2.1 Dosing Information

The recommended starting dose for zolmitriptan nasal spray in adult and pediatric patients 12 years of age and older is 2.5 mg. As the individual response to zolmitriptan nasal spray may vary, the dose should be adjusted on an individual basis. The maximum recommended single dose of zolmitriptan is 5 mg.

If the migraine has not resolved by 2 hours after taking zolmitriptan, or returns after a transient improvement, another dose may be administered at least 2 hours after the previous dose.

The maximum daily dose should not exceed 10 mg in any 24-hour period.

The safety of zolmitriptan in the treatment of an average of more than four headaches in a 30-day period has not been established.

2.2 Dosing in Patients with Hepatic Impairment

Zolmitriptan nasal spray is not recommended in patients with moderate to severe hepatic impairment because of increased zolmitriptan blood levels in these patients and elevation of blood pressure in some of these patients. The recommended dosage of zolmitriptan nasal spray in patients with mild hepatic impairment is the same as for patients with normal hepatic function [see Dosage and Administration (2.1), Warnings and Precautions (5.8), Use in Specific Populations (8.6) and Clinical Pharmacology (12.3)].

2.3 Dosing in Patients taking Cimetidine

If zolmitriptan is co-administered with cimetidine, limit the maximum single dose of zolmitriptan to 2.5 mg, not to exceed 5 mg in any 24-hour period [see Drug Interactions (7.4) and Clinical Pharmacology (12.3)].

5.1 Myocardial Ischemia, Myocardial Infarction, and Prinzmetal’s Angina

Zolmitriptan is contraindicated in patients with ischemic or vasospastic coronary artery disease (CAD). There have been rare reports of serious cardiac adverse reactions, including acute myocardial infarction, occurring within a few hours following administration of zolmitriptan. Some of these reactions occurred in patients without known CAD. 5-HT1 agonists including zolmitriptan may cause coronary artery vasospasm (Prinzmetal’s Angina), even in patients without a history of CAD.

Perform a cardiovascular evaluation in triptan-naïve patients who have multiple cardiovascular risk factors (e.g., increased age, diabetes, hypertension, smoking, obesity, strong family history of CAD) prior to receiving zolmitriptan. Do not administer zolmitriptan if there is evidence of CAD or coronary artery vasospasm [see Contraindications (4)]. For patients with multiple cardiovascular risk factors who have a negative cardiovascular evaluation, consider administrating the first zolmitriptan dose in a medically-supervised setting and performing an electrocardiogram (ECG) immediately following zolmitriptan administration. For such patients, consider periodic cardiovascular evaluation in intermittent long-term users of zolmitriptan.

5.2 Arrhythmias

Life-threatening disturbances of cardiac rhythm including ventricular tachycardia and ventricular fibrillation leading to death have been reported within a few hours following the administration of 5-HT1 agonists. Discontinue zolmitriptan if these disturbances occur. Patients with Wolff-Parkinson-White Syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders should not receive zolmitriptan [see Contraindications (4)].

5.3 Chest, Throat, Neck, and/or Jaw Pain/Tightness/Pressure

As with other 5-HT1 agonists, sensations of tightness, pain, pressure, and heaviness in the precordium, throat, neck, and jaw commonly occur after treatment with zolmitriptan and is usually non-cardiac in origin. However, if a cardiac origin is suspected, patients should be evaluated. Patients shown to have CAD and those with Prinzmetal’s variant angina should not receive 5-HT1 agonists [see Contraindications (4)].

5.4 Cerebrovascular Events

Cerebral hemorrhage, subarachnoid hemorrhage, and stroke have occurred in patients treated with 5-HT1 agonists, and some have resulted in fatalities. In a number of cases, it appears possible that the cerebrovascular events were primary, the 5-HT1 agonist having been administered in the incorrect belief that the symptoms experienced were a consequence of migraine, when they were not. Discontinue zolmitriptan if a cerebrovascular event occurs.

As with other acute migraine therapies, before treating headaches in patients not previously diagnosed as migraineurs, and in migraineurs who present with symptoms atypical for migraine, other potentially serious neurological conditions should be excluded. Zolmitriptan should not be administered to patients with a history of stroke or transient ischemic attack [see Contraindications (4)].

5.5 Other Vasospasm Reactions

5-HT1 agonists, including zolmitriptan, may cause non-coronary vasospastic reactions, such as peripheral vascular ischemia, gastrointestinal vascular ischemia and infarction (presenting with abdominal pain and bloody diarrhea), splenic infarction, and Raynaud’s syndrome. In patients who experience symptoms or signs suggestive of vasospasm reaction following the use of any 5-HT1 agonist, the suspected vasospasm reaction should be ruled out before receiving additional zolmitriptan doses [see Contraindications (4)].

Reports of transient and permanent blindness and significant partial vision loss have been reported with the use of 5-HT1 agonists. Since visual disorders may be part of a migraine attack, a causal relationship between these events and the use of 5-HT1 agonists have not been clearly established.

5.6 Medication Overuse Headache

Overuse of acute migraine drugs (e.g. ergotamine, triptans, opioids, or a combination of drugs for 10 or more days per month) may lead to exacerbation of headache (medication overuse headache). Medication overuse headache may present as migraine-like daily headaches, or as a marked increase in frequency of migraine attacks. Detoxification of patients, including withdrawal of the overused drugs, and treatment of withdrawal symptoms (which often includes a transient worsening of headache) may be necessary.

5.7 Serotonin Syndrome

Serotonin syndrome may occur with triptans, including zolmitriptan, particularly during co-administration with selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and MAO inhibitors [see Drug Interactions (7.5)]. Serotonin syndrome symptoms may include mental status changes (e.g., agitation, hallucinations, coma), autonomic instability (e.g., tachycardia, labile blood pressure, hyperthermia), neuromuscular aberrations (e.g., hyperreflexia, incoordination), and/or gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea). The onset of symptoms usually rapidly occurs within minutes to hours of receiving a new or a greater dose of a serotonergic medication. Zolmitriptan treatment should be discontinued if serotonin syndrome is suspected [see Drug Interactions (7.5) and Patient Counseling Information (17)].

5.8 Increase in Blood Pressure

Significant elevations in systemic blood pressure have been reported in patients treated with 5-HT1 agonists including patients without a history of hypertension. Very rarely these increases in blood pressure have been associated with significant clinical events. In healthy subjects treated with 5 mg of zolmitriptan oral tablet, an increase of 1 and 5 mm Hg in the systolic and diastolic blood pressure, respectively, was seen. In a study of patients with moderate to severe liver impairment, 7 of 27 patients experienced 20 to 80 mm Hg elevations in systolic and/or diastolic blood pressure after a dose of 10 mg of zolmitriptan oral tablet. As with all triptans, blood pressure should be monitored in zolmitriptan-treated patients. Zolmitriptan is contraindicated in patients with uncontrolled hypertension [see Contraindications (4)].

6.1 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.

Adults

Among 460 patients treating 1180 single attacks with zolmitriptan nasal spray in a blinded placebo controlled trial (Study 1), there was a low withdrawal rate related to adverse reactions: 5 mg (1.3%), 2.5 mg (0%), and placebo (0.4%). None of the withdrawals were due to a serious event. One patient was withdrawn due to abnormal ECG changes from baseline that were incidentally found 23 days after the last dose of zolmitriptan nasal spray.

The most common adverse reactions (≥ 5% and > placebo) in any dosage strength in clinical trials for zolmitriptan nasal spray were: unusual taste, paresthesia, hyperesthesia, and dizziness. The incidence of adverse reactions was generally dose-related.

Table 1 lists the adverse reactions from the controlled clinical trial (Study 1) that occurred in ≥ 2% of patients in either the 2.5 or 5 mg zolmitriptan nasal spray dose groups and with an incidence greater than placebo.

Table 1: Adverse reactions in a Placebo-Controlled Study in Adult Patients with Migraine (Study 1)

In Study 1, adverse reactions occurring in ≥ 1% and < 2% of patients in all attacks in either zolmitriptan nasal spray dose group and with incidence greater than that of placebo were: abdominal pain, chills, throat pressure, facial edema, chest pressure, palpitation, dysphagia, arthralgia, myalgia, and depersonalization.

The incidence of adverse reactions in controlled clinical trials was not affected by gender, weight, or age of the patients (18-39 vs. 40-65 years of age), or presence of aura. There were insufficient data to assess the impact of race on the incidence of adverse reactions.

Local Adverse Reactions:

Among 460 patients using zolmitriptan 2.5 mg or 5 mg in the controlled clinical trial, approximately 3% noted local irritation or soreness at the site of administration. Adverse reactions of any kind, perceived in the nasopharynx (which may include systemic effects of triptans) were severe in about 1% of patients and approximately 57% resolved in 1 hour. Nasopharyngeal examinations, in a subset of patients participating in two long term trials of up to one-year duration, failed to demonstrate any clinically significant changes with repeated use of zolmitriptan nasal spray.

All nasopharyngeal adverse reactions with an incidence of ≥ 2% of patients in any zolmitriptan nasal spray dose groups are included in Table 1.

Other Adverse Reactions:

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. Reaction frequencies are calculated as the number of patients who used zolmitriptan nasal spray and reported a reaction divided by the total number of patients exposed to zolmitriptan nasal spray (n=3059). All reported reactions are included except those already listed in the previous table, those too general to be informative, and those not reasonably associated with the use of the drug. Reactions are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: infrequent adverse reactions are those occurring in 1/100 to 1/1,000 patients and rare adverse reactions are those occurring in fewer than 1/1,000 patients.

General: Infrequent: allergic reactions.

Cardiovascular: Infrequent: arrhythmias, hypertension, syncope and tachycardia. Rare: angina pectoris and myocardial infarct.

Digestive: Rare: stomatitis.

Neurological: Infrequent: agitation, amnesia, anxiety, depression, insomnia, and nervousness. Rare: convulsions.

Respiratory: Infrequent: bronchitis, increased cough, dyspnea, epistaxis, laryngeal edema, pharyngitis, rhinitis, and sinusitis.

Skin: Infrequent: pruritus, rash, and urticaria.

Urogenital: Infrequent: polyuria and urinary urgency. Rare: urinary frequency.

Special senses: Infrequent: tinnitus. Rare: conjunctivitis, dry eye, and visual field defect.

The adverse reaction profile seen with zolmitriptan nasal spray is similar to that seen with zolmitriptan tablets and zolmitriptan oral disintegrating tablets except for the occurrence of local adverse reactions from the nasal spray.

Pediatric Patients 12 to 17 Years of Age

The safety of zolmitriptan nasal spray in the acute treatment of migraine in pediatric patients 12 to 17 years of age was established in two studies [see Pediatric Use (8.4) and Clinical Studies (14.2)].

The most common adverse reactions (incidence of ≥ 2% of pediatric patients receiving 2.5 mg and 5 mg zolmitriptan nasal spray and numerically greater than placebo) after a single dose are summarized in Table 2. Dysgeusia (unusual taste) was the most common adverse reaction, with a numerically greater incidence for patients receiving zolmitriptan compared to placebo (10% vs. 2%). Other common adverse reactions were nasal discomfort, dizziness, oropharyngeal pain, and nausea.

Table 2 lists the adverse reactions from the pooled placebo-controlled studies that occurred in ≥ 2% of pediatric patients 12 to 17 years of age in either the 2.5 mg or 5 mg zolmitriptan dose groups and with an incidence greater than placebo.

Table 2: Adverse reactions in Pooled Placebo-Controlled Studies in Pediatric Patients 12 to 17 years of Age with Migraine

The adverse reaction profile was similar across gender. There were insufficient data to assess the impact of race on the incidence of adverse reactions.

