DIHYDROERGOTAMINE MESYLATE

WARNING Serious and/or life-threatening peripheral ischemia has been associated with the coadministration of DIHYDROERGOTAMINE with potent CYP 3A4 inhibitors including protease inhibitors and macrolide antibiotics. Because CYP 3A4 inhibition elevates the serum levels of DIHYDROERGOTAMINE, the risk for vasospasm leading to cerebral ischemia and/or ischemia of the extremities is increased. Hence, concomitant use of these medications is contraindicated. (See also CONTRAINDICATIONS and WARNINGS section)


Mechanis m of Action
Dihydroergotamine binds with high affinity to 5-HT and 5-HT receptors. It also binds with high affinity to serotonin 5-HT , 5-HT , and 5-HT receptors, noradrenaline α , α and α1 receptors, and dopamine D and D receptors.
The therapeutic activity of dihydroergotamine in migraine is generally attributed to the agonist effect at 5-HT receptors. Two current theories have been proposed to explain the efficacy of 5-HT receptor agonists in migraine. One theory suggests that activation of 5-HT receptors located on intracranial blood vessels, including those on arterio-venous anastomoses, leads to vasoconstriction, which correlates with the relief of migraine headache. The alternative hypothesis suggests that activation of 5-HT receptors on sensory nerve endings of the trigeminal system results in the inhibition of pro-inflammatory neuropeptide release. In addition, dihydroergotamine possesses oxytocic properties. (See CONTRAINDICATIONS)

Absorption
Dihydroergotamine mesylate is poorly bioavailable following oral administration. Following intranasal administration, however, the mean bioavailability of dihydroergotamine mesylate is 32% relative to the injectable administration. Absorption is variable, probably reflecting both intersubject differences of absorption and the technique used for self-administration.

Distribution
Dihydroergotamine mesylate is 93% plasma protein bound. The apparent steady-state volume of distribution is approximately 800 liters.

Metabolism
Four dihydroergotamine mesylate metabolites have been identified in human plasma following oral administration. The major metabolite, 8'-β-hydroxydihydroergotamine, exhibits affinity equivalent to its parent for adrenergic and 5-HT receptors and demonstrates equivalent potency in several venoconstrictor activity models, in vivo and in vitro. The other metabolites, i.e., dihydrolysergic acid, dihydrolysergic amide and a metabolite formed by oxidative opening of the proline ring are of minor importance. Following nasal administration, total metabolites represent only 20%-30% of plasma AUC. The systemic clearance of dihydroergotamine mesylate following I.V. and I.M. administration is 1.5 1D L/min. Quantitative pharmacokinetic characterization of the four metabolites has not been performed.

Excretion
The major excretory route of dihydroergotamine is via the bile in the feces. After intranasal administration the urinary recovery of parent drug amounts to about 2% of the administered dose compared to 6% after I.M. administration. The total body clearance is 1.5 L/min which reflects mainly hepatic clearance. The renal clearance (0.1 L/min) is unaffected by the route of dihydroergotamine administration. The decline of plasma dihydroergotamine is biphasic with a terminal half-life of about 10 hours.

Subpopulations
No studies have been conducted on the effect of renal or hepatic impairment, gender, race, or ethnicity on dihydroergotamine pharmacokinetics. Dihydroergotamine mesylate nasal spray is contraindicated in patients with severely impaired hepatic or renal function. (See CONTRAINDICATIONS)

Interactions
The pharmacokinetics of dihydroergotamine did not appear to be significantly affected by the concomitant use of a local vasoconstrictor (e.g., fenoxazoline).
Multiple oral doses of the β-adrenoceptor antagonist propranolol, used for migraine prophylaxis, had no significant influence on the Cmax, Tmax or AUC of dihydroergotamine doses up to 4 mg. Pharmacokinetic interactions have been reported in patients treated orally with other ergot alkaloids (e.g., increased levels of ergotamine) and macrolide antibiotics, principally troleandomycin, presumably due to inhibition of cytochrome P450 3A metabolism of the alkaloids by troleandomycin. Dihydroergotamine has also been shown to be an inhibitor of cytochrome P450 3A catalyzed reactions and rare reports of ergotism have been obtained from patients treated with dihydroergotamine and macrolide antibiotics (e.g., troleandomycin, clarithromycin, erythromycin), and in patients treated with dihydroergotamine and protease inhibitors (e.g. ritonavir), presumably due to inhibition of cytochrome P450 3A metabolism of ergotamine (See CONTRAINDICATIONS) . No pharmacokinetic interactions involving other cytochrome P450 isoenzymes are known.

