Zileuton

Products

Zileuton is commercially available in the United States in tablet and powder form (Zyflo). It is not currently approved in many countries.

Structure and properties

Zileuton (C11H12N2O2S, Mr = 236.3 g/mol) is an almost odorless, white, crystalline powder that is practically insoluble in water. It exists as a racemate. Both enantiomers are pharmacologically active.

Effects

Zileuton is anti-inflammatory, antiasthmatic, and antiallergic. It is a specific inhibitor of 5-lipoxygenase, thus inhibiting the formation of leukotrienes (LTB4, LTC4, LTD4, and LTE4). These are inflammatory mediators involved in the development of inflammation, edema, mucus formation, and bronchoconstriction in the airways.

Indications

For the treatment of chronic bronchial asthma.

Dosage

According to the SmPC. Zileuton has a short half-life and therefore must be administered four times daily. However, sustained-release dosage forms have been developed that must be taken less frequently.

Contraindications

Zileuton is contraindicated hypersensitivity, acute liver disease, and elevation of transaminases. For complete precautions, see the drug label.

Interactions

Drug-drug interactions have been described with theophylline, warfarin, propranolol, and terfenadine.

Adverse effects

The most common possible adverse effects include headache, pain, abdominal pain, weakness, injury, dyspepsia, nausea, and muscle pain.