Aromasin


exemestane

Aromasin

Pharmacologic class: Aromatase inhibitor

Therapeutic class: Hormonal antineoplastic

Pregnancy risk category D

Action

Inhibits conversion of androgens to estrogen, which reduces estrogen concentrations and limits cancer cell growth in estrogen-dependent breast tumors

Availability

Tablets: 25 mg

Indications and dosages

Advanced breast cancer

Adults: 25 mg P.O. once daily after a meal

Contraindications

• Hypersensitivity to drug or its components

• Premenopausal women, including pregnant women

Precautions

Use cautiously in:

• moderate to severe hepatic insufficiency or renal impairment

• concurrent use of estrogencontaining drugs

• breastfeeding patients

• children (safety and efficacy not established).

Administration

• Administer after meals with a full glass of water.

• Know that drug shouldn't be taken by premenopausal women or by patients receiving drugs that contain estrogen.

Adverse reactions

CNS: headache, dizziness, confusion, asthenia, fatigue, weakness, hypoesthesia, paresthesia, pain, anxiety, insomnia, depression

CV: hypertension, chest pain

EENT: sinusitis

GI: nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, anorexia

GU: urinary tract infection

Musculoskeletal: pathologic fractures, arthritis, back pain, skeletal pain

Respiratory: dyspnea, cough, bronchitis, upper respiratory tract infection

Skin: rash, itching, alopecia, diaphoresis

Other: increased appetite, fever, hot flashes, infection, flulike symptoms, edema, lymphedema

Interactions

Drug-drug. CYP3A4 inducers: decreased exemestane blood level

Patient monitoring

• Monitor vital signs, especially blood pressure.

• Check for adverse GI reactions. Give antiemetics, as prescribed, for nausea and vomiting.

• Assess bowel elimination pattern. Increase fluids and administer stool softeners, as needed, to ease constipation.

• Monitor pain level. Administer analgesics, as prescribed, to relieve pain.

• Monitor liver function tests, CBC, and blood urea nitrogen, creatinine, and electrolyte levels.

Patient teaching

• Advise patient to take with full glass of water after a meal.

• Tell patient to report depression, insomnia, or excessive anxiety.

• Instruct patient to wear cotton clothing to let skin breathe if drug causes increased sweating or hot flashes.

• As appropriate, review all other significant adverse reactions and interactions, especially those related to the drugs mentioned above.

exemestane

(ex-e-mes-tane) exemestane,

Aromasin

(trade name)

Classification

Therapeutic: antineoplastics
Pharmacologic: aromatase inhibitors
Pregnancy Category: X

Indications

Adjuvant treatment of breast cancer in postmenopausal women who have estrogen-receptor positive early disease and who have already received 2–3 yr of tamoxifen and are then switched to exemestane to complete a total of 5 yr of adjuvant therapy.Treatment of advanced postmenopausal breast cancer that has progressed despite tamoxifen therapy.

Action

Inhibits aromatase, an enzyme responsible for the conversion of androgen to estrogen. In postmenopausal women, the primary source of estrogen is androgen. Decreases circulating estrogen.

Therapeutic effects

Decreased spread of estrogen-sensitive breast cancer.

Pharmacokinetics

Absorption: 42% absorbed following oral administration.Distribution: Extensively distributed.Metabolism and Excretion: Mostly metabolized by the liver (CYP3A4 enzyme system); metabolites are excreted in urine (40%) and feces (40%); <1% excreted unchanged in urine.Half-life: 24 hr.

Time/action profile (suppression of circulating estrogen)

ROUTEONSETPEAKDURATION
POunknown2–3 days4–5 days

Contraindications/Precautions

Contraindicated in: Hypersensitivity;Premenopausal status; Obstetric: Pregnancy (may cause fetal harm); Lactation: Breast feeding should be avoided.Use Cautiously in: Pediatric: Safe and effective use not established.

Adverse Reactions/Side Effects

Central nervous system

  • fatigue (most frequent)
  • depression
  • insomnia

Cardiovascular

  • thromboembolism (life-threatening)
  • hypertension

Gastrointestinal

  • diarrhea
  • nausea

Genitourinary

  • endometrial hyperplasia
  • uterine polyps

Endocrinologic

  • visual disturbances

Dermatologic

  • alopecia (most frequent)
  • hot flashes (most frequent)
  • increased sweating (most frequent)
  • dermatitis

Musculoskeletal

  • arthralgia (most frequent)
  • musculoskeletal pain
  • carpal tunnel syndrome
  • muscle cramps
  • osteoporosis

Neurologic

  • neuropathy
  • paresthesia

Interactions

Drug-Drug interaction

CYP3A4 inducers including rifampin or phenytoin may ↓ levels and effectiveness; ↑ daily dose to 50 mg once daily.Estrogens can interfere with action.

Route/Dosage

Oral (Adults) 25 mg once daily; Concurrent use with CYP3A4 inducers—50 mg once daily.

Availability (generic available)

Tablets: 25 mg

Nursing implications

Nursing assessment

  • Assess patient for pain and other side effects periodically during therapy.
  • Lab Test Considerations: May cause ↑ GTT, AST, ALT, alkaline phosphatase, bilirubin, and creatinine levels.
    • Assess 25-hydroxy vitamin D levels prior to starting therapy. Supplement vitamin D deficiency with vitamin D due to high prevalence of vitamin D deficiency in women with early breast cancer.

Potential Nursing Diagnoses

Acute pain (Side Effects)

Implementation

  • Take 1 tablet daily after a meal.

Patient/Family Teaching

  • Instruct patient to take exemestane as directed at the same time each day. Take missed doses as soon as remembered unless it is almost time for next dose. Do not double doses. Advise patient to read the Patient Information leaflet before starting and with each Rx refill; changes may occur.
  • Advise patient not to take other estrogen-containing agents; may interfere with action of exemestane.
  • Inform patient that lower level of estrogen may lead to decreased bone mineral density over time and increased risk of osteoporosis and fracture.
  • Advise patient to notify health care professional immediately if chest pain or signs of heart failure or stroke occur.
  • Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
  • Exemestane is teratogenic; advise female patients to use effective contraception during therapy and to avoid breast feeding.
  • Explain need for follow-up blood tests to check liver and kidney function.

Evaluation/Desired Outcomes

  • Slowing of disease progression in women with breast cancer.

Aromasin

An irreversible, steroidal aromatase-inactivating anti-oestrogen used in postmenopausal women with oestrogen-dependent/oestrogen-receptor-positive breast cancer.
 
Adverse effects
Hot flushes, nausea, fatigue, increased sweating.