Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
Patient leaflets and SmPCs, drug interaction checker, official dosages and NHS pharmacy opening hours — all in one place.
The electronic medicines compendium (emc) no longer publishes a Summary of Product Characteristics for this product, which usually means it is no longer marketed in the UK. The patient leaflet below is kept for reference, but the product may not be available.
If you were prescribed this medicine, other products containing Sumatriptan succinate may still be available. Do not stop your treatment — ask your pharmacist or GP what to use instead.
for
Each Imigran Subject pre-filled cartridge syringe contains a single dose of sumatriptan, which belongs to a group of medicines called triptans (also known as 5-HT1 receptor agonists). Imigran Subject is used to treat migraine headache and a rare condition called cluster headache. Migraine and cluster headache symptoms may be caused by the temporary widening of blood vessels in the head. Imigran Subject is believed to reduce the widening of these blood vessels. This in turn helps to take away the headache and relieve other symptoms such as feeling or being sick (nausea or vomiting) and sensitivity to light and sound.
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e Imigran Subject
Don't use Imigran Subject: • • • • • • •
If you're allergic to sumatriptan, or any of the other ingredients of this medicine (listed in section 6) If you have a heart problem such as narrowing of the arteries (ischaemic heart disease) or chest pains (angina), or have already had a heart attack If you have circulation problems in your legs that cause cramp-like pains when you walk (peripheral vascular disease) If you have had a stroke or a mini-stroke (also called a transient ischaemic attack or TIA) If you have high blood pressure. You may be able to use Imigran if your high blood pressure is mild and is being treated If you have serious liver disease With other migraine medicines, including those which contain ergotamine, or similar medicines such as methysergide maleate; or any triptan or 5-HT1 agonist (such as naratriptan or zolmitriptan)
1
•
With any of the following anti-depressants:
Take special care with Imigran Subject Talk to your doctor or pharmacist before using Imigran. If you have any extra risk factors
2
Get medical help immediately. Section 4 (below) has more information about these possible side effects.
Other medicines and Imigran Tell your doctor or pharmacist if you're taking, have recently taken or might take any other medicines. This includes any herbal products or medicines you've bought without a prescription. Some medicines must not be taken with Imigran and others may cause adverse effects if they're taken with Imigran. You must tell your doctor if you are taking:
Pregnancy and breast-feeding •
•
If you are pregnant, think you may be pregnant or are planning to have a baby, ask your doctor for advice before taking this medicine. There is only limited information about the safety of Imigran for pregnant women, though up till now there is no evidence of any increased risk of birth defects. Your doctor will discuss with you whether or not you should use Imigran while you are pregnant Don't breast-feed your baby for 12 hours after using Imigran. If you express any breast milk during this time, discard the milk and don't give it to your baby. Some breastfeeding women report breast and/or nipple pain after use of sumatriptan. The pain is usually temporary and disappears in 3 to 12 hours.
Driving and using machines Either the symptoms of migraine or your medicine may make you drowsy. If you are affected, don't drive or operate machinery.
Imigran Subject contains •
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Sodium: This medicine contains less than 1 mmol sodium (23 mg) per syringe, that is to say essentially 'sodium-free'.
How to use Imigran Subject
Always use this medicine exactly as your doctor has told you. Check with your doctor or pharmacist if you are not sure. Imigran Subject is usually injected into the thigh. There's a step-by-step guide to using the syringe at the end of this leaflet (see section 7 overleaf).
When to use Imigran 3
• •
It's best to use Imigran as soon as you feel a migraine or a cluster headache coming on, although you can use it at any time during an attack Don't use Imigran to try to prevent an attack – only use it after your migraine symptoms start.
How much to use Adults aged 18 to 65
If your symptoms start to come back •
You can use a second Imigran injection if at least 1 hour has passed since the first injection.
If the first injection has no effect •
Don't use a new injection or any other Imigran preparation for the same attack.
If Imigran doesn't give you any relief: Ask your doctor or pharmacist for advice.
If you use more Imigran than you should Using too much Imigran could make you ill. If you have used more than two injections in 24 hours: Contact your doctor for advice. If you have further questions about the use of this medicine, ask your doctor or pharmacist.
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an injection using the Subject pen
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1
Swing open the lid of the carrycase.
2
Tear off the red seal from one of the cartridges. Open the blue hinged lid underneath the seal.
3
Take out the Subject pen from the carrycase. Check that the white rod is not sticking out beyond the end of the pen (see picture 11). If it is sticking out, place the pen back inside the carrycase, push firmly and the rod should click into place. The pen is now ready for use.