6.2 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:

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.

7.1 Ergot-Containing Drugs

Ergot-containing drugs have been reported to cause prolonged vasospastic reactions. Because these effects may be additive, use of ergotamine-containing or ergot-type medications (like dihydroergotamine or methysergide) and zolmitriptan within 24 hours of each other is contraindicated [see Contraindications (4)].

7.2 MAO-A Inhibitors

MAO-A inhibitors increase the systemic exposure of zolmitriptan. Therefore, the use of zolmitriptan in patients receiving MAO-A inhibitors is contraindicated [see Contraindications (4) and Clinical Pharmacology (12.3)].

7.3 5-HT1B/1D agonists (e.g. triptans)

Concomitant use of other 5-HT1B/1D agonists (including triptans) within 24 hours of zolmitriptan treatment is contraindicated because the risk of vasospastic reactions may be additive [see Contraindications (4)].

7.4 Cimetidine

Following administration of cimetidine, the half-life and AUC of zolmitriptan and its active metabolites were approximately doubled [see Clinical Pharmacology (12.3)]. If cimetidine and zolmitriptan are used concomitantly, limit the maximum single dose of zolmitriptan to 2.5 mg, not to exceed 5 mg in any 24-hour period [see Dosage and Administration (2.3) and Clinical Pharmacology (12.3)].

7.5 Selective Serotonin Reuptake Inhibitors/Serotonin Norepinephrine Reuptake Inhibitors and Serotonin Syndrome

Cases of life-threatening serotonin syndrome have been reported during combined use of selective serotonin reuptake inhibitors (SSRIs) or serotonin norepinephrine reuptake inhibitors (SNRIs) and triptans [see Warnings and Precautions (5.7)].

8.1 Pregnancy

Risk Summary

There are no adequate data on the developmental risk associated with the use of zolmitriptan in pregnant women. In reproductive toxicity studies in rats and rabbits, oral administration of zolmitriptan to pregnant animals resulted in embryolethality and fetal abnormalities (malformations and variations) at clinically relevant exposures (see Data).

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. The estimated rates of major birth defects (2.2%-2.9%) and miscarriage (17%) among deliveries to women with migraine are similar to rates reported in women without migraine.

Clinical Considerations

Disease-Associated Maternal and/or Embryo/Fetal Risk

Published data have suggested that women with migraine may be at increased risk of preeclampsia during pregnancy.

Data

Animal Data

When zolmitriptan was administered to pregnant rats during the period of organogenesis at oral doses of 100, 400, and 1200 mg/kg/day (plasma exposures (AUCs) ≈280, 1100, and 5000 times the human AUC at the maximum recommended human dose (MRHD) of 10 mg/day), there was a dose-related increase in embryolethality. A no-effect dose for embryolethality was not established. When zolmitriptan was administered to pregnant rabbits during the period of organogenesis at oral doses of 3, 10, and 30 mg/kg/day (plasma AUCs ≈1, 11, and 42 times the human AUC at the MRHD), there were increases in embryolethality and in fetal malformations and variations. The no-effect dose for adverse effects on embryo-fetal development was associated with a plasma AUC similar to that in humans at the MRHD. When female rats were given zolmitriptan during gestation, parturition, and lactation at oral doses of 25, 100, and 400 mg/kg/day (plasma AUCs ≈70, 280, and 1100 times that in human at the MRHD), an increased incidence of hydronephrosis was found in the offspring. The no-effect dose was associated with a plasma AUC ≈280 times that in humans at the MRHD.

8.2 Lactation

Risk Summary

There are no data on the presence of zolmitriptan or its metabolites in human milk, the effects on the breastfed infant, or the effects of zolmitriptan and its metabolites on milk production. In rats, oral dosing with zolmitriptan resulted in levels in milk up to 4 times that in maternal plasma.

The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for zolmitriptan and any potential adverse effects on the breastfed infant from zolmitriptan or from the underlying maternal condition.

8.4 Pediatric Use

Safety and effectiveness of zolmitriptan in pediatric patients under 12 years of age have not been established.

The efficacy of zolmitriptan nasal spray in the acute treatment of migraine in pediatric patients 12 to 17 years of age was established in a placebo-controlled study with a total of 81 pediatric patients receiving zolmitriptan 2.5 mg and 229 pediatric patients receiving zolmitriptan 5 mg [see Clinical Studies (14.2)].

In an earlier study with a different design, zolmitriptan 5 mg nasal spray was evaluated in the acute treatment of migraine headache in 171 pediatric patients 12 to 17 years of age. In that study, the efficacy of zolmitriptan nasal spray was not established.

The safety of zolmitriptan nasal spray in the acute treatment of migraine in pediatric patients 12 to 17 years of age was established in two placebo-controlled studies with a total of 81 pediatric patients receiving zolmitriptan 2.5 mg and 431 pediatric patients receiving zolmitriptan 5 mg [see Adverse Reactions (6.1)].

The safety profile of zolmitriptan nasal spray in pediatric patients 12 to 17 years of age is similar to the profile observed in adults [see Adverse Reactions (6.1)].

In the postmarketing experience with triptans, including zolmitriptan, there is a limited number of reports that describe pediatric patients who have experienced clinically serious adverse events; those that were reported are similar in nature to those reported rarely in adults.

8.5 Geriatric Use

Clinical studies of zolmitriptan did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy. Geriatric patients who have other cardiovascular risk factors (e.g., diabetes, hypertension, smoking, obesity, strong family history of coronary artery disease) should have a cardiovascular evaluation prior to receiving zolmitriptan [see Warnings and Precautions (5.1)]. The pharmacokinetics of zolmitriptan were similar in geriatric patients (aged > 65 years) compared to younger patients [see Clinical Pharmacology (12.3)].

8.6 Hepatic Impairment

The effect of hepatic disease on the pharmacokinetics of zolmitriptan nasal spray has not been evaluated. After oral administration, zolmitriptan blood levels were increased in patients with moderate to severe hepatic impairment, and significant elevation in blood pressure was observed in some of these patients [see Warnings and Precautions (5.8)]. Zolmitriptan nasal spray is not recommended in patients with moderate to severe hepatic impairment [see Dosage and Administration (2.2) and Clinical Pharmacology (12.3)].

12.1 Mechanism of Action

Zolmitriptan binds with high affinity to human recombinant 5-HT1D and 5-HT1B receptors, and moderate affinity for 5-HT1A receptors. The N-desmethyl metabolite also has high affinity for 5-HT1B/1D and moderate affinity for 5-HT1A receptors.

Current theories proposed to explain the etiology of migraine headache suggest that symptoms are due to local cranial vasodilatation and/or to the release of sensory neuropeptides (vasoactive intestinal peptide, substance P and calcitonin gene-related peptide) through nerve endings in the trigeminal system. The therapeutic activity of zolmitriptan for the treatment of migraine headache is thought to be due to the agonist effects at the 5-HT1B/1D receptors on intracranial blood vessels (including the arterio-venous anastomoses) and sensory nerves of the trigeminal system which result in cranial vessel constriction and inhibition of pro-inflammatory neuropeptide release.

12.3 Pharmacokinetics

Absorption, Distribution, Metabolism, and Excretion

Absorption

Zolmitriptan nasal spray is rapidly absorbed via the nasopharynx as detected in a Photon Emission Tomography (PET) study using 11C zolmitriptan. The mean relative bioavailability of the nasal spray formulation is 102%, compared with the oral tablet. Zolmitriptan was detected in plasma by 5 minutes and peak plasma concentration generally was achieved by 3 hours. The time at which maximum plasma concentrations were observed was similar after single (1 day) or multiple (4 days) nasal dosing. Plasma concentrations of zolmitriptan are sustained for 4 to 6 hours after dosing. Zolmitriptan and its active N-desmethyl metabolite display linear kinetics after single or multiple doses of zolmitriptan nasal spray over the dose range of 0.1 to 10 mg.

