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Uses

Vascular Headaches

Migraine

Zolmitriptan is used orally or intranasally for the acute treatment of attacks of migraine with or without aura in adults. The manufacturer states that zolmitriptan should not be used for the management of hemiplegic or basilar migraine or for the prophylaxis of migraine. Safety and efficacy have not been established for the management of cluster headaches.

Efficacy of zolmitriptan administered orally at dosages of 1, 2.5, or 5 mg has been evaluated for the acute treatment of migraine attacks in several randomized, placebo-controlled studies in adults with moderate to severe headaches. In these studies, substantially more patients receiving zolmitriptan achieved a response (mild or no headache pain) 2 hours after treatment than those receiving placebo. In dose-ranging studies, 65 or 60-67% of patients receiving zolmitriptan 2.5 or 5 mg, respectively, achieved a response 2 hours after treatment, compared with 27-50% of patients receiving zolmitriptan 1 mg; headache response at 2 hours in patients receiving zolmitriptan 2.5 mg did not differ substantially from that observed in patients receiving zolmitriptan 5 mg. The drug also relieved manifestations of migraine other than headache (including nausea, photophobia, and phonophobia) and reduced the need for supplemental migraine therapy. In long-term (6-12 months) open-label studies, intermittent zolmitriptan remained effective during subsequent migraine attacks.

Efficacy of zolmitriptan administered intranasally has been evaluated for the acute treatment of migraine attacks in a randomized, placebo-controlled study in adults with moderate to severe headaches. In this study, substantially more patients receiving zolmitriptan intranasally at a dosage of 5 mg achieved a response (mild or no headache pain) 2 hours after treatment than those receiving placebo (69 versus 31%, respectively). The drug also relieved manifestations of migraine other than headache (including nausea, photophobia, and phonophobia) and reduced the need for supplemental migraine therapy. Interim analysis of a similarly designed study supported these findings and showed that substantially more patients receiving intranasally administered zolmitriptan achieved a response 2 hours after treatment than those receiving placebo (70 versus 47%, respectively).

Limited data suggest that 2.5 or 5 mg of oral zolmitriptan is at least as effective as 25 or 50 mg of oral sumatriptan in alleviating the pain associated with migraine 2 hours after treatment.

The US Headache Consortium considers 5-HT_1B/1D receptor agonists (e.g., zolmitriptan) an appropriate treatment choice for the acute management of moderate to severe migraine headaches in patients without contraindications to these drugs and recommends use of 5-HT_1B/1D receptor agonists, dihydroergotamine, or ergotamine in patients with more severe migraine attacks as well as in patients in whom previous therapy with nonsteroidal anti-inflammatory agents (NSAIAs) or fixed-combination preparations such as acetaminophen, aspirin, and caffeine has been ineffective.

For further information on management and classification of migraine headache,

Dosage and Administration

General

Zolmitriptan is administered orally as conventional or orally disintegrating tablets without regard to meals. Zolmitriptan also can be administered intranasally.

Patients receiving zolmitriptan orally disintegrating tablets should be instructed not to remove a tablet from the blister package until just prior to dosing. The blister should then be peeled open, and the tablet placed on the tongue, where it will dissolve and be swallowed with saliva; administration with liquid is not necessary.

The patient information provided by the manufacturer should be consulted for directions on intranasal administration of zolmitriptan.

For the acute treatment of migraine attacks with or without aura in adults, the recommended initial oral dose of zolmitriptan is a single dose of 1.25 or 2.5 mg. The maximum recommended single oral dose of the drug is 5 mg. Single oral zolmitriptan doses of 1 (not commercially available in the US), 2.5, or 5 mg were effective in clinical studies, although the 2.5- and 5-mg doses were effective in a greater proportion of patients. The 5-mg dose provided little additional benefit compared with the 2.5-mg dose but was associated with an increased risk of adverse effects. A dose of 1.25 mg can be achieved by manually breaking the scored 2.5-mg conventional tablet in half. However, the manufacturer states that orally disintegrating tablets are not scored and should not be broken.

If the headache has not resolved by 2 hours following an initial oral dose of zolmitriptan, or if it recurs after transient improvement, the dose may be repeated after at least 2 hours. However, in patients who fail to respond to an initial dose, a diagnosis of migraine should be reconsidered prior to administration of a second oral dose . The maximum dosage of zolmitriptan to be administered orally in any 24-hour period is 10 mg. The safety of treating an average of more than 3 headaches with oral zolmitriptan per 30-day period has not been established.