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4
Push the Subject pen firmly into the opened cartridge pack and gently screw it clockwise (about half a turn) until it will twist no further.
5
Keeping your finger away from the blue release button pull the Subject pen out of the cartridge pack. You may have to pull quite hard to do this. A safety catch stops accidental injection until you are ready.
10
6
The loaded pen is now ready for immediate use. Do not try to put the loaded pen back into the carrycase until after you have used the injection, or the needle may be damaged and the pen will not inject correctly.
7
Press the pen with the long blue nose end firmly against a clean area of skin – usually the outside of the thigh (as in picture) – so the grey part slides down to cover part of the blue nose. This releases the safety catch.
8
Hold the pen firmly and press the blue release button at the top of the Subject pen. Count slowly to 10 keeping the Subject pen very still and the release button depressed. Do not take the pen away from the skin too soon or some of the injection may be wasted.
11
Then lift the pen away taking care not to touch the needle point. 9
Return the used cartridge syringe to the empty space in the cartridge pack straight away.
10
Pushing the pen down into the cartridge pack as far as it will go, unscrew the pen by twisting it anti-clockwise (about half a turn) until it comes away.
11
Withdraw the Subject pen from the cartridge pack. Close the blue hinged lid over the used syringe.
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12
Put the Subject pen back into the carrycase and push it down until it stays down. It will click into place. The Subject pen is then ready for use next time.
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Close the lid of the carrycase until you need to use the next cartridge syringe. When you have used both cartridges, remove and replace the cartridge pack. (See right.)
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How to remove the used cartridge pack 1
When both syringes have been used, you can remove the cartridge pack.
2
Hold the carrycase and press the two blue locating buttons with one hand.
3
Gently pull out the cartridge pack with the other hand.
4
Be careful to dispose of your empty cartridge packs safely. The cartridge pack will hold the used Subject cartridge syringes and needles until you can safely dispose of them. You should be able to do this at your doctor's surgery, so ask your doctor or practice nurse.
How to put a new cartridge pack into the carrycase Each Subject pen comes complete with an Imigran cartridge pack which contains two pre-filled cartridge syringes. 1
Swing open the lid of the carrycase, the Subject pen is already in its place.
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2
Push the cartridge pack into the carrycase, pressing the blue buttons on either side so it slides in smoothly.
3
It does not matter which side of the cartridge pack is closest to the Subject pen. 4
The cartridge pack is in the right position when the blue locating buttons show through the holes on either side of the carrycase.
5
Close the carrycase by swinging back the lid and snapping it shut.
6
You can keep your cartridge pack safely in the carrycase until you need to give yourself an injection. Keep your carrycase and any refill cartridge packs at a temperature below 30C/86F. If they are kept warmer than this for more than 24 hours it could spoil them.
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CE 2797 UKCA 0086 For Northern Ireland Only: The Authorised Representative is GlaxoSmithKline Trading Services Limited, 12 Riverwalk, Citywest Business Campus, Dublin 24, Ireland.
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Like all medicines, this medicine can cause side effects, but not everybody gets them. Some symptoms may be caused by the migraine itself. Allergic reaction: get doctor's help straight away The following side effects have occurred but their exact frequency is not known.
Very common side effects (affect more than 1 in 10 people)
Common side effects (affect up to 1 in 10 people)
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•
Pain, heaviness, pressure or tightness in the chest, throat or other parts of the body, or unusual sensations, including numbness, tingling and warmth or cold. These effects may be intense but generally pass quickly.
If these effects continue or become severe (especially the chest pain): Get medical help urgently. In a very small number of people these symptoms can be caused by a heart attack.
Other common side effects include: • • • • • •
Feeling sick (nausea) or being sick (vomiting), although this may be due to the migraine itself Tiredness or drowsiness Dizziness, feeling weak, or getting hot flushes Temporary increase in blood pressure Shortness of breath Aching muscles.
Rare side effects (affect up to 1 in 1,000 people)
Very rare side effects (affect up to 1 in 10,000 people)
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5
Imigran Subject
Keep this medicine out of the sight and reach of children. You may wish to carry Imigran Subject with you in case of a migraine attack. Always keep your injections in the case provided to protect them from the light. Store below 30oC. Don't use this medicine after the expiry date shown on the carton. The expiry date refers to the last day of that month. Do not throw away medicines via wastewater or household waste. Ask your doctor, practice nurse or pharmacist how to dispose of your empty Cartridge Packs safely. You may be able to do this at your doctor's surgery.
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What Imigran Subject contains • •
The active substance is sumatriptan (6 mg) The other ingredient is 0.5 ml sterile sodium chloride solution.
