ESTRAMUSTINE PHOSPHATE SODIUM
| ESTRAMUSTINE PHOSPHATE SODIUM (ess-tra-muss'teen) Emcyt Classifications: antineoplastic; alkylating agent; nitrogen mustard; Therapeutic:antineoplastic nitrogen mustard Prototype: Cyclophosphamide Pregnancy Category: D |
Availability
140 mg capsules
Action
Conjugate of estradiol and the carbamate of nitrogen mustard. Incorporation of estramustine in tumor tissues is probably due to the presence of estramustine-binding protein (EMBP), which is found in prostate carcinoma, glioma, melanoma, and breast carcinoma. Binds to proteins and microtubulin resulting in microtubule changes in the cell division cycle, thus arresting cell division in the G2/M phase of the cell cycle.
Therapeutic Effect
Major effectiveness reported to be in patients who have been refractory to estrogen therapy alone.
Uses
Palliative treatment of metabolic or progressive carcinoma of prostate.
Contraindications
Hypersensitivity to either estradiol or nitrogen mustard; active thrombophlebitis or thromboembolic disorders; pregnancy (category D), lactation.
Cautious Use
History of thrombophlebitis, thromboses, or thromboembolic disorders; cerebrovascular or coronary artery disease; gallstones or peptic ulcer; impaired liver function; metabolic bone diseases associated with hypercalcemia; diabetes mellitus; hypertension, conditions that might be aggravated by fluid retention (e.g., epilepsy, migraine, kidney dysfunction); older adult patients.
Route & Dosage
| Neoplasm Adult: PO 14 mg/kg/d in 3–4 divided doses |
Administration
Oral- Give with meals to reduce incidence of GI adverse effects. Some patients require drug withdrawal because of intolerable GI effects.
- Store at 2°–8° C (38°–46° F) in tight, light-resistant containers, unless otherwise directed by manufacturer.
Adverse Effects (≥1%)
CNS: Lethargy, emotional lability, insomnia, headache, anxiety. CV: CVA, MI, thrombophlebitis, CHF, peripheral edema. GI: Nausea, diarrhea, anorexia, flatulence, vomiting, thirst, GI bleeding. Hematologic: Leukopenia, thrombocytopenia, abnormalities in liver function tests, hypercalcemia, bone marrow depression (rare). Respiratory: Hoarseness, burning sensation in throat, dyspnea, upper respiratory discharge, pulmonary emboli. Skin: Rash, pruritus, urticaria, dry skin, easy bruising, flushing, peeling skin and fingertips, thinning hair. Special Senses: Tearing of eyes. Urogenital: Gynecomastia, breast tenderness, impotence. Endocrine: Decrease in glucose tolerance. Musculoskeletal: Leg cramps.Interactions
Food: Milk, dairy products, calcium supplements may decrease estramustine absorption.Pharmacokinetics
Absorption: Readily absorbed from GI tract. Peak: 2–3 h. Metabolism: Dephosphorylated in intestines to estramustine, estradiol, estrone, and nitrogen mustard; further metabolized in liver. Elimination: In feces via bile. Half-Life: 20 h.Nursing Implications
Assessment & Drug Effects
- Monitor weight and examine for peripheral edema. Be mindful that drug can cause CHF.
- Monitor I&O ratio and pattern to prevent dehydration and electrolyte imbalance, especially with vomiting or diarrhea.
- Observe diabetics closely because of possibility of estramustine-induced reduction in glucose tolerance. Monitor baseline and periodic glucose tolerance tests.
- Lab tests: Perform baseline and periodic liver enzymes and bilirubin tests; repeat after drug has been discontinued for 2 mo.
Patient & Family Education
- Eat small meals at frequent intervals to reduce drug-induced nausea, eat slowly, and try cold food if food odors are offensive.
- Drink liquids 1 h before or 1 h after rather than with meals; clear liquids may be more palatable.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug