Zolmitriptan

ZOLMITRIPTAN NASAL SPRAY is indicated for the acute treatment of migraine with or without aura in adults and pediatric patients 12 years of age and older. Limitations of Use Only use ZOLMITRIPTAN NASAL SPRAY if a clear diagnosis of migraine has been established. If a patient has no response to ZOLMITRIPTAN NASAL SPRAY treatment for the first migraine attack, reconsider the diagnosis of migraine before ZOLMITRIPTAN NASAL SPRAY is administered to treat any subsequent attacks. ZOLMITRIPTAN NASAL SPRAY is not indicated for the prevention of migraine attacks. Safety and effectiveness of ZOLMITRIPTAN NASAL SPRAY have not been established for cluster headache. Not recommended in patients with moderate or severe hepatic impairment [see Dosage and Administration (2.2) ] . ZOLMITRIPTAN NASAL SPRAY is a serotonin (5-HT) 1B/1D receptor agonist (triptan) indicated for the acute treatment of migraine with or without aura in adults and pediatric patients 12 years and older (1) Limitations of Use: Use only after a clear diagnosis of migraine has been established (1) Not intended for the prophylactic therapy of migraine (1) Not indicated for the treatment of cluster headache (1) Not recommended in patients with moderate to severe hepatic impairment (1)

Nasal Spray 2.5 mg and 5 mg. Nasal Spray: 2.5 mg and 5 mg (3)

Zolmitriptan is contraindicated in patients with: Ischemic coronary artery disease (angina pectoris, history of myocardial infarction, or documented silent ischemia), other significant underlying cardiovascular disease, or coronary artery vasospasm including Prinzmetal's angina [see Warnings and Precautions (5.1) ] Wolff-Parkinson-White Syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders [see Warnings and Precautions (5.2) ] History of stroke, transient ischemic attack (TIA) or history of hemiplegic or basilar migraine because these patients are at higher risk of stroke [see Warnings and Precautions (5.4) ] Peripheral vascular disease (PVD) [see Warnings and Precautions (5.5) ] Ischemic bowel disease [see Warnings and Precautions (5.5) ] Uncontrolled hypertension [see Warnings and Precautions (5.8) ] Recent use (i.e., within 24 hours) of another 5-HT 1 agonist, ergotamine-containing medication, or ergot-type medication (such as dihydroergotamine or methysergide) [see Drug Interactions (7.1 , 7.3) ] Concurrent administration of an MAO-A inhibitor or recent discontinuation of a MAO-A inhibitor (that is within 2 weeks) [see Drug Interactions (7.2) and Clinical Pharmacology (12.3) ] Known hypersensitivity to zolmitriptan (angioedema and anaphylaxis seen) [see Adverse Reactions (6.2) ] History of ischemic heart disease or coronary artery vasospasm (4) Symptomatic Wolff-Parkinson-White syndrome or other cardiac accessory conduction pathway disorders (4) History of stroke, transient ischemic attack, or hemiplegic or basilar migraine (4) Peripheral Vascular Disease (4) Ischemic bowel disease (4) Uncontrolled hypertension (4) Recent (within 24 hours) use of another 5-HT 1 agonist (e.g., another triptan) or of an ergot-type medication (4) MAO-A inhibitor used in past 2 weeks (4) Hypersensitivity to zolmitriptan (4)

Myocardial Ischemia, Myocardial Infarction, and Prinzmetal's Angina: Perform cardiac evaluation in patients with multiple cardiovascular risk factors (5.1) Arrhythmias: Discontinue dosing if occurs (5.2) Chest/throat/neck/jaw pain, tightness, pressure, or heaviness: Generally not associated with myocardial ischemia; evaluate for coronary artery disease in patients at high risk (5.3) Cerebral hemorrhage, subarachnoid hemorrhage, and stroke: Discontinue dosing if occurs (5.4) Gastrointestinal ischemic events, peripheral vasospastic reactions: Discontinue dosing if occurs (5.5) Medication Overuse Headache: Detoxification may be necessary (5.6) Serotonin syndrome: Discontinue dosing if occurs (5.7 , 7.5) Increase in blood pressure: very rarely associated with significant events (5.8)

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-HT 1 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-HT 1 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-HT 1 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-HT 1 agonists [see Contraindications (4) ] .

5.4 Cerebrovascular Events Cerebral hemorrhage, subarachnoid hemorrhage, and stroke have occurred in patients treated with 5-HT 1 agonists, and some have resulted in fatalities. In a number of cases, it appears possible that the cerebrovascular events were primary, the 5-HT 1 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-HT 1 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-HT 1 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-HT 1 agonists. Since visual disorders may be part of a migraine attack, a causal relationship between these events and the use of 5-HT 1 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-HT 1 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) ] .

The following adverse reactions are discussed in more detail in other sections of labeling: Myocardial Ischemia, Myocardial Infarction, and Prinzmetal's Angina [see Warnings and Precautions (5.1) ] Arrhythmias [see Warnings and Precautions (5.2) ] Chest, Throat, Neck and/or Jaw Pain/Tightness/Pressure [see Warnings and Precautions (5.3)] Cerebrovascular Events [see Warnings and Precautions (5.4)] Other Vasospasm Reactions [see Warnings and Precautions (5.5)] Medication Overuse Headache [see Warnings and Precautions (5.6) ] Serotonin Syndrome [see Warnings and Precautions (5.7) ] Increase in Blood Pressure [see Warnings and Precautions (5.8) ] The most common adverse reactions (≥ 5% and > placebo) were: Adults: unusual taste, paresthesia, dizziness, and hyperesthesia (6.1) Pediatrics: unusual taste (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Amneal Pharmaceuticals at 1-877-835-5472 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

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) Body System Adverse Reaction Placebo (N=228) Zolmitriptan 2.5 mg (N=224) Zolmitriptan 5 mg (N=236) Atypical Sensations Hyperesthesia 0% 1% 5% Paraesthesia 6% 5% 10% Warm Sensation 2% 4% 0% Ear/Nose/Throat Disorder/Discomfort of nasal cavity 2% 1% 3% Pain and Pressure Sensations Pain Location Specified 1% 2% 4% Throat Pain 1% 4% 4% Throat Tightness 1% <1% 2% Digestive Dry Mouth <1% 3% 2% Nausea 1% 1% 4% Neurological Dizziness 4% 6% 3% Somnolence 2% 1% 4% Other Unusual Taste 3% 17% 21% Asthenia 1% 3% 3% 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 orally disintegrating tablets except for the occurrence of local adverse reactions from the nasal spray (see zolmitriptan tablet/zolmitriptan oral disintegrating tablet Prescribing Information) . 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 Adverse Reaction Placebo (N=437) Zolmitriptan 2.5 mg (N=81) Zolmitriptan 5 mg (N=431) Unusual taste 2% 6% 10% Nasal discomfort 1% 3% 3% Dizziness 1% 0% 2% Oropharyngeal pain 2% 0% 2% Nausea 1% 1% 2% 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. […]

If co-administered with cimetidine: Maximum single dose of 2.5 mg, not to exceed 5 mg in any 24-hour period. (2.3 , 7.4)

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-HT 1B/1D agonists (e.g. triptans) Concomitant use of other 5-HT 1B/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) ] .

Pregnancy: Based on animal data, may cause fetal harm (8.1)

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. 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 are 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) ] .

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