What Imigran Subject looks like and contents of the pack Each Imigran injection treatment pack comes complete with an injection device (Pen) and a cartridge pack which contains two pre-filled syringes. Imigran injection is also available as refill packs, which contain one cartridge of 2 pre-filled syringes.
Marketing authorisation holder and manufacturer Product licence held by Glaxo Wellcome UK Ltd., GSK Medicines Research Centre, Gunnels Wood Road, Stevenage, Hertfordshire, SG1 2NY, UK Manufactured by Glaxo Operations UK Ltd., Harmire Road, Barnard Castle, County Durham DL12 8DT The information provided applies only to Imigran Subject.
Other formats To listen to or request a copy of this leaflet in Braille, large print or audio please call, free of charge:
0800 198 5000 (UK Only) Please be ready to give the following information: Product name Reference number
Imigran Subject 10949/0113
This is a service provided by the Royal National Institute of Blind People. Leaflet date: August 2025 Trademarks are owned by or licensed to the GSK group of companies.
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© 2025 GSK group of companies or its licensor.
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Step-by-step guide to using your Imigran Subject injection system
This leaflet shows you how to load the Subject pen and how to use it to give a dose of Imigran medicine. Please read this leaflet before using the injection system. The GlaxoSmithKline Subject injection system is designed for use with a medicine called Imigran. Each Subject injection system comes complete with an Imigran cartridge pack. The cartridge pack contains two pre-filled cartridge syringes. Subject refill packs containing one Imigran Subject cartridge are also available. Important: In the unlikely event that you have a problem with the Imigran Subject injection mechanism, please:
Description of parts
Imigran Injection, Subject comes as injection. Always follow the dose your doctor or pharmacist has given you, and read the leaflet that comes with the medicine.
The active substance in Imigran Injection, Subject is sumatriptan succinate.
This leaflet reproduces the patient information leaflet approved for Imigran Injection, Subject, as published on the electronic medicines compendium (emc). The version printed inside your medicine’s packaging is the one that applies to you.
Whether a medicine is available over the counter or on prescription only depends on its licence. Check the leaflet, or ask your pharmacist — they can tell you straight away.
The text above reproduces the patient information leaflet approved for this medicine, restructured for easier reading.
Subcutaneous Injection is indicated for the acute relief of migraine attacks, with or without aura, and for the acute treatment of cluster headache. Imigran should only be used where there is a clear diagnosis of migraine or cluster headache.
Imigran should not be used prophylactically. The recommended dose of Imigran should not be exceeded.
It is recommended to start the treatment at the first sign of a migraine headache or associated symptoms such as nausea, vomiting or photophobia. It is equally effective at whatever stage of the attack it is administered.
The efficacy of sumatriptan is independent of the duration of the attack when starting treatment. Administration during a migraine aura prior to other symptoms occurring may not prevent the development of a headache.
Imigran Injection should be injected subcutaneously using an auto-injector. Patients should be advised to observe strictly the instruction leaflet for the Imigran auto-injector especially regarding the safe disposal of syringes and needles.
Migraine:
Adult: The recommended adult dose of Imigran is a single 6 mg subcutaneous injection.
If a patient does not respond to the first dose of sumatriptan, a second dose should not be taken for the same attack. In these cases the attack can be treated with paracetamol, acetylsalicylic acid, or non-steroidal anti-inflammatory drugs. Sumatriptan injection may be taken for subsequent attacks.
If the patient has responded to the first dose, but the symptoms recur a second dose may be given in the next 24 hours, provided that there is a minimum interval of 1 hour between the two doses.
The maximum dose in 24 hours is two 6 mg injections (12 mg).
Imigran is recommended as monotherapy for the acute treatment of migraine and should not be given concomitantly with ergotamine or derivatives of ergotamine (including methysergide) (see section 4.3).
Cluster headache:
Adult:
The recommended adult dose is a single 6mg subcutaneous injection for each cluster attack. The maximum dose in 24 hours is two 6 mg injections (12 mg) with a minimum interval of one hour between the two doses.
Children and Adolescents (under 18 years of age):
Sumatriptan Injection is not recommended for use in children and adolescents due to insufficient data on safety and efficacy.
Older people (over 65):
Experience of the use of Imigran in patients aged over 65 years is limited. The pharmacokinetics do not differ significantly from a younger population but, until further clinical data are available, the use of Sumatriptan in patients aged over 65 years is not recommended.
Hypersensitivity to sumatriptan or to any of the excipients listed in section 6.1.
