2.1 Dosing Information

The recommended starting dose of zolmitriptan orally disintegrating tablets is 1.25 mg or 2.5 mg. The 1.25 mg dose can be achieved by manually breaking the functionally-scored 2.5 mg tablet in half. The maximum recommended single dose of zolmitriptan orally disintegrating tablets is 5 mg.

In controlled clinical trials, a greater proportion of patients had headache response following a 2.5 mg or 5 mg dose than following a 1 mg dose. There was little added benefit from the 5 mg dose compared to the 2.5 mg dose, but adverse reactions were more frequent with the 5 mg dose.

If the migraine has not resolved by 2 hours after taking zolmitriptan orally disintegrating tablets, or returns after a transient improvement, a second dose may be administered at least 2 hours after the first dose. The maximum daily dose is 10 mg in any 24-hour period.

The safety of zolmitriptan orally disintegrating tablets in the treatment of an average of more than three migraines in a 30-day period has not been established.

2.2 Administration of Zolmitriptan Orally Disintegrating Tablets

Instruct patients not to break zolmitriptan orally disintegrating tablets because they are not functionally-scored. Administration with liquid is not necessary.

Orally disintegrating tablets are packaged in a blister pack. Instruct patients not to remove the tablet from the blister until just prior to dosing. Subsequently, instruct patients to peel the blister pack open, and to place the orally disintegrating tablet on the tongue, where it will dissolve and it will be swallowed with the saliva.

2.3 Dosing in Patients with Hepatic Impairment

The recommended dose of zolmitriptan orally disintegrating tablets in patients with moderate to severe hepatic impairment is 1.25 mg (one-half of one 2.5 mg zolmitriptan tablet) because of increased zolmitriptan blood levels in these patients and elevation of blood pressure in some of these patients. Limit the total daily dose in patients with severe hepatic impairment to no more than 5 mg per day.

The use of zolmitriptan orally disintegrating tablets is not recommended in patients with moderate or severe hepatic impairment because these orally disintegrating tablets should not be broken in half [see Use in Specific Populations (8.6), and Clinical Pharmacology (12.3)].

2.4 Dosing in Patients taking Cimetidine

If zolmitriptan orally disintegrating tablets are co-administered with cimetidine, limit the maximum single dose of zolmitriptan orally disintegrating tablets to 2.5 mg, not to exceed 5 mg in any 24-hour period [see Drug Interactions (7.5), Clinical Pharmacology (12.3)].

5.1 Myocardial Ischemia, Myocardial Infarction, and Prinzmetal 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-HT1agonists including zolmitriptan may cause coronary artery vasospasm (Prinzmetal 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. Zolmitriptan is contraindicated in patients with Wolff-Parkinson-White Syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders [see Contraindications (4)].

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

As with other 5-HT1 agonists, sensations of tightness, pain, and pressure in the chest, throat, neck, and jaw commonly occur after treatment with zolmitriptan and is usually non-cardiac in origin. However, perform a cardiac evaluation if these patients are at high cardiac risk. 5-HT1 agonists including zolmitriptan are contraindicated in patients with CAD or Prinzmetal’s variant angina [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.

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, exclude other potentially serious neurological conditions. Zolmitriptan is contraindicated in 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 a vasospastic reaction following the use of any 5-HT1 agonist, rule out a vasospastic reaction 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. Discontinue zolmitriptan if serotonin syndrome is suspected [see Drug Interactions (7.4)].

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 serious adverse reactions. In healthy subjects treated with 5 mg of zolmitriptan, 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. As with all triptans, blood pressure should be monitored in zolmitriptan-treated patients. Zolmitriptan is contraindicated in patients with uncontrolled hypertension [see Contraindications (4)].

5.9 Risks in Patients with Phenylketonuria

Phenylalanine can be harmful to patients with phenylketonuria (PKU). Zolmitriptan orally disintegrating tablets contain phenylalanine (a component of aspartame). Each 2.5 mg and 5 mg orally disintegrating tablet contains 1.12 and 2.24 mg of phenylalanine, respectively.

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.

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.

Table 1: Adverse Reaction Incidence in Five Pooled Placebo-Controlled Migraine Clinical Trials*

 

*Only adverse reactions that were at least 2% more frequent in a zolmitriptan group compared to the placebo group are included.

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.

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:

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.

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 and its active N-desmethyl metabolite. Therefore, the use of zolmitriptan in patients receiving MAO-A inhibitors is contraindicated [see Contraindications (4), Clinical Pharmacology (12.3)].

7.3 5-HT1B/1D agonists

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 Selective Serotonin Reuptake Inhibitors and Serotonin Norepinephrine Reuptake Inhibitors

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

7.5 Cimetidine

Following administration of cimetidine, the half-life and blood levels of zolmitriptan and its active N-desmethyl metabolite 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 (2.4), Clinical Pharmacology (12.3)].

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% to 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 embryofetal 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

The safety and effectiveness in pediatric patients have not been established. Therefore, zolmitriptan is not recommended for use in patients under 18 years of age.

One randomized, placebo-controlled clinical trial of zolmitriptan tablets (2.5, 5 and 10 mg) evaluated 696 pediatric patients (aged 12 to 17 years) with migraines. This study did not demonstrate the efficacy of zolmitriptan compared to placebo in the treatment of migraine in adolescents. Adverse reactions in the adolescent patients treated with zolmitriptan were similar in nature and frequency to those reported in clinical trials in adults treated with zolmitriptan. Zolmitriptan has not been studied in pediatric patients less than 12 years old.

In the postmarketing experience with triptans, including zolmitriptan, there were no additional adverse reactions seen in pediatric patients that were not seen 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.

A cardiovascular evaluation is recommended for geriatric patients who have other cardiovascular risk factors (e.g., diabetes, hypertension, smoking, obesity, strong family history of coronary artery disease) 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 Patients with Hepatic Impairment

After oral zolmitriptan 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)]. Therefore, adjust the zolmitriptan dose and administer with caution in patients with moderate or severe hepatic impairment [see Dosage and Administration (2.3), Clinical Pharmacology (12)].

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.

Migraines are likely 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

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility