Concentrations of tinidazole and metronidazole in serum, saliva and alveolar bone

Comparative In Vitro Resistance of Human Periodontal Bacterial Pathogens to Tinidazole and Four Other Antibiotics

The in vitro resistance of selected red/orange complex periodontal pathogens to tinidazole was compared with four other antibiotics. Subgingival biofilm samples from 88 adults with severe periodontitis were anaerobically incubated on enriched Brucella blood agar with and without supplementation with tinidazole (16 mg/L), metronidazole (16 mg/L), amoxicillin (8 mg/L), doxycycline (4 mg/L), or clindamycin (4 mg/L). Growth of Porphyromonas gingivalis, Tannerella forsythia, Prevotella intermedia/nigrescens, Parvimonas micra, Fusobacterium nucleatum, Streptococcus constellatus, or Campylobacter rectus on antibiotic-supplemented plates indicated their in vitro antibiotic resistance. Tinidazole inhibited all test species, except P. intermedia/nigrescens, P. micra, and S. constellatus in 3.8%, 10.2%, and 88.9% of species-positive patients, respectively. Significantly fewer patients yielded tinidazole-resistant test species, and had significantly lower subgingival proportions of tinidazole-resistant organisms, than patients with amoxicillin, doxycycline, or clindamycin-resistant species, but not those with metronidazole-resistant strains. Joint in vitro species resistance to tinidazole and amoxicillin, or metronidazole and amoxicillin, was rare. Tinidazole performed in vitro similar to metronidazole, and markedly better than amoxicillin, doxycycline, or clindamycin, against fresh clinical isolates of red/orange complex periodontal pathogens. As a result of its similar antimicrobial spectrum, and more convenient once-a-day oral dosing, tinidazole should be considered in place of metronidazole for systemic periodontitis drug therapy.

Oral health status and oral hygiene practices of patients with peptic ulcer and how these affect Helicobacter pylori eradication from the stomach

BACKGROUND

Helicobacter pylori eradication from the oral cavity is more difficult than from the stomach. Thus, if the bacterium survives the antibacterial therapy in the oral cavity, it would be able to re-infect the stomach within a few weeks. Since oral health status could correspond to oral infection with H. pylori, the aim of the study was to determine whether oral health and oral hygiene practices affect the efficacy of H. pylori eradication from the stomach.

MATERIAL AND METHODS

The study was performed in 137 patients with peptic ulcer who had undergone a 7-day course of eradication treatment with one of two sets of drugs: 1, omeprazole, amoxicillin, and tinidazole or 2, omeprazole, clarithromycin, and tinidazole. The efficacy of H. pylori eradication from the stomach was evaluated at the second gastroscopy 4 weeks after cessation of eradication therapy by means of two methods: rapid urease test and histology. The examination of natural dentition and prosthetic restorations as well as the assessment of hygienic procedures referring to natural dentition and dentures accompanied the second gastroscopy.

RESULTS

No association was found between the efficacy of H. pylori eradication from the stomach and the number of natural teeth, decayed teeth, use of dentures, debris index, or periodontal index. However, an association between eradication success and some oral hygiene procedures were noted. Unexpectedly, in patients treated with omeprazole, amoxicillin and tinidazole, the removal of dental prosthesis for the night and brushing the natural teeth twice a day or more reduced the efficacy of H. pylori eradication from the stomach.

CONCLUSIONS

Oral health and oral hygiene practices seem unlikely to increase the efficacy of H. pylori eradication from the stomach.

Tinidazole: a nitroimidazole antiprotozoal agent

BACKGROUND

Tinidazole, a structural analogue of metrondazole, is an antiprotozoal agent that has been widely used in Europe and developing countries for >2 decades with established efficacy and acceptable tolerability. It was recently approved by the US Food and Drug Administration for the treatment of trichomoniasis, giardiasis, amebiasis, and amebic liver abscess.

OBJECTIVE

This article reviews the pharmacologic and pharmacokinetic properties and clinical usefulness of tinidazole.

METHODS

Relevant information was identified through a search of MEDLINE (1966-August 2005), Iowa Drug Information Service (1966-August 2005), and International Pharmaceutical Abstracts (1970-August 2005) using the terms tinidazole, Fasigyn, and nitroimidazole.

