Sumatriptan is used to treat migraines and cluster headaches. It helps to relieve pain and other symptoms of migraines/headaches including sensitivity to light or sound, nausea, and vomiting. Prompt treatment allows you to get back to your normal routine and may decrease your need for other pain medications. It does not prevent future migraines/headaches or reduce how often you may get a headache.

Sumatriptan belongs to a group of drugs called triptans. It affects a certain natural chemical (serotonin) that constricts blood vessels in the brain. It may also block other pain pathways in the brain.

Read the Patient Information Leaflet and Instructions for Use if available from your pharmacist before you start using sumatriptan and each time you get a refill. Ask your health care professional how to prepare and use this medication. If you have any questions, ask your doctor or pharmacist.

Inject this medication under the skin as soon as symptoms of your migraine/headache appear. The dosage is based on your medical condition and response to treatment. Before injecting each dose, clean the skin you are going to inject into (the injection site) with rubbing alcohol. This medication should never be injected into a vein or into a muscle. Also, never inject this medication through clothing.

If there is no improvement in your symptoms, do not use any more doses of this medication before talking to your doctor. If your symptoms are only partly relieved, or if your headache comes back, you may use a second injection after one hour or as directed by your doctor. Do not use more than 12 milligrams in a 24-hour period.

If your symptoms are only partly relieved or your headache returns, 2 hours after the injection you may switch to sumatriptan taken by mouth instead of using a second injection. After the initial injection you may take sumatriptan by mouth every 2 hours if needed to a maximum of 100 milligrams of tablets in a 24-hour period.

If you have never taken this medication before and you have risk factors for heart disease (see Precautions), you may need to be monitored for rare but serious side effects (such as chest pain) when you use the first dose. Your doctor may ask you to use the first dose in the office.

If you are using drugs for migraine attacks on 10 or more days each month, the drugs may actually make your headaches worse (medication overuse headache). Do not use medications more often or for longer than directed. Tell your doctor if you need to use this medication more often, or if the medication is not working as well, or if your headaches get worse.

Pain, swelling, bleeding, or bruising at the injection site may occur. Flushing, sensations of tingling/numbness/prickling/heat, weakness, drowsiness, or dizziness may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.

Sumatriptan can commonly cause chest/jaw/neck tightness, pain, or pressure that is usually not serious. However, these side effects are like symptoms of a heart attack, which may include chest/jaw/left arm pain, shortness of breath, or unusual sweating. Get medical help right away if these or other serious side effects occur, including:

• fast/irregular heartbeat
• fainting
• severe stomach/abdominal pain
• bloody diarrhea
• signs of a stroke (such as weakness on one side of the body, trouble speaking, sudden vision changes, confusion)

Tell your doctor right away if you have any serious side effects, including:

• blue fingers/toes/nails
• cold sensation of hands/feet
• hearing changes
• mental/mood changes
• seizures

This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms:

• fast heartbeat
• hallucinations
• loss of coordination
• severe dizziness
• severe nausea/vomiting/diarrhea
• twitching muscles
• unexplained fever
• unusual agitation/restlessness

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using sumatriptan, tell your doctor or pharmacist if you are allergic to it; or to other triptan drugs (such as zolmitriptan, rizatriptan); or if you have any other allergies. This product may contain inactive ingredients (such as latex found in some brands), which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• blood circulation problems (for example, in your legs, arms/hands, or stomach)
• certain types of headaches (hemiplegic or basilar migraine)
• heart problems (such as chest pain, irregular heartbeat, previous heart attack)
• liver disease
• seizure
• stroke or "mini-stroke" (transient ischemic attack)

Certain conditions can increase your risk for heart problems. Tell your doctor if you have any of these conditions, including:

• high blood pressure
• high cholesterol
• diabetes
• family history of heart disease
• overweight
• smoker
• postmenopausal (women)
• age more than 40 years (men)

If you are at high risk for heart disease, your doctor may want to check your heart before prescribing sumatriptan.

This drug may make you dizzy or drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness until you can do it safely. Limit alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

The risk of heart disease, liver disease, and high blood pressure increases with age. Older adults may be more sensitive to the side effects of this drug, especially increased blood pressure and heart problems.

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

This drug passes into breast milk in small amounts. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.

The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy" St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, SNRIs such as duloxetine/venlafaxine), among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.

If you also take any ergotamine medication (such as dihydroergotamine) or any other "triptan" drugs (such as zolmitriptan, rizatriptan), you will need to separate your sumatriptan dose from your dose of these other medications in order to lessen the chance of serious side effects. Ask your doctor how long you should wait between your doses of these drugs.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Do not share this medication with others.

Certain foods/beverages or food additives (such as red wine, cheese, chocolate, monosodium glutamate) as well as some lifestyle patterns (such as irregular eating/sleeping habits, stress) may bring about a migraine headache. Avoiding these "triggers" may help decrease the frequency of migraine headaches. Consult your doctor for more details.

Lab and/or medical tests (such as blood pressure) may be done while you are using this medication. Keep all medical and lab appointments. Consult your doctor for more details.

Not applicable. (See How to Use section.)

Different brands of this medication have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Keep all medications away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.