Zolmitriptan ODT

2.5 mg tablets are white/mottled white to cream white, round, flat-faced uncoated tablet, debossed with '715' on one side and plain on other the side.

5 mg tablets are white/mottled white to cream white round, biconvex, beveled, uncoated tablet, debossed with '717' on one side and plain on the other side.

Zolmitriptan orally disintegrating tablets are contraindicated in patients with:

• Ischemic coronary artery disease (angina pectoris, history of myocardial infarction, or documented silent ischemia), other significant underlying cardiovascular disease, or c oronary artery vasospasm including Prinzmetal's angina [see Warnings and Precautions (5.1) ]
• Wolff-Parkinson-White syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders [see Warnings and Precautions (5.2) ]
• History of stroke, transient ischemic attack (TIA), or history of hemiplegic or basilar migraine because these patients are at a higher risk of stroke [see Warnings and Precautions (5.4) ]
• Peripheral vascular disease (PVD) [see Warnings and Precautions (5.5) ]
• Ischemic bowel disease [see Warnings and Precautions (5.5) ]
• Uncontrolled hypertension [see Warnings and Precautions (5.8) ]
• Recent use (i.e., within 24 hours) of another 5-HT1  agonist, ergotamine-containing medication, or ergot-type medication (such as dihydroergotamine or methysergide) [see Drug Interactions (7.1, 7.3) ]
• Concurrent administration of a monoamine oxidase (MAO)-A inhibitor or recent use of a MAO-A inhibitor (that is within 2 weeks) [see Drug Interactions (7.2) and Clinical Pharmacology (12.3) ]
• Known hypersensitivity to zolmitriptan (angioedema and anaphylaxis seen) [see Adverse Reactions (6.2) ]

The following adverse reactions are described elsewhere in other sections of the prescribing information:

• Myocardial Ischemia, Myocardial Infarction, and Prinzmetal Angina [see Warnings and Precautions (5.1)].
• Arrthymias [see Warnings and Precautions (5.2)].
• Chest and or Throat, Neck and Jaw Pain/Tightness/Pressure [see Warnings and Precautions (5.3)].
• Cerebrovascular Events [see Warnings and Precautions (5.4)].
• Other Vasospasm Reactions [see Warnings and Precautions (5.5)].
• Medication Overuse Headache [see Warnings and Precautions (5.6)].
• Serotonin Syndrome [see Warnings and Precautions (5.7)].
• Increase in Blood Pressure [see Warnings and Precautions (5.8)].
• Risks in Patients with Phenylketonuria [see Warnings and Precautions (5.9)].

Clinical Trials Experience

Because clinical studies are conducted under widely varying conditions, adverse reaction rates observed in the clinical studies of a drug cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice.

In a long-term, open-label study where patients were allowed to treat multiple migraine attacks for up to 1 year, 8% (167 out of 2,058) withdrew from the trial because of adverse reaction.

The most common adverse reactions (> 5% and > placebo) in these trials were neck/throat/jaw pain, dizziness, paresthesia, asthenia, somnolence, warm/cold sensation, nausea, heaviness sensation, and dry mouth.

Table 1 lists the adverse reactions that occurred in > 2% of the 2,074 patients in any one of the zolmitriptan 1 mg, 2.5 mg, or 5 mg dose groups in the controlled clinical trials of zolmitriptan in patients with migraines (Studies 1, 2, 3, 4, and 5) [see Clinical Studies (14)]. Only adverse reactions that were at least 2% more frequent in a zolmitriptan group compared to the placebo group are included.

Several of the adverse reactions appear dose related, notably paresthesia, sensation of heaviness or tightness in chest, neck, jaw, and throat, dizziness, somnolence and possibly asthenia and nausea.

There were no differences in the incidence of adverse reactions in controlled clinical trials in the following subgroups: gender, weight, age, use of prophylactic medications, or presence of aura. There were insufficient data to assess the impact of race on the incidence of adverse reactions.

Less Common Adverse Reactions with Zolmitriptan Tablets

In the paragraphs that follow, the frequencies of less commonly reported adverse clinical reactions are presented. Because the reports include reactions observed in open and uncontrolled studies, the role of zolmitriptan in their causation cannot be reliably determined. Furthermore, variability associated with adverse reaction reporting, the terminology used to describe adverse reactions, etc., limit the value of the quantitative frequency estimates provided. Adverse reaction frequencies were calculated as the number of patients who used zolmitriptan tablets and reported a reaction divided by the total number of patients exposed to zolmitriptan tablets (n=4,027). Reactions were further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: infrequent adverse reactions (those occurring in 1/100 to 1/1,000 patients) and rare adverse reactions (those occurring in less than 1/1,000 patients).

