Categories: Drugs

Femara (Letrozole): Uses, Side Effects, Dosage & FAQs

Femara (Generic: Letrozole) belongs to a group of drugs known as an aromatase inhibitor. It used in the treatment of Breast Cancer in postmenopausal women.

Originally manufactured by Novartis, Femara was approved in 1997 by the Food and Drug Administration (FDA).

Femara Uses

  • It is used in estrogen receptor-positive early breast cancer in postmenopausal women.
  • Used in Early invasive breast cancer in postmenopausal ladies when five years of tamoxifen therapy have failed to work.
  • Advanced breast cancer in postmenopausal women.
  • It is additionally employed in pre-operative treatment in postmenopausal women with localized hormone receptor-positive breast cancer.
  • Commonly used in unexplained infertility. (off-lable use)
  • It is used to stimulate ovulation in women with polycystic ovary syndrome (PCOS).

Note: Your doctor may have suggested this medication for conditions other than those listed in this medication guide.

Contraindications

It is contraindicated in the following conditions:

  • Premenopausal women
  • Liver disease (especially cirrhosis)
  • Contraindicated in individuals best-known hypersensitivity to the active substance, or to any of the excipients.
  • Osteoporosis,
  • Osteopenia (low bone mineral density),
  • High cholesterol; or
  • if you also take tamoxifen.
  • The use of Femara might cause decreases in the density of your bones, will increase in bone fractures and osteoporosis.
  • Avoid if you are under 18 years of age

Precautions

Before Taking this drug,

  • Tell your doctor or pharmacist if you are allergic to Femara or any other ingredients in this medication.
  • Tell your GP if you have high cholesterol, liver disease, and osteoporosis.
  • Tell your doctor about your current as well as past medical history. Tell him your other prescriptions, and non-prescription drugs, nutritional supplement, you are taking.
  • Tell Your Doctor if you are pregnant or planning to become pregnant before starting Femara.
  • Don’t take Femara if you are still having periods. This drug is only used in women who are no longer having periods.
  • Always check the expiry date and Don’t take it after the Expiry date printed on the packing.

Mechanism Of Action

Letrozole is a Selective nonsteroidal inhibitor of the aromatase enzyme system; it inhibits the conversion of androgens to estrogens.

In adult nontumor- and tumor-bearing female, letrozole is as effective as ovariectomy in reducing uterine weight. It also causes elevating blood serum luteinizing hormone and inflicting the regression of estrogen-dependent tumors. In distinction to ovariectomy, treatment with letrozole doesn’t cause a rise in serum follicle-stimulating hormone.

Letrozole selectively inhibits gonadal steroidogenesis, however, has no important effect on adrenal mineralocorticoid or glucocorticoid synthesis.

Letrozole inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme. This inhibition leads to a reduction of estrogen synthesis in all tissues.

Treatment of women with letrozole significantly lowers blood serum estrone, estradiol and estrone sulfate. It has not been shown to significantly have an effect on adrenal corticosteroid synthesis, aldosterone synthesis, or synthesis of thyroid hormones.

Pharmacokinetics

Letrozole (Femara Tablet) is quickly absorbed with 100% bioavailability. It has Slow metabolism, the large volume of Distribution, and Time half (t½) of approximately 40 hours.

Drug Interactions

If you take other medicines or over the counter medicines at the same time, the effects of Femara Tablet may change. This may increase the risk of side effects or make your medications not work properly. Tell your doctor about all the medicines, supplements, herbal remedies, and vitamins you use. Femara can interact with the following medications:

  • Don’t Take letrozole if you are already taking tamoxifen.
  • While an interaction study with warfarin showed no clinically important effect of letrozole on warfarin pharmacokinetics.
  • Cimetidine showed no clinically important effect on letrozole pharmacokinetics.
  • Femara may also interact with Estrogens (Conjugated estrogens and ethinyl estradiol).
  • Avoid eating grapefruit and drinking grapefruit juice while taking letrozole because it slows down the break down of letrozole. This could cause letrozole levels in the blood to rise dangerously high.
  • Alcohol or marijuana can make you dizzier. Limit alcohol while taking Femara.
  • It may also interact with Citalopram, Thalidomide, and Clopidogrel.
  • It may also Interact with Birth Control pills.
  • According to a study published in the Journal, Cell Chemical Biology suggests that exposure to Estrogen mimicking compound could significantly reduce the effectiveness of anti-estrogen therapies like Letrozole and palbociclib combination.

