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Doxycycline hyclate oral 50mg and 100mg


Oral formulations of doxycycline (as doxycycline hyclate).

Drugs List

  • doxycycline 100mg capsules
  • doxycycline 50mg capsules
  • Therapeutic Indications


    Acne vulgaris
    Antibiotic sensitive infections
    Malaria - prophylaxis
    Prophylaxis of leptospirosis
    Prophylaxis of scrub typhus
    Prophylaxis of travellers' diarrhoea(enterotoxigenic E. coli)
    Treatment of chloroquine resistant malaria
    Treatment of louse and tick-borne fevers (Rickettsia, Babesia, Borrelia)
    Treatment of sexually transmitted infections

    Treatment of infections caused by susceptible strains of Gram-positive and Gram-negative bacteria and certain other micro-organisms.

    Types of infections include:
    Respiratory tract infections
    Chronic bronchitis, sinusitis, pneumonia and other lower respiratory tract infections due to susceptible strains of Streptococcus pneumoniae, Haemophilus influenzae, Klebsiella pneumoniae and other organisms including Mycobacteria pneumoniae.

    Urinary tract infections
    Due to susceptible strains of Klebsiella species, Enterobacter species, Escherichia coli, Streptococcus faecalis and other organisms.

    Sexually transmitted infections
    Due to Chlamydia trachomatis including uncomplicated urethral, endocervical or rectal infections. Non-gonococcal urethritis caused by Ureaplasma urealyticum (T-mycoplasma). Chancroid granuloma inguinale and lymphogranuloma venereum and as an alternative drug in the treatment of gonorrhoea and syphilis.

    Skin infections
    Acne vulgaris when antibiotic therapy is considered necessary.

    Ophthalmic infections
    Due to susceptible strains of gonococci, staphylococci and Haemophilus influenzae. Trachoma (although the infectious agent is not always eliminated). Inclusion conjunctivitis.

    Rickettsial infections
    Rocky mountain spotted fever, typhus, Q fever, Coxiella endocarditis and tick fevers.

    Other infections
    Psittacosis, brucellosis (in combination with streptomycin), cholera, bubonic plague, louse and tick-borne relapsing fever, tularaemia, glanders, melioidosis, chloroquine-resistant falciparum malaria, acute amoebiasis (as an adjunct to amoebicides), leptospirosis, gas gangrene and tetanus. Other infections due to susceptible strains of Yersina or Clostridium.

    Prophylaxis against the following infections:
    Scrub typhus, travellers' diarrhoea, leptospirosis and malaria.

    For up to date advice on geographical resistance patterns and appropriate prophylaxis, current guidelines should be consulted.
    Guidelines for Malaria Prevention from the Public Health England specifically developed for travellers from the United Kingdom may be obtained on the HPA website:

    Unlicensed Uses

    Lyme disease
    Treatment and prophylaxis of anthrax
    Treatment of rosacea



    Initial dose: 200mg on the first day (as a single or in divided doses).
    Maintenance dose: 100mg daily (up to 200mg daily in severe infections).
    Continue for 24 to 48 hours after symptoms have resolved.

    When used to treat streptococcal infections, therapy should be continued for ten days to prevent the development of rheumatic fever or glomerulonephritis.

    Dose regimes in specific infections

    Sexually transmitted diseases
    Uncomplicated gonococcal infection (except anorectal infections in men), uncomplicated urethral, endocervical, or rectal infection, and non-gonococcal urethritis: 100mg twice daily for seven days.
    Acute epididymo-orchitis or Neisseria gonorrhoea: 100mg twice daily for ten days.
    Pelvic inflammatory disease: 100mg twice daily for fourteen days.
    Primary or secondary syphilis: 300mg daily in divided doses for ten days.

    The following alternative dosing schedule may be suitable:
    Early syphilis: 100mg twice daily for fourteen days.
    Late latent syphilis: 100mg twice daily for twenty eight days.
    Neurosyphilis: 200mg twice daily for twenty eight days.

    Louse and tick-borne relapsing fevers
    100mg or 200mg according to severity as a single dose.

    Treatment of chloroquine resistant falciparum malaria
    200mg daily for at least seven days, to be given in conjunction with a rapid acting schizonticide such as quinine.

    Acne vulgaris
    50mg once daily for six to twelve weeks.
    Alternative sources suggest a dose of 100mg once daily.

    Prophylaxis of malaria
    100mg daily.
    Prophylaxis can begin one to two days before travel to malarial areas. It should be continued daily during travel in the malarial areas and for four weeks after the traveller leaves the malarial area.

    Prevention of scrub typhus
    200mg as a single dose.

    Prevention of traveller's diarrhoea
    200mg on the first day of travel (as a single dose or as 100mg every 12 hours), followed by 100mg daily throughout the stay in the area.

    Prevention of leptospirosis
    200mg once each week throughout the stay in the area and 200mg on completion of the trip.

    Treatment and prophylaxis of anthrax (unlicensed)
    100mg twice daily. Treatment should continue for sixty days as germination may be delayed.

    Treatment of rosacea if other antibiotics are not appropriate (unlicensed)
    100mg once daily.

    Lyme disease (unlicensed)
    100mg twice daily for ten to fourteen days for early Lyme disease. In cases of Lyme arthritis a duration of twenty eight days is recommended.


    Children aged 12 to 18 years
    (See Dosage; Adult)

    Children aged under 12 years (unlicensed)
    Prophylaxis and treatment of anthrax
    2.5mg/kg twice daily (maximum 100mg twice daily).


