Synarel
Synarel (nafarelin) is used to treat endometriosis and relieve related pain, including back pain, pelvic pain, and pain during sex. It's also used to stop early puberty in young children. It's easy to use since the medication comes as a nasal spray. Synarel (nafarelin) can cause bothersome side effects, like mood swings and acne.
What is Synarel (nafarelin)?
What is Synarel (nafarelin) used for?
- Endometriosis in adults
- Early puberty in young children
How Synarel (nafarelin) works
Synarel (nafarelin) is a gonadotropin-releasing hormone (GnRH) agonist, meaning that it acts like GnRH, a hormone that controls the release of sex hormones into your body.
For people with endometriosis, estrogen plays a role in endometrial tissue growth. By acting like GnRH, Synarel (nafarelin) prevents the release of estrogen, helping to shrink endometrial tissue and reduce pain.
For young children with early puberty, sex hormones trigger puberty. By acting like GnRH, Synarel (nafarelin) stops the releasing of these hormones, slowing down puberty progression, growth in height, bone maturation, and genital development.
Drug facts
Side effects of Synarel (nafarelin)
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Common Side Effects
Endometriosis:
- Hot flashes (90%)
- Lower sex drive (20-25%)
- Vaginal dryness (15-20%)
- Headaches (15-20%)
- Mood swings (15-20%)
- Acne (15-20%)
Early puberty:
- Acne (10%)
- Temporarily larger breast size (8%)
- Vaginal bleeding (8%)
- Mood swings (6%)
- Temporary increase in pubic hair growth (5%)
- Runny nose (5%)
Less Common Side Effects
Endometriosis:
- Nasal irritation
- Muscle pain
- Smaller breast size
- Swelling in the hands or ankles
- Sweating
- Excessive growth of facial or body hair
- Weight gain or weight loss
- Depression
- Trouble sleeping
Early puberty:
- Body odor
- Sweating
- Hot flashes
- White or brownish vaginal discharge
The following Synarel (nafarelin) side effects have also been reported
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
More common
For adults (female)
Breast enlargement
light vaginal bleeding between regular menstrual periods, called spotting
longer or heavier menstrual periods
vaginal bleeding between regular menstrual periods, called breakthrough bleeding
For children (male)
Body odor
growth of pubic hair
Less common or rare
Incidence not known
For adults (female)
difficulty with speaking
dizziness or lightheadedness
double vision
fainting
fast heartbeat
inability to move the arms, legs, or facial muscles
inability to speak
pain or discomfort in the arms, jaw, back, or neck
pain, redness, or swelling in the arm or leg
slow speech
sweating
troubled breathing
vomiting
yellow eyes or skin
Incidence not known
Anxiety or mental depression
changes in vision
cold, clammy, or pale skin
confusion
convulsions
headache
irregular heartbeats
nightmares or unusually vivid dreams
slow heart rate
vomiting
weakness
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
For adults (female)
dandruff
increase or decrease in sexual desire
increased hair growth, often abnormally distributed
mood swings
oily skin
pain during sexual intercourse
rapid weight gain
reduced breast size
stopping of menstrual periods
swelling of the feet or lower legs
vaginal dryness
Less common or rare
For adults (female)
Breast pain
headache (mild and transient)
irritated or runny nose
mental depression (mild and transient)
For children (male)
Irritated or runny nose
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
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Pros and cons of Synarel (nafarelin)
Pros
- Can be easier to use since it's a nasal spray
- Can take the medication at home
Cons
- Commonly causes acne and mood changes
- Might take up to 1 to 2 months to work
Pharmacist tips for Synarel (nafarelin)
- It's important to follow the directions on how to use Synarel (nafarelin) correctly.
- Before starting a new bottle of Synarel (nafarelin), prime the spray pump. This makes sure that you get a full dose of medication when you're ready to use it. Spray quickly and firmly into the air until you see a fine mist of liquid that comes out.
- Clean the Synarel (nafarelin) spray tip before and after each use to prevent the tip from getting clogged. Wipe the tip with your finger or a soft cloth for 15 seconds under running warm water, and then dry the tip with a soft cloth or tissue.
- Try to avoid sneezing while you're spraying Synarel (nafarelin) into your nose or after using the medication. This prevents any medication from accidentally coming out of your nose.
- Wait at least 2 hours after spraying Synarel (nafarelin) to use any other nasal sprays. This makes sure each medication can get absorbed all the way.
How to use Synarel (nafarelin):
- Gently blow your nose to clear your nostrils. If your child is too young to blow their nose, you can use a bulb syringe to help clear your child's nose.
