A drug that inhibits leukotriene formation, used to treat asthma.
[zi- (perhaps shortening and alteration of ENZYME) + LEU(KO)T(RIENE) + -ON3.]
Dictionary:
zi·leu·ton (zī-lū'tn) ![]() |
[zi- (perhaps shortening and alteration of ENZYME) + LEU(KO)T(RIENE) + -ON3.]
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| Drug Info: Zileuton |
Brand names: Zyflo®
Chemical formula:

Zileuton extended-release tablets
What are Zileuton extended-release tablets?
What should I tell my health care provider before I take this medicine?
They need to know if you have any of these conditions:
fever or infection
if you frequently drink alcohol containing drinks
liver disease
an unusual or allergic reaction to zileuton, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
breast-feeding
How should this medicine be used?
Take this medicine by mouth with a glass of water. Follow the directions on your prescription label. Take it within one hour after morning and evening meals. Take your doses at regular intervals. Do not crush, chew, or cut the tablets. Do not take your medicine more often than directed.
Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed. While this medicine has been used in children as young as 12 years of age, precautions do apply.
What drug(s) may interact with Zileuton?
alosetron
astemizole
caffeine
cisapride
cyclosporine
pimozide
propranolol
tacrine
terfenadine
theophylline or aminophylline
warfarin
Tell your prescriber or health care professional about all other medicines you are taking, including non-prescription medicines, nutritional supplements, or herbal products. Also tell your prescriber or health care professional if you are a frequent user of drinks with caffeine or alcohol, if you smoke, or if you use illegal drugs. These may affect the way your medicine works. Check with your health care professional before stopping or starting any of your medicines.
What should I watch for while taking Zileuton?
It may take a few weeks to notice the full benefit of this medicine. Tell your doctor or health care professional if your asthma symptoms do not improve. Take this medicine even when you do not have any asthma symptoms. Feeling well is a sign the medicine is working to control your asthma. Do not stop taking your medicine unless your doctor tells you to.
Talk to your doctor about what to do if you have an acute asthma attack. This medicine does not treat an acute attack. Always have your inhaled rescue medicine for asthma attacks with you.
What side effects may I notice from receiving Zileuton?
Side effects that you should report to your prescriber or health care professional as soon as possible:
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
dark urine
difficulty breathing, wheezing
fever
flu-like symptoms (chills, fatigue, fever, muscle aches)
unusual weakness or tiredness
yellowing of the skin or eyes
Side effects that usually do not require medical attention (report to your prescriber or health care professional if they continue or are bothersome):
abdominal pain
dizziness
headache
nausea
stomach upset
Where can I keep my medicine?
Keep out of the reach of children.
Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Throw away any unused medicine after the expiration date.
Last updated: 7/1/2002
Important Disclaimer: The drug information provided here is for educational purposes only. It is intended to supplement, not substitute for, the diagnosis, treatment and advice of a medical professional. This drug information does not cover all possible uses, precautions, side effects and interactions. It should not be construed to indicate that this or any drug is safe for you. Consult your medical professional for guidance before using any prescription or over the counter drugs.
| Wikipedia: Zileuton |
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Zileuton
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| Systematic (IUPAC) name | |
| (RS)-N-[1-(1-benzothien-2-yl)ethyl]-N-hydroxyurea | |
| Identifiers | |
| CAS number | |
| ATC code | none |
| PubChem | |
| DrugBank | |
| Chemical data | |
| Formula | C11H12N2O2S |
| Mol. mass | 236.291 g/mol |
| Pharmacokinetic data | |
| Bioavailability | Not yet established |
| Protein binding | 93% |
| Metabolism | Hepatic (CYP1A2, CYP2C9 and CYP3A4-mediated) |
| Half life | 2.5 hours |
| Excretion | Renal |
| Therapeutic considerations | |
| Pregnancy cat. |
C(US) |
| Legal status | |
| Routes | Oral |
Zileuton (trade name ZYFLO) is an orally active inhibitor of 5-lipoxygenase, and thus inhibits leukotrienes (LTB4, LTC4, LTD4, and LTE4) formation. Zileuton is used for the maintenance treatment of asthma. Zileuton was introduced in 1996 by Abbott Laboratories and is now marketed in two formulations by Cornerstone Therapeutics Inc. under the brand names ZYFLO and ZYFLO CR. The original immediate-release formulation of zileuton, known as ZYFLO, is taken four-times-per-day. The extended-release formulation, ZYFLO CR, is taken twice daily.
Contents |
Zileuton is indicated for the prophylaxis and chronic treatment of asthma in adults and children 12 years of age and older. Zileuton is not indicated for use in the reversal of bronchospasm in acute asthma attacks. Therapy with zileuton can be continued during acute exacerbations of asthma.
