doxycycline

Contraindicated in:

Hypersensitivity;
Some products contain alcohol or bisulfites and should be avoided in patients with known hypersensitivity or intolerance;
OB: ↑risk of bone growth inhibition and permanent staining of teeth in infant if used during 2nd or 3rd trimesters; may be used to treat anthrax in pregnant women due to the seriousness of the disease;
Lactation: Lactation.

Use Cautiously in:

Rep: Women of reproductive potential (↑ risk of intracranial hypertension if overweight or have a previous history of intracranial hypertension);
Pedi: Children <8 yr (may cause permanent staining of teeth) (may be used to treat anthrax or Rocky Mountain spotted fever in children <8 yr due to the seriousness of these diseases).

Adv. Reactions/Side Effects ⬆ ⬇

Derm: photosensitivity, DRUG RASH WITH EOSINOPHILIA AND SYSTEMIC SYMPTOMS (DRESS), ERYTHEMA MULTIFORME, EXFOLIATIVE DERMATITIS, rash, STEVENS-JOHNSON SYNDROME (SJS), TOXIC EPIDERMAL NECROLYSIS (TEN)

GI: diarrhea, nausea, vomiting, CLOSTRIDIOIDES DIFFICILE-ASSOCIATED DIARRHEA (CDAD), dysphagia, esophagitis, glossitis, HEPATOTOXICITY, PANCREATITIS

Hemat: blood dyscrasias

Local: phlebitis at IV site

Neuro: headache, intracranial hypertension

Misc: hypersensitivity reactions, superinfection

Interactions ⬆ ⬇

Drug-drug:

May ↑ effect of warfarin.
May ↓ effectiveness of estrogen-containing oral contraceptives.
Antacids, calcium, iron, and magnesium form insoluble compounds (chelates) and ↓ absorption and effectiveness of tetracyclines; this effect is least with doxycycline.
Cholestyramine, colestipol, and bismuth subsalicylate may ↓ absorption and effectiveness.
Barbiturates, carbamazepine, or phenytoin may ↓ effectiveness.
Isotretinoin may ↑ risk of intracranial hypertension; avoid concomitant use.

Drug-Food:

Calcium in foods or dairy products may ↓ absorption by forming insoluble compounds (chelates); this effect is minimal with doxycycline.

Availability ⬆ ⬇

(Generic available)

Immediate-release tablets: 20 mg; 50 mg; 75 mg; 100 mg; 150 mg
Immediate-release capsules: 50 mg; 75 mg; 100 mg; 150 mg
Delayed-release tablets: 50 mg; 60 mg; 75 mg; 100 mg; 150 mg; 200 mg
Delayed-release capsules (Oracea): 40 mg
Oral suspensionraspberry flavor: 25 mg/5 mL
Oral syrupraspberry-apple flavor: 50 mg/5 mL
Powder for injection: 100 mg/vial

Route/Dosage ⬆ ⬇

More Common Infections

PO (Adults and Children >8 yr and >45 kg): Most infections: 100 mg every 12 hr on the 1st day; then 100–200 mg once daily or 50–100 mg every 12 hr. Gonorrhea: 100 mg every 12 hr for 7 days or 200 mg once daily for 7 days (delayed-release tablets) or 300 mg followed 1 hr later by another 300-mg dose. Uncomplicated urethral, endocervical, or rectal infection caused by Chlamydia trachomatis: 100 mg every 12 hr for 7 days. Syphilis (early): 100 mg every 12 hr for 14 days. Syphilis (>1 yr duration): 100 mg every 12 hr for 4 wk. Malaria prophylaxis: 100 mg once daily (2 mg/kg once daily for children > 8 yr). Lyme disease: 100 mg twice daily; Periodontitis: 20 mg twice daily; Rosacea: 40 mg once daily in morning.
PO (Children >8 yr and <45 kg): Less severe infections: 2.2 mg/kg every 12 hr on the 1st day; then 2.2–4.4 mg/kg once daily or 1.1–2.2 mg/kg every 12 hr.
PO (Children >45 kg): Severe or life-threatening infections (Rocky Mountain spotted fever): 100 mg every 12 hr.
PO (Children <45 kg): Severe or life-threatening infections (Rocky Mountain spotted fever): 2.2 mg/kg every 12 hr.

Inhalational Anthrax (Postexposure)

PO IV (Adults and Children >45 kg): 100 mg IV every 12 hr; change to 100 mg PO every 12 hr when clinically appropriate for a total of 60 days; one or two other anti-infectives may be added initially, depending on clinical situation.
PO IV (Children ≤45 kg): 2.2 mg/kg IV every 12 hr; change to 2.2 mg/kg PO every 12 hr when clinically appropriate for a total of 60 days; one or two other anti-infectives may be added initially, depending on clinical situation.