RESULTS

In vitro, tinidazole exhibits activity against pathogenic protozoa (eg, Tricbomonas vaginalis, Entamoeba bistolytica, Giardia duodenalis), a wide range of clinically significant anaerobic bacteria (eg, Bacteroides fragilis, Clostridium difficile), and the microaerophilic bacterium Helicobacter pylori. In susceptible protozoal and bacterial cells, tinidazole is reduced to cytotoxic intermediates that covalently bind to DNA, causing irreversible damage. In human adults, tinidazole had a bioavailability of 100% and a V(d) of 50.7 L, was minimally bound to plasma protein (12%), had a plasma elimination t((1/2)) of 12.3 hours, and was eliminated primarily by hepatic metabolism (approximately 63%). Dose adjustment does not appear to be necessary on the basis of race, sex, or renal function. No data were found on the disposition of tinidazole in patients with hepatic insufficiency; therefore, use of tinidazole in patients with severe hepatic impairment (Child-Pugh class C) is not recommended. Clinical cure rates in patients with trichomoniasis, giardiasis, amebiasis, and amebic liver abscess were generally >90%. In comparative trials, tinidazole was as effective as metronidazole in the treatment of trichomoniasis and was significantly more effective than metronidazole in the treatment of giardiasis (P < 0.05) and amebiasis (P < 0.05). The most commonly reported (>1%) adverse effects included bitter taste, nausea, abdominal discomfort, anorexia, vomiting, and fatigue. The recommended dosage of tinidazole is a single dose of 2 g for trichomoniasis and giardiasis, and 2 g/d for 3 to 5 days for amebiasis.

CONCLUSIONS

Tinidazole appears to be a promising agent for the treatment of trichomoniasis, giardiasis, amebiasis, and amebic liver abscess. Clinical studies are needed to evaluate the use of tinidazole against anaerobic bacteria and H pylori.

Effect of antibacterial therapy and salivary secretion on the efficacy of Helicobacter pylori eradication in duodenal ulcer patients

OBJECTIVE

Oral health status may play a role in Helicobacter pylori eradication. Because adequate secretion of saliva promotes oral health, the aim of the study was to assess the effect of salivary secretion on the efficacy of H pylori eradication from the stomach.

STUDY DESIGN

The study involved 90 H pylori-positive subjects with duodenal ulcer (68 men, 22 women, aged 20-70 years) in whom saliva was collected under basal conditions for 45 min before antibacterial treatment began. They received no drugs for at least 3 days prior to saliva collection. A 7-day course of either of 2 eradication regimens--omeprazole, amoxicillin, and tinidazole (OAT); or omeprazole, amoxicillin, and clarithromycin (OAC)--was used. The efficacy of eradication therapy was evaluated 30 days after its completion.

RESULTS

The efficacy of H pylori eradication from the stomach (per protocol analysis) was 77.5% in the group of subjects treated with OAT and 81.6% with OAC. Combined analysis of both groups (OAT+OAC) showed reduced salivary secretion in subjects with eradication failure (0.395 +/- 0.266 vs 0.25 +/- 0.176 mL/min, P=.042). A similar outcome was obtained when the OAT group was analyzed separately (0.436 +/- 0.316 vs 0.211 +/- 0.216 mL/min, P=.022), but in the OAC group the difference was not significant. In the combined analysis, the efficacy of eradication therapy was lower in women than in men (52.9% vs 86.9%, P=.005). In women, it corresponded to salivary secretion (successful eradication 0.337 +/- 0.133 mL/min, unsuccessful eradication 0.180 +/- 0.144 mL/min, P=.043); whereas in men, the difference was not significant (successful eradication 0.405 +/- 0.282 mL/min, unsuccessful eradication 0.321 +/- 0.186 mL/min).

CONCLUSION

Low salivary secretion may contribute to the decrease in efficacy of H pylori eradication from the stomach, at least in subjects treated with certain drug regimens.

Role of antimicrobials in third molar surgery: prospective, double blind,randomized, placebo-controlled clinical study

AIM

To test the efficacy of two dosing regimens of antimicrobial prophylaxis during the removal of impacted lower third molars.

DESIGN

Double blind, prospective, placebo-controlled trial.

SETTING

Teaching hospital, India.

SUBJECTS

151 patients aged 19-36 having impacted lower third molars removed.

