Products
Erythromycin is commercially available for peroral administration in tablet and granular form (Erythrocin / Erythrocin ES). This article refers to the drugs intended for ingestion. Erythromycin was first approved in the 1950s.
Structure and properties
Erythromycin is a natural substance produced by the bacterium (formerly: ). In oral medications, it is present as erythromycin ethyl succinate, a white, crystalline, hygroscopic powder that is virtually insoluble in water. It is a mixture of erythromycin A, B, and C, with erythromycin A making up the largest portion. Erythromycin is acid labile and is partially broken down by stomach acid after ingestion. It has a low bioavailability of about 40%. Tablets containing erythromycin stearate are also commercially available in some countries.
Effects
Erythromycin (ATC J01FA01) has bacteriostatic properties against some Gram-positive and Gram-negative pathogens. The effects are due to inhibition of bacterial protein synthesis by binding to the 50S subunit of ribosomes. The half-life is short, 1 to 2 hours.
Indications
For the treatment of bacterial infectious diseases with susceptible pathogens. Indications include respiratory infections, skin infections, and sexually transmitted diseases. Macrolides are also given when penicillins cannot be used.
Dosage
According to the prescribing information. The drugs are usually taken three times daily on an empty stomach, that is, at least one hour before or two hours after meals. According to the German SmPC, children may also take the medication with food.
Contraindications
- Hypersensitivity, including to other macrolides.
- Severe hepatic insufficiency
- Combination with ergotamine or dihydroergotamine
- Combination with statins metabolized by CYP3A4.
- Combination with drugs that prolong the QT interval.
- Combination with astemizole, terfenadine, cisapride, domperidone, and pimozide.
- Congenital or acquired prolongation of the QT interval.
- Electrolyte balance disorders such as hypokalemia and hypomagnesemia
- Clinically relevant bradycardia and cardiac arrhythmias.
For complete precautions, see the drug label.
Interactions
Erythromycin is an inhibitor of CYP3A4 and thus may cause numerous drug-drug interactions.
Adverse effects
The most common possible adverse effects include:
