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At least 19 recordsLinked to original sources
PubMed1977

[Doxycycline levels in serum and pulmonary tissue. Intravenous application of doxycycline in pulmonary surgery (author's transl)].

Doxycycline levels were measured fluorimetrically in the serum and pulmonary tissue of 36 patients undergoing a pulmonary operation. Doxycycline 200 mg was given intravenously 20 hours before operation. The doxycycline concentration in pulmonary tissue (1.03 to 12.30 mug/g) were as high or higher than the serum doxycycline levels (0.94 to 7.82 mug/ml) in the majority of cases. This is possible as the lung has an ample blood supply and doxycycline is a lipophilic drug. There were large variations in the results, which was probably related to the underlying illness and to an altered blood circulation. The side effects were minimal. The daily infusions of doxycycline were continued over 5 days, no conclusions could be drawn about its possible prophylactic effect on postoperative infections.

Adolescent↗
PubMed1976

Doxycycline concentration levels in bone, soft tissue and serum after intravenous infusion of doxycycline. A clinical study.

As part of a longitudinal study, the influence of preoperative single dose doxycycline treatment on the overall incidence of early postoperative wound infections in orthopaedic surgery, 34 patients with various fractures were given an intravenous infusion of doxycycline 2-4 hours before the operation. The serum concentrations of doxycycline were determined on specimens taken during the operation and on 4 other occasions, the last being 48 hours after operation. All patients except 4 had serum concentration levels of 0.4 mug per ml or above at 48 hours. During the operation, specimens of skin, subcutaneous tissue, muscle and bone were also taken. The doxycycline concentrations were determined in the various tissues and correlated to the concomitant serum concentration. The results were analysed with regard to the possible influence of preoperative single dose doxycycline treatment for prevention of early postoperative infections.

Adipose Tissue↗
PubMed1978

Systemic prophylaxis with doxycycline in surgery of the colon and rectum.

A prospective double-blind study on the effects of doxycycline as a prophylactic antimicrobial in elective colonic surgery is presented. One hundred-eighteen patients were evaluated. Fifty-eight were treated and 60 were controls. Two hundred milligrams, doxycycline or placebo (two capsules) were given orally four to six hours prior to surgery and 100 mg or placebo (one capsule) for five days postoperatively. Doxycycline levels in serum and tissues were determined and related to the MICvalues of the contaminants of the operative field. A significantly lower incidence of abdominal wound sepsis, intra-abdominal complications, and septicemia was recorded in the doxycycline group compared to the control group, 12.1 and 45% respectively. The prophylactic effect was most pronounced in patients with a negative wound culture upon closure. Macroscopical peritoneal contamination was associated with less severe consequencies in the doxycycline group. Infections in the perineal field, 3/15 vs 8/17, appeared alone in the doxycycline group, whereas they were combined with abdominal sepsis in 6/8 among the controls. Treatment also reduced the incidence of repeat laparotomy due to septic complications, 0 vs 8. Thus systemic per and postoperative prophylaxis with doxycycline significantly reduced both the incidence and the severity of postoperative sepsis in potentially contaminated elective colorectal surgery without any adverse reactions.

Administration, Oral↗
PubMed1976

Effects of doxycycline in actively purging cholera patients: a double-blind clinical trial.

In 51 actively purging cholera patients the efficacy of doxycycline, a long-acting tetracycline, was compared with a placebo and tetracycline hydrochloride. Seventeen patients who were given doxycycline at the recommended dose of 2 mg/kg at the beginning of the study, at 12 h, and at the repeated dose once daily purged a mean volume of 5.1 liters of stool and received an average of 5.7 liters of intravenous fluid. Nineteen patients receiving the placebo purged 10.1 liters of stool and received 9.7 liters of fluid. Fifteen patients given tetracycline hydrochloride at 6-h intervals passed 4.8 liters of stool and received 5.5 liters of fluid. The durations of diarrhea calculated in 8-h periods were 3.5, 8.0, and 4.1 h in the respective groups receiving doxycycline, placebo, and tetracycline. The differences between the doxycycline and placebo treatments and the tetracycline and placebo treatments were statistically significant. Those receiving doxycycline became vibrio-free in about 3 days as compared with 2 days for those receiving tetracycline; the group given the placebo were vibrio positive for the duration of their hospitalization. The results show that in the treatment of cholera the administration of doxycycline once daily has effects equal to those when tetracycline is administered at 6-h intervals. This is a distinct advantage because it decreases the demand on nursing personnel in epidemics. Also, doxycycline may be safely administered in cases of suspected renal failure from prolonged shock in cholera.

Cholera↗
PubMed1975

Comparison of oral ampicillin and doxycycline in the treatment of uncomplicated gonorrhoea.

