"Most of us get headaches from time to time. Some are mild. Others cause throbbing pain. They can last for minutes or days. There are many different types of headaches. How you treat yours depends on which kind you have.
Myocardial Ischemia, Myocardial Infarction, And Prinzmetal’s Angina
The use of IMITREX Injection is contraindicated in patients with ischemic or vasospastic CAD. There have been rare reports of serious cardiac adverse reactions, including acute myocardial infarction, occurring within a few hours following administration of IMITREX Injection. Some of these reactions occurred in patients without known CAD. IMITREX Injection may cause coronary artery vasospasm (Prinzmetal's angina), even in patients without a history of CAD.
Perform a cardiovascular evaluation in triptan-naive patients who have multiple cardiovascular risk factors (e.g., increased age, diabetes, hypertension, smoking, obesity, strong family history of CAD) prior to receiving IMITREX Injection. If there is evidence of CAD or coronary artery vasospasm, IMITREX Injection is contraindicated. For patients with multiple cardiovascular risk factors who have a negative cardiovascular evaluation, consider administering the first dose of IMITREX Injection in a medically supervised setting and performing an electrocardiogram (ECG) immediately following administration of IMITREX Injection. For such patients, consider periodic cardiovascular evaluation in intermittent long-term users of IMITREX Injection.
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 IMITREX Injection if these disturbances occur. IMITREX Injection is contraindicated in patients with Wolff-Parkinson-White syndrome or arrhythmias associated with other cardiac accessory conduction pathway disorders.
Chest, Throat, Neck, And/Or Jaw Pain/Tightness/Pressure
Sensations of tightness, pain, pressure, and heaviness in the precordium, throat, neck, and jaw commonly occur after treatment with IMITREX Injection and are usually non-cardiac in origin. However, perform a cardiac evaluation if these patients are at high cardiac risk. The use of IMITREX Injection is contraindicated in patients with CAD and those with Prinzmetal's variant angina.
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. Also, patients with migraine may be at increased risk of certain cerebrovascular events (e.g., stroke, hemorrhage, TIA). Discontinue IMITREX Injection if a cerebrovascular event occurs.
Before treating headaches in patients not previously diagnosed with migraine or cluster headache or in patients who present with atypical symptoms, exclude other potentially serious neurological conditions. IMITREX Injection is contraindicated in patients with a history of stroke or TIA.
Other Vasospasm Reactions
IMITREX Injection 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 non-coronary vasospasm reaction following the use of any 5-HT1 agonist, rule out a vasospastic reaction before receiving additional IMITREX Injections.
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.
Medication Overuse Headache
Overuse of acute migraine drugs (e.g., ergotamine, triptans, opioids, or combination of these 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.
Serotonin syndrome may occur with IMITREX Injection, particularly during co-administration with selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), and MAO inhibitors [see DRUG INTERACTIONS]. 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 occurs within minutes to hours of receiving a new or a greater dose of a serotonergic medication. Discontinue IMITREX Injection if serotonin syndrome is suspected.
Increase In Blood Pressure
Significant elevation in blood pressure, including hypertensive crisis with acute impairment of organ systems, has been reported on rare occasions in patients treated with 5-HT1 agonists, including patients without a history of hypertension. Monitor blood pressure in patients treated with IMITREX. IMITREX Injection is contraindicated in patients with uncontrolled hypertension.
Anaphylactic/anaphylactoid reactions have occurred in patients receiving IMITREX. Such reactions can be life threatening or fatal. In general, anaphylactic reactions to drugs are more likely to occur in individuals with a history of sensitivity to multiple allergens. IMITREX Injection is contraindicated in patients with a history of hypersensitivity reaction to IMITREX.
Seizures have been reported following administration of IMITREX. Some have occurred in patients with either a history of seizures or concurrent conditions predisposing to seizures. There are also reports in patients where no such predisposing factors are apparent. IMITREX Injection should be used with caution in patients with a history of epilepsy or conditions associated with a lowered seizure threshold.
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION and Instructions for Use).
Risk of Myocardial Ischemia and/or Infarction, Prinzmetal’s Angina, Other Vasospasm-Related Events, Arrhythmias, and Cerebrovascular Events
Inform patients that IMITREX Injection may cause serious cardiovascular side effects such as myocardial infarction or stroke. Although serious cardiovascular events can occur without warning symptoms, patients should be alert for the signs and symptoms of chest pain, shortness of breath, irregular heartbeat, significant rise in blood pressure, weakness, and slurring of speech, and should ask for medical advice if any indicative sign or symptoms are observed. Apprise patients of the importance of this follow-up [see WARNINGS AND PRECAUTIONS].
Inform patients that anaphylactic/anaphylactoid reactions have occurred in patients receiving IMITREX Injection. Such reactions can be life threatening or fatal. In general, anaphylactic reactions to drugs are more likely to occur in individuals with a history of sensitivity to multiple allergens [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS].
Concomitant Use with Other Triptans or Ergot Medications
Inform patients that use of IMITREX Injection within 24 hours of another triptan or an ergot-type medication (including dihydroergotamine or methysergide) is contraindicated [see CONTRAINDICATIONS, DRUG INTERACTIONS].
Caution patients about the risk of serotonin syndrome with the use of IMITREX Injection or other triptans, particularly during combined use with SSRIs, SNRIs, TCAs, and MAO inhibitors [see WARNINGS AND PRECAUTIONS, DRUG INTERACTIONS].
Medication Overuse Headache
Inform patients that use of acute migraine drugs for 10 or more days per month may lead to an exacerbation of headache and encourage patients to record headache frequency and drug use (e.g., by keeping a headache diary) [see WARNINGS AND PRECAUTIONS].
Inform patients that IMITREX Injection should not be used during pregnancy unless the potential benefit justifies the potential risk to the fetus [see Use In Specific Populations].
Advise patients to notify their healthcare provider if they are breastfeeding or plan to breastfeed [see Use in Specific Populations].
Ability to Perform Complex Tasks
Treatment with IMITREX Injection may cause somnolence and dizziness; instruct patients to evaluate their ability to perform complex tasks after administration of IMITREX Injection.
How to Use IMITREX Injection
Provide patients instruction on the proper use of IMITREX Injection if they are able to self-administer IMITREX Injection in medically unsupervised situations.
Inform patients that the needle in the IMITREX STATdose Pen penetrates approximately 1/4 of an inch (5 to 6 mm). Inform patients that the injection is intended to be given subcutaneously and intramuscular or intravascular delivery should be avoided. Instruct patients to use injection sites with an adequate skin and subcutaneous thickness to accommodate the length of the needle.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
In carcinogenicity studies in mouse and rat in which sumatriptan was administered orally for 78 weeks and 104 weeks, respectively, at doses up to 160 mg/kg/day (the highest dose in rat was reduced from 360 mg/kg/day during Week 21). The highest dose to mice and rats was approximately 130 and 260 times the single MRHD of 6 mg administered subcutaneously on a mg/m² basis. There was no evidence in either species of an increase in tumors related to sumatriptan administration.
Sumatriptan was negative in in vitro (bacterial reverse mutation [Ames], gene cell mutation in Chinese hamster V79/HGPRT, chromosomal aberration in human lymphocytes) and in vivo (rat micronucleus) assays.
Impairment of Fertility
When sumatriptan was administered by subcutaneous injection to male and female rats prior to and throughout the mating period, there was no evidence of impaired fertility at doses up to 60 mg/kg/day or approximately 100 times the single human dose of 6 mg on a mg/m² basis. When sumatriptan (5, 50, 500 mg/kg/day) was administered orally to male and female rats prior to and throughout the mating period, there was a treatment-related decrease in fertility secondary to a decrease in mating in animals treated with doses greater than 5 mg/kg/day. It is not clear whether this finding was due to an effect on males or females or both.