The recommended dose of ZYFLO is one 600 mg tablet, four times per day. The tablets may be split in half to make them easier to swallow. The recommended dose of ZYFLO CR is two 600 mg extended-release tablets twice daily, within one hour after morning and evening meals, for a daily dose of 2400 mg. Do not split ZYFLO CR tablets in half.
Related compounds include montelukast (Singulair) and zafirlukast (Accolate). These two compounds are leukotriene receptor antagonists which block the action of specific leukotrienes, while zileuton inhibits leukotriene formation.
Research on mice suggests that Zileuton used alone or in combination with imatinib may inhibit chronic myeloid leukemia (CML). Lethal Cancer Knocked Down By One-two Drug Punch ScienceDaily (June 8, 2009).
The most serious side effect of ZYFLO and ZYFLO CR is a potential elevation of liver enzymes (in 2% of patients). Therefore, zileuton is contraindicated in patients with active liver disease or persistent hepatic function enzymes elevations greater than three time sthe upper limit of normal. Hepatic function should be assessed prior to initiating ZYFLO CR, monthly for the first 3 months, every 2-3 months for the remainder of the first year, and periodically thereafter.
Neuropsychiatric events, including sleep disorders and behavioral changes, may occur with ZYFLO and ZYFLO CR. Patients should be instructed to notify their healthcare provider if neuropsychiatric events occur while using ZYFLO or ZYFLO CR.
Zileuton is a weak inhibitor of CYP1A2[1] and thus has three clinically important drug interactions, which include increasing warfarin, theophylline, and propranolol levels. It has been shown to lower theophylline clearance significantly, doubling the AUC and prolonging half-life by nearly 25%. Because of theophylline's relation to caffeine (both being a methylxanthine, and theophylline being a metabolite of caffeine), caffeine's metabolism and clearance may also be reduced, but there are no drug interaction studies between zileuton and caffeine.[2] The R-isomer of warfarin metabolism and clearance is mainly affected by zileuton, while the S-isomer is not (because of metabolism via different enzymes). This can lead to an increase in prothrombin time.[3]
Zileuton is an active oral inhibitor of the enzyme 5-lipoxygenase, which forms leukotrienes from arachidonic acid. The chemical name of zileuton is (±)-1-(1-Benzo[b]thien-2-ylethyl)-l-hydroxyurea.
The molecular formula of zileuton is C11H12N2O2S with a molecular weight of 236.29. The formulation from the manufacturer is a racemic mixture of R(+) and S(-) enantiomers.[4]
Following oral administration zileuton is rapidly absorbed with a mean time to peak serum concentration of 1.7 hours and an average half-life elimination of 2.5 hours. Plasma concentrations are proportional to dose, whereas the absolute bioavailability is unknown.
The apparent volume of distribution of zileuton is approximately 1.2 L/kg. Zileuton is 93% bound to plasma proteins, primarily to albumin, with minor binding to alpha-1-acid glycoprotein.
Elimination of zileuton is primarily through metabolites in the urine (~95%) with the feces accounting for the next largest amount (~2%). The drug is metabolized by the cytochrome P450 enzymes: CYP1A2, 2C9, and 3A4.[4]
The most common adverse reactions reported by patients treated with ZYFLO CR were sinusitis (6.5%), nausea (5%), and pharyngolaryngeal pain (5%) vs. placebo, 4%, 1.5%, and 4% respectively.
Zileuton is a minor substrate of CYP1A2, 2C8/9, 3A4, and a weak inhibitor of CYP 1A2. The drug has been shown to increase the serum concentration or effects of theophylline, propranolol, and warfarin. It is advised that the doses of each medication be monitored and/or reduced accordingly.
The avoidance of alcohol is recommended due to increase risk of CNS depression as well as an increase risk in liver toxicity. In addition, the herbal supplement St. John's wort may decrease the serum levels of zileuton.[5]
Human experience of acute overdose with zileuton is limited. A patient in a clinical study took between 6.6 and 9.0 grams of zileuton immediate-release tablets in a single dose. Vomiting was inducted and the patient recovered without sequelae. Zileuton is not removed by dialysis.
The oral minimum lethal doses in mice and rats were 500-4000 and 300-1000 mg/kg, respectively (providign greater than 3 and 9 times the systemic exposure (AUC) achieved at the maximum recommended human daily oral dose, respectively). In dogs, at an oral dose of 1000 mg/kg (providing in excess of 12 times the systemic exposure (AUC) achieved at the maximum recommended human daily oral dose) no deaths occurred by nephritis was reported.
Should an overdose occur, the patient should be treated symptomatically and supportive measures instituted as required. If indicated, elimination of unabsorbed drug should be achieved by emesis or gastric lavage; usual precautions should be observed to maintain the airway. A Certified Poison Control Center should be consulted for up-to-date information on management of overdose with ZYFLO CR.
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This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
| Zyflo (trademark) | |
| Cornerstone Therapeutics Inc | |
| Zileuton extended-release tablets |
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