Doxycycline (7 brand names, 3 dosage forms, 1 route)
Available dosage forms: FOR SUSPENSION, TABLET, CAPSULE.
Routes of administration: ORAL.
Brand Names
- DOXYCHEL
- DOXYCYCLINE
- MONODOX
- ORACEA
- VIBRAMYCIN
- XYROSA
- ZENAVOD
Indications and Usage
To reduce the development of drug-resistant bacteria and maintain effectiveness of doxycycline hyclate and other antibacterial drugs, doxycycline hyclate should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.
Dosage and Administration
The usual dosage and frequency of administration of doxycycline differs from that of the other tetracyclines. Exceeding the recommended dosage may result in an increased incidence of side effects. Adults: The usual dose of oral doxycycline is 200 mg on the first day of treatment (administered 100 mg every 12 hours) followed by a maintenance dose of 100 mg/day. In the management of more severe infections (particularly chronic infections of the urinary tract), 100 mg every 12 hours is recommended. Pediatric Patients: For all pediatric patients weighing less than 45 kg with severe or life-threatening infections (e.g., anthrax, Rocky Mountain spotted fever), the recommended dosage is 2.2 mg/kg of body weight administered every 12 hours. Children weighing 45 kg or more should receive the adult dose. (See WARNINGS and PRECAUTIONS.) For pediatric patients with less severe disease (greater than 8 years of age and weighing less than 45 kg), the recommended dosage schedule is 4.4 mg/kg of body weight divided into two doses on the first day of treatment, followed by a maintenance dose of 2.2 mg/kg of body weight (given as a single daily dose or divided into twice daily doses). For pediatric patients weighing over 45 kg, the usual adult dose should be used. The therapeutic antibacterial serum activity will usually persist for 24 hours following recommended dosage. When used in streptococcal infections, therapy should be continued for 10 days. Administration of adequate amounts of fluid along with capsule and tablet forms of drugs in the tetracycline class is recommended to wash down the drugs and reduce the risk of esophageal irritation and ulceration. (See ADVERSE REACTIONS.) If gastric irritation occurs, it is recommended that doxycycline be given with food or milk. The absorption of doxycycline is not markedly influenced by simultaneous ingestion of food or milk. Studies to date have indicated that administration of doxycycline at the usual recommended doses does not lead to
Contraindications
This drug is contraindicated in persons who have shown hypersensitivity to any of the tetracyclines.
Adverse Reactions
Due to oral doxycycline’s virtually complete absorption, side effects of the lower bowel, particularly diarrhea, have been infrequent. The following adverse reactions have been observed in patients receiving tetracyclines: Gastrointestinal: anorexia, nausea, vomiting, diarrhea, glossitis, dysphagia, enterocolitis, inflammatory lesions (with monilial overgrowth) in the anogenital region, and pancreatitis. Hepatotoxicity has been reported rarely. These reactions have been caused by both the oral and parenteral administration of tetracyclines. Superficial discoloration of the adult permanent dentition, reversible upon drug discontinuation and professional dental cleaning has been reported. Permanent tooth discoloration and enamel hypoplasia may occur with drugs of the tetracycline class when used during tooth development. (See WARNINGS.) Rare instances of esophagitis and esophageal ulcerations have been reported in patients receiving capsule and tablet forms of the drugs in the tetracycline class. Most of these patients took medications immediately before going to bed. (See DOSAGE AND ADMINISTRATION.) Skin: toxic epidermal necrolysis, Stevens-Johnson syndrome, erythema multiforme, fixed drug eruption, skin hyperpigmentation, maculopapular and erythematous rashes. Exfoliative dermatitis has been reported but is uncommon. Photosensitivity is discussed above. (See WARNINGS.) Renal toxicity: Rise in BUN has been reported and is apparently dose related. (See WARNINGS.) Immune: Hypersensitivity reactions including urticaria, angioneurotic edema, anaphylaxis, anaphylactoid purpura, serum sickness, pericarditis, exacerbation of systemic lupus erythematosus, drug reaction with eosinophilia and systemic symptoms (DRESS), and Jarisch-Herxheimer reaction has been reported in the setting of spirochete infections treated with doxycycline. Blood: Hemolytic anemia, thrombocytopenia, neutropenia, and eosinophilia have been reported. Psychiatric: Depression, anxiety, suicidal ideation,
Drug Interactions
Because tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage. Since bacteriostatic drugs may interfere with the bactericidal action of penicillin, it is advisable to avoid giving tetracyclines in conjunction with penicillin. Absorption of tetracyclines is impaired by antacids containing aluminum, calcium, or magnesium, and iron-containing preparations. Absorption of tetracyclines is impaired by bismuth subsalicylate. Barbiturates, carbamazepine, and phenytoin decrease the half-life of doxycycline. Concurrent use of tetracycline may render oral contraceptives less effective.
Mechanism of Action
Mechanism of Action Doxycycline inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit. Doxycycline has bacteriostatic activity against a broad range of Gram-positive and Gram-negative bacteria. Resistance Cross resistance with other tetracyclines is common. Antimicrobial Activity Doxycycline has been shown to be active against most isolates of the following microorganisms, both in vitroand in clinical infections as described in the INDICATIONS AND USAGEsection of the package insert for doxycycline hyclate.
Overdosage
In case of overdosage, discontinue medication, treat symptomatically and institute supportive measures. Dialysis does not alter serum half-life and thus would not be of benefit in treating cases of overdosage.