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Topics in Antiviral Medicine Dec 2023Doxycycline postexposure prophylaxis (doxy-PEP) is a novel strategy now demonstrated in several clinical trials to dramatically reduce incidence rates of gonorrhea,... (Review)
Review
Doxycycline postexposure prophylaxis (doxy-PEP) is a novel strategy now demonstrated in several clinical trials to dramatically reduce incidence rates of gonorrhea, chlamydia, and syphilis in some key populations at high risk of sexually transmitted infections. Even so, much remains unknown about the long-term consequences of doxy-PEP, and several concerns, including the potential for the development of antibiotic resistance and disturbances to the microbiome, balance the benefits. This review highlights the history of antibiotic prophylaxis for sexually transmitted infections, and the rationale, current evidence, and future directions for doxy-PEP.
Topics: Humans; Doxycycline; Sexually Transmitted Diseases; Syphilis; Gonorrhea; Antibiotic Prophylaxis
PubMed: 38198668
DOI: No ID Found -
Antimicrobial Agents and Chemotherapy Apr 2023Mycoplasma genitalium is a sexually transmitted reproductive tract pathogen of men and women. M. genitalium infections are increasingly difficult to treat due to poor...
Mycoplasma genitalium is a sexually transmitted reproductive tract pathogen of men and women. M. genitalium infections are increasingly difficult to treat due to poor efficacy of doxycycline and acquired resistance to azithromycin and moxifloxacin. A recent clinical trial suggested that metronidazole may improve cure rates for women with pelvic inflammatory disease and reduced the detection of M. genitalium when included with standard doxycycline plus ceftriaxone treatment. As data regarding susceptibility of mycoplasmas to nitroimidazoles are lacking in the scientific literature, we determined the susceptibility of 10 M. genitalium strains to metronidazole, secnidazole, and tinidazole. MICs ranged from 1.6 to 12.5 μg/mL for metronidazole, 3.1 to 12.5 μg/mL for secnidazole, and 0.8 to 6.3 μg/mL for tinidazole. None of these agents was synergistic with doxycycline in checkerboard broth microdilution assays. Tinidazole was superior to metronidazole and secnidazole in terms of MIC and time-kill kinetics and was bactericidal (>99.9% killing) at concentrations below reported serum concentrations. Mutations associated with nitroimidazole resistance were identified by whole-genome sequencing of spontaneous resistant mutants, suggesting a mechanism for reductive activation of the nitroimidazole prodrug by a predicted NAD(P)H-dependent flavin mononucleotide (FMN) oxidoreductase. The presence of oxygen did not affect MICs of wild-type M. genitalium, but a nitroimidazole-resistant mutant was defective for growth under anaerobic conditions, suggesting that resistant mutants may have a fitness disadvantage in anaerobic genital sites. Clinical studies are needed to determine if nitroimidazoles, especially tinidazole, are effective for eradicating M. genitalium infections in men and women.
Topics: Male; Female; Humans; Nitroimidazoles; Doxycycline; Metronidazole; Tinidazole; Mycoplasma genitalium; Anti-Bacterial Agents; Mycoplasma Infections; Drug Resistance, Bacterial
PubMed: 37070857
DOI: 10.1128/aac.00006-23 -
Thorax Apr 1976The concentration of doxycycline hydrochloride was measured in serum and bronchial secretions in five patients with chronic bronchitis receiving doxycycline orally in... (Comparative Study)
Comparative Study Review
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.
Topics: Bacillus cereus; Bronchitis; Chronic Disease; Doxycycline; Haemophilus influenzae; Humans; Sputum
PubMed: 821169
DOI: 10.1136/thx.31.2.144 -
The Journal of Clinical Investigation Sep 2022Mitohormesis defines the increase in fitness mediated by adaptive responses to mild mitochondrial stress. Tetracyclines inhibit not only bacterial but also mitochondrial...
Mitohormesis defines the increase in fitness mediated by adaptive responses to mild mitochondrial stress. Tetracyclines inhibit not only bacterial but also mitochondrial translation, thus imposing a low level of mitochondrial stress on eukaryotic cells. We demonstrate in cell and germ-free mouse models that tetracyclines induce a mild adaptive mitochondrial stress response (MSR), involving both the ATF4-mediated integrative stress response and type I interferon (IFN) signaling. To overcome the interferences of tetracyclines with the host microbiome, we identify tetracycline derivatives that have minimal antimicrobial activity, yet retain full capacity to induce the MSR, such as the lead compound, 9-tert-butyl doxycycline (9-TB). The MSR induced by doxycycline (Dox) and 9-TB improves survival and disease tolerance against lethal influenza virus (IFV) infection when given preventively. 9-TB, unlike Dox, did not affect the gut microbiome and also showed encouraging results against IFV when given in a therapeutic setting. Tolerance to IFV infection is associated with the induction of genes involved in lung epithelial cell and cilia function, and with downregulation of inflammatory and immune gene sets in lungs, liver, and kidneys. Mitohormesis induced by non-antimicrobial tetracyclines and the ensuing IFN response may dampen excessive inflammation and tissue damage during viral infections, opening innovative therapeutic avenues.
