Doxycycline

Pronunciation: dok-see-SYE-kleen.

Last medically reviewed: August 14, 2026, by , MBBS, MD (Internal Medicine).

Generic name
doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation)
Drug class
Tetracycline-class antibiotic (semi-synthetic, broad-spectrum, bacteriostatic)
Form
Standard antibacterial-dose capsules/tablets (typically 50-200 mg, brands including Doryx, Vibramycin, Apo-Doxy, Doxine, depending on market); a separate, lower sub-antimicrobial-dose capsule (40 mg) specifically for rosacea
Route
Oral (capsule, tablet, or dispersible tablet)
Legal status
Prescription-only medicine in all markets reviewed

Availability and supply rules vary by country

Trade names by country: United States · United Kingdom · Canada · Australia · New Zealand

Australia: Doryx (7), APX-Doxycycline / Doxycycline Sandoz (generics) (7), Vibramycin -- DISCONTINUED, not currently available (7) · Full directory

What doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation) is and how it works

Doxycycline is a widely used, broad-spectrum antibiotic from the tetracycline class. At a standard dose, it treats many types of bacterial and some parasitic infections -- including respiratory infections, sexually transmitted infections, tick-borne and rickettsial illnesses, and early Lyme disease -- and is also used to prevent malaria in travellers and to prevent or treat anthrax after exposure. A separate, much lower dose of the same medicine is used only to treat the inflammatory lesions of rosacea, not to treat infections. (1)

Doxycycline does not carry a boxed warning, but it shares real, well-known risks common to all tetracycline-class antibiotics: it can permanently discolor developing teeth and affect bone growth if used in the second half of pregnancy or in children under 8, can make skin much more sensitive to sunburn, and can rarely cause a serious build-up of pressure around the brain (especially if combined with certain acne medicines called retinoids). It is generally well tolerated when taken as directed with plenty of water.

Mechanism of action: how doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation) works

Doxycycline is a semi-synthetic tetracycline-class antibiotic that inhibits bacterial protein synthesis by binding the 30S ribosomal subunit, giving it bacteriostatic activity against a broad range of gram-positive and gram-negative organisms, as well as some intracellular pathogens (chlamydiae, rickettsiae, mycoplasmas) and the malaria parasite. (1) (4)

What doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation) is used for

Bacterial and rickettsial infections

Treats a wide range of bacterial infections, including respiratory tract infections, rickettsial illnesses (such as Rocky Mountain spotted fever and typhus), chlamydial infections (including certain sexually transmitted infections), relapsing fever, and several other bacterial and some parasitic conditions when caused by susceptible organisms. In some current labels reviewed, it is also indicated for early localized or early disseminated Lyme disease. (1) (3) (8)

Malaria prevention and anthrax post-exposure prophylaxis

Used to prevent malaria caused by Plasmodium falciparum in short-term travellers to areas with drug-resistant malaria, and to reduce the risk of illness after exposure to inhaled anthrax spores (Bacillus anthracis), including as part of post-exposure treatment. (1)

Adjunctive treatment for severe acne

Used at a standard antibacterial dose as an add-on treatment for severe acne, alongside other acne treatments as directed by a prescriber. (1)

Rosacea (inflammatory lesions only) -- separate, lower-dose product

A separate, much lower (sub-antimicrobial) 40 mg dose of doxycycline is used specifically to treat the inflammatory bumps and pimples (papules and pustules) of rosacea in adults. This lower-dose product is not intended to treat infections and is a genuinely different clinical use from the standard antibacterial dose. (2)

Before taking doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation)

Do not take / not appropriate for

  • Do not take doxycycline if you are allergic to doxycycline or any other tetracycline-class antibiotic. (all countries) (1) (4)
  • Doxycycline is contraindicated in pregnancy and while breastfeeding, per the UK source reviewed, due to effects on teeth and bone development in the baby. (United Kingdom) (4)

