Adverse events are listed below by system organ class and frequency. Frequencies are defined as: very common (≥1/10), common (≥1/100, <1/10), uncommon (≥1/1000, <1/100), rare (≥1/10,000, <1/1000), very rare (<1/10,000), not known (cannot be estimated from the available data). Some of the symptoms reported as undesirable effects may be associated symptoms of migraine.
Immune system disorders
Not known: Hypersensitivity reactions ranging from cutaneous hypersensitivity (such as urticaria) to anaphylaxis.
Psychiatric disorders
Not known: Anxiety.
Nervous system disorders
Common: Dizziness, drowsiness, sensory disturbance including paraesthesia and hypoaesthesia.
Not known: Seizures, although 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; Tremor, dystonia, nystagmus, scotoma.
Eye disorders
Not known: Flickering, diplopia, reduced vision. Loss of vision including reports of permanent defects.
However, visual disorders may also occur during a migraine attack itself.
Cardiac disorders
Not known: Bradycardia, tachycardia, palpitations, cardiac arrhythmias, transient ischaemic ECG changes, coronary artery vasospasm, myocardial infarction, angina (see section 4.3 and 4.4).
Vascular disorders
Common: Transient increases in blood pressure arising soon after treatment. Flushing.
Not known: Hypotension, Raynaud's phenomenon.
Respiratory, thoracic and mediastinal disorders
Common: Dyspnoea
Gastrointestinal disorders
Common: Nausea and vomiting occurred in some patients but it is unclear if this is related to sumatriptan or the underlying condition.
Not known: Ischaemic colitis.
Not known: Diarrhoea.
Not known: Dysphagia.
Skin and subcutaneous tissue disorders
Not known: Hyperhidrosis.
Musculoskeletal and connective tissue disorders
Common: Sensations of heaviness (usually transient and may be intense and can affect any part of the body including the chest and throat). Myalgia.
Not known: Neck stiffness.
Not known: Arthralgia.
Reproductive system and breast disorders
Rare: Breast pain
General disorders and administration site conditions
Very common: Transient injection site pain. Injection site stinging/burning, swelling, erythema, bruising and bleeding have also been reported.
Common: Pain, sensations of heat or cold, pressure or tightness (these events are usually transient and may be intense and can affect any part of the body including the chest and throat).
Feelings of weakness, fatigue (both events are mostly mild to moderate in intensity and transient).
Not known: Pain trauma activated.
Not known: Pain inflammation activated.
Although direct comparisons are not available, flushing, paraesthesia and sensations of heat, pressure, and heaviness may be more common after sumatriptan injection.
Conversely, nausea, vomiting and fatigue appear to be less frequent with subcutaneous administration of sumatriptan injection than with tablets.
Investigations
Very rare: Minor disturbances in liver function tests have occasionally been observed.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme, website: www.mhra.gov.uk/yellowcard.