Topics: Animals; Anti-Bacterial Agents; Doxycycline; Humans; Influenza, Human; Mice; Orthomyxoviridae Infections; Tetracycline; Tetracyclines
PubMed: 35787521
DOI: 10.1172/JCI151540 -
Expert Review of Anti-infective Therapy Nov 2013Q fever is caused by the bacterium Coxiella burnetii and has both acute and chronic forms. The acute disease is a febrile illness often with headache and myalgia that... (Review)
Review
Q fever is caused by the bacterium Coxiella burnetii and has both acute and chronic forms. The acute disease is a febrile illness often with headache and myalgia that can be self-limiting, whereas the chronic disease typically presents as endocarditis and can be life threatening. The normal therapy for the acute disease is a 2 week course of doxycycline, whereas chronic disease requires 18-24 months of doxycycline in combination with hydroxychloroquine. Alternative treatments are used for pregnant women, young children and those who cannot tolerate doxycycline. Doxycycline resistance is rare, but has been reported. Co-trimoxazole is a currently recommended alternative treatment, but quinolones, rifampin and newer macrolides may also provide some benefit.
Topics: Anti-Infective Agents; Coxiella burnetii; Doxycycline; Female; Humans; Pregnancy; Pregnancy Complications, Infectious; Q Fever; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 24073941
DOI: 10.1586/14787210.2013.840534 -
Clinical Infectious Diseases : An... Aug 2022Despite clinical practice guideline recommendations to use doxycycline as part of combination therapy for some patients hospitalized with pneumonia, there is minimal... (Observational Study)
Observational Study
BACKGROUND
Despite clinical practice guideline recommendations to use doxycycline as part of combination therapy for some patients hospitalized with pneumonia, there is minimal evidence supporting this recommendation. Our aim was to examine the association between beta-lactam plus doxycycline and mortality for patients hospitalized with community-acquired pneumonia.
METHODS
We identified patients >65 years of age admitted to any US Department of Veterans Affairs hospital in fiscal years 2002-2012 with a discharge diagnosis of pneumonia. We excluded those patients who did not receive antibiotic therapy concordant with the 2019 American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) clinical practice guidelines. Using propensity score matching, we examined the association of doxycycline with 30- and 90-day mortality.
RESULTS
Our overall cohort was comprised of 70533 patients and 5282 (7.49%) received doxycycline. Unadjusted 30-day mortality was 6.4% for those who received a beta-lactam plus doxycycline versus 9.1% in those who did not (P < .0001), and 90-day mortality was 13.8% for those who received a beta-lactam + doxycycline versus 16.8% for those who did not (P < .0001). In the propensity score matched models, both 30- (odds ratio 0.72, 95% confidence interval [CI], .63-.84) and 90-day (0.83, 95% CI, .74-.92) mortality were significantly lower for those who received doxycycline.
CONCLUSIONS
In this retrospective observational cohort study, we found that doxycycline use, as part of guideline-concordant antibiotic therapy, was associated with lower 30- and 90-day mortality than regimens without doxycycline. While this supports the safety and effectiveness of antibiotic regimes that include doxycycline, additional studies, especially randomized clinical trials, are needed to confirm this.
Topics: Anti-Bacterial Agents; Community-Acquired Infections; Doxycycline; Drug Therapy, Combination; Humans; Pneumonia; Retrospective Studies; beta-Lactams
PubMed: 34751745
DOI: 10.1093/cid/ciab863 -
Deutsches Arzteblatt International Mar 2020
Topics: Antimalarials; Dermatitis, Phototoxic; Doxycycline; Female; Humans; Young Adult
PubMed: 32343652
DOI: 10.3238/arztebl.2020.0196 -
Journal of Infection in Developing... Feb 2023Doxycycline is an antibiotic with known gastrointestinal (GI) adverse effects. Esophagitis is the most pronounced among these effects, and might be associated with a...
