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 [Studies 2 and 3, see Clinical Studies (14.1)] following either a single 6 mg dose of sumatriptan succinate injection or placebo. Only reactions that occurred at a frequency of 2% or more in groups treated with sumatriptan succinate injection 6 mg and that occurred at a frequency greater than the placebo group are included in Table 1.
Table 1. Adverse Reactions Reported by at Least 2% of Subjects and at a Greater Frequency than Placebo in 2 Placebo-Controlled Migraine Clinical Trials (Studies 2 and 3)a
Adverse Reaction | Percent of Subjects Reporting
|
|---|
Sumatriptan Succinate Injection 6 mg Subcutaneous (n = 547)
| Placebo (n=370)
|
|---|
Atypical sensations Tingling Warm/hot sensation Burning sensation Feeling of heaviness Pressure sensation Feeling of tightness Numbness Feeling strange Tight feeling in head
| 42 14 11 7 7 7 5 5 2 2
| 9 3 4 < 1 1 2 < 1 2 < 1 < 1
|
Cardiovascular Flushing
| 7
| 2
|
Chest discomfort Tightness in chest Pressure in chest
| 5 3 2
| 1 < 1 < 1
|
Ear, nose, and throat Throat discomfort Discomfort: nasal cavity/sinuses
| 3 2
| < 1 < 1
|
Injection site reactionb
| 59
| 24
|
Miscellaneous Jaw discomfort
| 2
| 0
|
Musculoskeletal Weakness Neck pain/stiffness Myalgia
| 5 5 2
| < 1 < 1 < 1
|
Neurological Dizziness/vertigo Drowsiness/sedation Headache
| 12 3 2
| 4 2 < 1
|
Skin Sweating
| 2
| 1
|
a The sum of the percentages cited is greater than 100% because subjects may have experienced more than 1 type of adverse reaction. Only reactions that occurred at a frequency of 2% or more in groups treated with sumatriptan succinate injection and occurred at a frequency greater than the placebo groups are included.
b Includes injection site pain, stinging/burning, swelling, erythema, bruising, bleeding.
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 sumatriptan succinate injection as a treatment for cluster headache [Studies 4 and 5, see Clinical Studies (14.2)], no new significant adverse reactions were detected that had not already been identified in trials of sumatriptan succinate 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% sumatriptan succinate, 0% placebo), nausea and vomiting (4% sumatriptan succinate, 0% placebo), and bronchospasm (1% sumatriptan succinate, 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 sumatriptan succinate 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 Sumatriptan Succinate: The following adverse events occurred in clinical trials with sumatriptan succinate tablets and sumatriptan succinate nasal spray. Because the reports include events observed in open and uncontrolled trials, the role of sumatriptan succinate 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.