    Children under 12 years
    Second trimester of pregnancy
    Third trimester of pregnancy

    Precautions and Warnings

    First trimester of pregnancy
    Glucose-galactose malabsorption syndrome
    Hepatic impairment
    Hereditary fructose intolerance
    Lactose intolerance
    Myasthenia gravis
    Systemic lupus erythematosus

    Jarisch-Herxheimer reaction possible in treatment of Spirochetes infection
    May exacerbate myasthenia gravis
    Advise ability to drive/operate machinery may be affected by side effects
    Consult national/regional policy on the use of anti-infectives
    Drugs for malaria prophylaxis are not prescribable on the NHS
    Some formulations contain lactose
    Some formulations contain sucrose
    Swallow dose with plenty of fluid while sitting or standing
    If visual disturbances occur, perform ophthalmic evaluation
    Consider C. difficile if diarrhoea occurs within 2 months of treatment
    Consider pseudomembranous colitis if patient presents with diarrhoea
    Discontinue treatment if DRESS is suspected
    Prolonged use may result in superinfection with non-susceptible organisms
    Discontinue at first signs of skin erythema
    Discontinue if overgrowth of resistant organisms occurs
    Discontinue if photosensitivity occurs
    Discontinue if signs of raised intracranial pressure
    Advise patient not to take St John's wort concurrently
    Advise to avoid antacids/mineral supplements 2 hours before or after dose
    Advise patient to avoid alcohol during treatment
    Advise patient that photosensitivity possible
    Avoid excessive exposure to sunlight
    Avoid excessive exposure to UV light

    Oesophagitis and oesophageal ulceration have been reported in patients receiving doxycycline. The incidence of these effects can be minimised by taking the dose well before retiring to bed, while sitting or standing and with an adequate amount of fluid.

    When treating venereal disease, where syphilis is also suspected, appropriate diagnostic procedures (including dark-field examinations) should be conducted. In these cases, monthly serological tests should be made for at least four months.

    Pregnancy and Lactation


    Doxycycline is contraindicated in the second and third trimesters of pregnancy.

    The manufacturer contraindicates use in pregnancy.

    Tetracyclines cross the placenta and bind strongly to calcium ions effecting teeth and skeletal development in the foetus during the second and third trimesters.

    High doses in the second half of pregnancy have been associated with severe maternal hepatic toxicity.

    In the first trimester tetracyclines are considered to be second line therapy. In such cases doxycycline is the prefered agent. Inadvertent exposure to tetracyclines even after the fifteenth week is not an indication for termination of pregnancy or for invasive diagnostic procedures (Schaefer 2015).


    Although contraindicated by the manufacturer there is evidence of safety in short term use.

    Doxycyline is excreted into breast milk. However, studies on the closely related antibiotic tetracycline have shown undetectable serum levels in the infant.

    Avoid prolonged use or repeated courses during breastfeeding and monitor infant for rash and gastrointestinal effects.

    Side Effects

    Abdominal pain
    Abnormal liver function tests
    Anaphylactic shock
    Anaphylactoid purpura
    Anaphylactoid reaction
    Benign intracranial hypertension
    Black tongue
    Blood urea increased
    Blurred vision
    Brown-black microscopic discolouration of thyroid tissue
    Bulging fontanelles in infants
    Decreased appetite
    Drug rash with eosinophilia and systemic symptoms (DRESS)
    Enamel hypoplasia
    Erythema multiforme
    Exacerbation of systemic lupus erythematosus
    Exfoliative dermatitis
    Haemolytic anaemia
    Hepatic failure
    Hypersensitivity reactions
    Jarisch-Herxheimer reaction
    Loss of vision
    Maculopapular rash
    Oesophageal ulceration
    Peripheral oedema
    Pseudomembranous colitis
    Serum sickness
    Staphylococcal enteritis
    Stevens-Johnson syndrome
    Toxic epidermal necrolysis
    Vulvovaginal infections
    Yellowish-brown discolouration of teeth

    Effects on Laboratory Tests

    False elevations of urinary catecholamines may occur due to interference with the fluorescence test.


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: April 2019

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Summary of Products Characteristics: Doxycycline 50mg Capsules. Kent Pharmaceuticals. Revised September 2018.
    Summary of Products Characteristics: Doxycycline and Vibrox 100mg Capsules. Kent Pharmaceuticals. Revised December 2018.

    Summary of Products Characteristics: Doxycycline 50mg Capsules. Accord. Revised August 2018.
    Summary of Products Characteristics: Doxycycline 100mg Capsules. Accord. Revised August 2018.

    Summary of Products Characteristics: Doxycycline 50mg Capsules. Teva UK Ltd. Revised September 2018.
    Summary of Products Characteristics: Doxycycline 100mg Capsules. Teva UK Ltd. Revised September 2018.

    Summary of Products Characteristics: Doxycycline 100mg Capsules. Generics UK. Revised June 2018.

    The Welsh Medicines Information Centre (WMIC) Porphyria Information Service.
    Available at:
    Last revised: April 2018
    Last accessed: 07 March 2019

    The Norwegian Porphyria Centre (NAPOS).
    Available at:
    Last revised: 22 September 2018
    Last accessed: 07 March 2019

    NICE Evidence Services Available at: Last accessed: 11 March 2019.

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Doxycyline Last revised: 31 October 2018
    Last accessed: 18 March 2019.

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