doxycycline
Regulatory sources consulted
Approved indications
- Infections due to rickettsiae, Mycoplasma pneumoniae, Chlamydia, spirochetes, and other susceptible bacteria, according to culture and antimicrobial guidance.
Contraindications
Absolute
- Hypersensitivity to doxycycline, other tetracyclines, or excipients.
Clinical warnings
- Major warning · Risk of esophagitis and ulceration: take with plenty of water and remain upright for at least one hour. — CIMA/AEMPS, ficha técnica 47077
- Major warning · Avoid under age 8 unless a severe infection has no alternative because of tooth and bone risks. — CIMA/AEMPS, ficha técnica 47077
- Major warning · It may cause Clostridioides difficile-associated diarrhea, including after completion; stop and treat according to severity. — CIMA/AEMPS, ficha técnica 47077
- It may cause photosensitivity. Limit sun/UV exposure and stop for marked erythema. — CIMA/AEMPS, ficha técnica 47077
Drug interactions
- ModerateAntacids and products containing aluminum, calcium, magnesium, bismuth, or iron
Mechanism: Chelation reduces oral absorption.
Recommendation: Separate doxycycline from these products by 2–3 hours and take with plenty of water.
CIMA/AEMPS, ficha técnica 47077
- HighMethoxyflurane, nephrotoxic drugs, and penicillins
Mechanism: Combining tetracyclines with methoxyflurane has been associated with fatal renal toxicity; other nephrotoxic drugs increase risk, and tetracyclines may antagonize the bactericidal action of penicillins.
Recommendation: Do not combine with methoxyflurane; avoid other nephrotoxic drugs when possible and do not combine with penicillins without clinical review.
CIMA/AEMPS, ficha técnica 47077
- HighSystemic retinoids and anticoagulants
Mechanism: Retinoids increase intracranial-hypertension risk; anticoagulation may be potentiated.
Recommendation: Avoid retinoids; monitor INR with anticoagulants.
CIMA/AEMPS, ficha técnica 47077
Adverse events
Common (≥1%)
Nausea, abdominal pain, diarrhea, and photosensitive rash
Rare but serious
Ulcerative esophagitis, intracranial hypertension, anaphylaxis, and hepatotoxicity
Pregnancy and lactation
Avoid during pregnancy because of fetal risk, especially dental and bone effects from the second half. Avoid breastfeeding during treatment.
Recent literature (PubMed)
Acne vulgaris commonly affects adults, adolescents, and preadolescents aged 9 years or older. The objective of this study was to provide evidence-based recommendations for the management of acne. A work group conducted a systematic review and applied the Grading of Recommendations, Assessment, Development, and Evaluation approach for assessing the certainty of evidence and formulating and grading recommendations. This guideline presents 18 evidence-based recommendations and 5 good practice statements. Strong recommendations are made for benzoyl peroxide, topical retinoids, topical antibiotics, and oral doxycycline. Oral isotretinoin is strongly recommended for acne that is severe, causing psychosocial burden or scarring, or failing standard oral or topical therapy. Conditional recommendations are made for topical clascoterone, salicylic acid, and azelaic acid, as well as for oral minocycline, sarecycline, combined oral contraceptive pills, and spironolactone. Combining topical therapies with multiple mechanisms of action, limiting systemic antibiotic use, combining systemic antibiotics with topical therapies, and adding intralesional corticosteroid injections for larger acne lesions are recommended as good practice statements. Analysis is based on the best available evidence at the time of the systematic review. These guidelines provide evidence-based recommendations for the management of acne vulgaris.
Syphilis is an infectious disease caused by Treponema pallidum, a gram-negative, spirochete bacterium. Worldwide, an estimated 8 million adults aged 18 to 49 years acquired syphilis in 2022. From 2019 to 2023, US syphilis cases increased by 61% overall, with diagnoses among females increasing by 112% and congenital syphilis cases increasing by 106%. Syphilis is transmitted via contact with infectious lesions during vaginal, anal, or oral sex or via the placenta during pregnancy. Individuals at increased risk for syphilis include people with HIV, those engaging in condomless sex with multiple partners, and men who have sex with men (MSM)-who comprised one-third (32.7%) of all males with primary and secondary syphilis in 2023. Early syphilis is defined as syphilis in the first year after infection and includes symptomatic (primary and secondary) and asymptomatic (early latent) stages. Primary syphilis is characterized by painless anogenital lesions. Secondary syphilis is associated with a diffuse rash, mucocutaneous lesions, and lymphadenopathy. Syphilis diagnosed more than a year after infection is referred to as late syphilis and includes asymptomatic (late latent) and symptomatic (tertiary) stages. Neurosyphilis, which can occur at any stage, can lead to meningitis, uveitis, hearing loss, or stroke. In pregnancy, up to 40% of fetuses with in-utero exposure to syphilis are stillborn or die from their infection during infancy. The diagnosis of syphilis relies on serologic reactivity along with a clinical history and presentation consistent with active or latent syphilis infection. The recommended treatment for syphilis is benzathine penicillin G administered as intramuscular doses of 2.4 million units: a single injection for early stage and 3 weekly injections for late latent stage syphilis. Strategies to identify and prevent syphilis infections include (1) screening of sexually active people aged 15 to 44 years at least once and at least annually for those at increa