General

Infrequent were allergic reactions.

Cardiovascular

Infrequent were arrhythmias, hypertension, and syncope. Rare was tachycardia.

Neurological

Infrequent were agitation, anxiety, depression, emotional lability and insomnia; Rare were amnesia, hallucinations, and cerebral ischemia.

 Skin

Infrequent were pruritus, rash and urticaria.

 Urogenital

Infrequent were polyuria, urinary frequency and urinary urgency.

Adverse Reactions with Zolmitriptan Oral Disintegrating Tablets

The adverse reaction profile seen with zolmitriptan oral disintegrating tablets was similar to that seen with zolmitriptan tablets.

Postmarketing Experience

The following adverse reactions were identified during post approval use of zolmitriptan. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

The reactions enumerated include all except those already listed in the Clinical Trials Experience section above or the Warnings and Precautions section.

Hypersensitivity Reactions

As with other 5-HT1B/1D agonists, there have been reports of anaphylaxis, anaphylactoid, and hypersensitivity reactions including angioedema in patients receiving zolmitriptan. Zolmitriptan is contraindicated in patients with a history of hypersensitivity reaction to zolmitriptan.

There is no experience with acute overdose of zolmitriptan. Clinical study subjects who received single 50 mg oral doses of zolmitriptan commonly experienced sedation.

There is no specific antidote to zolmitriptan. In cases of severe intoxication, intensive care procedures are recommended, including establishing and maintaining a patent airway, ensuring adequate oxygenation and ventilation, and monitoring and support of the cardiovascular system.

The elimination half-life of zolmitriptan is 3 hours [see Clinical Pharmacology (12.1)]; therefore, monitor patients after overdose with zolmitriptan for at least 15 hours or until symptoms or signs resolve. It is unknown what effect hemodialysis or peritoneal dialysis has on the plasma concentrations of zolmitriptan.

Zolmitriptan orally disintegrating tablets contain zolmitriptan, which is a selective 5-hydroxytryptamine1B/1D(5-HT1B/1D) receptor agonist. Zolmitriptan is chemically designated as (S)-4-[[3-[2-(dimethylamino)ethyl]-1H-indol-5-yl]methyl]-2-oxazolidinone and has the following chemical structure:

The molecular formula is C16H21N3O2, representing a molecular weight of 287.36.

Zolmitriptan is a white to off-white crystalline powder that is readily soluble in water.

Each zolmitriptan orally disintegrating tablet, intended for oral administration,contains 2.5 mg or 5 mg of zolmitriptan. In addition, each tablet contains the following inactive ingredients: anhydrous citric acid, aspartame, colloidal silicon dioxide, crospovidone, gelatin, magnesium stearate,mannitol, microcrystalline cellulose, orange flavor, polacrilin potassium and sodium stearyl fumarate.

Zolmitriptan Tablets

The efficacy of zolmitriptan tablets in the acute treatment of migraine headaches was demonstrated in five randomized, double-blind, placebo-controlled studies (Studies 1, 2, 3, 4, and 5), of which two utilized the 1 mg dose, two utilized the 2.5 mg dose and four utilized the 5 mg dose. In Study 1, patients treated their headaches in a clinic setting. In the other studies, patients treated their headaches as outpatients. In Study 4, patients who had previously used sumatriptan were excluded, whereas in the other studies no such exclusion was applied.

Patients enrolled in these 5 studies were predominantly female (82%) and Caucasian (97%) with a mean age of 40 years (range 12 to 65). Patients were instructed to treat a moderate to severe headache. Headache response, defined as a reduction in headache severity from moderate or severe pain to mild or no pain, was assessed at 1, 2, and, in most studies, 4 hours after dosing. Associated symptoms such as nausea, photophobia, and phonophobia were also assessed. Maintenance of response was assessed for up to 24 hours post-dose. A second dose of zolmitriptan tablets or other medication was allowed 2 to 24 hours after the initial treatment for persistent and recurrent headache. The frequency and time to use of these additional treatments were also recorded. In all studies, the effect of zolmitriptan was compared to placebo in the treatment of a single migraine attack.