Cutaneous Anthrax

PO (Adults ): 100 mg every 12 hr for 60 days; some patients may require IV therapy initially depending on clinical situation.
PO (Children >8 yr and >45 kg): 100 mg every 12 hr; some patients may require IV therapy initially depending on clinical situation.
PO (Children >8 yr and ≤45 kg): 2.2 mg/kg every 12 hr; some patients may require IV therapy initially depending on clinical situation.
PO (Children ≤8 yr): 2.2 mg/kg every 12 hr; some patients may require IV therapy initially depending on clinical situation.

US Brand Names ⬆ ⬇

Acticlate, Doryx, Doryx MPC, Doxy, Oracea, Targadox, Vibramycin

Action ⬆ ⬇

Inhibits bacterial protein synthesis at the level of the 30S bacterial ribosome.
Low-dose products used in the management of periodontitis inhibit collagenase.

Therapeutic effects:

Bacteriostatic action against susceptible bacteria.

Spectrum:

Includes activity against some gram-positive pathogens:
- Bacillus anthracis(anthrax),
- Clostridium perfringens,
- Clostridium tetani,
- Listeria monocytogenes,
- Nocardia,
- Propionibacterium acnes,
- Actinomyces israelii.
Active against some gram-negative pathogens:
- Haemophilus influenzae,
- Legionella pneumophila,
- Yersinia enterocolitica,
- Yersinia pestis,
- Neisseria gonorrhoeae,
- Neisseria meningitidis.
Also active against several other pathogens, including:
- Mycoplasma,
- Treponema pallidum,
- Chlamydia,
- Rickettsia,
- Borrelia burgdorferi.

Classifications ⬆ ⬇

Therapeutic Classification: anti-infectives

Pharmacologic Classification: tetracyclines

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed from the GI tract.

Distribution: Widely distributed, some CSF and good bone penetration.

Metabolism/Excretion: 20–40% excreted unchanged in urine; some inactivation in intestine and some enterohepatic circulation with excretion in bile and feces.

Half-Life: 14–17 hr (↑ in severe renal impairment).

Canadian Brand Names ⬆ ⬇

Apprilon, Doxycin, Doxytab, Periostat

Time/Action Profile ⬆ ⬇

(plasma concentrations)

ROUTE	ONSET	PEAK	DURATION
PO	1–2 hr	1.5–4 hr	12 hr
IV	rapid	end of infusion	12 hr

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication around the clock and to finish the drug completely as directed, even if feeling better. Take missed doses as soon as possible unless it is almost time for next dose; do not double doses. Advise patient that sharing of this medication may be dangerous.
- Advise patient to avoid taking antacids, calcium, magnesium-containing medications, sodium bicarbonate, and iron supplements within 1–3 hr of oral doxycycline.
- Instruct patient to notify health care professional immediately if rash, diarrhea, abdominal cramping, fever, or bloody stools occur and not to treat with antidiarrheals without consulting health care professionals.
- Advise patient to use sunscreen and protective clothing to prevent photosensitivity reactions.
- Advise patient to report the signs of superinfection (black, furry overgrowth on the tongue, vaginal itching or discharge, loose or foul-smelling stools) or intracranial hypertension (headache, blurred vision, diplopia, vision loss). Women who are overweight, are of childbearing age, or have a history of intracranial hypertension are at greater risk for developing doxycycline-associated intracranial hypertension. Skin rash, pruritus, and urticaria should also be reported.
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
- Instruct patient to notify health care professional of medication regimen before treatment or surgery.
- Caution patient to discard outdated or decomposed doxycycline; they may be toxic.
- Advise females of reproductive potential to use a nonhormonal method of contraception while taking doxycycline and until next menstrual period. Advise patient to notify health care professional promptly if pregnancy is planned or suspected or if breastfeeding. May be used for short term. Consider developmental and health benefits of breastfeeding with the mother’s clinical need for doxycyline and any potential adverse effects on the breastfed child from doxycyline or from the underlying maternal condition.
- Instruct patient to notify health care professional if symptoms do not improve within a few days for systemic preparations.
Malaria Prophylaxis: Advise patient to avoid being bitten by mosquitoes by using protective measures, especially from dusk to dawn (staying in well-screened areas, using mosquito nets, covering the body with clothing, using an effective insect repellent). Doxycycline prophylaxis should begin 1–2 days before travel to the malarious area and continued daily while in the malarious area; after leaving the malarious area, it should be continued for 4 more wk to avoid development of malaria. Do not exceed 4 mo.

section name header

Indications ⬇

Contraind./Precautions ⬆ ⬇