusion, dysarthria, irritability, depression, weakness, and insomnia. Hypersensitivity: Urticaria, erythematous rash, Stevens-Johnson Syndrome, toxic epidermal necrolysis, flushing, nasal congestion, dryness of the mouth (or vagina or vulva), and fever. Renal: Dysuria, cystitis, polyuria, incontinence, and a sense of pelvic pressure. Instances of darkened urine have been reported by approximately one patient in 100,000. Although the pigment which is probably responsible for this phenomenon has not been positively identified, it is almost certainly a metabolite of metronidazole and seems to have no clinical significance. Other: Proliferation of Candida in the vagina, dyspareunia, decrease of libido, proctitis, and fleeting joint pains sometimes resembling "serum sickness." If patients receiving FLAGYL drink alcoholic beverages, they may experience abdominal distress, nausea, vomiting, flushing, or headache. A modification of the taste of alcoholic beverages has also been reported. Rare cases of pancreatitis, which generally abated on withdrawal of the drug, have been reported. Crohn's disease patients are known to have an increased incidence of gastrointestinal and certain extraintestinal cancers. There have been some reports in the medical literature of breast and colon cancer in Crohn's disease patients who have been treated with metronidazole at high doses for extended periods of time. A cause and effect relationship has not been established. Crohn's disease is not an approved indication for FLAGYL. OVERDOSAGE Single oral doses of metronidazole, up to 15 g, have been reported in suicide attempts and accidental overdoses. Symptoms reported include nausea, vomiting, and ataxia. Oral metronidazole has been studied as a radiation sensitizer in the treatment of malignant tumors. Neurotoxic effects, including seizures and peripheral neuropathy, have been reported after 5 to 7 days of doses of 6 to 10.4 g every other day. Treatment There is no specific antidote for FLAGYL overdose; therefore, management of the patient should consist of symptomatic and supportive therapy. DOSAGE AND ADMINISTRATION In elderly patients, the pharmacokinetics of metronidazole may be altered, and, therefore, monitoring of serum levels may be necessary to adjust the metronidazole dosage accordingly. Trichomoniasis In the Female One-day treatment − two grams of FLAGYL, given either as a single dose or in two divided doses of one gram each, given in the same day. Seven-day course of treatment − 250 mg three times daily for seven consecutive days. There is some indication from controlled comparative studies that cure rates as determined by vaginal smears and signs and symptoms, may be higher after a seven-day course of treatment than after a one-day treatment regimen. The dosage regimen should be individualized. Single-dose treatment can assure compliance, especially if administered under supervision, in those patients who cannot be relied on to continue the seven-day regimen. A seven-day course of treatment may minimize reinfection by protecting the patient long enough for the sexual contacts to obtain appropriate treatment. Furthermore, some patients may tolerate one treatment regimen better than the other. Pregnant patients should not be treated during the first trimester. (See CONTRAINDICATIONS). In pregnant patients for whom alternative treatment has been inadequate, the one-day course of therapy should not be used, as it results in higher serum levels which can reach the fetal circulation (see PRECAUTIONS- Pregnancy). When repeat courses of the drug are required, it is recommended that an interval of four to six weeks elapse between courses and that the presence of the trichomonad be reconfirmed by appropriate laboratory measures. Total and differential leukocyte counts should be made before and after re-treatment. In the Male Treatment should be individualized as it is for the female. Amebiasis Adults For acute intestinal amebiasis (acute amebic dysentery): 750 mg orally three times daily for 5 to 10 days. For amebic liver abscess: 500 mg or 750 mg orally three times daily for 5 to 10 days. Pediatric patients 35 to 50 mg/kg/24 hours, divided into three doses, orally for 10 days. Anaerobic Bacterial Infections In the treatment of most serious anaerobic infections, FLAGYL I.V. (metronidazole hydrochloride) or FLAGYL I.V. RTU® (metronidazole) is usually administered initially. The usual adult oral dosage is 7.5 mg/kg every six hours (approx. 500 mg for a 70-kg adult). A maximum of 4 g should not be exceeded during a 24-hour period. The usual duration of therapy is 7 to 10 days; however, infections of the bone and joint, lower respiratory tract, and endocardium may require longer treatment. Patients with severe hepatic disease metabolize metronidazole slowly, with resultant accumulation of metronidazole and its metabolites in the plasma. Accordingly, for such patients, doses below those usually recommended should be administered cautiously. Close monitoring of plasma metronidazole levels2 and toxicity is recommended. The dose of FLAGYL should not be specifically reduced in anuric patients since accumulated metabolites may be rapidly removed by dialysis. HOW SUPPLIED FLAGYL 250-mg tablets are round, blue, film coated, with SEARLE and 1831 debossed on one side and FLAGYL and 250 on the other side; supplied as bottles of 50 and 100. NDC Number Size 25-1831-50 bottle of 50 25-1831-31 bottle of 100 FLAGYL 500-mg tablets are oblong, blue, film coated, with FLAGYL debossed on one side and 500 on the other side; bottles of 50 and 100. NDC Number Size 25-1821-50 bottle of 50 25-1821-31 bottle of 100 Storage and Stability Store below 77°F (25°C) and protect from light. https://dailymed.nlm.nih.gov/dailymed/archives/fdaDrugInfo.cfm?archiveid=49998