Clinical Trials
The efficacy of dihydroergotamine mesylate nasal spray for the acute treatment of migraine headaches was evaluated in four randomized, double blind, placebo controlled studies in the U.S. The patient population for the trials was predominantly female (87%) and Caucasian (95%) with a mean age of 39 years (range 18 to 65 years). Patients treated a single moderate to severe migraine headache with a single dose of study medication and assessed pain severity over the 24 hours following treatment. Headache response was determined 0.5, 1, 2, 3 and 4 hours after dosing and was defined as a reduction in headache severity to mild or no pain. In studies 1 and 2, a four-point pain intensity scale was utilized; in studies 3 and 4, a five-point scale was used that included both pain response and restoration of function for "severe" or "incapacitating" pain, a less clear endpoint. Although rescue medication was allowed in all four studies, patients were instructed not to use them during the four hour observation period. In studies 3 and 4, a total dose of 2 mg was compared to placebo. In studies 1 and 2, doses of 2 and 3 mg were evaluated, and showed no advantage of the higher dose for a single treatment. In all studies, patients received a regimen consisting of 0.5 mg in each nostril, repeated in 15 minutes (and again in another 15 minutes for the 3 mg dose in studies 1 and 2).
The percentage of patients achieving headache response 4 hours after treatment was significantly greater in patients receiving 2 mg doses of dihydroergotamine mesylate nasal spray compared to those receiving placebo in 3 of the 4 studies (see Tables 1 & 2    The Kaplan-Meier plots below (Figures 1 & 2) provides an estimate of the probability that a patient will have responded to a single 2 mg dose of dihydroergotamine mesylate nasal spray as a function of the time elapsed since initiation of treatment.
Headache response was defined as a reduction in headache severity to mild or no pain. Headache response was based on pain intensity as interpreted by the patient using a fourpoint pain intensity scale. p value < 0.001 p value < 0.01 † † ‡

*
Headache response was defined as a reduction in headache severity to mild or no pain. Headache response was evaluated on a five-point scale that included both pain response and restoration of function for "severe" or "incapacitating" pain. p value < 0.01 † *The figure shows the probability over time of obtaining a response following treatment with dihydroergotamine mesylate nasal spray. Headache response was based on pain intensity as interpreted by the patient using a four-point pain intensity scale. Patients not achieving response within 4 hours were censored to 4 hours. *The figure shows the probability over time of obtaining a response following treatment with dihydroergotamine mesylate nasal spray. Headache response was evaluated on a five-point scale that confounded pain response and restoration of function for "severe" or "incapacitating" pain. Patients not achieving response within 4 hours were censored to 4 hours.
For patients with migraine-associated nausea, photophobia, and phonophobia at baseline, there was a lower incidence of these symptoms at 2 and 4 hours following administration of dihydroergotamine mesylate nasal spray compared to placebo.
Patients were not allowed to use additional treatments for eight hours prior to study medication dosing and during the four hour observation period following study treatment. Following the 4 hour observation period, patients were allowed to use additional treatments. For all studies, the estimated probability of patients using additional treatments for their migraines over the 24 hours following the single 2 mg dose of study treatment is summarized in Figure 3 below.
* Kaplan-Meier plot based on data obtained from all studies with patients not using additional treatments censored to 24 hours. All patients received a single treatment of study medication for their migraine attack. The plot also includes patients who had no response to the initial dose.
Neither age nor sex appear to effect the patient's response to dihydroergotamine mesylate nasal spray. While patients with menstrual migraine, migraine with aura, and migraine without aura by medical history were included in the clinical evaluation of dihydroergotamine mesylate nasal spray, patients were not required to report the specific type of migraine treated with study medication. Thus, neither the effect of menses on migraine nor the presence or the absence of aura were assessed. The racial distribution of patients was insufficient to determine the effect of race on the efficacy of dihydroergotamine mesylate nasal spray.

