Čo je Doxycycline?
Doxycycline is a broad-spectrum tetracycline antibiotic used to treat a wide range of bacterial infections. In the context of sexual health, it is the preferred first-line antibiotic for the treatment of Chlamydia trachomatis infection (chlamydia) and non-gonococcal urethritis (NGU) in non-pregnant adults, as recommended by WHO and European STI treatment guidelines.
Doxycycline is listed on the WHO Model List of Essential Medicines and is one of the most widely used antibiotics in sexual health medicine globally. It is available in two salt forms — doxycycline hyclate and doxycycline monohydrate — which are clinically equivalent.
Ako funguje Doxycycline?
Doxycycline inhibits bacterial protein synthesis by binding reversibly to the 30S ribosomal subunit of bacteria. This blocks the attachment of aminoacyl-tRNA to the messenger RNA-ribosome complex, preventing the addition of new amino acids to growing polypeptide chains.
The result is:
- Inhibition of protein synthesis: Bacteria cannot produce the proteins essential for growth, metabolism, and replication
- Bacteriostatic activity: Doxycycline stops bacterial growth and reproduction rather than directly killing bacteria, allowing the immune system to clear the infection
- Broad spectrum: Active against a wide range of gram-positive, gram-negative, and atypical organisms including intracellular pathogens such as Chlamydia, Mycoplasma, and Rickettsia species
Doxycycline’s ability to treat intracellular organisms (bacteria that live inside host cells) is particularly important in sexual health, where Chlamydia trachomatis is an obligate intracellular pathogen.
Pharmacokinetic properties:
- High oral bioavailability (~93%), nearly equivalent to intravenous dosing
- Long half-life (~18–22 hours), allowing twice-daily dosing
- Widely distributed in tissues, including into the genital tract
- Eliminated via bile and faeces (unlike most antibiotics excreted by the kidneys — less dose adjustment needed in renal impairment)
Pre koho je určený/á Doxycycline?
In sexual health, doxycycline is the preferred treatment for:
- Chlamydia (Chlamydia trachomatis): First-line treatment for uncomplicated genital chlamydia in non-pregnant adults (100 mg twice daily for 7 days)
- Non-gonococcal urethritis (NGU): First-line treatment, usually caused by Chlamydia trachomatis or Mycoplasma genitalium
- Lymphogranuloma venereum (LGV): Caused by Chlamydia trachomatis serovars L1–L3; treated with doxycycline 100 mg twice daily for 21 days
- Pelvic inflammatory disease (PID): Used as part of combination regimens
- Syphilis: Second-line option for patients allergic to penicillin (2–4 weeks depending on stage)
- Epididymo-orchitis: When caused by Chlamydia trachomatis
Doxycycline is not appropriate for:
- Pregnant women (contraindicated — use amoxicillin or erythromycin instead)
- Children under 12 years (risk of dental discolouration)
- Patients with known tetracycline allergy
- Viral or fungal infections
Dávkovanie
| Indication | Dose | Duration |
|---|---|---|
| Chlamydia (uncomplicated) | 100 mg twice daily | 7 days |
| NGU | 100 mg twice daily | 7 days |
| LGV | 100 mg twice daily | 21 days |
| Pelvic inflammatory disease (PID) | 100 mg twice daily | 14 days (part of combination) |
| Syphilis (early, penicillin allergy) | 100 mg twice daily | 14 days |
| Syphilis (late latent, penicillin allergy) | 100 mg twice daily | 28 days |
Doxycycline capsules/tablets should be swallowed with a full glass of water and taken in an upright position (not immediately before lying down) to prevent oesophageal irritation.
Vedľajšie účinky
Časté vedľajšie účinky (postihujúce 1 až 10 zo 100 osôb)
- Nausea
- Vomiting
- Diarrhoea
- Abdominal pain
- Photosensitivity (increased sensitivity to sunlight — use sunscreen and avoid prolonged sun exposure during treatment)
Less common side effects
- Oesophageal irritation or ulceration (take with adequate water and do not lie down immediately after)
- Headache
- Dizziness
- Vaginal thrush (candidiasis) — antibiotic disruption of normal flora
- Skin rash
Serious side effects (rare)
- Severe photosensitivity reactions: Avoid direct sunlight and UV exposure during treatment
- Intracranial hypertension (pseudotumour cerebri): Rare — persistent headache, visual changes, or vomiting should be assessed by a doctor
- Serious allergic reactions: Including anaphylaxis, angioedema
- Clostridioides difficile colitis: Severe persistent diarrhoea
Doxycycline vs alternatívy
| Antibiotic | Dose | Duration | Notes |
|---|---|---|---|
| Doxycycline (1st line) | 100 mg twice daily | 7 days | Preferred; highest efficacy for genital chlamydia |
| Zithromax/Azithromycin (1st line) | 1 g single dose | 1 day | Convenient; slightly lower rectal chlamydia efficacy |
| Amoxicillin | 500 mg three times daily | 7 days | Pregnancy alternative |
| Erythromycin | 500 mg four times daily | 7 days | Pregnancy alternative; GI side effects |
Doxycycline vs Azithromycin: Both are first-line options for uncomplicated genital chlamydia. A 2021 meta-analysis and updated European guidelines favour doxycycline as the preferred option for genital chlamydia due to higher microbiological cure rates, particularly for rectal infection. Azithromycin single-dose remains an alternative when adherence to a 7-day course is a concern.
Ako získať Doxycycline online v Európe
Doxycycline je liek viazaný na lekársky predpis vo všetkých členských štátoch EÚ. Nemožno ho legálne vydať bez platného predpisu od licencovaného lekára.
Prescrivia pôsobí ako technologický sprostredkovateľ: nepredpisujeme lieky, nezamestnávame lekárov ani nepredávame lieky. Naša platforma spája pacientov s nezávislými lekármi registrovanými v EÚ, ktorí môžu vykonávať dôverné online zdravotné posúdenia.
Postup je nasledovný:
- Vyplňte zdravotný dotazník: Provide details of your symptoms, recent STI testing, sexual history, and any relevant allergies or current medications.
- Posúdenie lekárom: An independent EU-registered doctor reviews your assessment. If doxycycline is clinically appropriate, they may issue a prescription.
- Predpis a vybavenie: The prescription is sent to a licensed EU pharmacy partner for dispensing and direct delivery.
Important: Prescrivia does not guarantee that a prescription will be issued. A positive chlamydia test or strong clinical indication is typically required. All prescribing decisions are made independently by qualified medical professionals.
Dôležité bezpečnostné informácie
Do not take Doxycycline if you:
- Are pregnant or breastfeeding
- Are under 12 years of age
- Have a known allergy to tetracycline antibiotics
- Are taking isotretinoin (increased risk of intracranial hypertension)
Tell your doctor before taking Doxycycline if you:
- Have liver disease
- Have systemic lupus erythematosus (SLE) — photosensitivity risk is increased
- Are taking antacids, calcium supplements, iron, or bismuth-containing products (take at least 2–3 hours apart)
- Are taking warfarin (monitoring of anticoagulation may be needed)
- Are taking oral contraceptives (additional contraceptive precautions are not required, but discuss with your doctor)
Partner notification: If diagnosed with chlamydia or another STI, sexual partners from the preceding 6 months should be informed, offered testing, and treated. This is essential to prevent reinfection.
Test of cure: A test of cure is not routinely recommended after standard doxycycline treatment for chlamydia, but may be advised in pregnancy, or if adherence was uncertain.
Zdroje
Lekárske informácie na tejto stránke vychádzajú z nasledujúcich zdrojov:
- World Health Organization (WHO). WHO Guidelines for the Treatment of Chlamydia trachomatis. 2016. who.int
- European STI Guidelines Editorial Board. 2015 European guideline on the management of Chlamydia trachomatis infections. Journal of the European Academy of Dermatology and Venereology.
- World Health Organization (WHO). WHO Model List of Essential Medicines. 22nd edition, 2021.
- Dombrowski JC, et al. Doxycycline versus azithromycin for the treatment of rectal chlamydia in men who have sex with men. Clinical Infectious Diseases. 2021.
Tento obsah je pravidelne prehodnocovaný s ohľadom na aktualizované klinické usmernenia. Je poskytovaný len na informačné účely a nepredstavuje lekárske poradenstvo. Vždy sa poraďte s kvalifikovaným zdravotníckym pracovníkom o rade týkajúcej sa Vašich individuálnych zdravotných okolností.
Frequently asked questions
- Na čo sa používa Doxycycline?
- Doxycycline is a first-line antibiotic for the treatment of chlamydia (Chlamydia trachomatis), non-gonococcal urethritis (NGU), lymphogranuloma venereum (LGV), and certain cases of pelvic inflammatory disease (PID). It is also used as part of combination regimens for syphilis in penicillin-allergic patients.
- Ako dlho is the doxycycline course for chlamydia?
- The WHO and European STI guidelines recommend doxycycline 100 mg twice daily for 7 days as the preferred first-line treatment for uncomplicated genital chlamydia. For lymphogranuloma venereum (LGV), the same dose is continued for 21 days.
- Can I take Doxycycline with food?
- Doxycycline can and should be taken with food or milk to reduce the risk of oesophageal irritation and gastrointestinal side effects. However, avoid taking it with dairy products, calcium-rich foods, antacids, or iron supplements within 2–3 hours, as these can significantly reduce absorption.
- Je bezpečné during pregnancy?
- No. Doxycycline is contraindicated during pregnancy and breastfeeding. It can affect fetal bone and tooth development and cause permanent tooth discolouration in the developing child. Pregnant women with chlamydia should be treated with amoxicillin or erythromycin instead — a doctor will advise on the appropriate alternative.
- Can I drink alcohol while taking Doxycycline?
- Moderate alcohol consumption does not significantly affect the efficacy of doxycycline, and the interaction is not considered clinically significant in most patients. However, alcohol may worsen gastrointestinal side effects, and heavy alcohol use can theoretically reduce doxycycline blood levels. It is generally advisable to avoid excessive alcohol during any antibiotic course.
Liečba
Prescrivia je iba sprostredkovateľská platforma. Neposkytujeme lekárske služby, nepredpisujeme liečbu ani nevydávame lieky. Všetky lekárske rozhodnutia robia nezávislí lekári registrovaní v EÚ. Všetky lieky vydávajú licencované lekárne v EÚ. Táto platforma uľahčuje spojenie medzi pacientmi a poskytovateľmi zdravotnej starostlivosti.