Minocycline

Fig. 1. Tetracycline (1) and its derivatives chlortetracycline (7-chlorotetracycline) (2) oxytetracycline (5-hydroxytetracycline) (3), demeclocycline (6-demethyl-7-chlorotetracycline) (4) methacycline (6-demethyl-6-deoxy-5-hydroxy-6-methylenetetracycline) (5) doxycycline (6a-deoxy-5-hydroxytetracycline) (6) and minocycline (6-demethy1-6-deoxy-7-dimethy1 amino tetracycline) (7). Substituents at positions not specifically...

In the United States, the manufacturers of fermentation-derived tetracyclines (1), (2), and (3) are the Ledede Laboratories, a division of American Cyanamid Co., Charles Pfizer Inc., Bristol Laboratories, and RacheUe Laboratories. There are also several manufacturers abroad. Tetracycline is now sold genetically by many companies. Pfizer s doxycycline (6) and Ledede s minocycline (7), both semisynthetic tetracyclines, are the only members of the group that have increasing sales. Table 1 fists the commercial tetracyclines and the corresponding trade names. 

Tetracyclines are used as alternative dnigs in a variety of circumstances when the patient is unable to take the dnig of choice, eg, in patients allergic to penicillin (88,89). Tetracyclines are widely known to cause staining of teeth (and are therefore contra-indicated in children developing permanent teeth), photosensitivity, and, in the case of minocycline, vestibular toxicity. Details of these adverse effects and others associated with administration of tetracyclines have been comprehensively reviewed (96—101). 

A combination of amphotericin B, miconazole (16), and rifampin (17) was used to successfully cure one patient. In addition, tetracycline (7) and minocycline (18) have been recommended although their clinical efficacy have not been estabUshed. No proven therapeutic agents exist for treating A.catbamoeba infections, however, the phenothiazines, trifluoperazine [117-89-5] and chlorpromazine [50-53-3], show promise in vitro. 

Some antibiotics, such as the tetracyclines, tetracycline (7), doxycycline (78), and minocycline (17), chloramphenicol (79), and clindamycin (23) have modest antimalarial properties, but are slow-acting. 

In a synthesis of minocycline, interesting use was made of a reductive alkylation of a nitro function, accompanied by loss of a diazonium group. The sequence provides a clever way of utilizing the unwanted 9-nitro isomer that arises from nitration of 6-demethyl-6-deoxytetracycline (//). When di-azotization was complete, urea and 40% aqueous formaldehyde were added, and the entire solution was mixed with 10% palladium-on-carbon and reduced under hydrogen. No further use of this combined reaction seems to have been made. 

A large number of molecules have provided experimental evidence of neuroprotection in in vitro and in vivo models of Parkinson s disease and many of these putative neuroprotective substances are now the objects of clinical trials. Recently, a team of experts has identified potential neuroprotective agents to be tested in pilot studies [4]. Twelve compounds have been considered for clinical trials caffeine, coenzyme Q 10, creatine, estrogen, GPI1485, GM-1 ganglioside, minocycline, nicotine, pramipexole, ropinirol, rasagiline, and selegiline (for individual discussion see [4]). 

Tetracyclines. It is important to give the tetracyclines on an empty stomach tetracyclines are not to be taken with dairy products (milk or cheese). The exceptions are doxycycline (Vibramycin) and minocycline (Minocin), which may be taken with dairy products or food. The nurse should give clindamycin with food or a full glass of water. The nurse can give troleandomycin and clarithromycin without regard to meals. All tetracyclines should be given with a full glass of water (240 mL). 

C21H21N3O9 4199-35-3) see Minocycline (/ )-[2-(dimethylamino)-2-oxo-l-[(phenylthio)methyl] ethyl]carbamic acid phenylmethyl ester (C,9H22N20iS 197302-34-4) see Nelfinavir mesylate lV-[3-[3-(dimethylamino)-l-oxo-2-propenylJphenyl]acet-amide... 

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