For the acute treatment of migraine attacks with or without aura in adults, a single intranasal zolmitriptan dose of 5 mg was effective in adults in controlled clinical studies. A 5-mg dose is administered into one nostril using the single-use nasal spray. If the headache returns, a single 5-mg dose may be repeated after 2 hours; however, the efficacy of a second dose has not been established in controlled clinical studies. A diagnosis of migraine should be reconsidered prior to administration of a second intranasal dose in patients who fail to respond to an initial dose. The maximum dosage of zolmitriptan to be administered intranasally in any 24-hour period is 10 mg (i.e., 2 sprays). A dose of less than 5 mg can be achieved only with use of oral formulations of the drug. Because individuals may vary in their response to zolmitriptan nasal spray, the choice of dose and route of administration must be made on an individual basis. The safety of treating an average of more than 4 headaches with intranasal zolmitriptan per 30-day period has not been established.

Special Populations

When zolmitriptan is used in patients with moderate to severe hepatic impairment, an oral dose of 1.25 mg is recommended. In patients with severe hepatic impairment, the maximum dosage to be administered orally in any 24-hour period is 5 mg. A dose of 1.25 mg can be achieved by manually breaking the scored 2.5-mg conventional tablet in half. Because the orally disintegrating tablets are not scored and should not be broken, use of this formulation in patients with moderate to severe hepatic impairment is not recommended. Because systemic exposure is similar following oral or intranasal administration, dosage adjustments with oral and intranasal formulations should be similar; however, recommended doses for patients with hepatic impairment can be achieved only with use of conventional oral formulations.

Dosage selection for geriatric patients should be cautious, usually starting at the low end of the dosage range, and reflect the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy in such patients.

Cautions

Contraindications

Ischemic heart disease (e.g., angina pectoris, myocardial infarction, silent ischemia), coronary vasospasm (e.g., Prinzmetal variant angina), Wolff-Parkinson-White syndrome or cardiac arrhythmias associated with other accessory pathway conduction disorders, uncontrolled hypertension, other serious underlying cardiovascular disease, history of stroke or transient ischemic attack, peripheral vascular disease, or ischemic bowel disease. Basilar or hemiplegic migraine. Treatment within the previous 24 hours with another 5-HT₁ receptor agonist or with an ergot alkaloid (e.g., ergotamine, dihydroergotamine, methysergide [no longer commercially available in the US]). Concurrent or recent (within 2 weeks) treatment with a monoamine oxidase-A (MAO-A) inhibitor. Known hypersensitivity to zolmitriptan or any ingredient in the formulation.

Warnings/Precautions

Careful Diagnosis of Migraine

Zolmitriptan should be used only in patients in whom a clear diagnosis of migraine has been established. If the first attack of migraine treated with zolmitriptan fails to respond to the drug, the diagnosis of migraine should be reconsidered before zolmitriptan is administered to treat subsequent attacks. Care should be taken to exclude other potentially serious neurologic disorders before zolmitriptan is administered to patients not previously diagnosed with migraine or to patients who present with atypical symptoms.

Cardiac Effects

Serious cardiac events, including acute myocardial infarction and fatal or life-threatening cardiac rhythm disturbances (e.g., ventricular tachycardia or fibrillation), have occurred within a few hours following administration of 5-HT₁ receptor agonists. Myocardial ischemia/infarction or coronary vasospasm (e.g., Prinzmetal variant angina) may occur even in patients without a history of coronary artery disease. Use of zolmitriptan is contraindicated in patients with ischemic or vasospastic heart disease. The drug should be discontinued if disturbances in cardiac rhythm occur.(See Cautions: Contraindications.)

Although sensations of tightness, pain, pressure, and heaviness in the precordium, throat, neck, and jaw occur frequently following administration of 5-HT₁ receptor agonists, these sensations usually are noncardiac in origin. However, the manufacturer states that a cardiovascular evaluation should be performed if the patient is at high cardiac risk.