Acne vulgaris is an inflammatory disease of the pilosebaceous unit of the skin that primarily involves the face and trunk and affects approximately 9% of the population worldwide (approximately 85% of individuals aged 12-24 years, and approximately 50% of patients aged 20-29 years). Acne vulgaris can cause permanent physical scarring, negatively affect quality of life and self-image, and has been associated with increased rates of anxiety, depression, and suicidal ideation. Acne vulgaris is classified based on patient age, lesion morphology (comedonal, inflammatory, mixed, nodulocystic), distribution (location on face, trunk, or both), and severity (extent, presence or absence of scarring, postinflammatory erythema, or hyperpigmentation). Although most acne does not require specific medical evaluation, medical workup is sometimes warranted. Topical therapies such as retinoids (eg, tretinoin, adapalene), benzoyl peroxide, azelaic acid, and/or combinations of topical agents are first-line treatments. When prescribed as a single therapy in a randomized trial of 207 patients, treatment with tretinoin 0.025% gel reduced acne lesion counts at 12 weeks by 63% compared with baseline. Combinations of topical agents with systemic agents (oral antibiotics such as doxycycline and minocycline, hormonal therapies such as combination oral contraception [COC] or spironolactone, or isotretinoin) are recommended for more severe disease. In a meta-analysis of 32 randomized clinical trials, COC was associated with reductions in inflammatory lesions by 62%, placebo was associated with a 26% reduction, and oral antibiotics were associated with a 58% reduction at 6-month follow-up. Isotretinoin is approved by the US Food and Drug Administration for treating severe recalcitrant nodular acne but is often used to treat resistant or persistent moderate to severe acne, as well as acne that produces scarring or significant psychosocial distress. Acne vulgaris affects approximately 9% of the pop
Leptospirosis is a zoonotic bacterial infection that is prevalent across all continents and is caused by pathogenic spirochaetes of the genus Leptospira. Although infection can be asymptomatic, symptomatic disease can vary in severity from mild to severe illness, the latter characterized by icterus and/or multi-organ dysfunction and potentially death. An estimated one million cases of leptospirosis occur globally each year, resulting in ~60,000 deaths. The pathogenesis of severe leptospirosis is poorly understood but is believed to involve an interplay between genetic predisposition, pathogen virulence and dysregulated immune responses that trigger a cytokine storm with associated immunoparesis. Leptospira are susceptible to several low-cost antibiotics, including benzyl penicillin, doxycycline, cephalosporins and macrolides, when used in the early phase of infection. Late disease with organ dysfunction is treated with supportive care, and the benefit of antibiotics during late disease is doubtful. Very few countries have licensed a vaccine for human leptospirosis, and available vaccines only protect against rodent-associated serogroups. Exposure control by behavioural modifications and personal protective measures are the major preventative measures in leptospirosis, and the efficacy of prophylactic antibiotics has not been confirmed in clinical trials. Future research is needed to accurately estimate leptospirosis disease burden across the globe, to understand the pathophysiology of severe leptospirosis to inform the design of targeted immunotherapies and vaccines, and to develop cost-effective and accurate point-of-care diagnostics.
Approximately 1 in 5 adults in the US had a sexually transmitted infection (STI) in 2018. This review provides an update on the epidemiology, diagnosis, and treatment of gonorrhea, chlamydia, syphilis, Mycoplasma genitalium, trichomoniasis, and genital herpes. From 2015 to 2019, the rates of gonorrhea, chlamydia, and syphilis increased in the US; from 1999 to 2016, while the rates of herpes simplex virus type 1 (HSV-1) and HSV-2 declined. Populations with higher rates of STIs include people younger than 25 years, sexual and gender minorities such as men and transgender women who have sex with men, and racial and ethnic minorities such as Black and Latinx people. Approximately 70% of infections with HSV and trichomoniasis and 53% to 100% of extragenital gonorrhea and chlamydia infections are asymptomatic or associated with few symptoms. STIs are associated with HIV acquisition and transmission and are the leading cause of tubal factor infertility in women. Nucleic acid amplification tests have high sensitivities (86.1%-100%) and specificities (97.1%-100%) for the diagnosis of gonorrhea, chlamydia, M genitalium, trichomoniasis, and symptomatic HSV-1 and HSV-2. Serology remains the recommended method to diagnose syphilis, typically using sequential testing to detect treponemal and nontreponemal (antiphospholipid) antibodies. Ceftriaxone, doxycycline, penicillin, moxifloxacin, and the nitroimidazoles, such as metronidazole, are effective treatments for gonorrhea, chlamydia, syphilis, M genitalium, and trichomoniasis, respectively, but antimicrobial resistance limits oral treatment options for gonorrhea and M genitalium. No cure is available for genital herpes. Effective STI prevention interventions include screening, contact tracing of sexual partners, and promoting effective barrier contraception. Approximately 1 in 5 adults in the US had an STI in 2018. Rates of gonorrhea, chlamydia, and syphilis in the US have increased, while rates of HSV-1 and HSV-2 have declined.