IMITREX injection adverse reactions

# Adverse Reactions
The following adverse reactions are discussed in more detail in other sections of the labeling:
- Myocardial ischemia, myocardial infarction, and Prinzmetal's angina 
- Arrhythmias 
- Chest, throat, neck, and/or jaw pain/tightness/pressure 
- Cerebrovascular events 
- Other vasospasm reactions 
- Medication overuse headache 
- Serotonin syndrome 
- Increase in blood pressure 
- Anaphylactic/anaphylactoid reactions 
- Seizures 

### Clinical Trials Experience
Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Migraine Headache: Table 1 lists adverse reactions that occurred in 2 US placebo-controlled clinical trials in migraine subjects  following either a single 6-mg dose of IMITREX Injection or placebo. Only reactions that occurred at a frequency of 2% or more in groups treated with IMITREX Injection 6 mg and that occurred at a frequency greater than the placebo group are included in Table 1.
The incidence of adverse reactions in controlled clinical trials was not affected by gender or age of the subjects. There were insufficient data to assess the impact of race on the incidence of adverse reactions.
Cluster Headache: In the controlled clinical trials assessing the efficacy of IMITREX Injection as a treatment for cluster headache , no new significant adverse reactions were detected that had not already been identified in trials of IMITREX in subjects with migraine.
Overall, the frequency of adverse reactions reported in the trials of cluster headache was generally lower than in the migraine trials. Exceptions include reports of paresthesia (5% IMITREX, 0% placebo), nausea and vomiting (4% IMITREX, 0% placebo), and bronchospasm (1% IMITREX, 0% placebo).
Other Adverse Reactions: In the paragraphs that follow, the frequencies of less commonly reported adverse reactions are presented. Reaction frequencies were calculated as the number of subjects reporting a reaction divided by the total number of subjects (N = 6,218) exposed to subcutaneous IMITREX Injection. All reported reactions are included except those already listed in the previous table. Reactions are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent are defined as those occurring in at least 1/100 subjects, infrequent are those occurring in 1/100 to 1/1,000 subjects, and rare are those occurring in fewer than 1/1,000 subjects.
- Cardiovascular: Infrequent were hypertension, hypotension, bradycardia, tachycardia, palpitations, and syncope. Rare was arrhythmia.
- Gastrointestinal: Frequent was abdominal discomfort.
- Musculoskeletal: Frequent were muscle cramps.
- Neurological: Frequent was anxiety. Infrequent were mental confusion, euphoria, agitation, tremor. Rare were myoclonia, sleep disturbance, and dystonia.
- Respiratory: Infrequent was dyspnea.
- Skin: Infrequent were erythema, pruritus, and skin rashes.
- Miscellaneous: Infrequent was serotonin agonist effect.
Adverse Events Observed With Other Formulations of IMITREX: The following adverse events occurred in clinical trials with IMITREX Tablets and IMITREX Nasal Spray. Because the reports include events observed in open and uncontrolled trials, the role of IMITREX in their causation cannot be reliably determined. All reported events are included except those already listed, those too general to be informative, and those not reasonably associated with the use of the drug.
- Cardiovascular: Angina, cerebrovascular lesion, heart block, peripheral cyanosis, phlebitis, thrombosis.
- Gastrointestinal: Abdominal distention and colitis.
- Neurological: Convulsions, hallucinations, syncope, suicide, and twitching.
- Miscellaneous: Edema, hypersensitivity, swelling of extremities, and swelling of face.

### Postmarketing Experience
The following adverse reactions have been identified during postapproval use of IMITREX Tablets, IMITREX Nasal Spray, and IMITREX Injection. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. These reactions have been chosen for inclusion due to either their seriousness, frequency of reporting, or causal connection to IMITREX or a combination of these factors.
- Blood: Hemolytic anemia, pancytopenia, thrombocytopenia.
- Ear, Nose, and Throat: Deafness.
- Eye: Ischemic optic neuropathy, retinal artery occlusion, retinal vein thrombosis.
- Neurological: Central nervous system vasculitis, cerebrovascular accident, serotonin syndrome, subarachnoid hemorrhage.
- Non-Site Specific: Angioedema, cyanosis, temporal arteritis.
- Skin: Exacerbation of sunburn, hypersensitivity reactions (allergic vasculitis, erythema, pruritus, rash, shortness of breath, urticaria), photosensitivity. Following subcutaneous administration of IMITREX, pain, redness, stinging, induration, swelling, contusion, subcutaneous bleeding, and, on rare occasions, lipoatrophy (depression in the skin) or lipohypertrophy (enlargement or thickening of tissue) have been reported.
- Urogenital: Acute renal failure.