METHODS

Random allocation into three groups: placebo (n= 34), metronidazole 1g orally, 1 hour preoperatively (n= 44), or metronidazole 400mg orally eight hourly for 5 days postoperatively (n= 47). Patients were recalled on the sixth postoperative day for assessment of pain scores on the second and sixth days, swelling, differences in mouth opening between preoperative and the sixth postoperative day, and the state of the wound.

RESULTS

There were no significant differences in the outcome between the three groups (P= 0.09).

CONCLUSION

Antimicrobial prophylaxis does not seem to reduce morbidity after removal of lower third molars.

Concentrations of tinidazole in gingival crevicular fluid and plasma in dogs after multiple dose administration

Tinidazole 15 mg/kg was administered to eight Beagle dogs with gingivitis or periodontitis twice daily for 3 days. Tinidazole concentrations in blood and gingival crevicular fluid (GCF) were measured 1, 3, 6 and 9 h after the morning dose each day. The concentration of tinidazole was determined by high performance liquid chromatography (HPLC). The mean concentration of tinidazole in GCF for each dog ranged from 6.05 to 9.32 micrograms/mL at different time points after the first dose, and on the first day the highest concentration was observed 6 h after the drug administration. Tinidazole concentrations were 34 +/- 4%-72 +/- 9% (mean +/- SEM) of simultaneous plasma concentration. At steady-state, on the third treatment day, the mean tinidazole concentrations in GCF ranged from 6.68 to 13.1 micrograms/mL, i.e. 44 +/- 6%-75 +/- 25% of the corresponding concentrations in plasma. Tinidazole concentration in GCF exceeded the MIC values for putative path-ogenic periodontal bacteria and it is concluded that, when indicated, tinidazole could be used for chemotherapy of periodontitis in dogs.

Does metronidazole prevent alveolitis sicca dolorosa? A double-blind, placebo-controlled clinical study

The effect of a single preoperative dose of metronidazole in the prevention of alveolitis sicca dolorosa (ASD) after surgical removal of one impacted, non-infected mandibular third molar was investigated. A patient sample of 270 were given either 1000 mg of metronidazole or placebo at least 30 min before surgery. The preoperative recordings included gender, age, tooth to be removed, experience of surgeon, time of test medication, and duration of surgery. No difference was found between the metronidazole and placebo groups in the occurrence of ASD. The duration of surgery and the experience of the operating surgeons had no effect on the occurrence of ASD. The present study failed to demonstrate any preventive effect of a single dose of metronidazole on the development of ASD.

Penetration of tinidazole into the gingival crevicular fluid in dogs

Tinidazole was administered as a single oral dose of 15 mg kg-1 to 12 dogs, and its concentration in the plasma and gingival crevicular fluid (GCF) was measured at one and two hours by high performance liquid chromatography. Tinidazole was detectable in GCF in five dogs at one hour (6.8 +/- 2.6 micrograms ml-1) and in six dogs at two hours (9.2 +/- 1.4 micrograms ml-1) and in all plasma samples. In those animals with no detectable tinidazole in GCF, either the concentration of tinidazole in plasma was low or the volume of the GCF sample was insufficient for determination. The observed tinidazole levels in GCF exceeded the minimal inhibitory concentration values for most anaerobic oral bacteria.

Pharmacokinetics of tinidazole in dogs and cats

Pharmacokinetics of tinidazole in dogs and cats after single intravenous (15 mg/kg) and oral doses (15 mg/kg or 30 mg/kg) were studied in a randomized crossover study. Tinidazole was completely absorbed at both oral dose levels in cats and dogs. Peak tinidazole concentration in plasma was 17.8 micrograms/ml in dogs and 22.5 micrograms/ml in cats after 15 mg/kg p.o. The oral dose of 30 mg/kg resulted in peak levels of 37.9 micrograms/ml in dogs and 33.6 micrograms/ml in cats. The apparent total plasma clearance of the drug was about twofold higher in dogs than in cats, resulting in an elimination half-life that was twice as long in cats (8.4 h) as in dogs (4.4 h). The apparent volume of distribution was 663 ml/kg in dogs and 536 ml/kg in cats. Therapeutic plasma drug concentrations higher than the MIC values of most tinidazole-sensitive bacteria were achieved for 24 h in cats and for 12 h in dogs after a single oral dose of 15 mg/kg. From the pharmacokinetic standpoint tinidazole seems to be well-suited to clinical use in small animal practice.

