Zileuton
ZYFLO
Pronunciation: zye-LOO-ton (ZYE-floe)
What it is5-lipoxygenase inhibitor suppressing leukotriene synthesis; asthma maintenance.
Why this oneUpstream synthesis blockade inhibits more leukotriene effects than receptor antagonists do.
What limits itHepatotoxicity requires liver monitoring; frequent dosing and increased theophylline or warfarin exposure complicate use.
FDA-approved for
- asthma maintenance (1996)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Asthma (symptomatic treatment / prophylaxis) | adult & ≥12 yr | 600 mg QID | 600 mg QID (2400 mg/day) | 2400 mg/day |
Renal Undefined
Hepatic Contraindicated in active liver disease or transaminases ≥3×ULN
Instructions
- May be taken with meals and at bedtime
- Evaluate hepatic transaminases before initiation and periodically during treatment
Available strengths
- ER tab 600 mg
Contraindications
- Active liver disease or transaminase elevations ≥3×ULN
Cautions
- Hepatotoxicity (ALT elevations ≥3×ULN); monitor transaminases
- Neuropsychiatric events (sleep disorders, behavior changes)
- Low white blood cell count
Adverse reactions
- Headache
- Elevated ALT
- Nausea
- Dyspepsia
- Myalgia
Pregnancy Undefined
Lactation Undefined
Cost
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 600 mg | ER tab | 120 QID | $245.91 | offered |
Generic entry2017
NO BOXED WARNINGS
Principal riskHepatotoxicity; four-times-daily dosing
Classes and tags
Clinical profile
Legacy pregnancy categoryC
Defining liabilityTremor, tachycardia or anticholinergic effects; excessive beta-agonist exposure can cause hypokalemia and arrhythmia.