Amerge is a headache medicine that narrows blood vessels around the brain. This medicine also reduces substances in the body that can trigger headache pain, sensitivity to light and sound, and other migraine symptoms.

Amerge is used to treat migraine headaches. This medicine will only treat a headache that has already begun. It will not prevent headaches or reduce the number of attacks.

Amerge should not be used to treat a common tension headache, a headache that causes loss of movement on one side of your body, or any headache that seems to be different from your usual migraine headaches. Use Amerge only if your condition has been confirmed by a doctor as migraine headaches.

Amerge may also be used for purposes not listed in this medication guide.

You should not use Amerge if you have uncontrolled high blood pressure, heart problems, certain heart rhythm disorders, severe liver or kidney disease, a history of heart attack or stroke, or circulation problems that cause a lack of blood supply within the body.

Do not take Amerge within 24 hours before or after using another migraine headache medicine.

Your doctor may want to give your first dose of Amerge in a hospital or clinic setting to quickly treat any serious side effects that occur.

Follow all directions on your prescription label. Never use more than your recommended dose. Overuse of migraine headache medicine can make headaches worse. Tell your doctor if the medicine seems to stop working as well in treating your migraine attacks.

Take Amerge as soon as you notice migraine symptoms.

Take 1 tablet whole with a full glass of water.

After taking a tablet: If your headache does not go away completely, or if it goes away and comes back, call your doctor before taking a second tablet.

Do not take the second tablet until at least 4 hours have passed since you took the first tablet. Do not take more than 5 milligrams (mg) of naratriptan in 24 hours.

If your symptoms have not improved after taking 2 tablets in 24 hours, contact your doctor before taking any more tablets.

Tell your doctor if you have more than four headaches in one month (30 days).

Amerge can raise blood pressure to dangerous levels. Your blood pressure may need to be checked often while you are using this medicine. If you use this medicine long-term, your heart function may need to be checked using an electrocardiograph or ECG (sometimes called an EKG).

Store at room temperature away from moisture, heat, and light.

You should not use this medicine if you are allergic to Amerge, or if you have:

• severe or uncontrolled high blood pressure;

• past or present heart problems;

• history of coronary artery disease, heart attack, or stroke, including "mini-stroke";

• Wolff-Parkinson-White syndrome or other heart rhythm disorder;

• a blood vessel disorder or circulation problems that cause a lack of blood supply within the body;

• severe liver or kidney disease; or

• a headache that seems different from your usual migraine headaches.

To make sure Amerge is safe for you, tell your doctor if you have:

• liver or kidney disease;

• high blood pressure, a heart rhythm disorder; or

• coronary heart disease (or risk factors such as diabetes, menopause, smoking, being overweight, having high cholesterol, having a family history of coronary artery disease, being older than 40 and a man, or being a woman who has had a hysterectomy).

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

It is not known whether naratriptan passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

Do not give this medicine to anyone younger than 18.

Since Amerge is used as needed, it does not have a daily dosing schedule. Call your doctor if your symptoms do not improve after using Amerge.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include tiredness, neck stiffness, loss of coordination, or feeling light-headed.

Do not take Amerge within 24 hours before or after using another migraine headache medicine, including:

• medicines like Amerge--almotriptan, eletriptan, frovatriptan, rizatriptan, sumatriptan, zolmitriptan, and others; or

• ergot medicine--dihydroergotamine, ergotamine, ergonovine, methylergonovine.

Amerge may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Amerge may cause serious side effects. Stop using Amerge and call your doctor at once if you have:

• fast or pounding heartbeats;

• numbness or tingling and a pale or blue-colored appearance in your fingers or toes;

• pain or heavy feeling in your legs, hip pain, burning pain in your feet;

• sudden and severe stomach pain, bloody diarrhea, constipation, fever, weight loss;

• dangerously high blood pressure--severe headache, blurred vision, pounding in your neck or ears, nosebleed, anxiety, confusion, severe chest pain, shortness of breath, irregular heartbeats, seizure;

• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;

• high levels of serotonin in the body--agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination, fainting; or

• signs of a stroke--sudden numbness or weakness (especially on one side of the body), sudden severe headache, slurred speech, problems with vision or balance.

Common side effects of Amerge may include:

• dizziness, drowsiness;

• feeling weak or tired;

• numbness or tingling;

• flushing (warmth, redness, or tingly feeling);

• nausea; or

• pain or tightness in your jaw, neck, or throat.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Taking Amerge while you are using certain other medicines can cause high levels of serotonin to build up in your body, a condition called "serotonin syndrome," which can be fatal. Tell your doctor if you also use:

• medicine to treat depression;

• medicine to treat a psychiatric disorder;

• a narcotic (opioid) medication; or

• medicine to prevent nausea and vomiting.

This list is not complete. Other drugs may interact with naratriptan, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.