- Bend your head back a little, and place the spray tip into one nostril, making sure it doesn’t go too far into the nose. Aim the tip towards the back and outer side of the nose.
- Block the other nostril with a finger. Then sniff in gently as you push the plunger down quickly and firmly.
- Wait about 30 seconds before spraying into the same nostril again. Then repeat these steps in the other nostril for 2 sprays.
- Keep your head tilted back for a few seconds to let the medication cover the back of the nose.
More tips for using Synarel (nafarelin) for endometriosis:
- If you're following the typical dosing, one nasal spray device should last 30 days (60 sprays). Don’t use any leftover medication because it might not be enough for a full dose. Refill your prescription a few days before it runs out to make sure you don't miss any doses.
- It's important to use non-hormonal birth control, like condoms or Paragard (copper IUD), while you're taking Synarel (nafarelin). Having unprotected sex during treatment can possibly lead to an unplanned pregnancy, and taking this medication while pregnant can cause birth defects.
- Because Synarel (nafarelin) stops your body from releasing estrogen, you might experience symptoms of menopause, which normally happens later in life. Common symptoms include hot flashes, night sweats, and vaginal dryness. Let your provider know if these symptoms are too bothersome.
- If you have hot flashes, try cutting back on spicy foods, alcohol, and caffeine since these foods and drinks can make you feel worse. Keeping a fan nearby and your room cool can also help you feel more comfortable.
More tips for using Synarel (nafarelin) for early puberty:
- If your child is on the typical dosing, one bottle should last about 7 days (about 56 sprays). Don’t use any medication left over in the bottle after 7 days. This leftover amount might not be enough for a full dose, which could make the medication not work as well. Plan to refill your child's prescription a few days before the medication runs out.
- You might continue to see signs of puberty in your child, like vaginal bleeding or breast enlargement, during the first month of treatment as the medication takes time to work. This is normal and should go away within 2 months. If these signs don't improve or disappear after 2 months, let your your child's pediatrician know.
Common questions about Synarel (nafarelin)
It's not completely clear how long it takes Synarel (nafarelin) to start working for endometriosis. A small study showed that people who took Synarel (nafarelin) had some improvements in menstrual pain, pelvic pain, pelvic tenderness, and pain during sex by month 3 of treatment. Another study showed that 60% of women who took Synarel (nafarelin) were symptom-free, 32% had mild symptoms, and 8% had moderate-to-severe symptoms by the end of 6-month treatment. Since it might take some time to feel improvement, be sure to continue taking the medication as directed by your prescriber.
Typically, your monthly menstrual periods eventually stop while you're taking Synarel (nafarelin). You might stop having periods after 2 months of regular use, but it takes time to work. During the first 2 months, you might still have your normal period, breakthrough bleeding, or spotting. Missing doses can also cause breakthrough bleeding. Let your prescriber know if you're still having periods after 2 months of taking Synarel (nafarelin) regularly. They might adjust your dose. Menstrual periods typically come back within 2 to 3 months of stopping the medication.
It's best to limit how much alcohol you drink while you're taking Synarel (nafarelin). Alcohol might worsen hot flashes, which is a common side effect of the medication. In addition, drinking too much alcohol while you're taking Synarel (nafarelin) can put you at higher risk for bone loss. Speak with your prescriber if you have additional questions.
Depending on the situation, some reproductive endocrinologists follow protocols that use GnRH agonists like Synarel (nafarelin) off-label to help with in vitro fertilization (IVF). GnRH agonists can sometimes be used to help trigger final egg maturation before egg retrieval. GnRH agonists cause a rapid rise in sex hormone levels at first, which causes eggs to mature. It's thought that using GnRH agonists also helps to lowers the risk for ovarian hyperstimulation syndrome (OHSS), a rare but serious complication of IVF. Talk to your reproductive endocrinologist to see if Synarel (nafarelin) is the right option for you for IVF.
Some studies suggest that Synarel (nafarelin) can help lessen bleeding, improve menstrual pain and pelvic discomfort, and shrink the size of fibroids. Keep in mind that this is considered an "off-label" use of Synarel (nafarelin) because it's not FDA approved for this particular purpose. Ask your prescriber about whether Synarel (nafarelin) is right for you if you have fibroids.
You might still notice some signs of puberty in your child during the first month of treatment with Synarel (nafarelin), such as vaginal bleeding or breast enlargement. This is normal and should go away within 2 months. Missing doses might also cause breakthrough bleeding. If these signs don't improve after 2 months, contact your child's pediatrician. They might recommend blood tests to check hormone levels during the first 6 to 8 weeks and regular visits to monitor growth.
