Tetracycline contraindications

Discuss the uses, general drug action, adverse reactions, contraindications, precautions, and interactions of the tetracyclines, macrolides, and... 

These antibiotics are effective in die treatment of infections caused by a wide range of gram-negative and gram-positive microorganisms. The tetracyclines are used in infections caused by Rickettsiae (Rocky Mountain spotted fever, typhus fever, and tick fevers). Tetracyclines are also used in situations in which penicillin is contraindicated, in the treatment of intestinal amebiasis, and in some skin and soft tissue infections. Oral... 

The tetracyclines are contraindicated if the patient is known to be hypersensitive to any of the tetracyclines. Tetracyclines also are contraindicated during pregnancy because of die possibility of toxic effects to the developing fetus. The tetracyclines are classified Pregnancy Category D drag. These drug also are contraindicated... 

Cephalexin is considered safe and effective. Nitrofurantoin should not be used after week 37 due to concern for hemolytic anemia in the newborn. Sulfa-containing drugs may increase risk for kernicterus in the newborn and should be avoided during the last weeks of gestation. Folate antagonists, such as trimethoprim, are relatively contraindicated during the first trimester because of their association with cardiovascular malformations. Fluoroquinolones and tetracyclines are contraindicated. 

Children Tetracyclines generally should not be used in children less than 8 years of age (except for anthrax, including inhalational) unless other drugs are not likely to be effective or are contraindicated. 

VLa.2,6. Other antimalarials. Doxycydine (see Section ILb) is a useful and effective short-term prophylactic agent for travellers to chloroquine-resistant areas and can be used as an alternative when mefloquine or proguanil is unavailable or mefloquine is contraindicated. In combination with quinine also tetracycline is used as an antimalarial. 

Contraindications Hypersensitivity to tetracyclines or sulfites, severe hepatic dysfunction... 

Orodental infection caused by mixed aerobic, anaerobic bacteria including Vincent s infection caused by Fusobac-terium. Tetracycline also prove to be beneficial in peridontal inflammation by scavenging free radicals. Its use in pregnancy, lactation and in children is contraindicated. Its use in dentistry is very much restricted due to its chelating effect on teeth and bones. 

Because of potential toxicity, bacterial resistance, and the availability of other effective drugs (eg, cephalosporins), chloramphenicol is all but obsolete as a systemic drug. It may be considered for treatment of serious rickettsial infections, such as typhus or Rocky Mountain spotted fever, in children for whom tetracyclines are contraindicated, ie, those under 8 years of age. It is an alternative to a b-lactam antibiotic for treatment of meningococcal meningitis occurring in patients who have major hypersensitivity reactions to penicillin or bacterial meningitis caused by penicillin-resistant strains of pneumococci. The dosage is 50-100 mg/kg/d in four divided doses. 

Hepatic dysfunction Antibiotics that are concentrated or eliminated by the liver (for example, erythromycin, tetracycline) are contraindicated in treating patients with liver disease. 

Correct answer = A. Most urinary tract infections are due to E. coii and can usually be treated with cotrimoxazole. However, this patient is near term and the sulfa in the cotrimoxazole might put the infant at risk due to kernicterus. Thus, the first generation cephalosporin, cefadroxil, is appropriate since it would be effective orally against penicillinase producing E. coii. Ceftriaxone, while it would be effective, would have to be administered parenterally. Penicillin V is not effective against E. coii. Tetracycline deposits in teeth and skeleton of the fetus and is contraindicated. 

Correct choice = E. Only tetracycline is deposited in bone and thus is contraindicated in children under age 8. Ciprofloxacin damages developing articular cartilage in young experimental animals, which is why it is contraindicated In children under 18 years of age. All the other statements pertain to both antibiotics. 

Tetracyclines are recommended as first-line treatment. When tetracyclines are not tolerated or contraindicated, erythromycin is an alternative. However erythromycin has problems with resistance and gastrointestinal adverse effects. If compliance is a problem, either doxycycline or lymecycline may be prescribed (can be taken once daily with food). Minocycline is second-line treatment (e.g. if oral antibiotic has failed). 

