Zyflo (Zileuton) - Side Effects and Adverse Reactions

ADVERSE REACTIONS

Clinical Studies:

A total of 5542 patients have been exposed to zileuton in clinical trials, 2252 of them for greater than 6 months and 742 for greater than 1 year.

Adverse events most frequently occurring (frequency ≥3%) in ZYFLO-treated patients and at a frequency greater than placebo-treated patients are summarized in Table 2.

Proportion of Patients Experiencing Adverse Events in Placebo-Controlled Studies in Asthma

Less common adverse events occurring at a frequency of greater than 1% and more commonly in ZYFLO-treated patients included: arthralgia, chest pain, conjunctivitis, constipation, dizziness, fever, flatulence, hypertonia, insomnia, lymphadenopathy, malaise, neck pain/rigidity, nervousness, pruritus, somnolence, urinary tract infection, vaginitis, and vomiting.

The frequency of discontinuation from the asthma clinical studies due to any adverse event was comparable between ZYFLO (9.7%) and placebo-treated (8.4%) groups.

In placebo-controlled clinical trials, the frequency of ALT elevations ≥3xULN was 1.9% for ZYFLO-treated patients, compared with 0.2% for placebo-treated patients. In controlled and uncontrolled trials, one patient developed symptomatic hepatitis with jaundice, which resolved upon discontinuation of therapy. An additional 3 patients with transaminase elevations developed mild hyperbilirubinemia that was less than three times the upper limit of normal. There was no evidence of hypersensitivity or other alternative etiologies for these findings. ZYFLO is contraindicated in patients with active liver disease or transaminase elevations greater than or equal to 3xULN (see CONTRAINDICATIONS).  It is recommended that hepatic transaminases be evaluated at initiation of and during therapy with ZYFLO (see PRECAUTIONS, Hepatic).

Occurrences of low white blood cell count (≤2.8 x 10⁹/L) were observed in 1.0% of 1,678 patients taking ZYFLO and 0.6% of 1,056 patients taking placebo in placebo-controlled studies. These findings were transient and the majority of cases returned toward normal or baseline with continued ZYFLO dosing. All remaining cases returned toward normal or baseline after discontinuation of ZYFLO. Similar findings were also noted in a long-term safety surveillance study of 2458 patients treated with ZYFLO plus usual asthma care versus 489 patients treated only with usual asthma care for up to one year. The clinical significance of these observations is not known.

In the long-term safety surveillance trial of ZYFLO plus usual asthma care versus usual asthma care alone, a similar adverse event profile was seen as in other clinical trials.

Post-Marketing Experience: Cases of sleep disorders and behavior changes have been reported (see PRECAUTIONS, Neuropsychiatric Events).  Rash and urticaria have been also reported with ZYFLO.

REPORTS OF SUSPECTED ZYFLO SIDE EFFECTS / ADVERSE REACTIONS

Possible Zyflo side effects / adverse reactions in 46 year old female

Reported by a individual with unspecified qualification from United States on 2011-10-04

Patient: 46 year old female weighing 115.6 kg (254.3 pounds)

Reactions: Blood Pressure Increased, Cataract, Overdose, Drug Prescribing Error, Sinusitis

Suspect drug(s):
Advair HFA
    Dosage: bid
    Indication: Asthma

Maxair
    Dosage: bid;inh
    Indication: Asthma

Medrol
    Indication: Sinusitis

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-06-01
    End date: 2010-06-01

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-06-01
    End date: 2010-06-01

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-08-01
    End date: 2010-09-14

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-06-01
    End date: 2010-06-01

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-06-01
    End date: 2010-06-01

Milnacipran Hydrochloride (Milnacipran Hydrochloride)
    Dosage: 200 mg;bid ; 12.5 mg;qd ; 12.5 mg;bid ; 50 mg;bid ; 50 mg;bid ; 100 mg;bid
    Indication: Fibromyalgia
    Start date: 2010-07-01
    End date: 2010-08-01

Pulmicort
    Dosage: 180 ug;bid
    Indication: Asthma

Rhinocort
    Dosage: 32 ug;qd
    Indication: Seasonal Allergy

Theophylline
    Dosage: 200 mg;qam ; 400 mg;hs
    Indication: Asthma

Zyflo
    Dosage: 1200 mg;tid
    Indication: Asthma

Other drugs received by patient: B12 /00056201/; Percocet; Multi-Vitamins; Nexium; Xyzal; Relpax; Topamax; Calcium with Vitamin D /00944201/

Possible Zyflo side effects / adverse reactions in 50 year old female

Reported by a consumer/non-health professional from United States on 2011-12-01

Patient: 50 year old female

Reactions: Abnormal Dreams, Anxiety, Nausea, Flatulence, Chest Pain, Eructation

Suspect drug(s):
Zyflo