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Drugs List

  • nafarelin 200microgram nasal spray
  • SYNAREL 200microgram nasal spray
  • Dosage

    Nafarelin nasal spray pump delivers 200 micrograms of nafarelin base per spray


    Start treatment between days 2 and 4 of the menstrual cycle.
    200micrograms (1 spray) into one nostril in the morning and 200 micrograms(1 spray) into the other nostril in the evening.
    Maximum dose 400 micrograms per day.
    Duration of therapy should not exceed 6 months.
    Only one 6 month course of therapy is advised.

    Ovarian stimulation before in vitro fertilisation
    Begin treatment either in the early follicular phase (day 2) or the mid-luteal phase (usually day 21).
    Employ the long protocol, whereby nafarelin is continued through a period of transient gonadotropin stimulation lasting 10 - 15 days (the flare effect) through to pituitary desensitisation (down regulation).
    Down regulation is considered to be serum estradiol less than or equal to 50pg/ml and serum progesterone less than or equal to 1ng/ml, majority of patients down regulate within 4 weeks.

    Recommended dose of 400 micrograms twice daily as one spray into each nostril in the morning and evening.
    Maximum dose 800 micrograms per day.
    Once down regulation is achieved, controlled stimulation with gonadotrophins e.g. Human Menopausal Gonadotrophin (HMG) is commenced and the nafarelin dosage maintained until the administration of Human Chorionic Gonadotrophin (HCG) at follicular maturity (usually a further 8 to 12 days)
    If down regulation is not achieved within 12 weeks of therapy, discontinue and cancel the cycle.

    Treatment should have ceased at least 3 days before fertilised embryos are placed in the uterine cavity.


    Not applicable


    Children under 18 years - contraindicated as no information available.

    Additional Dosage Information

    If the use of a nasal decongestant is required at the time of nafarelin administration, administer 30 minutes after nafarelin dose.


    Children under 18 years
    Undiagnosed gynaecological bleeding
    Pregnancy - exclude pregnancy before use - see Pregnancy section

    Precautions and Warnings

    Metabolic bone disease.

    A small loss of trabecula bone mineral content occurs during 6 months of treatment. Although this is mainly reversible within 6 months of stopping treatment, there are no data on the effect of repeat courses on bone loss. Retreatment or use for longer than 6 months is therefore contraindicated.

    Bone mineral density should be assessed before retreatment after a course of therapy if further treatment of endometriosis and fibroids is contemplated.

    Exclude pregnancy prior to commencing treatment and advise patients to use non-hormonal barrier methods of contraception.

    Nafarelin inhibits ovulation, however breakthrough ovulation and a potential for conception may occur if doses are missed. Discontinue if pregnancy occurs and inform patient of potential risk to foetal development.

    Nafarelin treatment must be stopped at least 3 days before fertilised embryos are placed in the uterine cavity.

    There is an increased risk of incident depression, which may be severe. Patients should be informed accordingly and treated as appropriate if required.

    Ovarian cysts have been reported to occur in the first two months of therapy with nafarelin; many of these events have occurred in patients with polycystic ovarian disease. These cyst enlargements may resolve spontaneously, generally by about four to six weeks of therapy, but occasionally require discontinuation of the drug and/or surgical intervention.

    In controlled ovarian stimulation prior to in vitro fertilisation, transient ovarian cyst formation is a recognised complication of GnRH agonist use. These cysts tend to progress spontaneously over a number of weeks and are more common when GnRH agonists are commenced in the follicular phase of the cycle.

    Use with caution in patients with polycystic ovarian syndrome as they are greater risk of excessive follicular recruitment when undergoing ovulation induction regimes.

    Suppression of the pituitary-gonadal system occurs with administration of nafarelin. Normal function is usually restored within 8 weeks after discontinuation. Diagnostic tests of pituitary gonadal function conducted during treatment and up to 8 weeks after discontinuation of therapy may be misleading.

    Sneezing during or immediately after dosing may impair absorption of nafarelin. If sneezing occurs upon administration, repeating the dose, may be advisable.

    If the use of a nasal decongestant is required at the time of nafarelin administration, administer 30 minutes after nafarelin dose.

    Contains benzalkonium chloride which may cause contractions of the respiratory passage. It may cause oedema in the nasal mucosa, especially on long term use.

    Pregnancy and Lactation


    Contraindicated as the safety in human pregnancy has not been established. Exclude pregnancy before commencing treatment.
    Should pregnancy occur, therapy should be discontinued and the woman informed of the potential risk to foetal development.
    Non hormonal barrier methods of contraception should be employed during therapy.

    Animal studies in rats have shown dose related foetal mortality and a decrease in foetal weight when administered intramuscularly. These effects on rat foetal mortality are logical consequences of the alterations in hormonal levels brought about by nafarelin in this species.
    Use of nafarelin in human pregnancy has not been studied.

    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14-17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Contraindicated as it is not known whether or to what extent nafarelin is secreted in the breast milk.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at


    Advise women of the need for non-hormonal barrier contraception during treatment.

    Advise patients to administer other nasal preparations at least 30 minutes after nafarelin dose.

    Advise patients to repeat dose if sneezing occurs during or immediately after dosing.

    Advise patients to report new or worsening symptoms of depression to their doctor.

    Side Effects

    Hypersensitivity reactions
    Chest pain
    Hot flushes
    Changes in libido
    Vaginal dryness
    Emotional lability
    Changes in breast size
    Irritation of nasal mucosa
    Ovarian cysts
    Decrease in trabecular bone density
    Increases in serum transaminases (reversible)
    Increase in serum alkaline phosphatase (reversible)
    Blurred vision
    Weight gain
    Weight loss
    Menopausal-like symptoms
    Uterine haemorrhage
    Oestrogen deficiency


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: December 2012

    Reference Sources

    British National Formulary, 64th Edition (2012) Pharmaceutical Press, London.

    Summary of Product Characteristics: Synarel Nasal Spray. Pharmacia Ltd. Revised July 2012.

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    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

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    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.