Tell your clinician about

  • Whether you are pregnant, planning to become pregnant, or breastfeeding.
  • If this medicine is intended for a child under 8 years old.
  • Any history of liver or kidney problems.
  • Any history of severe headaches or vision problems.
  • All other medicines you take, especially blood thinners (anticoagulants), antacids, iron or calcium supplements, retinoid acne medicines (such as isotretinoin), or anti-seizure medicines.
  • Whether you will be having general anaesthesia with methoxyflurane.
(1) (4)

How to take doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation)

  • Take doxycycline exactly as your prescriber directs, for the full course even if you start feeling better, unless your prescriber tells you otherwise.
  • Swallow capsules or tablets with a full glass of water, sitting or standing upright, to reduce the risk of throat or food-pipe (oesophageal) irritation -- avoid taking your dose right before lying down or going to bed.
  • Doxycycline can generally be taken with or without food, though taking it with food (avoiding dairy products, calcium, iron, or antacids around the same time) can help reduce stomach upset without significantly reducing its effectiveness, unlike some older tetracyclines.
  • Space doxycycline doses apart from antacids, iron supplements, or calcium/magnesium products by at least 2-3 hours, since these can reduce how much of the medicine your body absorbs.
  • Use sun protection and limit sun/UV exposure while taking doxycycline, since it can make your skin much more sensitive to sunburn.
(1) (4) (8)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8)

Missed dose

If you miss a dose, take it as soon as you remember, unless it is almost time for your next dose -- in that case, skip the missed dose and continue your normal schedule. Do not take a double dose to make up for a missed one. Contact your prescriber if you are unsure, especially for malaria prevention or a fixed-length course such as anthrax prophylaxis.

Overdose

Seek medical advice or emergency help if too much doxycycline has been taken. No specific antidote exists; treatment is supportive, and dialysis does not significantly alter its elimination. (1)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Nausea, vomiting, or stomach upset.

What to notice: Nausea, vomiting, or stomach upset.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Diarrhoea.

What to notice: Diarrhoea.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Sun sensitivity (photosensitivity).

What to notice: Sun sensitivity (photosensitivity).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Vaginal itching or thrush (yeast infection).

What to notice: Vaginal itching or thrush (yeast infection).

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Headache.

What to notice: Headache.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (4)

Serious warnings

Tooth discoloration and enamel hypoplasia (in pregnancy and young children) — high caution

Symptoms: Not applicable to the person taking it directly -- this is a risk to a developing baby or young child's teeth.

Action: Tell your prescriber if you are pregnant (especially in the last half of pregnancy) or if this medicine is being considered for a child up to age 8, since it may permanently discolor developing teeth (yellow-gray-brown) and affect enamel. (1)

Effects on bone growth (in pregnancy and young children) — high caution

Symptoms: Not applicable to the person taking it directly -- this is a risk to a developing baby or young child.

Action: Tell your prescriber if you are pregnant (second or third trimester) or if this medicine is being considered for a young child, since it may reversibly slow bone growth. (1)

Increased sun sensitivity (photosensitivity) — moderate caution

Symptoms: An exaggerated, sunburn-like reaction occurring more easily or severely than usual.

Action: Limit sun and UV exposure, use sun protection, and contact your prescriber at the first sign of a skin reaction, since they may advise stopping the medicine. (1) (8)

Severe headache with vision changes (pseudotumor cerebri / benign intracranial hypertension) — high caution

Symptoms: Severe headache, blurred or double vision, or other visual disturbances -- which can rarely lead to permanent vision loss if not addressed promptly.

Action: Contact your prescriber promptly or seek urgent eye/medical evaluation if this occurs -- this risk is higher if combined with retinoid acne medicines such as isotretinoin, which should generally be avoided together with doxycycline. (1) (4)

Oesophageal (food-pipe) irritation or ulceration — moderate caution

Symptoms: Chest pain, painful or difficult swallowing, or a burning sensation behind the breastbone.