Single-dose concentrations of tinidazole in gingival crevicular fluid, serum, and gingival tissue in adults with periodontitis

Previous studies have shown that metronidazole is effective in the treatment of subgingival microflora associated with destructive periodontitis. The aim of this study was to determine whether tinidazole, a close analogue of metronidazole, would reach sufficient concentrations in serum, gingival crevicular fluid, and gingival tissue, to inhibit putative periodontopathic bacteria. Ten adult patients with moderate to advanced periodontitis took a single 2-g dose of tinidazole orally. Samples were assayed by high-performance liquid chromatography. The concentrations of tinidazole in serum and GCF were in a similar range (3.2-46.5 micrograms/mL). Tinidazole was not detected in the GCF in three of the patients. The drug was found in gingival tissue obtained at two h (0.17 +/- 0.14 micrograms/mg) and six h (0.15 +/- 0.18 micrograms/mg) after oral administration. The mean concentration of tinidazole in serum at 24 h (13 +/- 3.0 micrograms/mL) is greater than the minimum inhibitory concentration for anaerobic bacteria as reported by others. The present data suggest that a single 2-g oral dose of tinidazole may lead to the presence of potentially bactericidal levels of tinidazole for up to 24 h in the periodontal pockets of some patients with periodontitis.

Selective suppression of the anaerobic oropharyngeal microflora with local metronidazole

Anaerobic microorganisms of the normal oropharyngeal flora have been shown to be the main pathogens in orofacial infections of odontogenic origin. Reduction of the density of anaerobes in the oral cavity as a prophylactic measure before oral surgery may be a rational way to reduce the frequency of post-operative infections. This report describes a local antibiotic regimen that can reduce anaerobic pathogens in the oral cavity. Over a period of 7 days, 10 healthy individuals applied locally 1.5-2 g of an antibiotic preparation consisting of 0.5% metronidazole in 99.5% Orabase paste three times daily. The paste had antibacterial activity against obligate anaerobic micro-organisms such as bacteroides, fusobacteria and leptotrichia, known pathogens in orofacial infections. Fusobacteria and leptotrichia were eliminated in all subjects. Bacteroides species were eliminated in five subjects and significantly decreased in three subjects. The aerobic microflora was not affected. No new colonisation of the oropharynx was observed during the treatment period. The pre-treatment numbers of different micro-organisms were re-established within 2-9 days after the withdrawal of metronidazole treatment.

Burning mouth sensation associated with fusospirochetal infection in edentulous patients

Six middle-aged and elderly edentulous, systemically ill patients complaining of burning mouth sensation had a fusospirochetal infection of the oral mucosa. Metronidazole was successful in the treatment of three of these patients.

Postoperative complications after surgical removal of mandibular third molars. Effects of penicillin V and chlorhexidine

A random material of 112 patients, was investigated after surgical removal of impacted lower third molars. 2 experimental groups and 1 control group were studied. Prophylactic medication with penicillin V combined with preoperative rinsing using 0.2% chlorhexidine gluconate (Hibitane) was found to reduce postoperative symptoms, when compared with preoperative rinsing alone. In both cases, patients were compared with the control group.

Concentrations of metronidazole and tinidazole in female reproductive organs after a single intravenous infusion and after repeated oral administration

Concentrations of metronidazole and tinidazole in serum and gynecological organs were analyzed after a single 500 mg intravenous infusion and after three days of treatment with 400 mg t.i.d. of metronidazole or 500 mg b.i.d. of tinidazole. The studies were performed in 67 patients subjected to hysterectomy and/or oophorectomy because of myomatosis uteri, carcinoma uteri or endometriosis. At the time of organ removal (about 30 min after infusion), metronidazole and tinidazole levels in serum were 14.5 +/- 0.45 mg/l and 12.3 +/- 0.38 mg/l, respectively. Concentrations of both drugs in the uterus and Fallopian tube were about the same as the simultaneous serum levels and concentrations in the ovaries about 55% thereof. At steady-state, the concentrations of tinidazole in serum (23.5 +/- 1.0 mg/l) were remarkably higher than those of metronidazole (13.5 +/- 0.84 mg/l) about three hours after the last oral dose. Drug concentrations in organs of the female reproductive tract were 70 to 100% those of the simultaneous serum levels.