Tetracyclines are contraindicated in patients with known hypersensitivity or intolerance to any member of the tetracycline femily. The use of tetracyclines during tooth development can cause permanent discoloration of teeth and is thus contraindicated in pregnant or breast-feeding women and in children 8 years of age or younger. 

Trachoma can be effectively treated with a 4- to 6-week course of topical tetracycline ointment. Additionally, oral tetracycline 250 mg four times a day or doxycycline 100 mg orally twice a day for 14 days is an effective option if not contraindicated. Alternatively, azithromycin in a single oral dose (20 mg/kg) was found to be equally effective in resolving active trachoma and offers the advantage of increased compliance. Reinfection rates are high, especially in endemic areas. In patients with severe conjunctival cicatrization, surgical intervention may be required to correct trichiasis and entropion and to prevent corneal scarring. 

Relative contraindications to sulfonamides are systemic lupus erythematosus and a known predisposition to lupuslike reactions. Allergic reactions to antimicrobials are frequent in patients with Sjogren s sjmdrome. They are especially susceptible to reactions to penidUins, cephalosporins, and sulfonamides, but reactions to macrohdes and tetracyclines also seem to be over-represented in these patients (210). 

The authors mentioned that their previous study had not shown a teratogenic potential of doxycycline (164), but concluded, far more prudently, that all tetracyclines are contraindicated during pregnancy. 

Co-administration of tetracyclines with antacids or other drugs containing divalent or trivalent cations, such as calcium, magnesium, or iron, is contraindicated. Tetracyclines form complexes with such cations, which are very poorly or not at all absorbed (75,174,175). 

Concurrent use of tetracycline has been considered contraindicated because of the risk of benign intracranial hypertension. However, although either compound alone can provoke this rare adverse effect, there is no evidence of any additive effect (12). 

B Nongonococcal urethritis is primarily caused by C. trachomatis. Infections caused by C. trachomatis can be treated with tetracyclines, azithromycin, or macrolides. Doxycyline is contraindicated in pregnant women because of the effects on fetal teeth and... 

Side effects Adverse reactions Contraindications delay in wound healing None known Anemia, increased LDL cholesterol, muscle pain, fever, nausea, vomiting Do not take with tetracycline. 

According to the CDC, use amoxidUin only after 10-14 days of fluoroquinolones or doxycycline treatment and only then if there are contraindications to fluoroquinolones or tetracyclines such as pregnancy, lactation, age <18 years or intolerance... 

Other Agents - Erythromycin in a dose of 0.5 gm four times daily for 7 days is usually given for NGU when tetracycline is contraindicated. Cure rates and relapse rates are comparable to those seen with the tetracyclines but the total experience is much less than with the tetracyclines and there are no studies correlating success rates with trachomatis or U. urealyticum isolation. trachomatis is generally susceptible (MIC... 

Tetracyclines are also contraindicated in pregnant women, nursing mothers, and children younger than 8 years of age because they can cause dental staining and defects in enamelization of deciduous and permanent teeth, as well as a decrease in bone growth. "... 

Eor pregnant women with chlamydial urogenital infections, treatment can reduce the risk of pregnancy complications and transmission to the newborn significantly. Because the use of tetracyclines and fluoroquinolones is contraindicated during pregnancy, erythromycin base and amoxicillin are the recommended drug treatments (see Table 115-8). Some clinicians prefer amoxicillin to erythromycin because of better patient tolerability and, as a resulf improved patient compliance. Patients intolerant of... 

Another point that has defied explanation is this SM is bacteriocidal only during periods of high rates of protein synthesis. Thus other protein inhibitors such as tetracyclines or chloramphenicol should interfere with its action, yet this theoretical drug interaction is not necessarily clinically contraindicated. In fact, a combination of streptomycin and tetracycline is the treatment of choice for glanders and brucellosis. 

Describe the contraindications of the exposure to sunlight with tetracycline therapy. 

Tetracyclines cause photosensitivity and exposure to sunlight is thus contraindicated. 

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