Patients with multiple cardiovascular risk factors (e.g., postmenopausal women; men older than 40 years of age; patients with risk factors such as hypertension, hypercholesterolemia, smoking, obesity, diabetes, or family history of coronary artery disease) who have not previously received therapy with a 5-HT₁ receptor agonist should undergo cardiovascular evaluation prior to initiation of 5-HT₁ receptor agonist therapy. If the evaluation provides evidence of coronary artery disease or coronary artery vasospasm, the drug should not be administered. For patients with a satisfactory cardiovascular evaluation, the manufacturer states that consideration should be given to administration of the first dose in a medically supervised setting with electrocardiographic monitoring performed immediately following administration of the dose. Periodic cardiovascular evaluation is recommended for patients with risk factors for coronary artery disease who are receiving intermittent long-term therapy with 5-HT₁ receptor agonists.

For further information on the systematic approach to administering 5-HT₁ receptor agonists in patients with risk factors for the development of coronary artery disease,

Cerebrovascular Effects

Cerebral or subarachnoid hemorrhage and stroke, sometimes fatal, have occurred in patients receiving 5-HT₁ receptor agonists. In a number of cases, it appears possible that the cerebrovascular event was the primary event, and the 5-HT₁ receptor agonist was administered in the mistaken belief that the patient's symptoms were caused by a migraine attack. Patients with migraine may be at increased risk for certain cerebrovascular events (e.g., stroke, hemorrhage, transient ischemic attack). Therapy with 5-HT₁ receptor agonists should be discontinued in patients experiencing a cerebrovascular event.(See Cautions: Contraindications.)

Other Cardiovascular or Vasospastic Effects

Noncoronary vasospastic reactions, including peripheral vascular ischemia, GI ischemia and infarction (presenting with abdominal pain and bloody diarrhea), splenic infarction, and Raynaud's syndrome, have been reported in patients receiving 5-HT₁ receptor agonists, including zolmitriptan.(See Cautions: Contraindications.) Transient or permanent blindness and partial vision loss also have been reported very rarely in patients receiving 5-HT₁ receptor agonists, although visual disorders may occur as manifestations of migraine attacks. Patients experiencing signs or symptoms suggestive of vasospastic reactions following administration of any 5-HT₁ receptor agonist should be evaluated to rule out vasospastic reactions before receiving additional doses of zolmitriptan.

Substantial increases in blood pressure, including hypertensive crisis with acute impairment of organ systems, have been reported rarely following administration of 5-HT₁ receptor agonists in patients with or without a history of hypertension.(See Cautions: Contraindications.) Blood pressure should be monitored in all patients receiving zolmitriptan. In healthy individuals receiving zolmitriptan 5 mg, increases in systolic and diastolic blood pressure of 1 and 5 mm Hg, respectively, were observed. However, substantial increases in blood pressure have been observed in patients with moderate to severe hepatic disease.(See Hepatic Impairment under Warnings/Precautions: Specific Populations, in Cautions.)

Increases in mean pulmonary arterial pressure have been observed following administration of another 5-HT₁ receptor agonist to patients with suspected coronary artery disease who were undergoing cardiac catheterization.

Serotonin Syndrome

Potentially life-threatening serotonin syndrome has been reported in patients receiving 5-HT₁ receptor agonists, particularly in those receiving concomitant therapy with selective serotonin-reuptake inhibitors (SSRIs) or selective serotonin- and norepinephrine-reuptake inhibitors (SNRIs). Serotonin syndrome also may occur in patients receiving 5-HT₁ receptor agonists concomitantly with MAO inhibitors or tricyclic antidepressants. Symptoms of serotonin syndrome 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 GI symptoms (e.g., nausea, vomiting, diarrhea). If concurrent therapy with a 5-HT₁ receptor agonist and an SSRI or SNRI is clinically warranted, the patient should be observed carefully, particularly during initiation of therapy, when dosage is increased, or when another serotonergic agent is initiated. If manifestations of serotonin syndrome occur, treatment with zolmitriptan and any concurrently administered serotonergic agents should be discontinued and supportive and symptomatic treatment should be initiated.

Medication Overuse Headache

Excessive use of drugs indicated for the management of acute migraine attacks (e.g., use of 5-HT₁ receptor agonists, ergotamine, opiates, or certain analgesic combinations on a regular basis for 10 or more days per month) may result in migraine-like daily headaches or a marked increase in the frequency of migraine attacks. Detoxification, including withdrawal of the overused drugs; treatment of withdrawal symptoms (which often include transient worsening of headaches); and consideration of prophylactic therapy for migraine attacks may be necessary.

