Femara (Letrozole) Dosage and Side Effects
FEMARA is used to treat breast cancer in its advanced stages, and in women who have finished menopause.
Proper Use of this medication
The usual dosage is one tablet of FEMARA to be taken once daily. The tablet should be swallowed whole with a small glass of water. You can take FEMARA with or without food. It is best to take FEMARA at about the same time every day.
If overdosage is known or suspected, contact your doctor or the nearest poison control centre for advice immediately. Show the pack of tablets. Medical treatment may be necessary.
If you forget to take a dose of FEMARA, don't worry, take the missed dose as soon as you remember. However, if it is almost time for the next dose (e.g. within 2 or 3 hours), skip the missed dose and go back to your regular dosage schedule. Do not take a double dose to make up for the one that you missed.
As with all medicines, patients taking FEMARA may experience side effects. Most side effects that have been observed were mild to moderate and will generally disappear after a few days to a few weeks of treatment. Check with your doctor if the unwanted effects do not go away during treatment or become bothersome.
Some side effects, such as hot flashes, hair loss or vaginal bleeding may be due to the lack of estrogen in your body.
Very common side effects (they affect more than 10 in every 100 patients):
- increased level of cholesterol (hypercholesterolemia)
- hot flushes
- increased sweating
- night sweat
- fatigue (including weakness and malaise (generally feeling unwell)
- pain in bones and joints (arthralgia).
Common side effects (they affect between 1 to 10 in every 100 patients):
- gastrointestinal disorders (such as, nausea, vomiting, indigestion, constipation, diarrhea)
- increase in or loss of appetite
- increased blood sugar (hyperglycaemia)
- urinary incontinence
- pain in muscles
- bone loss (osteoporosis)
- bone fractures
- weight increase
- hair loss
- vaginal bleeding
- dry skin
- raised blood pressure (hypertension)
- abdominal pain.
Uncommon side effects (they affect between 1 to 10 in every 1000 patients):
- nervous disorders (such as nervousness, irritability, drowsiness)
- pain or burning sensation in the hands or wrists (carpal tunnel syndrome)
- reduced sense of touch (dysaesthesia)
- eye irritation
- palpitations, rapid heart rate
- itchy rash (urticaria), rapid swelling of face, lips, tongue, throat (angioedema)
- severe allergic reaction (anaphylactic reaction)
- vaginal disorders (such as discharge or dryness)
- joint stiffness (arthritis)
- breast pain
- thirst, taste disorder, dry mouth
- dryness of mucous membranes
- weight decrease
- urinary tract infection, increased frequency of urination
- abnormal liver function test results (blood test disorders).
Side effects with frequency not known:
- trigger finger, a condition in which your finger or thumb catches in a bent position.
If any of these affects you severely, tell your doctor.
Warnings and Precautions
Serious Warnings and Precautions
FEMARA should be used under the supervision of a doctor experienced in the use of anti-cancer drugs.
FEMARA reduces blood estrogen levels which may cause a reduction in bone mineral density and a potential increase in bone loss (osteoporosis) and/or bone fractures.
The use of aromatase inhibitors, including FEMARA, may increase the risk of cardiovascular events compared to tamoxifen, such as heart attacks and stroke. Women at risk of heart disease should be carefully monitored by their doctor.
You should not use FEMARA if you may become pregnant, are pregnant and/or breastfeeding. There is a potential risk of harm to you and the fetus, including risk of fetal malformations. If you have the potential to become pregnant (this includes women who are perimenopausal or who recently became postmenopausal), you should discuss with your doctor about the need for effective contraception.
If there is exposure to FEMARA during pregnancy, you should contact your doctor immediately to discuss the potential of harm to your fetus and potential risk for loss of the pregnancy.
FEMARA should not be used in children and adolescents under 18 years of age.
Before you take FEMARA:
Tell your doctor if you:
- have a serious kidney or serious liver disease;
- are taking hormone replacement therapy;
- are taking other medication to treat your cancer;
- have a personal or family history of osteoporosis or have ever been diagnosed with low bone density or have a recent history of fractures (in order for your doctor to assess your bone health on a regular basis);
- have a personal or family history of high blood cholesterol or lipid levels. FEMARA may increase lipid levels;
- have or have had cardiovascular or heart disease including any of the following: heart attack, stroke or uncontrolled blood pressure. FEMARA may increase the risk of cardiovascular or heart diseases;
- have an intolerance to milk sugar (lactose);
- have pain in bones, or joints or muscles.
Your level of hormones may be checked by your doctor before you take FEMARA and regularly during the first 6 months of treatment to confirm your menopausal status (cessation of periods).
Driving a vehicle or using machinery:
FEMARA tablets are unlikely to affect your ability to drive a car or to use machinery. However, some patients may occasionally feel tired, dizzy, sleepy or experience visual disorders. If this happens, you should not drive or operate any tools or machinery until you feel normal again.
Interactions with this medication
Please tell your doctor or pharmacist if you are taking or have recently taken any other prescription or over-the-counter medicines, vitamins or natural health products during your treatment with FEMARA. This includes in particular:
- Other anti-estrogens or estrogen-containing therapies.
These substances may diminish the action of FEMARA.
Other related products
Other related products
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.