Puberty should restart in your child after they stop taking Synarel (nafarelin). Your child will start to experience monthly menstrual periods, breast and other genital development, and pubic hair growth again within 1 year after stopping Synarel (nafarelin).
Your child can take Synarel (nafarelin) until you or your child wishes for puberty to continue.
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Risks and warnings for Synarel (nafarelin)
Synarel (nafarelin) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Unplanned pregnancy and risk for birth defects (endometriosis)
Accidental or unplanned pregnancies can happen if you have unprotected sex while you're taking Synarel (nafarelin), even though the medication typically blocks ovulation from happening. Your body might accidentally release an egg (ovulate) during treatment, especially if you miss doses of Synarel (nafarelin) one right after another. And because you might not get your menstrual period every month, you might not know if you do get pregnant.
Because the medication can cause birth defects if used during pregnancy, it's important to use birth control while you're taking Synarel (nafarelin). Use non-hormonal birth control, such as diaphragms, condoms, or Paragard (copper IUD), to prevent unplanned pregnancy. Hormonal birth control methods (e.g., pill, patch, vaginal ring) might not work well, since Synarel (nafarelin) affects your hormone levels. Let your prescriber know right away if you think there's a possibility you might be pregnant while you're taking this medication.
Ovarian cysts (endometriosis)
- Risk factors: History of polycystic ovarian syndrome (PCOS)
Some people have developed ovarian cysts during the first 2 months of using Synarel (nafarelin). Your risk of getting ovarian cysts is higher if you also have polycystic ovarian syndrome (PCOS). Symptoms of an ovarian cyst can include pelvic pain, pain during sex, and bloating. The cysts generally go away on their own after about 4 to 6 weeks. But tell your healthcare provider if these symptoms become bothersome or if they don't go away. Get medical help right away if you feel any severe cramps or pelvic pain.
Loss of bone density (endometriosis)
- Risk factors: Using Synarel (nafarelin) for more than 6 months | Long-term alcohol or tobacco use | Family history of osteoporosis | Taking other medications that cause bone thinning
Synarel (nafarelin) lowers your estrogen levels. This can cause a very small amount of bone loss during treatment. Let your prescriber know about your medical history and the medications you take so they can check your risk for bone loss. In addition, the risk of bone loss isn't known beyond 6 months of regular use. It's recommended that Synarel (nafarelin) should only be used for at most 6 months during your entire lifetime to be safe and to lower your risk of bone loss.
Depression (endometriosis)
- Risk factors: History of depression
It's possible that GnRH agonists like Synarel (nafarelin) can cause new or worsening depression. Tell your healthcare provider if you have a history of depression so they know to follow up with you about your mental health. Let your prescriber know if you or a loved one notices any signs or symptoms of depression, such as feeling sad or hopeless, having trouble concentrating, or having trouble sleeping.
Seizures (early puberty)
- Risk factors: History of seizures | History of stroke | History of central nervous system tumors | Taking medications that can cause seizures
Some children have had seizures while taking GnRH agonists like Synarel (nafarelin). People who've had seizures in the past or people who are taking medications that can cause seizures, such as bupropion (Wellbutrin) and sertraline (Zoloft), are at a higher risk for seizures with this medication. Let your child's pediatrician know if they've had a seizure in the past before they start Synarel (nafarelin).
Mood changes (early puberty)
- Risk factors: History of mental health conditions | History of health conditions that raise the risk of depression
GnRH agonists like Synarel (nafarelin) can cause mood changes in children. These behaviors can include crying, irritability, impatience, anger, and aggression. Children taking GnRH agonists for early puberty can also develop depression, rarely with suicidal thoughts and behavior. Children with a history of mental health conditions or other conditions that raise the risk of depression are more likely to experience depression while taking Synarel (nafarelin). Let your child's pediatrician know if you notice new or worsening changes in mood in your child.
High blood pressure in the skill (early puberty)
Children who have taken GnRH agonists like Synarel (nafarelin) have experienced high blood pressure in the skull, or pseudotumor cerebri (idiopathic intracranial hypertension). Contact your child's pediatrician if they start to have headache, vision changes, eye pain, ringing in the ears, dizziness, and nausea.
Synarel (nafarelin) dosage
Nasal spray| Dosage | Quantity | Price as low as | Price per unit |
|---|---|---|---|
| 8ml of 2mg/ml | 1 nasal spray | $3,085.26 | $3,085.26 |
Typical dosage for Synarel (nafarelin)
Endometriosis:
- The typical dose is 1 spray into one nostril in the morning and 1 spray into the other nostril in the evening, separated by about 12 hours. If needed, your provider might raise your dose to 1 spray into each nostril in the morning and evening (a total of 4 sprays per day).