INDICATIONS AND USAGE
Dihydroergotamine mesylate nasal spray is indicated for the acute treatment of migraine headaches with or without aura.
Dihydroergotamine mesylate nasal spray is not intended for the prophylactic therapy of migraine or for the management of hemiplegic or basilar migraine.

CONTRAINDICATIONS
There have been a few reports of s erious advers e events as s ociated with the coadminis tration of dihydroergotamine and potent CYP 3A4 inhibitors , s uch as proteas e inhibitors and macrolide antibiotics , res ulting in vas os pas m that led to cerebral is chemia and/or is chemia of the extremities . The us e of potent CYP 3A4 inhibitors (ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is , therefore contraindicated (See WARNINGS: CYP 3A4 Inhibitors ).

Dihydroergotamine mes ylate nas al s pray s hould not be given to patients with is chemic heart dis eas e (angina pectoris , his tory of myocardial infarction, or documented s ilent is chemia) or to patients who have clinical s ymptoms or findings cons is tent with coronary artery vas os pas m including Prinzmetal's variant angina. (See WARNINGS)
Becaus e dihydroergotamine mes ylate nas al s pray may increas e blood pres s ure, it s hould not be given to patients with uncontrolled hypertens ion.

Dihydroergotamine mes ylate nas al s pray s hould not be adminis tered to patients with hemiplegic or bas ilar migraine.
In addition to those conditions mentioned above, dihydroergotamine mesylate nasal spray is also contraindicated in patients with known peripheral arterial disease, sepsis, following vascular surgery, and severely impaired hepatic or renal function.
Dihydroergotamine mesylate nasal spray may cause fetal harm when administered to a pregnant woman. Dihydroergotamine possesses oxytocic properties and, therefore, should not be administered during pregnancy. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.
There are no adequate studies of dihydroergotamine in human pregnancy, but developmental toxicity has been demonstrated in experimental animals. In embryofetal development studies of dihydroergotamine mesylate nasal spray, intranasal administration to pregnant rats throughout the period of organogenesis resulted in decreased fetal body weights and/or skeletal ossification at doses of 0.16 mg/day (associated with maternal plasma dihydroergotamine exposures [AUC] approximately 0.4 -1.2 times the exposures in humans receiving the MRDD of 4 mg) or greater. A no effect level for embryo-fetal toxicity was not established in rats. Delayed skeletal ossification was also noted in rabbit fetuses following intranasal administration of 3.6 mg/day (maternal exposures approximately 7 times human exposures at the MRDD) during organogenesis. A no effect level was seen at 1.2 mg/day (maternal exposures approximately 2.5 times human exposures at the MRDD). When dihydroergotamine mesylate nasal spray was administered intranasally to female rats during pregnancy and lactation, decreased body weights and impaired reproductive function (decreased mating indices) were observed in the offspring at doses of 0.16 mg/day or greater. A no effect level was not established. Effects on development occurred at doses below those that produced evidence of significant maternal toxicity in these studies. Dihydroergotamine-induced intrauterine growth retardation has been attributed to reduced uteroplacental blood flow resulting from prolonged vasoconstriction of the uterine vessels and/or increased myometrial tone.
Dihydroergotamine mesylate nasal spray is contraindicated in patients who have previously shown hypersensitivity to ergot alkaloids.

Dihydroergotamine mesylate should not be used by nursing mothers. (See PRECAUTIONS)
Dihydroergotamine mesylate should not be used with peripheral and central vasoconstrictors because the combination may result in additive or synergistic elevation of blood pressure.

WARNINGS
Dihydroergotamine mes ylate nas al s pray s hould only be us ed where a clear diagnos is of migraine headache has been es tablis hed.