INTRODUCTION
Doxycycline is an antibiotic with known gastrointestinal (GI) adverse effects. Esophagitis is the most pronounced among these effects, and might be associated with a prolonged duration of therapy. The aim of this study is to evaluate the incidence of esophagitis and other GI side effects in adults who received doxycycline for at least a month.
METHODOLOGY
This retrospective descriptive study included adults who received oral doxycycline for at least one month between 2016 and 2018. The primary outcome was the frequency of esophagitis. The secondary outcomes were frequency of and discontinuation due to GI adverse effects.
RESULTS
A total of 189 subjects were included with a median age of 32 years. The median duration of doxycycline use was 44 days (interquartile range 30-60). Twelve patients (6.3%) reported having GI adverse effects resulting in doxycycline discontinuation in five of them (2.6%), and three patients (1.6%) had esophagitis. The incidence of GI adverse effects was significantly higher in patients who were ≥ 50 years than < 50 years old (8/50 vs. 4/139; p = 0.003) and in those who received a daily dose of 200 mg than 100 mg (12/93 vs. 0/96; p < 0.001).
CONCLUSIONS
GI adverse events, including esophagitis, are not rare with long-term use of oral doxycycline, particularly in older age and a higher dose of 200 mg/day. Future large and randomized studies are needed to compare the efficacy and safety of different doxycycline doses.
Topics: Adult; Humans; Doxycycline; Retrospective Studies; Anti-Bacterial Agents; Esophagitis
PubMed: 36897904
DOI: 10.3855/jidc.16677 -
Journal of the American Association For... 2016Despite the extensive use of doxycycline in tetracycline-inducible rodent models, little is known regarding its stability in feed or water or the most effective route or...
Despite the extensive use of doxycycline in tetracycline-inducible rodent models, little is known regarding its stability in feed or water or the most effective route or dose. We assessed the concentrations of doxycycline in reverse-osmosis-purified (RO; pH 6.0) and acidified RO (pH 2.6) water in untinted or green-tinted bottles. Doxycycline remained stable in all groups for 7 d and in acidified water in untinted bottles for 14 d. Fungal growth occurred in nonacidified water in tinted and untinted bottles by 12 and 14 d, respectively, and in tinted bottles containing acidified water on day 14, but not in untinted bottles with acidified water. Doxycycline concentrations were also assessed before and at various points after the pelleting of feed from 2 vendors. Each batch was divided for storage at 4 °C, at room temperature, or within ventilated mouse isolator cages and then sampled monthly for 6 mo. Drying caused the greatest decline in doxycycline concentration, whereas γ-irradiation plus shipping and storage condition had minimal effect. Two mouse lines with tetracycline-inducible promoters received 25, 150, or 467 μg/mL or 2 mg/mL doxycycline in water and 200 or 625 ppm in feed before analysis of GFP expression. GFP was expressed in Rosa-rtTA2 mice at 150 μg/mL, whereas Cags-rtTA3 mice required 25 μg/mL. These studies indicate that 1) doxycycline-compounded feed can be handled in the same manner as standard rodent feed, 2) tinted water bottles are not necessary for maintaining drug concentrations, and 3) concentrations lower than those used typically may be effective in lines with tetracycline-inducible promoters.
Topics: Animal Feed; Animals; Anti-Bacterial Agents; Doxycycline; Female; Male; Mice; Mice, Inbred C57BL; Tetracycline; Water
PubMed: 27423155
DOI: No ID Found -
The Cochrane Database of Systematic... Jun 2021Posterior blepharitis is common and causes ocular surface and lid damage as well as discomfort. It affects 37% to 47% of all ophthalmology patients; its incidence...
BACKGROUND
Posterior blepharitis is common and causes ocular surface and lid damage as well as discomfort. It affects 37% to 47% of all ophthalmology patients; its incidence increasing with age. It is a multifactorial disease associated with multiple other pathologies, such as rosacea, meibomianitis, and infections. Treatment usually focuses on reliefing the symptoms by using artificial tears, lid scrubs, and warm compresses. The condition may be notoriously difficult to manage adequately once it becomes chronic. One such management approach for chronic blepharitis is the use of oral antibiotics for both their antibacterial as well as anti-inflammatory properties. There are currently no guidelines regarding the use of oral antibiotics, including antibiotic type, dosage, and treatment duration, for the treatment of chronic blepharitis.
OBJECTIVES
To assess the benefits and harms of oral antibiotic use for people with chronic blepharitis.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2020, Issue 8); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 29 August 2020.
