Tetracyclines hypersensitivity

Antibiotics Cephalosporins Chloramphenicol Neomycin Sulfathiazole Spiramycin Quinolones Tetracyclines Hypersensitivity Anaphylaxis, urticaria, rash, granulocytopenia Rash, dermatitis, urticaria Dermal exposure-rash, dermatitis Rash, dermatitis, urticaria Rash, dermatitis, urticaria Photosensitivity Photosensitivity, anaphylaxis, asthma, dermatitis... 

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... 

Pseudomembranous colitis Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range in severity from mild to life-threatening. Hypersensitivity reactions Administer tigecycline with caution to patients with known hypersensitivity to tetracycline class antibiotics. 

Topical tetracyclines are sometimes used to treat acne and minor superficial pyogenic infections of the skin. Patients hypersensitive to one member of this class of antibiotics may also be hypersensitive to other tetracyclines. Photosensitization may occur. 

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

Hypersensitivity reactions (drug fever, skin rashes) to tetracyclines are uncommon. Most adverse effects are due to direct toxicity of the drug or to alteration of microbial flora. 

Gastrointestinal distress (nausea, vomiting, diarrhea) may be a problem with tetracycline use. Hypersensitivity reactions (such as rashes) may also occur, as well as an increase in skin sensitivity to ultraviolet light (photosensitivity).16 Tetracyclines form chemical complexes with calcium that may impair the growth and development of calcified tissues such as bone and teeth, especially in children.69 Tetracyclines also cause discoloration of teeth in children and pregnant women, apparently because of the tetracycline-calcium interaction.69 As mentioned previously, development of tetracycline-resistant strains and resulting superinfections may be a serious problem during tetracycline therapy. 

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. 

For drug screening purposes, the titratable repression of the Tet promoter by addition of tetracycline allows control over the cellular concentration of a specific target protein. Similar to antisense RNA-based cell sensitization described in Section 7.2.2.1, this approach provides a MOA (mechanism of action)-based assay because cells with reduced target protein levels become hypersensitive... 

A photosensitivity reaction, which manifests as an exaggerated simburn, is common in patients receiving any tetracycline drug. Hypersensitivity reactions to tetracyclines including anaphylaxis, urticaria, periorbital edema, and morbilliform rashes can occur but are uncommon. 

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. 

Allergic reactions to tetracyclines are less than half as common as allergic reactions to penicillin. For this reason, tetracyclines are alternatives in patients with allergic reactions to other antibiotics. Exceptional observations of anaphylactic shock have been reported (37,38). In a few cases tetracychnes were assumed to be the cause of hypersensitivity myocarditis (39). Pneumonitis with eosinophiha has been described in association with tetracychnes (40). A serum sickness-hke syndrome was probably associated with minocycline in a 19-year-old man treated for acne (41). Allergic and toxic reactions may in some cases have been caused by degraded formulations or additives (42). Tumor-inducing effects have not been reported. 

Cardiovascular reactions to tetracyclines have often been associated with other symptoms of hypersensitivity, such as urticaria, angioedema, bronchial obstruction, and arterial hypotension (37,56). Such reactions occurred in patients who had tolerated tetracyclines previously and were therefore considered as anaphylactic. 

Not for patients who are hypersensitive to lidocaine, procaine, and other caine medication because IM injection of tetracyclines contains caine medication... 

Answer B. Indications for the use of penicillin G are currently limited for a number of reasons. The drug has a narrow spectrum, is susceptible to beta-lactamases, and may cause hypersensitivity, and alternative antibiotics are available. However, penicillin G remains the drug of choice in syphilis, usually given IM as benzathine penicillin G, but as the Na or K salt IV in neurosyphilis. What would you do for patients who are highly allergic to penicillins (Consider tetracyclines, or possibly desensitization.)... 

Tetracyclines can cause gastric irritation, particularly in large doses, and can also cause tooth discoloration in children. Hepatotoxicity may be seen with large doses (> 2g), as well as nephrotoxicity. Hypersensitivity reactions can also be seen. 

Various skin reactions rarely may follow the use of any of the tetracyclines. More severe allergic responses are angioedema and anaphylaxis anaphylactoid reactions can occur even with oral administration. Other hypersensitivity reactions are burning of the eyes, cheilosis, glossitis, pruritus ani or vulvae, and vaginitis, which can persist for months after cessation of therapy. Fever, eosinophilia, and asthma also have been observed. Cross-sensitization among the various tetracyclines is common. 

A 24-year-old woman has primary syphilis. She has a history of penicillin hypersensitivity, so tetracycline will be used to treat the infection. Which one of the following statements about the proposed drug treatment of this patient is false ... 

Spectinomycin (2 g intramuscularly) is the appropriate choice in this case. Avoid cephalosporins in patients with a history of severe hypersensitivity to penicillins, and avoid fluoroquinolones (see Chapter 46) in pregnancy. Tetracyclines have been used in the past for gonorrhea but not as single doses, and they too should be avoided in pregnancy. The answer is (D). 

B) A hypersensitivity to the drug as in other drug allergic reactions (sulphonamides, penicillins, tetracyclines and a number of other drugs). 

---