Sumatriptan should not be given to patients who have had myocardial infarction or have ischaemic heart disease, coronary vasospasm (Prinzmetal's angina), peripheral vascular disease or patients who have symptoms or signs consistent with ischaemic heart disease.
Sumatriptan should not be administered to patients with a history of cerebrovascular accident (CVA) or transient ischaemic attack (TIA).
Sumatriptan should not be administered to patients with severe hepatic impairment.
The use of sumatriptan in patients with moderate and severe hypertension and mild uncontrolled hypertension is contraindicated.
The concomitant administration of ergotamine or derivatives of ergotamine (including methysergide) or any triptan/5-hydroxytryptamine1 (5-HT1) receptor agonist with sumatriptan is contraindicated. (see section 4.5)
Concurrent administration of monoamine oxidase inhibitors and sumatriptan is contraindicated.
Imigran Injection must not be used within two weeks of discontinuation of therapy with monoamine oxidase inhibitors.
Warnings: Imigran should only be used where there is a clear diagnosis of migraine or cluster headache.
Sumatriptan is not indicated for use in the management of hemiplegic, basilar or opthalmoplegic migraine.
The needle shield of the pre-filled syringe may contain dry natural latex rubber that has the potential to cause allergic reactions in latex sensitive individuals.
Imigran Injection should not be given intravenously because of its potential to cause vasospasm. The vasospasm may result in arrhythmias, ischaemic ECG changes or myocardial infarction.
Before treating with sumatriptan, care should be taken to exclude potentially serious neurological conditions (e.g. CVA, TIA) if the patient presents with atypical symptoms or if they have not received an appropriate diagnosis for sumatriptan use.
Following administration, sumatriptan can be associated with transient symptoms including chest pain and tightness which may be intense and involve the throat (see section 4.8). Where such symptoms are thought to indicate ischaemic heart disease, no further doses of sumatriptan should be given and appropriate evaluation should be carried out.
Sumatriptan should not be given to patients with risk factors for ischaemic heart disease, including those patients who are heavy smokers or users of nicotine substitution therapies, without prior cardiovascular evaluation (see section 4.3). Special consideration should be given to postmenopausal women and males over 40 with these risk factors. These evaluations however, may not identify every patient who has cardiac disease and, in very rare cases, serious cardiac events have occurred in patients without underlying cardiovascular disease.
If the patient experiences symptoms which are severe or persistent or are consistent with angina, further doses should not be taken until appropriate investigations have been carried out to check for the possibility of ischaemic changes.
Sumatriptan should be administered with caution to patients with mild controlled hypertension, since transient increases in blood pressure and peripheral vascular resistance have been observed in a small proportion of patients (see section 4.3).
There have been rare post-marketing reports describing patients with serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) following the use of a selective serotonin reuptake inhibitor (SSRI) and sumatriptan. Serotonin syndrome has been reported following concomitant treatment with triptans and serotonin noradrenaline reuptake inhibitors (SNRIs).
If concomitant treatment with sumatriptan and an SSRI/SNRI is clinically warranted, appropriate observation of the patient is advised (see section 4.5)
Sumatriptan should be administered with caution to patients with conditions which may affect significantly the absorption, metabolism or excretion of the drug e.g. impaired hepatic (Child Pugh grade A or B; see section 5.2) or renal function (see section 5.2).
Sumatriptan should be used with caution in patients with a history of seizures or other risk factors which lower the seizure threshold, as seizures have been reported in association with sumatriptan (see section 4.8).
Patients with known hypersensitivity to sulphonamides may exhibit an allergic reaction following administration of Sumatriptan. Reactions may range from cutaneous hypersensitivity to anaphylaxis. Evidence of cross-sensitivity is limited, however, caution should be exercised before using sumatriptan in these patients.
Undesirable effects may be more common during concomitant use of triptans and herbal preparations containing St John's Wort (Hypericum perforatum).
Prolonged use of any type of painkiller for headaches can make them worse. If this situation is experienced or suspected, medical advice should be obtained and treatment should be discontinued. The diagnosis of medication overuse headache (MOH) should be suspected in patients who have frequent or daily headaches despite (or because of) the regular use of headache medications.
This medicine contains less than 1 mmol sodium (23 mg) per syringe, that is to say essentially 'sodium-free'.
Studies in healthy subjects show that Imigran does not interact with propranolol, flunarizine, pizotifen or alcohol.
There are limited data on an interaction with preparations containing ergotamine or another triptan/5-HT1 receptor agonist. The increased risk of coronary vasospasm is a theoretical possibility and concomitant administration is contraindicated (see section 4.3).