Use In Specific Populations
Pregnancy Category C
There are no adequate and well-controlled trials of IMITREX Injection in pregnant women. In developmental toxicity studies in rats and rabbits, oral administration of sumatriptan to pregnant animals was associated with embryolethality, fetal abnormalities, and pup mortality. When administered by the intravenous route to pregnant rabbits, sumatriptan was embryolethal. IMITREX Injection should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Oral administration of sumatriptan to pregnant rats during the period of organogenesis resulted in an increased incidence of fetal blood vessel (cervicothoracic and umbilical) abnormalities. The highest no-effect dose for embryofetal developmental toxicity in rates was 60 mg/kg/day, or approximately 100 times the single maximum recommended human dose (MRHD) of 6 mg administered subcutaneously on a mg/m² basis. Oral administration of sumatriptan to pregnant rabbits during the period of organogenesis resulted in increased incidences of embryolethality and fetal cervicothoracic vascular and skeletal abnormalities. Intravenous administration of sumatriptan to pregnant rabbits during the period of organogenesis resulted in an increased incidence of embryolethality. The highest oral and intravenous no-effect doses for developmental toxicity in rabbits were 15 and 0.75 mg/kg/day, or approximately 50 and 2 times, respectively, the single MRHD of 6 mg administered subcutaneously on a mg/m² basis.
Oral administration of sumatriptan to rats prior to and throughout gestation resulted in embryofetal toxicity (decreased body weight, decreased ossification, increased incidence of skeletal abnormalities). The highest no-effect dose was 50 mg/kg/day, or approximately 80 times the single MRHD of 6 mg administered subcutaneously on a mg/m² basis. In offspring of pregnant rats treated orally with sumatriptan during organogenesis, there was a decrease in pup survival. The highest no-effect dose for this effect was 60 mg/kg/day, or approximately 100 times the single MRHD of 6 mg administered subcutaneously on a mg/m² basis. Oral treatment of pregnant rats with sumatriptan during the latter part of gestation and throughout lactation resulted in a decrease in pup survival. The highest no-effect dose for this finding was 100 mg/kg/day, or approximately 160 times the single MRHD of 6 mg administered subcutaneously on a mg/m² basis.
Sumatriptan is excreted in human milk following subcutaneous administration. Infant exposure to sumatriptan can be minimized by avoiding breastfeeding for 12 hours after treatment with IMITREX Injection.
Safety and effectiveness in pediatric patients have not been established. IMITREX Injection is not recommended for use in patients younger than 18 years of age.
Two controlled clinical trials evaluated IMITREX Nasal Spray (5 to 20 mg) in 1,248 pediatric migraineurs 12 to 17 years of age who treated a single attack. The trials did not establish the efficacy of IMITREX Nasal Spray compared with placebo in the treatment of migraine in pediatric patients. Adverse reactions observed in these clinical trials were similar in nature to those reported in clinical trials in adults.
Five controlled clinical trials (2 single-attack trials, 3 multiple-attack trials) evaluating oral IMITREX (25 to 100 mg) in pediatric patients 12 to 17 years of age enrolled a total of 701 pediatric migraineurs. These trials did not establish the efficacy of oral IMITREX compared with placebo in the treatment of migraine in pediatric patients. Adverse reactions observed in these clinical trials were similar in nature to those reported in clinical trials in adults. The frequency of all adverse reactions in these patients appeared to be both dose- and age-dependent, with younger patients reporting reactions more commonly than older pediatric patients.
Postmarketing experience documents that serious adverse reactions have occurred in the pediatric population after use of subcutaneous, oral, and/or intranasal IMITREX. These reports include reactions similar in nature to those reported rarely in adults, including stroke, visual loss, and death. A myocardial infarction has been reported in a 14-year-old male following the use of oral IMITREX; clinical signs occurred within 1 day of drug administration. Clinical data to determine the frequency of serious adverse reactions in pediatric patients who might receive subcutaneous, oral, or intranasal IMITREX are not presently available.
Clinical trials of IMITREX Injection did not include sufficient numbers of patients 65 years of age and older to determine whether they respond differently from younger patients. 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 CAD) prior to receiving IMITREX Injection [see WARNINGS AND PRECAUTIONS].
Last reviewed on RxList: 7/1/2015
This monograph has been modified to include the generic and brand name in many instances.
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