An account is given of a computer-processed 1-year study comprising 1,124 patients (625 males and 499 females) with uncomplicated gonorrhoea. Alternate patients were treated with either two oral doses of 1 g. ampicillin 5 hours apart, or 0.3 g. doxycycline in a single oral dose. Ampicillin remained as efficacious as in 1968 to 1970, in both males and females, in whom the failure rates were 1.1 and 1 per cent. respectively. After doxycycline the failure rate was 8.1 per cent. in males, 5.7 per cent. in females, and 7.1 per cent. overall. Ampicillin was significantly better than doxycycline in the treatment of men (P less than 0.001) as well as of women (0.05 greater than P greater than 0.01). 89.7 per cent. (29/29) of the relapses in doxycycline-treated patients occurred in those harbouring strains sensitive to tetracycline. Sensitivity to doxycycline followed the pattern of tetracycline sensitivity. Thus sensitivity tests with these antibiotics provided no practical aid to therapy. The high incidence of nausea and vomiting in patients treated with doxycycline (12 per cent.) makes it inadvisable to increase the dose; instead, multiple doses are necessary to obtain satisfactory results. There were very few adverse reactions to ampicillin; a rash occurred in only three patients (0.5 per cent.). In the group treated with doxycycline, 31.5 per cent. of the patients infected by streptomycin-resistant strains relapsed compared with only 1.8 per cent. of patients infected by streptomycin-sensitive strains. This difference is highly significant (P less than 0.001). Thus the sensitivity of gonococcal strains to streptomycin in vitro may serve as a valuable guide to the likely outcome of treatment with tetracyclines.

Administration, Oral↗
PubMed1976

Systemic prophylaxis with doxycycline in surgery of the colon and rectum.

A prospective randomized double-blind study on the effects of doxycycline as prophylactic antibiotic in elective colonic surgery is presented. 82 patients were evaluated. 39 were treated and 43 were controls. Mechanical cleansing of the bowel and a low residue diet for two days was routine. 200 mg doxycycline or placebo (2 capsules) were given orally 4-6 hours preoperatively and 100 mg (1 capsule) for 5 postoperative days. A significantly lower incidence of wound sepsis, intraabdominal complications and septicemia was registered in the doxycycline compared to the control group, 12.8 and 44.2 per cent respectively. After proctectomies, infections in the perineal field occurred in 3/9 and 5/10 cases in respective groups. In the doxycycline group, however, they were the only complication, whereas among the controls they were generally combined with infections in the abdominal field, 4/5. Peroperative contamination seemed to carry easier consequences in the doxycycline group. The results are discussed further. Doxycycline appears to be an excellent antibiotic for peroperative and short postoperative prophylactic use in potentially contaminated abdominal operations, not only because of its observed effects, but also when its negligible tendency to cause adverse reactions is taken into consideration. Bacterial cultures, concentrations of doxycycline in serum and tissues and their relation to infections will be accounted for and discussed in a separate paper.

Bacteriological Techniques↗
PubMed1979

Solubility of doxycycline in aqueous solution.

The solubility of doxycyline monohydrate and doxycycline hydrochloride dihydrate was investigated in aqueous solution. The hydrochloride dihydrate salt was isolated and identified from solutions initially containing doxycycline hyclate in water. The pKa' = 3.09 (mu = 0.1 and 25 degrees) for protonation of doxycycline was determined spectrophotometrically. The pH-solubility profiles were determined for doxycycline monohydrate in water and in 1.0 M NaNO3-HNO3 and NaCl-HCl. The pH-solubility profile at 25 degrees for doxycycline in aqueous hydrochloric acid without added salt reached a sharp maximum fo 50 mg/ml at pH 2.16. Added chloride ion strongly suppressed the solubility of the hydrochloride dihydrate salt. The apparent solubility product was not constant but decreased as the concentration of added salt increased. A theoretical model was developed involving dimerization of doxycycline and applied to the experimental data. The dimerization constant, Kd = 24 M-1, and true solubility product, K0sp = 1.8 X 10(-3) M2, were calculated. The effect of concentration on NMR and visible spectra indicated that dimerization resulted from intermolecular hydrogen bonding of the phenolic beta-diketone portion of the molecule.

Doxycycline↗
PubMed1978

Prophylactic doxycycline for travelers' diarrhea. Results of a prospective double-blind study of Peace Corps volunteers in Kenya.

We performed a randomized double-blind study to determine the efficacy of doxycycline (100 mg daily) in preventing travelers' diarrhea among 39 Peace Corps volunteers during their first five weeks in Kenya. The volunteers took either doxycycline or placebo for three weeks and were observed for an additional two weeks. Nine of 21 taking placebo and one of 18 taking doxycycline had travelers' diarrhea during the treatment period (P = 0.012). The protection seemed to persist for at least one week after the drug was stopped. Enterotoxigenic Escherichia coli was the only pathogen isolated from the placebo group, but was not detected in persons taking doxycycline. None of these organisms were resistant to doxycycline or tetracycline, whereas resistance to tetracyclines and other antibiotics was common among the nonenterotoxigenic Esch. coli. We conclude that doxycycline effectively prevented most episodes of travelers' dirrhea.

Adult↗
PubMed1976

Doxycycline in the treatment of cholera.

Doxycycline was compared with tetracycline in the treatment of cholera. Four types of treatment were compared: Group A was given 200 mg of doxycycline on admission and 100 mg on the second day; Group B was given 200 mg of doxycycline on admission only; Group C was given 300 mg of doxycycline on admission only; and Group D received 500 mg of tetracycline every 6 h for 48 h. Tetracycline showed a slight advantage in respect of duration of diarrhoea and vibrio excretion compared with doxycycline given as a single dose of 300 mg, but fluid intake and output were about the same in these two groups. The other two doxycycline treatment schedules did not compare well with tetracycline treatment.

Adolescent↗
PubMed1979

Prophylactic doxycycline for travelers' diarrhea: results of a prospective double-blind study of Peace Corps volunteers in Morocco.

A second randomized double-blind study to determine the efficacy of doxycycline, 100 mg daily, for the prevention of travelers' diarrhea was carried out among 50 Peace Corps Volunteers during their first 10 wk in Morocco. The volunteers took either doxycycline or placebo for 3 wk, and were observed for an additional 7 wk. Eleven of 24 taking the placebo and 2 of 26 taking doxycycline had travelers' diarrhea during the treatment period (P less than 0.01). One week after cessation of the doxycycline, however, persons in that group developed an increase in frequency of travelers' diarrhea (P less than 0.05) so that by 3 wk after the drug was stopped, there were no differences between groups. Enterotoxigenic E. coli, most of which were sensitive to doxycycline, were the most frequently isolated pathogens during the entire study. This study corroborates the effectiveness of doxycycline prophylaxis for travelers' diarrhea.

Adult↗
PubMed1977

Doxycycline in abdominal surgery.

Twenty patients undergoing urgent or emergency surgical procedures where intra-abdominal infection was suspected were treated with doxycycline hyclate. Wound infections involving anaerobic, aerobic, or facultative bacteria developed in four of 11 patients treated with doxycycline alone. Nine other patients received higher doses of doxycycline plus gentamicin sulfate. Five of these had postoperative infections primarily involving anaerobic organisms. Bacteremia with a doxycycline-resistant Bacteroides fragilis developed in one patient during therapy. Serum levels of doxycycline, even at the higher dosage, were below the minimal inhibitory concentrations (MICs) of a number of potential pathogens isolated at the time of surgery. Doxycycline is not indicated in cases of serious intra-abdominal infection unless the infecting flora are known to be susceptible.

Abdomen↗
PubMed1978

[On the circulation compatibility of doxycycline and rolitetracycline in conscious minipigs (author's transl)].

The effect of large doses of doxycycline (Vibravenös) and rolitetracycline on blood pressure, heart rate and ECG was investigated in 36 conscious minipigs. The antibiotics were infused into the v. tibialis at doses of 16, 24 and 32 mg/kg at injection periods of 4, 6 and 8 min. The dosage applied was about 10-20 times higher than the therapeutical single dose of doxycycline and about 4-8 times higher than the single dose of rolitetracycline. 16 mg doxycycline or rolitetracycline/kg resulted in a minor short-lasting increase of blood pressure and extension of the P-Q interval in the ECG. The definitely pathological P-Q value of 160 ms was not observed in any of the cases treated with doxycycline, whereas rotitetracycline led to clearly pathological P-Q values in 2/6 of the cases, and to AV block in 4/6 of the cases. Neither after doxycycline nor after rolitetracycline did the increased dose of 24 and 32 mg/kg result in an enhanced effect on circulation. However, both the blood pressure and the P-Q values following 32 mg rolitetracycline/kg significantly exceeded those following 32 mg doxycycline/kg. These trials suggest that with regard to circulatory tolerance there are no objections to increasing the usual therapeutical dose of intravenous doxycycline if the injection time is adequately extended.

Animals↗
PubMed1976

Microcalorimetry as a tool for evaluation of antibacterial effects of doxycycline and tetracycline.