The pharmacokinetics of the N-desmethyl metabolite are similar to that of zolmitriptan for all nasal spray dosages. The N-desmethyl metabolite is detected in plasma by 15 minutes and peak plasma concentration is generally achieved by 3 hours after administration.

Food has no significant effect on the bioavailability of zolmitriptan.

Distribution

Plasma protein binding of zolmitriptan is 25% over the concentration range of 10-1000 ng/mL. The mean apparent volume of distribution for zolmitriptan nasal spray formulation is 8.4 L/kg.

Metabolism

Zolmitriptan is converted to an active N-desmethyl metabolite such that the metabolite concentrations are about two-thirds that of zolmitriptan. Because the 5HT1B/1D potency of the metabolite is 2 to 6 times that of the parent compound, the metabolite may contribute a substantial portion of the overall effect after zolmitriptan administration.

Excretion

The mean elimination half-life for zolmitriptan and N-desmethyl metabolite following single or multiple nasal spray administration are approximately 3 hours, similar to the half-life values seen after oral tablet administration.

In a study with orally administered zolmitriptan, total radioactivity recovered in urine and feces was 65% and 30% of the administered dose, respectively. In urine, unchanged zolmitriptan and N-desmethyl metabolite accounted for 8% and 4% of the dose, respectively, whereas the inactive indole acetic acid and N-oxide metabolites accounted for 31% and 7% of the dose, respectively.

Mean total plasma clearance for zolmitriptan nasal spray is 25.9 mL/min/kg, of which one-sixth is renal clearance. The renal clearance is greater than the glomerular filtration rate suggesting renal tubular secretion.

Specific Populations

Age:

The pharmacokinetics of orally administered zolmitriptan in healthy elderly non-migraineur volunteers (age 65-76 yrs) was similar to those in younger non-migraineur volunteers (age 18-39 yrs).

Sex:

Mean plasma concentrations of orally administered zolmitriptan were up to 1.5-fold higher in females than males.

Race:

There are no significant differences in the pharmacokinetics of orally administered zolmitriptan in Japanese and Caucasians.

Renal Impairment:

The effect of renal impairment on the pharmacokinetics of zolmitriptan nasal spray has not been evaluated. After orally dosing zolmitriptan, renal clearance was reduced by 25% in patients with severe renal impairment (Clcr ≥ 5 ≤ 25 mL/min) compared with the normal group (Clcr ≥ 70 mL/min); no significant change in clearance was observed in the moderately renally impaired group (Clcr ≥ 26 ≤ 50 mL/min).

Hepatic Impairment:

The effect of hepatic disease on the pharmacokinetics of zolmitriptan nasal spray has not been evaluated. In patients with severe hepatic impairment, the mean Cmax, Tmax, and AUC of zolmitriptan dosed orally were increased 1.5-fold, 2-fold (2 vs. 4 hours), and 3-fold, respectively, compared to subjects with normal hepatic function. Seven out of 27 patients experienced 20 to 80 mm Hg elevations in systolic and/or diastolic blood pressure after a 10 mg zolmitriptan dose [see Dosage and Administration (2.2) and Use in Specific Populations (8.6)].

Hypertensive Patients:

No differences in the pharmacokinetics of oral zolmitriptan or its effects on blood pressure were seen in mild to moderate hypertensive volunteers compared with normotensive controls.

Drug Interactions

All drug interaction studies were performed in healthy volunteers using a single 10 mg dose of zolmitriptan and a single dose of the other drug except where otherwise noted. Eight drug interaction studies have been performed with zolmitriptan tablets and one study (xylometazoline) was performed with nasal spray.

Xylometazoline:

An in vivo drug interaction study with zolmitriptan nasal spray indicated that 1 spray (100 μL dose) of xylometazoline (0.1% w/v), a decongestant, administered 30 minutes prior to a 5 mg nasal dose of zolmitriptan did not alter the pharmacokinetics of zolmitriptan.