Femara Side Effects

It is very useful for the treatment and improvement of above-mentioned conditions, but there are certain side effects of Femara. Like any other medicine, Femara can cause some side effects along with its beneficial effects. It is important to know the side effects before taking.

Most people do not feel all the side effects of Femara. Side effects are often predictable in terms of appearance and duration. The side effects from Femara are almost always reversible and disappear once treatment is complete. The following is a list of possible side-effects that may occur from Femara Tablet.

Most common Femara Side effects

The most common side effects from Femara Tablet Include:

  • Nausea,
  • Vomiting,
  • Hot flushes,
  • Dyspepsia,
  • Dizziness,
  • Headache,
  • Diarrhea,
  • Constipation,
  • Anorexia,
  • Depression,
  • Hypercholesteremia,
  • Raised sweating,
  • Alopecia,
  • Increased craving,
  • Peripheral edema,
  • Skin rashes,
  • Bone fracture,
  • Osteoporosis etc.

Less Common Side Effects

Less common Side effects from Femara Tablet include

  • Tachycardia,
  • High blood pressure,
  • Palpitation,
  • Cough,
  • Dyspnea,
  • Anxiety,
  • Insomnia,
  • Memory impairment,
  • Taste disturbance,
  • Urticaria,
  • Pruritis,
  • Dry skin,
  • Urinary frequency,
  • Abdominal pain,
  • Thrombophlebitis,
  • Urinary tract infection,
  • Viginal discharge,
  • Vigina bleeding,
  • Pyrexia,
  • Breast pain,
  • Cataract,
  • Blurred vision,
  • Eye irritation,
  • Leucopenia,
  • Carpal tunnel syndrome,
  • Arthritis,
  • Tumor pain, and
  • General edema.

Rare Femara side effects

Very rare side effect from Femara Tablet includes:

  • Arterial thrombosis,
  • Cerebrovascular infarction, and
  • Embolism.

Note: This is not a complete list of Femara side effects. Stop using This drug and Consult your doctors if You experience the above effects or other serious side effects from Femara Tablet.

Femara In Pregnancy & Breast Feeding

  • Letrozole should be avoided in pregnant women because it causes birth defects in a child. Manufacturer recommendation the use of contraceptives until postmenopausal status totally established.
  • While just in the case of lactating women it’s unknown if letrozole is present in human milk. There isn’t any information on the effects of letrozole on the breastfed infant or milk production.

Femara Dosage

  • The standard recommended dose of Letrozole for all type of breast cancer treatment is 2.5 mg per day.
  • Duration of therapy is usually 5 years but some doctors may recommend it for a longer period of time.
  • You can take without regard to meals.
  • If you believe that you have taken an overdose, contact an emergency room or poison center.
  • If you miss a dose of letrozole, try to take it as soon as you remember.
  • However, if it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule.
  • Do not take extra doses to make up for lost ones.

Frequently Asked Questions

Q. 1 What is Femara?

It is a selective nonsteroidal inhibitor of the aromatase enzyme system; it inhibits the conversion of androgens to estrogen. It is used in breast cancer and infertility.

Q.2 Is it safe to use Femara Tablet during pregnancy & Breast Feeding?

No, the use of this drug is not recommended in pregnant and breastfeeding women.

Q.3 Is Femara a Chemotherapy?

No, Femara belongs to hormonal therapy drugs. Hormonal therapies require the presence of specific receptors (binding sites) in the cancer cell for estrogen and/or progesterone. Most hormonal therapies are drugs taken daily in the form of tablets. Breast cancer that has neither estrogen nor progesterone receptors does not respond to hormone therapy.

Q.4 Can I stop immediately or can I slow down my consumption?

Some medications should be immediately reduced or stopped due to rebound effects. Consult your doctor for specific recommendations for your body, health and other medicines that you may use.

Q.5 Is it safe to drive or use heavy machinery when used?

You should not drive if you feel drowsy, dizzy or low blood pressure by taking the Femara Tablets. Pharmacists also recommend patients that they do not drink alcohol with medication as alcohol increases the side effects of drowsiness. Please check these effects on your body when using Femara Tablet. Always consult your doctor for special recommendations on body and health.

Q.6 Is Femara cause addiction or adaptation?

Most medicines have no abuse. Do not medicate yourself and increase the body’s dependence on medication without the advice of a doctor.

Q.7 Can you drink while on letrozole (Femara)?