Sensitivity Reactions

Hypersensitivity reactions (e.g., angioedema, anaphylaxis) have been reported in patients receiving zolmitriptan.

Ocular Effects

Accumulation of zolmitriptan and/or its metabolites in melanin-rich tissues (such as the eye) may occur over time, resulting in potential toxicity in these tissues with extended use.

Phenylketonuria

Individuals with phenylketonuria (i.e., homozygous genetic deficiency of phenylalanine hydroxylase) and other individuals who must restrict their intake of phenylalanine should be warned that each zolmitriptan 2.5- or 5-mg orally disintegrating tablet contains aspartame, which is metabolized in the GI tract to provide 2.81 or 5.62 mg of phenylalanine, respectively, following oral administration. Zolmitriptan conventional tablets do not contain aspartame.

Specific Populations

Pregnancy

Category C.

Lactation

Zolmitriptan is distributed into milk in rats. It is not known whether zolmitriptan is distributed into milk in humans. A decision should be made whether to discontinue nursing or the drug, taking into account the importance of the drug to the woman.

Pediatric Use

Safety and efficacy of zolmitriptan have not been established in children younger than 18 years of age. Randomized, placebo-controlled studies in adolescents 12-17 years of age with migraine headaches failed to demonstrate efficacy of the drug. Adverse effects reported in adolescents were similar to those reported in adults. Serious adverse events have been reported during postmarketing experience in a limited number of pediatric patients receiving 5-HT₁ receptor agonists, including zolmitriptan. Zolmitriptan has not been studied in children younger than 12 years of age,

Geriatric Use

Experience in patients 65 years of age and older is insufficient to determine whether they respond differently than younger adults; dosage in geriatric patients should be selected with caution.

Pharmacokinetic profile of zolmitriptan in geriatric patients is similar to that in younger adults.

Hepatic Impairment

Peak plasma concentrations, time to achieve peak plasma concentrations, and area under the plasma concentration-time curve (AUC) of zolmitriptan reportedly were 1.5-, 2-, and 3-fold higher, respectively, in patients with severe hepatic impairment receiving orally administered zolmitriptan compared with healthy individuals. The effect of hepatic impairment on the pharmacokinetics of intranasally administered zolmitriptan has not been evaluated. Substantial elevation of blood pressure (increase in systolic and/or diastolic blood pressure of 20-80 mm Hg) was observed in some patients with moderate to severe hepatic impairment following a 10-mg dose of zolmitriptan. The drug should be used with caution in patients with moderate to severe hepatic impairment; dosage adjustment is recommended in such patients.(See Dosage and Administration: Special Populations.)

Renal Impairment

Clearance of zolmitriptan reportedly was reduced by 25% in patients with severe renal impairment (creatinine clearance of 5-25 mL/minute) receiving orally administered zolmitriptan; no substantial change in clearance was observed in patients with moderate renal impairment (creatinine clearance of 26-50 mL/minute). The effect of renal impairment on the pharmacokinetics of intranasally administered zolmitriptan has not been evaluated.

Common Adverse Effects

Adverse effects occurring in 2% or more of patients receiving orally administered zolmitriptan and more frequently (by at least 2 percentage points) with zolmitriptan than with placebo include dizziness, paresthesia, neck/throat/jaw/chest symptoms (e.g., pain, tightness, pressure, heaviness), other sensations of heaviness/pressure/tightness, nausea, somnolence, warm or cold sensation, asthenia, dry mouth, dyspepsia, dysphagia, vertigo, and sweating.

Adverse effects occurring in 2% or more of patients receiving intranasal zolmitriptan and more frequently with zolmitriptan than with placebo include paresthesia, hyperesthesia, unusual taste, throat pain, pain of specified location, nausea, somnolence, disorder or discomfort of the nasal cavity, asthenia, tightness of the throat, and dry mouth.

Drug Interactions

Acetaminophen

Potential pharmacokinetic interaction (increased time to peak plasma concentrations of acetaminophen).

