Products
Rifamycin is commercially available in the form of ear drops (Otofa). It has been approved in many countries since 1988.
Structure and properties
Rifamycin (Rifamycin SV) is present in the drug as rifamycin sodium, a fine or slightly granular red powder that is soluble in water (C37H46NNaO12, Mr = 720 g/mol). It is obtained by a chemical transformation from rifamycin B, which is formed during the growth of certain strains of . Rifamycin can also be obtained directly from.
Effects
Rifamycin (ATC S02AA12) has bacteriostatic or bactericidal properties against Gram-positive and Gram-negative germs. The effects are due to inhibition of DNA-dependent RNA polymerase.
Indications
For the treatment of acute episodes of chronic otitis media with suppuration of the tympanic membrane.
Dosage
According to the SmPC. The drops are either placed in the ear canal three times daily or an ear canal bath is given twice daily. See also under Administration of Ear Drops. The duration of treatment should be limited to 7 to 10 days.
Contraindications
Rifamycin is contraindicated in hypersensitivity. For complete precautions, see the drug label.
Interactions
There are no known interactions with topical application in the ear canal.
Adverse effects
Possible adverse effects include hypersensitivity reactions such as redness, irritation, and itching. Rifamycin causes pink discoloration in the ear canal.