The heat effects produced by a strain of Escherichia coli in the presence of doxycycline and tetracycline were determined by calorimetric measurements using batch and flow microcalorimeters of the heat-conduction type. There was a clear difference in the capacity of the two tetracyclines to suppress the metabolism of the test bacterium as indicated by the heat production registered. In the presence of doxycycline or tetracycline in a concentration of 0.4 mug/ml (half the minimum inhibitory concentration, MIC), the time interval between the start of the experiment and a heat production of 2 muW/ml was 4.5 h for tetracycline and 7.3 h for doxycycline. When the antibiotics, in a concentration of 1.6 mug/ml (2 X MIC), were added to the culture during the logarithmic growth phase, tetracycline depressed heat production much less than doxycycline. Almost immediately after the addition of the two tetracyclines studied, heat production decreased sharply. The heat production rose again 1 h after tetracycline had been added, but remained at a low level for at least 16 h after doxycycline.--The results suggest that there are differences in the kinetics of the antibacterial action of doxycycline and tetracycline. Microcalorimetric studies provide new information for determining antibacterial activities of antibiotics, information that cannot be obtained by means of conventional bacteriological techniques. Such studies might be of value for the establishment of optimal dose regimens.

Calorimetry↗
PubMed1977

Penetration of ocular compartments by tetracyclines. II. An experimental study with doxycycline.

Using radioactive tracer method the distribution of intravenously injected doxycycline of 7 mg/kg was studied in the rabbit eye. Long-lasting antibiotic concentration of 1 microgram/g or more was measured from all vascularized ocular structures. Vitreous body doxycycline concentration, almost equal to that of aqueous humor, was 0.3 microgram/g. Doxycycline concentration in the cornea exceeded that in the aqueous humor. In all vascularized ocular structures plasma antibiotic concentration was at least once achieved, indicating good penetrability of doxycycline into the tissues. This good penetrability is obviously related to the high lipoidsolubility of doxycycline, whereas its high protein binding is reflected in low concentrations in the aqueous humor.

Animals↗
PubMed1978

Single-dose doxycycline for cholera.

To determine the efficacy of single-dose doxycycline in the treatment of cholera, we carried out a randomized prospective trial in 65 patients. Treatment consisted of either a single dose of 200 mg of doxycycline (or 4 mg/kg in patients less than 15 years old) or multiple doses of doxycycline, 500 mg over 4 days (or 10 mg/kg in patients less than 15 years old). There were no differences between the groups in the volumes of intravenous fluid required, volumes of diarrheal stool, or durations of diarrhea. The mean duration of positive stool cultures for Vibrio cholerae was similar for the two groups, although in both groups several patients continued to excrete Vibrios in the stool for more than 3 days. Blood levels of antibiotic demonstrated that the doxycycline was absorbed in spite of the rapid transit time associated with severe diarrhea. These results suggest that although tetracycline remains the drug of choice for cholera, doxycycline is a reasonable alternative, and that a single dose of 200 mg (4 mg/kg in children) is effective clinically.

Adult↗
PubMed1976

Doxycycline in serum and bronchial secretions.

The concentration of doxycycline hydrochloride was measured in serum and bronchial secretions in five patients with chronic bronchitis receiving doxycycline orally in normal therapeutic dosage for seven days (200 mg day 1, 100 mg days 2 to 7). After the loading dose of 200 mg, serum concentrations ranged between 5-40 and 3-45 mug/ml (mean 4-33 mug/ml) at 3 hours, declining to between 2-28 and 1-21 mug/ml (mean 1-71 mug/ml) at 23 hours. The mean serum levels for days 2 to 7 were 2-15, 1-79, and 1-38 at 3, 8, and 23 hours respectively. There was considerable individual variability and a wide range of concentrations of doxycycline in the sputum (0-07 to 2-10 mug/ml, mean 0-34 mug/ml). During the course of treatment there was a progressive increase in sputum levels and sputum/serum concentration ratios. There was no correlation between sputum concentration and degree of purulence. The clinical efficacy of doxycycline does not appear to be related to sputum concentration, although the progressive increase in sputum doxycycline levels may be relevant in preventing recurrence of acute infection when the drug is administered as long-term prophylactic therapy.

Bacillus cereus↗
PubMed1975

Comparative clinical study of doxycycline and minocycline.

Doxycycline and minocycline were given intravenously to patients with a serious underlying disease who presented a pulmonary infection or a wound infection. Both therapies were easy to administer and well tolerated. However they should not be used in the initial therapy since resistant strains may occur. The clinical and bacteriological effectiveness of doxycycline and minocycline were similar. In pneumococcal pulmonary infections, the rates of favorable clinical response to doxycycline and minocycline were 73% and 76% respectively. In infections caused by bacteroides sp.(mainly infections of wounds), doxycycline or minocycline resulted in a 75% rate of favorable clinical responses and in a 71% rate of favorable bacteriological responses. Adverse side effects were rare and of minor importance with the exception of bacteriological colonization by doxycycline-resistant or minocycline-resistant microorganisms. This complica-tion occurred in 39% of the patients who were treated with these drugs and resulted in clinical superinfection in 8% of the patients.

Adult↗