Cimetidine

Potential pharmacokinetic interaction (approximately twofold increase in half-life of and systemic exposure to zolmitriptan and its active metabolite). When zolmitriptan and cimetidine are used concomitantly, the maximum recommended single dose of zolmitriptan is 2.5 mg and the total dosage administered in any 24-hour period should not exceed 5 mg.

Ergot Alkaloids and Other 5-HT1 Receptor Agonists

Potential pharmacologic interaction (additive vasospastic effects) when zolmitriptan is used concomitantly with ergot alkaloids (e.g., ergotamine, dihydroergotamine, methysergide [no longer commercially available in the US]) and other 5-HT_1B/1D receptor agonists. Use of oral or intranasal zolmitriptan within 24 hours is contraindicated.

Metoclopramide

A single 10-mg dose of metoclopramide did not alter the pharmacokinetics of zolmitriptan or its metabolites.

Monoamine Oxidase (MAO) Inhibitors

Potential pharmacokinetic interaction (increased plasma concentrations of zolmitriptan and its active metabolite) with MAO-A inhibitors.(See Description.) Selegiline, a selective MAO-B inhibitor, did not alter the pharmacokinetics of zolmitriptan or its active metabolite. Use of oral or intranasal zolmitriptan within 2 weeks of MAO-A inhibitor therapy is contraindicated.

Oral Contraceptives

Potential pharmacokinetic interaction (increased plasma concentrations of zolmitriptan; possible delay in achieving peak zolmitriptan concentrations).

Propranolol

Potential pharmacokinetic interaction (increased plasma concentrations of zolmitriptan).

Selective Serotonin-reuptake Inhibitors and Selective Serotonin- and Norepinephrine-reuptake Inhibitors

Potential pharmacologic interaction (potentially life-threatening serotonin syndrome). If concomitant use is clinically warranted, the patient should be observed carefully, particularly during treatment initiation, when dosage is increased, or when another serotonergic agent is initiated.(See Serotonin Syndrome under Cautions: Warnings/Precautions.)

Pretreatment with oral fluoxetine (20 mg daily for 4 weeks) did not alter the pharmacokinetic profile or effect on blood pressure of a single 10-mg dose of zolmitriptan.

Topical Vasoconstrictors

Topical application of xylometazoline to the nasal mucosa 30 minutes prior to an intranasal zolmitriptan dose did not alter the pharmacokinetics of zolmitriptan.

Pharmacokinetics

Absorption

Bioavailability

Zolmitriptan is well absorbed after oral administration, with peak plasma concentrations attained within 1.5 hours (conventional tablets) or 3 hours (orally disintegrating tablets). The drug is rapidly absorbed via the nasopharynx after intranasal administration, with peak plasma concentrations attained within 3 hours.

Mean absolute bioavailability after oral administration is approximately 40%; mean bioavailability of nasal solution is 102% compared with oral tablet.

Mean plasma concentrations after oral administration are increased by up to 1.5-fold in females compared with males.

Food

Food does not substantially affect bioavailability.

Distribution

Plasma Protein Binding

25%.

Elimination

Metabolism

Zolmitriptan undergoes hepatic metabolism to form 3 principal metabolites, including N-desmethyl zolmitriptan (5-HT_1B/1D potency is 2-6 times that of zolmitriptan). Formation of N-desmethyl zolmitriptan may depend on CYP1A2; MAO-A appears to mediate metabolism of N-desmethyl zolmitriptan.

Elimination Route

Zolmitriptan is excreted in urine (65%) and feces (30%) as unchanged drug and metabolites; a dose is recovered in urine as unchanged drug (8%) and as indole acetic acid (31%), N-oxide (7%), and N-desmethyl (4%) metabolites.

Half-life

Approximately 3 hours for zolmitriptan and active N-desmethyl metabolite after oral or intranasal administration.

Special Populations

In patients with severe hepatic impairment, peak plasma concentrations, time to achieve peak plasma concentrations, and AUC are 1.5-, 2-, and 3-fold higher, respectively, than in healthy individuals after oral administration. Pharmacokinetics of nasal spray have not been evaluated in patients with hepatic impairment.

In patients with severe renal impairment (Cl_cr 5-25 mL/minute), clearance is reduced by 25% after oral administration; there is no substantial change in clearance in patients with moderate renal impairment (Cl_cr 26-50 mL/minute). Pharmacokinetics of the nasal spray have not been evaluated in patients with renal impairment.