Fluoxetine:

The pharmacokinetics of zolmitriptan, as well as its effect on blood pressure, were unaffected by 4 weeks of pre-treatment with oral fluoxetine (20 mg/day).

MAO Inhibitors:

Following one week of administration of moclobemide (150 mg twice-daily), a specific MAO-A inhibitor, there was an increase of about 25% in both Cmax and AUC for zolmitriptan and a 3-fold increase in the Cmax and AUC of the active N-desmethyl metabolite of zolmitriptan [see Contraindications (4) and Drug Interactions (7.2)].

Selegiline, a selective MAO-B inhibitor, at a dose of 10 mg/day for 1 week, had no effect on the pharmacokinetics of zolmitriptan and its metabolite.

Propranolol:

Cmax and AUC of zolmitriptan increased 1.5-fold after one week of dosing with propranolol (160 mg/day). Cmax and AUC of the N-desmethyl metabolite were reduced by 30% and 15%, respectively. There were no interactive effects on blood pressure or pulse rate following administration of propranolol with zolmitriptan.

Acetaminophen:

A single 1g dose of acetaminophen does not alter the pharmacokinetics of zolmitriptan and its N-desmethyl metabolite. However, zolmitriptan delayed the Tmax of acetaminophen by one hour.

Metoclopramide:

A single 10 mg dose of metoclopramide had no effect on the pharmacokinetics of zolmitriptan or its metabolites.

Oral Contraceptives:

Retrospective analysis of pharmacokinetic data across studies indicated that mean Cmax and AUC of zolmitriptan were 30% and 50% higher, respectively, and Tmax was delayed by one-half hour in females taking oral contraceptives compared to females not taking oral contraceptives. The effect of zolmitriptan on the pharmacokinetics of oral contraceptives has not been studied.

Cimetidine:

Following the administration of cimetidine, the half-life and AUC of a 5 mg dose of zolmitriptan and its active metabolite were approximately doubled. A dosage adjustment is therefore required [see Drug Interactions (7.4)].

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

Carcinogenesis

Zolmitriptan was administered to mice and rats at doses up to 400 mg/kg/day. Mice were dosed for 85 weeks (males) and 92 weeks (females); rats were dosed for 101 weeks (males) and 86 weeks (females). There was no evidence of drug-induced tumors in mice at plasma exposures (AUC) up to approximately 700 times that in humans at the maximum recommended human dose (MRHD) of 10 mg/day. In rats, there was an increase in the incidence of thyroid follicular cell hyperplasia and thyroid follicular cell adenomas in male rats receiving 400 mg/kg/day. No increase in tumors was observed in rats at 100 mg/kg/day, a dose associated with a plasma AUC≈700 times that in humans at the MRHD.

Mutagenesis

Zolmitriptan was positive in an in vitro bacterial reverse mutation (Ames) assay and in an in vitro chromosomal aberration assay in human lymphocytes. Zolmitriptan was negative in an in vitro mammalian gene cell mutation (CHO/HGPRT) assay and in oral in vivo micronucleus assays in mouse and rat.

Impairment of Fertility

Studies of male and female rats administered zolmitriptan prior to and during mating and up to implantation showed no impairment of fertility at oral doses up to 400 mg/kg/day. The plasma exposure (AUC) at this dose was approximately 3000 times that in humans at the MRHD.

14.1 Adults

The efficacy of zolmitriptan nasal spray 2.5 mg and 5 mg in the acute treatment of migraine headache with or without aura in adults was demonstrated in Study 1, a randomized, outpatient, double-blind, placebo-controlled trial.

In Study 1, 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 15, 30, 45 minutes and 1, 2, and 4 hours after dosing. Pain-free response rates and associated symptoms such as nausea, photophobia, and phonophobia were also assessed. A dose of escape medication was allowed 4 to 24 hours after the initial treatment for persistent and recurrent headache.

In Study 1, of the patients taking zolmitriptan nasal spray 2.5 mg or 5 mg, 83% were female and 99% were Caucasian, with a mean age of 41 years (range 18 to 65 years).