- You typically start treatment with Synarel (nafarelin) between days 2 and 4 of your menstrual cycle. The recommended length of treatment is 6 months.
Early puberty:
- The typical dosing is 2 sprays into each nostril in the morning and 2 sprays into each nostril in the evening (total of 8 sprays each day).
- If needed, your child's provider might raise the dose to 3 sprays of Synarel (nafarelin) three times a day, alternating between nostrils each time you spray the medication into your child's nose (total of 9 sprays each day).
Interactions between Synarel (nafarelin) and other drugs
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
- Bepridil
- Cisapride
- Dronedarone
- Mesoridazine
- Pimozide
- Piperaquine
- Saquinavir
- Sparfloxacin
- Terfenadine
- Thioridazine
- Ziprasidone
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Alfuzosin
- Amiodarone
- Amisulpride
- Amitriptyline
- Anagrelide
- Apomorphine
- Aripiprazole
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Asenapine
- Astemizole
- Atazanavir
- Azithromycin
- Bedaquiline
- Buprenorphine
- Ceritinib
- Chloroquine
- Chlorpromazine
- Ciprofloxacin
- Citalopram
- Clarithromycin
- Clofazimine
- Clomipramine
- Clozapine
- Crizotinib
- Cyclobenzaprine
- Dabrafenib
- Dasatinib
- Delamanid
- Desipramine
- Deutetrabenazine
- Disopyramide
- Dofetilide
- Dolasetron
- Domperidone
- Donepezil
- Doxepin
- Droperidol
- Ebastine
- Efavirenz
- Encorafenib
- Entrectinib
- Eribulin
- Erythromycin
- Escitalopram
- Famotidine
- Felbamate
- Fingolimod
- Flecainide
- Fluconazole
- Fluoxetine
- Formoterol
- Foscarnet
- Fosphenytoin
- Fostemsavir
- Galantamine
- Gatifloxacin
- Gemifloxacin
- Glasdegib
- Granisetron
- Halofantrine
- Haloperidol
- Hydroquinidine
- Hydroxychloroquine
- Hydroxyzine
- Ibutilide
- Iloperidone
- Imipramine
- Inotuzumab Ozogamicin
- Itraconazole
- Ivabradine
- Ivosidenib
- Ketoconazole
- Lapatinib
- Lefamulin
- Lenvatinib
- Leuprolide
- Levofloxacin
- Lofexidine
- Lumefantrine
- Macimorelin
- Mefloquine
- Methadone
- Metronidazole
- Mifepristone
- Mirtazapine
- Mizolastine
- Moxifloxacin
- Nelfinavir
- Nilotinib
- Norfloxacin
- Octreotide
- Ofloxacin
- Olanzapine
- Ondansetron
- Osilodrostat
- Osimertinib
- Oxaliplatin
- Ozanimod
- Paliperidone
- Panobinostat
- Paroxetine
- Pasireotide
- Pazopanib
- Pentamidine
- Perphenazine
- Pimavanserin
- Pipamperone
- Pitolisant
- Ponesimod
- Posaconazole
- Probucol
- Procainamide
- Prochlorperazine
- Promethazine
- Propafenone
- Protriptyline
- Quetiapine
- Quinidine
- Quinine
- Ranolazine
- Ribociclib
- Rilpivirine
- Risperidone
- Ritonavir
- Selpercatinib
- Sertindole
- Sertraline
- Sevoflurane
- Siponimod
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
- Solifenacin
- Sorafenib
- Sotalol
- Sulpiride
- Sunitinib
- Tacrolimus
- Tamoxifen
- Telaprevir
- Telavancin
- Telithromycin
- Tetrabenazine
- Tolterodine
- Toremifene
- Trazodone
- Triclabendazole
- Trimipramine
- Vandetanib
- Vardenafil
- Vemurafenib
- Venlafaxine
- Vilanterol
- Vinflunine
- Voclosporin
- Voriconazole
- Vorinostat
- Zuclopenthixol
How much does Synarel (nafarelin) cost?
$3,085.26
Synarel (nafarelin) contraindications
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Synarel (nafarelin) will not be safe for you to take.
- Abnormal vaginal bleeding
- Currently pregnant
- Currently breastfeeding
- Allergy to other GnRH agonists
What are alternatives to Synarel (nafarelin)?
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