Action: Always take doxycycline with a full glass of water while sitting or standing, and avoid lying down for at least 30 minutes to an hour afterward; contact your prescriber if these symptoms occur. (1) (4)

Severe diarrhoea (possible C. difficile infection) — high caution

Symptoms: Watery or bloody diarrhoea, stomach cramps, or fever, which can start during treatment or even weeks after stopping.

Action: Contact your prescriber promptly -- do not treat diarrhoea yourself with anti-diarrhoeal medicine until you have checked with your prescriber, since this can rarely be a serious bowel infection. (1) (4)

Liver problems — moderate caution

Symptoms: Yellowing of the skin or eyes, dark urine, or unusual tiredness.

Action: Contact your prescriber promptly -- rare liver problems have been reported with tetracycline-class antibiotics, more often with kidney impairment. (1) (4)

Interactions

  • Methoxyflurane (a general anaesthetic): concurrent use with tetracyclines, including doxycycline, has been reported to result in fatal kidney (renal) toxicity -- tell your care team about any doxycycline use before any planned anaesthesia. (1)
  • Anticoagulants (blood thinners such as warfarin): doxycycline may increase their effect, and a downward dose adjustment may be needed. (1) (4)
  • Antacids, iron, calcium, magnesium, zinc, and bismuth-containing products: can reduce how much doxycycline your body absorbs -- space doses apart by at least 2-3 hours. (1) (4)
  • Oral retinoids (isotretinoin, acitretin): avoid combining with doxycycline due to an increased risk of pseudotumor cerebri (raised pressure around the brain). (4)
  • Barbiturates, carbamazepine, and phenytoin: can shorten doxycycline's half-life, potentially reducing its effectiveness. (1) (4)
  • Penicillin-type antibiotics: avoid combining, as doxycycline's bacteriostatic action may interfere with penicillin's bactericidal action. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Doxycycline is contraindicated in pregnancy per the UK source reviewed, and the US source reviewed advises it can permanently affect a developing baby's teeth and bone growth if used in the second half of pregnancy -- discuss any pregnancy or possible pregnancy with your prescriber before starting. (1) (2) (3) (4) (5) (6) (7) (8)

Breastfeeding

Contraindicated while breastfeeding per the UK source reviewed, since tetracyclines pass into breast milk. (1) (2) (3) (4) (5) (6) (7) (8)

Children

May cause permanent tooth discoloration and reversible bone-growth inhibition in children up to about age 8; the UK source reviewed advises reserving it for life-threatening conditions in this age group when no alternative exists. (1) (2) (3) (4) (5) (6) (7) (8)

Elderly

Specific dose adjustment for older adults was not detailed in the sources reviewed beyond standard adult dosing; monitor as with any antibiotic course. (1) (2) (3) (4) (5) (6) (7) (8)

Hepatic_impairment

Use with caution; tetracycline-class antibiotics have rarely been associated with liver problems, especially when combined with kidney impairment. (1) (2) (3) (4) (5) (6) (7) (8)

Renal_impairment

Doxycycline is one of the tetracyclines that can still be used with relatively less dose adjustment in mild-moderate renal impairment compared to some older tetracyclines, but the US source reviewed notes that even usual doses can lead to excessive drug accumulation and possible toxicity if significant renal impairment exists -- discuss with your prescriber. (1) (2) (3) (4) (5) (6) (7) (8)

Monitoring

Before starting

  • Pregnancy status in anyone who could become pregnant
  • Age (particularly for children up to 8 years old)
  • Known allergy to tetracycline-class antibiotics
  • Review of other medicines, especially anticoagulants, antacids/iron, and retinoid acne medicines

During treatment

  • Watch for signs of severe headache with vision changes, severe diarrhoea, unusual sun sensitivity, or swallowing pain/chest discomfort.
  • Anticoagulant effect may need closer monitoring, with dose adjustment if required.
  • Liver function may be checked if clinically indicated, especially with kidney impairment.
(1) (4)

Storage

Store at room temperature, away from moisture and direct light, out of reach of children.

Study the drug class: Tetracyclines

Professional information

Clinician-facing context only, sourced from the current US FDA prescribing information (general doxycycline hyclate capsules and the separate rosacea-only 40 mg product), the UK emc SmPC, and the EMA's Article 35 referral reviewed for this dossier; verify against the current full label before prescribing.

United States

Indication: Broad-spectrum antibacterial use, malaria prophylaxis, anthrax post-exposure prophylaxis, early Lyme disease (in the label reviewed), and a separate rosacea-only indication at a lower dose

Dose summary: Standard: typically 100 mg twice daily on day one then 100 mg once or twice daily depending on infection. Malaria prophylaxis: 100 mg once daily. Anthrax: 100 mg twice daily for 60 days. Early Lyme disease: 100 mg twice daily for 10-21 days. Rosacea: separate 40 mg once-daily dose.

Renal context: Even usual doses can lead to excessive systemic accumulation and possible toxicity if significant renal impairment exists, per the US label reviewed. (1) (3) (2)

United Kingdom / European Union

Indication: Broad-spectrum antibacterial use, malaria prophylaxis, travellers' diarrhoea prevention

Dose summary: Typically 100-200 mg on day one then 100 mg once daily, varying by indication, per the UK SmPC reviewed.

Renal context: Not specifically detailed in the sources reviewed. (4) (5)

Mechanism of action

Hepatic guidance

Rare hepatotoxicity has been reported with tetracycline-class antibiotics, more pronounced with pre-existing renal impairment; monitor liver function where clinically indicated.

Overdose note

No specific antidote exists; manage with supportive care. Doxycycline is not significantly removed by dialysis. (1) (4)

Frequently asked questions

Is doxycycline available in the US, UK, Europe, Canada, Australia, and New Zealand?

Yes, doxycycline is authorised and marketed in all six regions reviewed, though under different brand names: the United States (Doryx, Vibramycin, and generic doxycycline hyclate), the United Kingdom and much of the European Union (generic Doxycycline Capsules, Vibramycin-D, and other nationally authorised brands), Canada (Apo-Doxy), Australia (Doryx and generic products -- though Vibramycin specifically was discontinued there in 2018-2022), and New Zealand (Doxine). (1) (4) (6) (7) (8)

Does doxycycline have a boxed warning?

No. This was directly checked against the current US FDA labels for both the standard antibacterial-dose product and the separate, lower-dose rosacea-only product, and neither carries a boxed warning. Doxycycline still has real, well-known tetracycline-class warnings to be aware of, including effects on developing teeth and bone, sun sensitivity, and rare but serious effects on pressure around the brain. (1) (2)

Can children take doxycycline?

Doxycycline is generally avoided in children under 8 years old because it can permanently discolor developing teeth and may affect bone growth. In some situations where no suitable alternative exists for a serious infection, a prescriber may still decide the benefits outweigh this risk -- this is always an individual clinical decision. (1) (4)

Why do I need to be careful in the sun while taking doxycycline?

Doxycycline, like other tetracycline antibiotics, can cause photosensitivity -- an exaggerated sunburn-like reaction to sunlight or UV light. Use sun protection, limit direct sun exposure, and contact your prescriber if you notice an unusual skin reaction. (1) (8)

What is the mechanism of action of doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation)?

Doxycycline is a semi-synthetic tetracycline-class antibiotic that inhibits bacterial protein synthesis by binding the 30S ribosomal subunit, giving it bacteriostatic activity against a broad range of gram-positive and gram-negative organisms, as well as some intracellular pathogens (chlamydiae, rickettsiae, mycoplasmas) and the malaria parasite. (1) (4)

What is the generic name of Doxycycline?

The generic name is doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation). (1) (2)

What class of drug is doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation)?