CYP 3A4 Inhibitors (e.g. Macrolide Antibiotics and Proteas e Inhibitors )
There have been rare reports of s erious advers e events in connection with the coadminis tration of dihydroergotamine and potent CYP 3A4 inhibitors , s uch as proteas e inhibitors and macrolide antibiotics , res ulting in vas os pas m that led to cerebral is chemia and/or and is chemia of the extremities . The us e of potent CYP 3A4 inhibitors with dihydroergotamine s hould therefore be avoided (See CONTRAINDICATIONS) . Examples of s ome of the more potent CYP 3A4 inhibitors include: antifungals ketoconazole and itraconazole, the proteas e inhibitors ritonavir, nelfinavir, and indinavir, and macrolide antibiotics erythromycin, clarithromycin, and troleandomycin. Other les s potent CYP 3A4 inhibitors s hould be adminis tered with caution. Les s potent inhibitors include s aquinavir, nefazodone, fluconazole, grapefruit juice, fluoxetine, fluvoxamine, zileuton, and clotrimazole. Thes e lis ts are not exhaus tive, and the pres criber s hould cons ider the effects on CYP 3A4 of other agents being cons idered for concomitant us e with dihydroergotamine.

Fibrotic Complications
There have been reports of pleural and retroperitoneal fibrosis in patients following prolonged daily use of injectable dihydroergotamine mesylate. Rarely, prolonged daily use of other ergot alkaloid drugs has been associated with cardiac valvular fibrosis. Rare cases have also been reported in association with the use of injectable dihydroergotamine mesylate; however, in those cases, patients also received drugs known to be associated with cardiac valvular fibrosis.
Administration of dihydroergotamine mesylate nasal spray, should not exceed the dosing guidelines and should not be used for chronic daily administration (see DOSAGE AND ADMINISTRATION). It is recommended that patients who are intermittent long-term us ers of dihydroergotamine mes ylate nas al s pray and who have or acquire ris k factors predictive of CAD, as des cribed above, undergo periodic interval cardiovas cular evaluation as they continue to us e dihydroergotamine mes ylate nas al s pray.

Cardiac Events and Fatalities
No deaths have been reported in patients using dihydroergotamine mesylate nasal spray. However, the potential for adverse cardiac events exists. Serious adverse cardiac events, including acute myocardial infarction, life-threatening disturbances of cardiac rhythm, and death have been reported to have occurred following the administration of dihydroergotamine mesylate injection. Considering the extent of use of dihydroergotamine mesylate in patients with migraine, the incidence of these events is extremely low.

Drug-As s ociated Cerebrovas cular Events and Fatalities
Cerebral hemorrhage, subarachnoid hemorrhage, stroke, and other cerebrovascular events have been reported in patients treated with dihydroergotamine mesylate injection; and some have resulted in fatalities. In a number of cases, it appears possible that the cerebrovascular events were primary, the dihydroergotamine mesylate injection having been administered in the incorrect belief that the symptoms experienced were a consequence of migraine, when they were not. It should be noted that patients with migraine may be at increased risk of certain cerebrovascular events (e.g., stroke, hemorrhage, transient ischemic attack).

Other Vas os pas m Related Events
Dihydroergotamine mesylate nasal spray, like other ergot alkaloids, may cause vasospastic reactions other than coronary artery vasospasm. Myocardial and peripheral vascular ischemia have been reported with dihydroergotamine mesylate nasal spray.
Dihydroergotamine mesylate nasal spray associated vasospastic phenomena may also cause muscle pains, numbness, coldness, pallor, and cyanosis of the digits. In patients with compromised circulation, persistent vasospasm may result in gangrene or death, dihydroergotamine mesylate nasal spray should be discontinued immediately if signs or symptoms of vasoconstriction develop.

Increas e in Blood Pres s ure
Significant elevation in blood pressure has been reported on rare occasions in patients with and without a history of hypertension treated with dihydroergotamine mesylate nasal spray and dihydroergotamine mesylate injection. Dihydroergotamine mesylate nasal spray is contraindicated in patients with uncontrolled hypertension. (See CONTRAINDICATIONS) An 18% increase in mean pulmonary artery pressure was seen following dosing with another 5HT1 agonist in a study evaluating subjects undergoing cardiac catheterization.