In all five studies, the percentage of patients achieving headache response 2 hours after treatment was significantly greater among patients who received zolmitriptan tablets at all doses (except for the 1 mg dose in the smallest study) compared to those who received placebo. In Studies 1 and 3, there was a statistically significant greater percentage of patients with headache response at 2 hours in the higher dose groups (2.5 and/or 5 mg) compared to the 1 mg dose group. There were no statistically significant differences between the 2.5 and 5 mg dose groups (or of doses up to 20 mg) for the primary end point of headache response at 2 hours in any study. The results of these controlled clinical studies are summarized in Table 2.

The estimated probability of achieving an initial headache response by 4 hours following treatment in pooled Studies 2, 3, and 5 is depicted in Figure 1.

Figure 1

Estimated Probability of Achieving Initial Headache Response (Reduction in Headache Severity from Moderate or Severe Pain to Mild or No Headache) Within 4 Hours of Treatment in Pooled Studies 2, 3, and 5*

*In this Kaplan-Meier plot, the averages displayed are based on pooled data from 3 placebo controlled, outpatient trials. Patients not achieving headache response or taking additional treatment prior to 4 hours were censored at 4 hours.

For patients with migraine associated photophobia, phonophobia, and nausea at baseline, there was a decreased incidence of these symptoms following administration of zolmitriptan tablets as compared with placebo.

Two to 24 hours following the initial dose of study treatment, patients were allowed to use additional treatment for pain relief in the form of a second dose of study treatment or other medication. The estimated probability of patients taking a second dose or other medication for migraine over the 24 hours following the initial dose of study treatment is summarized in Figure 2.

Figure 2

The Estimated Probability Of Patients Taking A Second Dose Or Other Medication For Migraines Over The 24 Hours Following The Initial Dose Of Study Treatment in Pooled Studies 2, 3, and 5*

*In this Kaplan-Meier plot, patients not using additional treatments were censored at 24 hours. The plot includes both patients who had headache response at 2 hours and those who had no response to the initial dose. The studies did not allow taking additional doses of study medication within 2 hours post-dose.

The efficacy of zolmitriptan was unaffected by presence of aura; duration of headache prior to treatment; relationship to menses; gender, age, or weight of the patient; pre-treatment nausea or concomitant use of common migraine prophylactic drugs.

Zolmitriptan Orally Disintegrating Tablets

The efficacy of zolmitriptan 2.5 mg orally disintegrating tablets was demonstrated in a randomized, placebo-controlled trial (Study 6) that was similar in design to the trials of zolmitriptan tablets. Patients were instructed to treat a moderate to severe headache. Of the 471 patients treated in Study 6, 87% were female and 97% were Caucasian, with a mean age of 41 years (range 18-62).

At 2 hours post-dosing, there was a statistically significant greater percentage of patients treated with zolmitriptan 2.5 mg orally disintegrating tablets with a headache response (reduction in headache severity from moderate or severe pain to mild or no headache) compared to patients treated with placebo (63% vs. 22%). The estimated probability of achieving an initial headache response by 2 hours following treatment with zolmitriptan orally disintegrating tablets is depicted in Figure 3.

Figure 3

Estimated Probability of Achieving Initial Headache Response (Reduction in Headache Severity from Moderate or Severe Pain to Mild or No Headache) Within 2 Hours in Study 6*

*In this Kaplan-Meier plot, patients taking additional treatment or not achieving headache response prior to 2 hours were censored at 2 hours.

For patients with migraine-associated photophobia, phonophobia and nausea at baseline, there was a decreased incidence of these symptoms following administration of zolmitriptan as compared to placebo.

Two to 24 hours following the initial dose of study treatment, patients were allowed to use additional treatment in the form of a second dose of study treatment or other medication. The estimated probability of patients taking a second dose or other medication for migraine over the 24 hours following the initial dose of study treatment in Study 6 is summarized in Figure 4.

Figure 4

The Estimated Probability of Patients Taking a Second Dose or Other Medication for Migraines Over the 24 Hours Following The Initial Dose of Study Treatment in Study 6*

*In this Kaplan-Meier plot, patients not taking additional treatments were censored at 24 hours. The plot includes both patients who had headache response at 2 hours and those who had no response to the initial dose. Taking another dose of study medication was allowed 2 hours post-dose in Study 6. In contrast to studies of zolmitriptan tablets (Studies 1, 2, 3, 4, and 5), Study 6 allowed re-dosing of zolmitriptan oral disintegrating tablets prior to 4 hours.