The period of time that should elapse between the use of sumatriptan and ergotamine-containing preparations or another triptan/5-HT1 receptor agonist is not known. This will also depend on the doses and types of products used. The effects may be additive. It is advised to wait at least 24 hours following the use of ergotamine-containing preparations or another triptan/5-HT1 receptor agonist before administering sumatriptan. Conversely, it is advised to wait at least 6 hours following use of sumatriptan before administering an ergotamine-containing product and at least 24 hours before administering another triptan/5-HT1 receptor agonist.
An interaction may occur between sumatriptan and MAOIs and concomitant administration is contraindicated (see section 4.3).
There have been rare post-marketing reports describing patients with serotonin syndrome (including altered mental status, autonomic instability and neuromuscular abnormalities) following the use of SSRIs and sumatriptan. Serotonin syndrome has also been reported following concomitant treatment with triptans and SNRIs (see section 4.4).
Pregnancy
Post-marketing data from the use of sumatriptan during the first trimester in over 1,000 women are available. Although these data contain insufficient information to draw definitive conclusions, they do not point to an increased risk of congenital defects. Experience with the use of sumatriptan in the second and third trimester is limited.
Evaluation of experimental animal studies does not indicate direct teratogenic effects or harmful effects on peri- and postnatal development. However, embryofoetal viability might be affected in the rabbit (see section 5.3). Administration of sumatriptan should only be considered if the expected benefit to the mother is greater than any possible risk to the foetus.
Breast-feeding
Sumatriptan is excreted into breast milk, with average relative infant doses of < 4% following administration of a single dose of sumatriptan. Infant exposure can be minimised by avoiding breast feeding for 12 hours after treatment, during which time any breast milk expressed should be discarded.
There have been reports of breast pain and/or nipple pain following sumatriptan intake in breastfeeding women (see section 4.8). The pain was usually transient and disappeared in 3 to 12 hours.
No studies on the effects on the ability to drive and use machines have been performed. Drowsiness may occur as a result of migraine or treatment with sumatriptan. This may influence the ability to drive and to operate machinery.
Adverse events are listed below by system organ class and frequency. Frequencies are defined as: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1000 to <1/100), rare (≥1/10000 to <1/1000), very rare (<1/10000), not known (cannot be estimated from the available data). Some of the symptoms reported as undesirable effects may be associated symptoms of migraine.
Clinical Trial Data
Nervous System Disorders
Common:
Dizziness, drowsiness, sensory disturbance including paraesthesia and hypoaesthesia.
Vascular Disorders
Common:
Transient increases in blood pressure arising soon after treatment. Flushing.
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.
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.
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).
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
Post-Marketing Data
Immune System Disorders
Not known:
Hypersensitivity reactions ranging from cutaneous hypersensitivity to anaphylaxis.
Nervous System Disorders
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, angina, myocardial infarction (see sections 4.3 and 4.4).
Vascular Disorders
Not known:
Hypotension, Raynaud's phenomenon.
Gastrointestinal Disorders
Not known:
Ischaemic colitis, diarrhoea, dysphagia.
Musculoskeletal, Connective Tissue and Bone Disorders
Not known:
Neck stiffness.
Arthralgia.
Reproductive system and breast disorders
Rare:
Breast pain.
General Disorders and Administration Site Conditions
Not known:
Pain trauma activated, pain inflammation activated.
Psychiatric disorders
Not known:
Anxiety.
Skin and subcutaneous tissue disorders
Not known:
Hyperhidrosis.
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 at Website: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.
There have been some reports of overdose with Imigran Injection. Patients have received single injections of up to 12 mg subcutaneously without significant adverse effects. Doses in excess of 16 mg subcutaneously were not associated with side effects other than those mentioned.
If overdose with Imigran occurs, the patient should be monitored for at least ten hours and standard supportive treatment applied as required.
It is unknown what effect haemodialysis or peritoneal dialysis has on the plasma concentrations of Imigran.
Medicines sold in Romania with the same active substance: Cunoscut în România ca
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Romanian medicines in the UK →
Medicines sold in Poland with the same active substance: W Polsce znany jako
Same active substance. The strength, the form and whether you need a prescription can differ. Always ask a pharmacist before you switch. Polish medicines in the UK →
Ask anything about Imigran Injection, Subject. The assistant answers only from this leaflet — if the leaflet does not cover it, it will say so. It does not give medical advice.
Answers come from the patient leaflet published on the electronic medicines compendium (emc). They are not medical advice. Ask a pharmacist or your GP if you are unsure. For urgent help call NHS 111, or 999 in an emergency.
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