Synarel (for the nose) is used to treat central precocious puberty in boys and girls. Central precocious puberty is early sexual development that occurs at or before 8 years of age in girls or 9 years of age in boys, with bone development that is advanced for the child's age.

Synarel is also used to treat endometriosis in women who are at least 18 years old.

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

Do not use if you are pregnant. Use effective birth control, and tell your doctor if you become pregnant.

Some children using nafarelin have had new or worsening mental problems. Call your doctor right away if your child has any unusual changes in mood or behavior (anger, aggression, crying, feeling restless or irritable).

Nafarelin may also cause seizures, especially in people who have had a seizure, epilepsy, a brain tumor, or blood vessel problems in the brain. Your risk of a seizure may also be higher if you take certain antidepressant medications.

You should not use Synarel if you have abnormal vaginal bleeding that has not been checked by a doctor.

Your doctor will perform tests to make sure this medicine is the right treatment for your child's condition.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Do not miss any doses of this medicine. Skipping doses or not using Synarel correctly may cause a hormonal imbalance that could lead to unwanted side effects.

Read and carefully follow all Instructions for using the nasal spray. Ask your doctor or pharmacist if you do not understand these instructions.

Tilt your head slightly back when using the nasal spray. Use only the number of sprays your doctor has prescribed, and allow at least 30 seconds between sprays.

Your doctor will need to check your child's progress with frequent medical tests, especially during the first 6 to 8 weeks of using Synarel.

Nafarelin can increase certain hormones when you first start using this medicine. This may cause your child's symptoms of precocious puberty to get worse for a short time. Call your doctor if pubertal signs continue for longer than 1 month.

If you have regular menstrual periods, they should stop while you are using Synarel. Tell your doctor if your periods continue for longer than 1 month after you start using this medicine.

Do not use a Synarel spray bottle for longer than 30 days. The amount of medicine left in the bottle after 30 days of regular use will not be enough for another full dose. Get your prescription refilled before the 30 days are up so you don't run out of medicine.

Store Synarel in an upright position at room temperature, away from moisture, heat, and light. Do not freeze. Keep the bottle tightly capped when not in use.

You should not use Synarel if you are allergic to nafarelin or similar medicines such as goserelin, leuprolide, histrelin, or triptorelin.

If you are woman, you should not use Synarel if you have:

• abnormal vaginal bleeding that has not been checked by a doctor; or

• if you are pregnant or breastfeeding.

Tell your doctor if you have ever had:

• epilepsy or other seizure disorder;

• mental illness;

• a tumor or blood vessel problem in your brain;

• polycystic ovary disease;

• low bone mineral density;

• osteoporosis (in you or a family member); or

• if you smoke or drink large amounts of alcohol.

Do not use Synarel if you are pregnant. It could harm the unborn baby. You may need to have a negative pregnancy test before starting this treatment.

Even though this medicine may cause you not to ovulate or have regular menstrual periods, you should use effective nonhormonal birth control to prevent pregnancy while you are using this medicine.

Synarel can make hormonal birth control less effective, including birth control pills, injections, implants, skin patches, and vaginal rings. Use barrier birth control to prevent pregnancy: condom, diaphragm, cervical cap, or contraceptive sponge.

You should not breastfeed while using Synarel.

Use the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

It is very important that you DO NOT MISS A DOSE of Synarel.

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

Try not to sneeze or blow your nose just after using the spray. This can make nafarelin less effective.

Avoid using any other nasal sprays within 2 hours after your dose of nafarelin nasal. If you have a stuffy nose, ask your doctor before using a decongestant nasal spray.

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

Synarel may cause serious side effects. Call your doctor at once if you have:

• vaginal spotting or continued menstrual bleeding;

• pelvic pain or swelling;

• a seizure;

• depression--mood changes, feelings of low self-worth, loss of interest in things you once enjoyed, new sleep problems, thoughts about hurting yourself;

• increased pressure inside the skull--severe headaches, ringing in your ears, dizziness, nausea, vision problems, pain behind your eyes; or

• signs of a pituitary gland problem--sudden headache, confusion, vision changes, vomiting, weak pulse, slowed breathing.

Some children using nafarelin have had new or worsening mental problems. Call your doctor right away if your child has any unusual changes in mood or behavior (anger, aggression, crying, feeling restless or irritable).

Some side effects can be expected during the first month of using Synarel and are not a reason to stop using the medicine. Tell your doctor if you have any side effect that is ongoing or bothersome.

Common side effects of Synarel may include:

• vaginal bleeding, discharge, or dryness;

• hot flashes;

• acne;

• increase or decrease in breast size;

• runny nose;

• headaches, muscle pain;

• mood changes;

• decreased interest in sex;

• itchy, red, or flaky rash;

• increased body odor; or

• increase in pubic hair growth.

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.

Tell your doctor about all your other medicines, especially:

• an antidepressant;

• seizure medicine; or

• steroid medicine.

This list is not complete. Other drugs may affect Synarel, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.