Central nervous system tetracyclines

Parenterally administered penicillin is recommended for all stages of syphilis. Alternative agents may be used in allergic individuals and include doxycycline, minocycline, tetracycline, or erythromycin base or stearate. Some patients may not respond favorably to alternative modalities. Therefore, in patients who must be administered penicillin (i.e., patients who are pregnant or have central nervous system [CNS] involvement) or are allergic, desensitization must be performed before the drug is initiated. 

For any medicinal chemist or pharmacologist the similarity of this compound with the antibiotic tetracycline is striking. However, none of them would a priori forecast that BMS-192548 exhibits central nervous system (CNS) activities. Actually, the compound turns out to be a ligand for the neuropeptide Y receptor preparations. ... 

Do tetracyclines cross into the central nervous system (CNS) ... 

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