Local Irritation
Approximately 30% of patients using dihydroergotamine mesylate nasal spray (compared to 9% of placebo patients) have reported irritation in the nose, throat, and/or disturbances in taste. Irritative symptoms include congestion, burning sensation, dryness, paraesthesia, discharge, epistaxis, pain, or soreness. The symptoms were predominantly mild to moderate in severity and transient. In approximately 70% of the above mentioned cases, the symptoms resolved within four hours after dosing with dihydroergotamine mesylate nasal spray. Examinations of the nose and throat in a small subset (N = 66) of study participants treated for up to 36 months (range 1-36 months) did not reveal any clinically noticeable injury. Other than this limited number of patients, the consequences of extended and repeated use of dihydroergotamine mesylate nasal spray on the nasal and/or respiratory mucosa have not been systematically evaluated in patients.
Nasal tissue in animals treated with dihydroergotamine mesylate daily at nasal cavity surface area exposures (in mg/mm ) that were equal to or less than those achieved in humans receiving the maximum recommended daily dose of 0.08 mg/kg/day showed mild mucosal irritation characterized by mucous cell and transitional cell hyperplasia and squamous cell metaplasia. Changes in rat nasal mucosa at 64 weeks were less severe than at 13 weeks. Local effects on respiratory tissue after chronic intranasal dosing in animals have not been evaluated.

PRECAUTIONS General
Dihydroergotamine mesylate nasal spray may cause coronary artery vasospasm; patients who experience signs or symptoms suggestive of angina following its administration should, therefore, be evaluated for the presence of CAD or a predisposition to variant angina before receiving additional doses. Similarly, patients who experience other symptoms or signs suggestive of decreased arterial flow, such as ischemic bowel syndrome or Raynaud's syndrome following the use of any 5-HT agonist are candidates for further evaluation. (See WARNINGS).

Information for Patients
The text of a patient information sheet is printed at the end of this insert. To assure safe and effective use of dihydroergotamine mesylate nasal spray, the information and instructions provided in the patient information sheet should be discussed with patients.
Once the nasal spray applicator has been prepared, it should be discarded (with any remaining drug) after 8 hours.
Patients should be advised to report to the physician immediately any of the following: numbness or tingling in the fingers and toes, muscle pain in the arms and legs, weakness in the legs, pain in the chest, temporary speeding or slowing of the heart rate, swelling, or itching.
Prior to the initial use of the product by a patient, the prescriber should take steps to ensure that the patient understands how to use the product as provided. (See Patient Information Sheet and product packaging).
Administration of dihydroergotamine mesylate nasal spray, should not exceed the dosing guidelines and should not be used for chronic daily administration (see DOSAGE AND ADMINISTRATION).

Vas ocons trictors
Dihydroergotamine mesylate nasal spray should not be used with peripheral vasoconstrictors because the combination may cause synergistic elevation of blood pressure.

Sumatriptan
Sumatriptan has been reported to cause coronary artery vasospasm, and its effect could be additive with dihydroergotamine mesylate nasal spray. Sumatriptan and dihydroergotamine mesylate nasal spray should not be taken within 24 hours of each other. (See CONTRAINDICATIONS)

2
Although the results of a clinical study did not indicate a safety problem associated with the administration of dihydroergotamine mesylate nasal spray to subjects already receiving propranolol, there have been reports that propranolol may potentiate the vasoconstrictive action of ergotamine by blocking the vasodilating property of epinephrine.

Nicotine
Nicotine may provoke vasoconstriction in some patients, predisposing to a greater ischemic response to ergot therapy.

CYP 3A4 Inhibitors (e.g. Macrolide Antibiotics and Proteas e Inhibitors )
See CONTRAINDICATIONS and WARNINGS.

SSRI's
Weakness, hyperreflexia, and incoordination have been reported rarely when 5HT agonists have been coadministered with SSRI's (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline). There have been no reported cases from spontaneous reports of drug interaction between SSRI's and dihydroergotamine mesylate nasal spray or dihydroergotamine mesylate injection.

Oral Contraceptives
The effect of oral contraceptives on the pharmacokinetics of dihydroergotamine mesylate nasal spray has not been studied.

Carcinogenes is
Assessment of the carcinogenic potential of dihydroergotamine mesylate in mice and rats is ongoing.

Mutagenes is
Dihydroergotamine mesylate was clastogenic in two in vitro chromosomal aberration assays, the V79 Chinese hamster cell assay with metabolic activation and the cultured human peripheral blood lymphocyte assay. There was no evidence of mutagenic potential when dihydroergotamine mesylate was tested in the presence or absence of metabolic activation in two gene mutation assays (the Ames test and the in vitro mammalian Chinese hamster V79/HGPRT assay) and in an assay for DNA damage (the rat hepatocyte unscheduled DNA synthesis test). Dihydroergotamine was not clastogenic in the in vivo mouse and hamster micronucleus tests.