SELECTION CRITERIA
We included randomized controlled trials (RCTs) comparing oral antibiotics with placebo in adult participants with chronic blepharitis (including staphylococcal, seborrhoeic, or Meibomian Gland Dysfunction (MGD)).
DATA COLLECTION AND ANALYSIS
We used standard Cochrane methodology and graded the certainty of the body of evidence for six outcomes using the GRADE classification.
MAIN RESULTS
We included two studies with 220 participants (numbers of eyes unclear). One parallel-group RCT comparing oral doxycycline (40 mg once a day) with placebo enrolled 70 participants with blepharitis and facial rosacea in the USA. Follow-up duration was three months. One three-arm RCT conducted in South Korea investigated the effect of high-dose (200 mg twice a day) and low-dose (20 mg twice a day) doxycycline versus placebo after one month of study medication. It enrolled 50 participants with chronic MGD in each study arm (i.e. 150 participants enrolled in total). The two studies did not evaluate the same outcome measurements, which precluded any meta-analysis. The evidence for the effect of oral antibiotics on subjective improvement in symptoms was very uncertain. One study suggested that there was little to no effect of oral doxycycline on subjective symptoms based on the Ocular Surface Disease Index (OSDI) scores ranging from 0 to 100 (higher score indicates worse condition) (mean difference (MD) 3.55, 95% confidence interval (CI) -4.61 to 11.71; n = 70) and bulbar conjunctival hyperemia ranging from 0 (clear) to 4 (severe) (MD -0.01, 95% CI -0.38 to 0.36; n = 70) at 12 weeks. The three-arm RCT showed that oral doxycycline may slightly improve number of symptoms (MD -0.56, 95% CI -0.95 to -0.17; n = 93 (high-dose doxycycline versus placebo); MD -0.48, 95% CI -0.86 to -0.10; n = 93 (low-dose doxycycline versus placebo)) and proportion of participants with symptom improvement (risk ratio (RR) 6.13, 95% CI 2.61 to 14.42; n = 93 (high-dose doxycycline versus placebo); RR 6.54, 95% CI 2.79 to 15.30; n = 93 (low-dose doxycycline versus placebo)) at one month, but the evidence is very uncertain. We judged the certainty of evidence for subjective symptoms as very low. One study evaluated aqueous tear production by Schirmer's test (mm/5 min) (higher score indicates better condition) and tear film stability by measuring tear film break-up time (TBUT) in seconds (higher score indicates better condition) at one month. We found very low certainty evidence that oral doxycycline may improve these clinical signs. The estimated MD in Schirmer's test score after one month of treatment was 4.09 mm (95% CI 2.38 to 5.80; n = 93) in the high-dose doxycycline group versus the placebo group and 3.76 mm (95% CI 1.85 to 5.67; n = 93) in the low-dose doxycycline group versus the placebo group. The estimated MD in TBUT after one month was 1.58 seconds (95% CI 0.57 to 2.59; n = 93) when comparing the high-dose doxycycline group with the placebo group, and 1.70 seconds (95% CI 0.96 to 2.44; n = 93) when comparing the low-dose doxycycline group with the placebo group. Although there was a noted improvement in these scores, their clinical importance remains uncertain. One study suggested that oral doxycycline may increase the incidence of serious side effects: 18 (39%) participants in the high-dose doxycycline group, 8 (17%) in the low-dose doxycycline group, and 3 (6%) out of 47 participants in the placebo group experienced serious side effects (RR 6.13, 95% CI 1.94 to 19.41; n = 93 (high-dose doxycycline versus placebo); RR 2.72, 95% CI 0.77 to 9.64; n = 93 (low-dose doxycycline versus placebo)). Additionally, one study reported that one case of migraine headache and five cases of headache were observed in the oral doxycycline group, and one case of non-Hodgkin's lymphoma was observed in the placebo group. We judged the certainty of evidence for adverse events as very low.
AUTHORS' CONCLUSIONS
There was insufficient evidence to draw any meaningful conclusions on the use of oral antibiotics for chronic blepharitis. Very low certainty evidence suggests that oral antibiotics may improve clinical signs, but may cause more adverse events. The evidence for the effect of oral antibiotics on subjective symptoms is very uncertain. Further trials are needed to provide high quality evidence on the use of oral antibiotics in the treatment of chronic blepharitis.
Topics: Administration, Oral; Adult; Anti-Bacterial Agents; Bias; Blepharitis; Chronic Disease; Doxycycline; Drug Administration Schedule; Humans; Randomized Controlled Trials as Topic
PubMed: 34107053
DOI: 10.1002/14651858.CD013697.pub2