The two-hour headache response rates in patients treated with zolmitriptan nasal spray were significantly higher among patients receiving zolmitriptan nasal spray at all doses, compared with placebo (see Table 3).

Table 3: First Attack Data: Percentage of Adult Patients with Headache Response to Zolmitriptan Nasal Spray (Mild or No Headache) 2 Hours Following Treatment in Study 1

*p < 0.001 in comparison with placebo

The estimated probability of achieving an initial headache response following treatment with zolmitriptan nasal spray is depicted in Figure 1.

Figure 1: Estimated probability of achieving an initial headache response after treatment in Study 1

Note: Figure 1 shows the Kaplan-Meier plot of the probability over time of obtaining headache response (moderate or severe headache improving to mild or no pain) following treatment with zolmitriptan nasal spray. The estimates displayed are based on a placebo controlled, outpatient trial providing evidence of efficacy. Patients not achieving headache response or taking additional treatment prior to 4 hours were censored to 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 nasal spray as compared with placebo.

Four 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: Estimated probability of patients taking an escape medication within the 24 hours following the initial dose of study treatment in Study 1

*This Kaplan-Meier plot is based on data obtained from the placebo controlled clinical trial. 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. It should be noted that the protocol did not allow remedication within 4 hours post dose.

The efficacy of zolmitriptan was unaffected by presence of aura; presence of headache upon awakening, relationship to menses; gender, age or weight of the patient; or presence of pre-treatment nausea.

The efficacy of zolmitriptan nasal spray 5 mg was further supported by an interim analysis of another similarly designed trial. The 2-hour headache response rates for the first 210 subjects in that study for zolmitriptan 5 mg and placebo were 70% and 47%, respectively (N=108 and 102, respectively, p=0.0006).

14.2 Pediatric Patients 12 to 17 Years of Age

The efficacy of zolmitriptan nasal spray in the acute treatment of migraine headache with or without aura in pediatrics patients 12 to 17 years of age was demonstrated in Study 2, a randomized, double-blind, placebo-controlled trial with a single-blind run-in period.

Patients had to have an established diagnosis of migraine (history indicating the presence of migraine for at least 1 year) with or without aura with a typical untreated migraine headache attack lasting 3 hours or more. The study included treatment of a single migraine headache attack with 1 dose of single-blind placebo during the 30-day run-in period. If the patient met all conditions for randomization, including a lack of response to the placebo run-in, a subsequent single migraine headache attack was treated with 1 blinded dose of either zolmitriptan nasal spray 5 mg, 2.5 mg, or matching placebo.

In Study 2, of the patients taking zolmitriptan nasal spray 2.5 mg or 5 mg, 62% were female and 93% were Caucasian, with a mean age of 14 years (range 12 to 17 years).

Study 2 evaluated the proportion of pediatric patients 12 to 17 years of age who had no headache pain at 2 hours following treatment. Headache response (defined as a reduction in migraine-related headache pain severity from moderate or severe pain to mild or no pain) and the absence of nausea, photophobia, and phonophobia at 2 hours post treatment were also assessed. As shown in Table 4, the percentage of pediatric patients 12 to 17 years of age with no headache pain at 2 hours following treatment was significantly higher for zolmitriptan nasal spray 5 mg than placebo.

Table 4: Percentage of Pediatric Patients 12 to 17 Years of Age with No Headache Pain, With Headache Response, No Nausea, No Photophobia, and No Phonophobia Two Hours after Treatment in Study 2

*p < 0.05 in comparison with placebo

Two to 24 hours following the initial dose of study treatment, patients were allowed to use their usual medication for pain relief. The estimated probability of patients taking escape medication during the first 24 hours following the initial dose of study treatment is summarized in Figure 3.

Figure 3: Estimated Probability of Pediatric Patients 12 to 17 Years of Age Taking an Escape Medication Within the 24 Hours Following the Initial Dose of Study Treatment in Study 2