Impairment of Fertility
There was no evidence of impairment of fertility in rats given intranasal doses of dihydroergotamine mesylate nasal spray up to 1.6 mg/day (associated with mean plasma dihydroergotamine mesylate exposures [AUC] approximately 9 to 11 times those in humans receiving the MRDD of 4 mg).

Pregnancy
See CONTRAINDICATIONS.

Nurs ing Mothers
Ergot drugs are known to inhibit prolactin. It is likely that dihydroergotamine mesylate nasal spray is excreted in human milk, but there are no data on the concentration of dihydroergotamine in human milk. It is known that ergotamine is excreted in breast milk and may cause vomiting, diarrhea, weak pulse, and unstable blood pressure in nursing infants. Because of the potential for these serious adverse events in nursing infants exposed to dihydroergotamine mesylate nasal spray, nursing should not be undertaken

Us e in the Elderly
There is no information about the safety and effectiveness of dihydroergotamine mesylate nasal spray in this population because patients over age 65 were excluded from the controlled clinical trials.

ADVERSE REACTIONS
During clinical s tudies and the foreign pos tmarketing experience with dihydroergotamine mes ylate nas al s pray there have been no fatalities due to cardiac events .
Serious cardiac events, including some that have been fatal, have occurred following use of the parenteral form of dihydroergotamine mesylate, but are extremely rare. Events reported have included coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia, and ventricular fibrillation. (See CONTRAINDICATIONS, WARNINGS, and PRECAUTIONS).
Fibrotic complications have been reported in association with long term use of injectable dihydroergotamine mesylate (see WARNINGS: Fibrotic Complications).

Incidence in Controlled Clinical Trials
Of the 1,796 patients and subjects treated with dihydroergotamine mesylate nasal spray doses 2 mg or less in U.S. and foreign clinical studies, 26 (1.4%) discontinued because of adverse events. The adverse events associated with discontinuation were, in decreasing order of frequency: rhinitis 13, dizziness 2, facial edema 2, and one each due to cold sweats, accidental trauma, depression, elective surgery, somnolence, allergy, vomiting, hypotension, and paraesthesia.
The most commonly reported adverse events associated with the use of dihydroergotamine mesylate nasal spray during placebo-controlled, double-blind studies for the treatment of migraine headache and not reported at an equal incidence by placebo-treated patients were rhinitis, altered sense of taste, application site reactions, dizziness, nausea, and vomiting. The events cited reflect experience gained under closely monitored conditions of clinical trials in a highly selected patient population. In actual clinical practice or in other clinical trials, these frequency estimates may not apply, as the conditions of use, reporting behavior, and the kinds of patients treated may differ.
Dihydroergotamine mesylate nasal spray was generally well tolerated. In most instances these events were transient and self-limited and did not result in patient discontinuation from a study. The following table summarizes the incidence rates of adverse events reported by at least 1% of patients who received dihydroergotamine mesylate nasal spray for the treatment of migraine headaches during placebocontrolled, double-blind clinical studies and were more frequent than in those patients receiving placebo.

Other Advers e Events During Clinical Trials
In the paragraphs that follow, the frequencies of less commonly reported adverse clinical events are presented. Because the reports include events observed in open and uncontrolled studies, the role of dihydroergotamine mesylate nasal spray in their causation cannot be reliably determined. Furthermore, variability associated with adverse event reporting, the terminology used to describe adverse events, etc., limit the value of the quantitative frequency estimates provided. Event frequencies are calculated as the number of patients who used dihydroergotamine mesylate nasal spray in placebo-controlled trials and reported an event divided by the total number of patients (n=1796) exposed to dihydroergotamine mesylate nasal spray. All reported events 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. Events are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent adverse events are defined as those occurring in at least 1/100 patients; infrequent adverse events are those occurring in 1/100 to 1/1,000 patients; and rare adverse events are those occurring in fewer than 1/1,000 patients.