Doxycycline is classed as: Tetracycline-class antibiotic (semi-synthetic, broad-spectrum, bacteriostatic). (1) (2)

References

  1. DOXYCYCLINE HYCLATE capsules, USP -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · dated 2026-01-01 · accessed 2026-07-30 · source 1
  2. DOXYCYCLINE capsule, 40 mg (sub-antimicrobial dose) -- full prescribing informationU.S. Food and Drug Administration / DailyMed (NIH), full prescribing information · United States · dated 2026-01-01 · accessed 2026-07-30 · source 2
  3. Doxycycline -- FDA label confirming early Lyme disease indicationU.S. Food and Drug Administration -- approved drug label · United States · dated 2025-01-01 · accessed 2026-07-30 · source 3
  4. Doxycycline 100mg Capsules -- Summary of Product Characteristicselectronic medicines compendium (emc), United Kingdom -- Summary of Product Characteristics (SmPC) · United Kingdom · dated 2025-01-01 · accessed 2026-07-30 · source 4
  5. Doxycycline hyclate -- Article 35 referral, harmonisation of nationally authorised product informationEuropean Medicines Agency (EMA) -- Article 35 referral assessment report · European Union · dated 2026-01-01 · accessed 2026-07-30 · source 5
  6. APO-DOXY and APO-DOXY-TABS (doxycycline hyclate capsules and tablets) -- Product MonographHealth Canada -- Product Monograph · Canada · dated 2026-01-01 · accessed 2026-07-30 · source 6
  7. DORYX doxycycline capsules/tablets -- ARTG entries; VIBRAMYCIN doxycycline -- discontinuation and ARTG cancellationTherapeutic Goods Administration (TGA), Australia -- Australian Register of Therapeutic Goods (ARTG); cancellations-by-sponsors register · Australia · dated 2022-03-04 · accessed 2026-07-30 · source 7
  8. DOXINE (doxycycline hyclate) 100 mg film-coated tablets -- New Zealand Data SheetMedsafe (New Zealand Medicines and Medical Devices Safety Authority) -- New Zealand Data Sheet · New Zealand · dated 2026-01-01 · accessed 2026-07-30 · source 8

Brand names by country

Single-ingredient doxycycline (as doxycycline hyclate, doxycycline monohydrate, or doxycycline calcium, depending on formulation) names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • doxycycline hyclate100 mg0mL, 200 mg/20mL · slate run pharmaceuticals, llc
  • ORACEA40 mg · galderma laboratories, l.p.

United Kingdom

  • Doxycycline Capsules (generic) (4)emc current smpc confirmed · 50 mg, 100 mg · Multiple generic manufacturers
  • Vibramycin-D (dispersible tablets) (4)emc current smpc confirmed · 100 mg · Pfizer

Canada

  • DOXYCIN
  • ATRIDOX
  • PERIOSTAT
  • APPRILON
  • APO-DOXY

Australia

  • Doryx (7)tga artg registered confirmed · 50 mg, 60 mg, 80 mg, 200 mg · Mayne Pharma International Pty Ltd
  • APX-Doxycycline / Doxycycline Sandoz (generics) (7)tga artg registered confirmed · 100 mg · Apotex/Sandoz
  • Vibramycin -- DISCONTINUED, not currently available (7)tga artg registration cancelled 2018 2022 · 100 mg · Pfizer Australia Pty Ltd

New Zealand

  • Doxine (8)medsafe data sheet confirmed · 100 mg · Confirmed via Medsafe data sheet
View brands in additional countries.

European Union

Doxycycline hyclate (various nationally authorised generic brands) (5)

This page provides general reference information about doxycycline and is not a substitute for advice from the prescriber managing your treatment. All dosing and treatment decisions, including starting, changing, or stopping this medicine, should be made with your prescriber.

Last medically reviewed: August 14, 2026, by , MBBS, MD (Internal Medicine). See the medical review policy.

Related medicines

Related conditions

Pharmacology