tetracycline

REMS

Treatment of various infections due to unusual organisms, including::
- Mycoplasma
  ,
- Chlamydia
  ,
- Rickettsia
  ,
- Borrelia burgdorferi
  .
Treatment of gonorrhea and syphilis in penicillin-allergic patients.
Prevention of exacerbations of chronic bronchitis.
Treatment of acne.

Action ⬆ ⬇

Inhibits bacterial protein synthesis at the level of the 30S bacterial ribosome.

Therapeutic effects:

Bacteriostatic action against susceptible bacteria.

Spectrum:

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

Pharmacokinetics ⬆ ⬇

Absorption: 60–80% absorbed after oral administration.

Distribution: Widely distributed, some CSF and good bone penetration; crosses the placenta and enters breast milk.

Metabolism/Excretion: Excreted mostly unchanged by the kidneys.

Half-Life: 6–12 hr.

Time/Action Profile ⬆ ⬇

(blood levels)

ROUTE	ONSET	PEAK	DURATION
PO	1–2 hr	2–4 hr	6–12 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Some products contain alcohol or bisulfites and should be avoided in patients with known hypersensitivity or intolerance;
Pedi: Children 8 yr (permanent staining of teeth);
OB: Risk of permanent staining of teeth in infant if used during last half of pregnancy;
Lactation: Lactation.

Use Cautiously in:

Cachectic or debilitated patients;
Renal disease;
Nephrogenic diabetes insipidus.
OB: Women of childbearing age

Adv. Reactions/Side Effects ⬆ ⬇

Derm: photosensitivity, rashes

GI: diarrhea, nausea, vomiting, esophagitis, hepatotoxicity, pancreatitis

Hemat: blood dyscrasias

Neuro: dizziness, intracranial hypertension

Misc: hypersensitivity reactions, superinfection

Interactions ⬆ ⬇

Drug-drug:

May ↑ the effect of warfarin.
May ↓ effectiveness of estrogen-containing oral contraceptives.
Antacids,calcium, iron, and magnesium form insoluble compounds (chelates) and ↓ absorption of tetracycline.
Sucralfate may bind to tetracycline and prevent its absorption from the GI tract.
Cholestyramine orcolestipol↓ absorption.
Adsorbentantidiarrheal agents may ↓ absorption.
Barbiturates, phenytoin, orcarbamazepine may ↓ activity of doxycycline.
Isotretinoin may ↑ risk of intracranial hypertension; avoid concomitant use

Calcium in foods or dairy products↓ absorption by forming insoluble compounds (chelates).

Route/Dosage ⬆ ⬇

PO (Adults ): 250–500 mg q 6 hr or 500 mg–1 g q 12 hr. Chronic treatment of acne: 500 mg–2 g/day for 3 wk, then ↓ to 125 mg–1 g/day.
PO (Children ≥8 yr): 6.25–12.5 mg/kg q 6 hr or 12.5–25 mg/kg q 12 hr.

Availability ⬆ ⬇

(Generic available)

Capsules: 250 mg; 500 mg
In combination with: bismuth subcitrate potassium and metronidazole (Pylera). See Appendix [not included in this PDA edition].

Assessment ⬆ ⬇

Infection: Assess for infection (vital signs; appearance of wound, sputum, urine, and stool; WBC) at beginning of and throughout therapy.
- Obtain specimens for culture and sensitivity before initiating therapy. First dose may be given before receiving results.

Lab Test Considerations:

Renal and hepatic functions and CBC should be monitored periodically during long-term therapy.
- May cause ↑ AST, ALT, serum alkaline phosphatase, bilirubin, and amylase concentrations. Tetracyclines, except doxycycline, may cause elevated serum BUN.
- May cause false ↑ in urinary catecholamine levels.

Implementation ⬆ ⬇

May cause yellow-brown discoloration and softening of teeth and bones if administered prenatally or during early childhood. Not recommended for children <8 yr of age or during pregnancy or lactation.
PO: Administer around the clock. Administer at least 1 hr before or 2 hr after meals. Administer with a full glass of liquid at least 1 hr before going to bed to avoid esophageal ulceration.
- Avoid administration of calcium, antacids, magnesium-containing medications, sodium bicarbonate, or iron supplements within 1–3 hr of tetracycline.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication around the clock and to finish the drug completely, as directed, even if feeling better. If a dose is missed, take as soon as possible unless almost time for next dose; do not double doses. Advise patient that sharing of this medication may be dangerous.
- Advise patient to avoid taking milk or other dairy products concurrently with tetracycline. Also avoid taking antacids, calcium, magnesium-containing medications, sodium bicarbonate, and iron supplements within 1–3 hr of tetracycline.
- Caution 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, of childbearing age or have a history of intracranial hypertension are at greater risk for developing tetracycline-associated intracranial hypertension. Skin rash, pruritus, and urticaria should also be reported.
- Instruct patient to notify health care professional of medication regimen before treatment or surgery.
- Advise female patients to use a nonhormonal method of contraception while taking tetracycline and until next menstrual period.
- Instruct patient to notify health care professional if symptoms do not improve within a few days for systemic preparations.
- Caution patient to discard outdated or decomposed tetracycline; may be toxic.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