Estolate salt

Cholestatic hepatitis may occur when drug therapy lasts longer than 10 days or repeated courses are prescribed. The hepatitis is characterized by fever, enlarged and tender liver, hyperbilirubinemia, dark urine, eosinophilia, elevated serum bilirubin, and elevated transaminase levels. Hepatitis has been associated with the estolate salt of erythromycin but not with other formulations. Although the hepatitis usually occurs 10 to 20 days after the initiation of therapy, it can occur within hours in a patient who has had such a reaction in the past. The hepatitis is believed to be the result of both a hepatotoxic effect and a hypersensitivity reaction this latter effect is reversible on withdrawal of the drug. Erythromycin and derivatives induce hepatic microsomal enzymes and interfere with the actions of various drugs, including theophylline and carbamazepine. 

Erythromycin 1.4 h Unknown Abdominal pain idiosyncratic hepatotoxicity with estolate salt. Interaction with fluoroquinolones, cisapride, disopyramide, terfenadine, orasiemizole can induce OT prolongation and torsade de pointes can elevate serum theophylline levels. (Inhibits hepatic cytochrome P-450 3A4.) Administration of more than 4 g/day may cause tinnitus, ototoxicity. 

Cholestatic jaundice This side effect occurs, especially with the estolate form of erythromycin, presumably as the result of a hypersensitivity reaction to the estolate form (the lauryl salt of the propionyl ester of erythromycin). It has also been reported for other forms of the drug. 

Taste acceptability is a particular issue with oral liquid dosage forms, lozenges, and chewable tablets. The problem may be overcome by the preparation of poorly soluble salts. Thus the bitterness of erythromycin and of bacitracin may be ameliorated by use of the estolate (lauryl sulfate) and zinc salts, respectively. Propoxaphene may be taste masked by forming the napsylate, the solubility of which may be further reduced and the taste improved by adding a common-ion salt such as sodium or calcium napsylate. 

Mann JM, Erythromycin estolate, APDS, 1, 101-117 (1972). NB Estolate = dodecyl sulfate salt. 

Combinations of a 2 -ester and a lipophilic acid-addition salt have also been extensively employed. Erythromycin estolate (2 -propionate, lauryl sulphate salt) has been widely used due to its better oral absorption than other forms of erythromycin [62, 67, 68]. Similar results have been found with erythromycin acistrate (2 -acetate, stearate salt) [69, 70], which is reported to be less hepatotoxic in animals than other forms of erythromycin [71], Two salts of 2 -propionylerythromycin,A-acetyIcysteinate (erythromycin stinoprate) and mercaptosuccinate, are being investigated as combinations of an antimicrobial and mucolytic agent [72-74],... 

Propanoyl, dodecyl sulfate salt Erythromycin estolate, BAN, USAN. Propionylerythromycin lauryl sulfate. Ilosone. Many other names [3521-62-8] Antibacterial agent. 

Erythromycin estolate, which is a complex salt of the propionate of erythromycin (XXIV), and the detergent moiety lauryl sulphate is the only derivative of this antibiotic to produce hepatotoxicity in man [193,194]. An investigational drug erythromycin cetyl sulphate was withdrawn from trials in man when the incidence of hepatotoxic effects reached 10 to 15%. Consequently, Dujovne has examined the role of the detergent anions in these preparations on their toxic actions [193, 194]. 

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