Letrozole and alcohol can both cause headaches and nausea. These side effects may worsen if you take both drugs at the same time. If possible, try to avoid or restrict alcohol consumption while taking letrozole. Always Consult your Doctor before using this drug with Other.

Q.8 Does Femara increase the chances of getting pregnant?

With this drug, a woman’s pregnancy chances increase by about 15% per month. Ovulation was successful in women who did not ovulate naturally. The combined use of Femara with other drugs significantly increases a woman’s chance of pregnancy.

Q.9 Does it cause hair loss?

Some women who take letrozole and other such drugs can experience hair loss due to the estrogenic effects of these treatments. However, these treatments are unlikely to result in complete hair loss.

Q.10 Can Femara cause multiple births?

According to the Center for disease control & Prevention, Fertility treatments of all types can increase the chances of multiple births.

Another study published in the New England Journal Of Medicine, The percentage of multiple pregnancies are more in case of Letrozole as compared to clomiphene.

Q.11 Can Femara cause birth defects?

If taken during pregnancy, Femara can cause birth defects. However, when taken to cause ovulation, Femara appears to be safe.

Q. 12 How much does Femara cost?

The price of a 2.5 mg Femara tablet is approximately $ 750 for a 30 tablets strip. This Femara cost is for cash paying customers only and are not valid with insurance plans. The latest version of Femara is covered by 73% of the insurance plans with a share of 60 to 80$. However, some pharmacy vouchers or cash prizes may be lower.

Q. 13 Do Femara side effects go away?

Side effects from Femara are 1% in the majority of the patients and These side-effects are reversible. some side effects may go away on their own over time. Contact your physician.

Q. 14 How long should I stay on letrozole?

Suggested hormonal therapy is 10 years.  First 5 years tamoxifen and then next 5 years Femara. But it’s better you consult your healthcare provider about how long you can expect to take it for.

Q. 15 When should I take Femara?

The usual recommended dose for fertility purpose is 2.5 mg every day for 5-7 days. The ideal time to begin is on the third or fourth day of the cycle.

The usual recommended dose of Letrozole for all type of breast cancer treatment is 2.5 mg per day. You can take it without regard to meals. Duration of therapy is usually 5 years but some doctors may recommend it for a longer period of time.

Q. 16 What are the benefits of taking letrozole?

It inhibits the conversion of androgens to estrogen. That’s why Femara is used in estrogen receptor-positive early breast cancer in postmenopausal women, and other types of breast cancer. It improves the chance of survival as it helps to lower your risk of breast cancer recurrence.

It is also used in the treatment of infertility.

Q. 17 Does letrozole cause bone pain?

The use of Femara can drop your estrogen levels which ultimately can cause pain in the joint and muscle.

Q. 18 How does Femara work?

Femara inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme. This inhibition leads to a reduction of estrogen synthesis in all tissues.

When taking the medicine, it prevents the androgens in your body from converting into estrogen. When estrogen is blocked, the pituitary gland receives the required message for the production of follicle stimulating hormone (FSH), which stimulates the production of an ovary egg.

Treatment of women with this medicine significantly lowers blood serum estrone, estradiol and estrone sulfate.  It has not been shown to significantly have an effect on adrenal corticosteroid synthesis, aldosterone synthesis, or synthesis of thyroid hormones.

Q. 19 How to take Femara to get pregnant?

Letrozole is usually taken once daily for five days. If you started treatment on day 3, you are probably ovulating once between day 14 and day 17 of your cycle. To think, you will start having sex before ovulating. If you started the treatment on the fifth day, you will probably ovulate between the 16th and 19th days.

Q.  20 How do you take Femara for infertility?

Take two pills daily, starting on Cycle Day 3 and ending on Cycle Day 7.

You can take the two tablets together, but you have to take it for five consistent days. You can take it any time of day.

Note: The first day of menses is Cycle Day 1.

Q.21 Are Femara and letrozole the same?

It is the brand name of Letrozole manufactured by Novartis Pharmaceutical company. They both are the same thing but Femara is brand and Letrozole is Generic.

Q. 22 What is the generic for Femara?

Generic of Femara is Letrozole which is a non-steroidal aromatase inhibitor. It is used to treat breast cancer in postmenopausal women.

Please Feel free to ask any question related to this topic in the comments section.

View Comments

  • Thank you. This is very comprehensive

  • My name is amjid by preofession I am pharmacist at oncology setup....thats very helpfull

  • I recommend all my friends and fellows to follow this blog.This is such an amazing place to learn new things!! Keep sharing

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