Renal dosing is not required of any of three agents discussed
Aromatase inhibitors are used as adjuvant therapy in estrogen receptor positive
postmenopausal breast cancer patients.
They are added to the plan after 3 to 5 years of tamoxifen therapy and
continued for at least 5 years.
They are also used as first-line treatment in cases of advanced or
There are unlabeled uses for ovarian cancer and to stimulate
ovulation in anovulatory women done within specialty care
The aromatase inhibitors are oral agents taken once daily.
Anastrazole is given as a 1 mg tablet, exemestane is a 25 mg tablet, and
letrozole comes in a 2.5 mg dose.
There is no increasing in dosage over time.
All forms of these medications are considered hazardous agents that require
special handling and disposal.
All are contradindicated in pregnancy and breast feeding
Adverse Drug Reactions
Adverse effects for the drug class include various pain syndromes, vertigo,
insomnia resulting in daytime sleepiness and confusion, increased risk of blood
clots, and hair loss.
A key concern is the loss of bone mass.
Bone loss can be significant when considering the concurrent
osteoporotic risks of postmenopause
All patients should be on calcium and vitamin D
Hypertension occurs in 10% of patients.
A life-threatening increase in blood clotting can result in MI, stroke, or
Hot flashes can be intense
Drug interactions vary by agent, but none should be taken with tamoxifen or an
Anastrazole cannot be taken with pimozide.
Both anastrazole and letrazole will decrease the effect of digoxin and vitamin K
Exemestane should not be taken with axtinib or simeprevir.
It will decrease the effect of aripiprazole and saxagliptin and increase the
effect of methadone and vitamin K antagonists.
Letrozole cannot be taken with tegafur
Education and Lifestyle Management
Patient education follows the standards for how to take the medication, when to
report adverse effects, and the need for close monitoring of LFT labs
Patients should be encouraged to discuss issues of pain and fatigue with the
provider prior to just stopping the medications.