Pos t-introduction Reports
Voluntary reports of adverse events temporally associated with dihydroergotamine products used in the management of migraine that have been received since the introduction of the injectable formulation are included in this section save for those already listed above. Because of their source (open and uncontrolled clinical use), whether or not events reported in association with the use of dihydroergotamine are causally related to it cannot be determined. There have been reports of pleural and retroperitoneal fibrosis in patients following prolonged daily use of injectable dihydroergotamine mesylate. Dihydroergotamine mesylate nasal spray is not recommended for prolonged daily use. (See DOSAGE AND ADMINISTRATION) To report SUSPECTED ADVERSE REACTIONS, contact Leucadia Pharmaceuticals at 1-877-411-9681 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

DRUG ABUSE AND DEPENDENCE
Currently available data have not demonstrated drug abuse or psychological dependence with dihydroergotamine. However, cases of drug abuse and psychological dependence in patients on other forms of ergot therapy have been reported. Thus, due to the chronicity of vascular headaches, it is imperative that patients be advised not to exceed recommended dosages.

OVERDOSAGE
To date, there have been no reports of acute overdosage with this drug. Due to the risk of vascular spasm, exceeding the recommended dosages of dihydroergotamine mesylate nasal spray is to be avoided.
Excessive doses of dihydroergotamine may result in peripheral signs and symptoms of ergotism. Treatment includes discontinuance of the drug, local application of warmth to the affected area, the administration of vasodilators, and nursing care to prevent tissue damage.
In general, the symptoms of an acute dihydroergotamine mesylate nasal spray overdose are similar to those of an ergotamine overdose, although there is less pronounced nausea and vomiting with dihydroergotamine mesylate nasal spray. The symptoms of an ergotamine overdose include the following: numbness, tingling, pain, and cyanosis of the extremities associated with diminished or absent peripheral pulses; respiratory depression; an increase and/or decrease in blood pressure, usually in that order; confusion, delirium, convulsions, and coma; and/or some degree of nausea, vomiting, and abdominal pain.
In laboratory animals, significant lethality occurs when dihydroergotamine is given at I.V. doses of 44 mg/kg in mice, 130 mg/kg in rats, and 37 mg/kg in rabbits.
Up-to-date information about the treatment of overdosage can often be obtained from a certified Regional Poison Control Center. Telephone numbers of certified Poison Control Centers are listed in the Physicians' Desk Reference (PDR).*

DOSAGE AND ADMINISTRATION
The s olution us ed in dihydroergotamine mes ylate nas al s pray (4 mg/mL) is intended for intranas al us e and mus t not be injected.
In clinical trials, dihydroergotamine mesylate nasal spray has been effective for the acute treatment of migraine headaches with or without aura. One spray (0.5 mg) of dihydroergotamine mesylate nasal spray should be administered in each nostril. Fifteen minutes later, an additional one spray (0.5 mg) of dihydroergotamine mesylate nasal spray should be administered in each nostril, for a total dosage of four sprays (2 mg) of dihydroergotamine mesylate nasal spray. Studies have shown no additional benefit from acute doses greater than 2 mg for a single migraine administration. The safety of doses greater than 3 mg in a 24 hour period and 4 mg in a 7 day period has not been established.
Dihydroergotamine mesylate nasal spray, should not be used for chronic daily administration.
Prior to administration, the pump must be primed (i.e., squeeze 4 times) before use (see administration instructions). Once the nasal spray applicator has been prepared, it should be discarded (with any remaining drug in opened vial) after 8 hours.

Prior to administration, the pump must be primed (i.e., squeeze 4 times) before use. (See administration instructions)
Once the nas al s pray applicator has been prepared, it s hould be dis carded (with any remaining drug in opened vial after 8 hours ).

HOW SUPPLIED
Dihydroergotamine mesylate nasal spray is available (as a clear, colorless to light yellow aqueous solution) in 3.5 mL amber glass vials containing 4 mg of dihydroergotamine mesylate, USP.
Dihydroergotamine mesylate nasal spray is provided as a package of 8 units, administration instruction sheet, and one package insert. Each unit consists of one vial and one sprayer. (NDC 24201-463-08) Store below 25°C (77°F). Do not refrigerate or freeze.

Manufactured for:
Leucadia Pharmaceuticals Carlsbad, CA 92011 USA