AMIFOSTINE
| AMIFOSTINE (am-i-fos'teen) Ethyol Classifications: cytoprotective agent; Therapeutic: cytoprotective agent Pregnancy Category: C |
Availability
500 mg vial
Action
Amifostine reduces cytotoxic damage induced by radiation or antineoplastic agents in well-oxygenated cells. Protective effects appear to be mediated by the formation of a metabolite of amifostine that removes free radicals from normal cells exposed to cisplatin.
Therapeutic Effect
Amifostine is cytoprotective in the kidney, bone marrow, and GI mucosa, but not in the brain or spinal cord. The cytoprotection results in decreased myelosuppression and peripheral neuropathy.
Uses
Reduction of the cumulative renal toxicity associated with cisplatin, xerostomia.
Unlabeled Uses
Reduction of paclitaxel toxicity.
Contraindications
Sensitivity to aminothiol compounds or mannitol, patients with potentially curable malignancies, hypotensive patients or those who are dehydrated, lactation; exfoliated dermatitis; pregnancy (category C).
Cautious Use
Patients at risk for hypocalcemia, cardiovascular disease (i.e., arrhythmias, CHF, TIA, CVA); radiation therapy; renal disease.
Route & Dosage
| Renal Protection Adult: IV 910 mg/m2 once daily prior to chemotherapy Reduction of Xerostomia Adult: IV 200 mg/m2 prior to radiation therapy |
Administration
Intravenous
PREPARE: IV Infusion: Reconstitute by adding 9.7 mL of NS injection to a single-dose vial to yield 50 mg/mL. May be further diluted with NS to a concentration as low as 5 mg/mL. ADMINISTER: IV Infusion: Infuse over no more than 15 min, beginning 30 min before chemotherapy; place patient in supine position prior to and during infusion. For xerostomia, infuse over 3 min; begin 15–30 min before radiation. INCOMPATIBILITIES Solution/additive: Do not mix with any solutions other than NS. Y-site: Acyclovir, amphotericin B, chlorpromazine, cisplatin, ganciclovir, hydroxyzine, prochlorperazine. |
- Store reconstituted solution at 15°–30° C (59°–86° F) for 5 h or refrigerate up to 24 h.
Adverse Effects (≥1%)
CV: Transient reduction in blood pressure. GI: Nausea, vomiting. Other: Infusion reactions (flushing, feeling of warmth or coldness, chills, dizziness, somnolence, hiccups, sneezing), hypocalcemia, hypersensitivity reactions.Interactions
Drug: ANTIHYPERTENSIVES could cause or potentiate hypotension.Pharmacokinetics
Onset: 5–8 min. Metabolism: In liver to active free thiol metabolite. Elimination: Renally excreted. Half-Life: 8 min.Nursing Implications
Assessment & Drug Effects
- Monitor for S&S of hypocalcemia and fluid balance if vomiting is significant.
- Monitor BP every 5 min during infusion. Stop infusion if systolic BP drops significantly from baseline (e.g., baseline[drop]: <100[20], 100–119[25], 120–139[30], 140–179[40], >180[50]) and place patient flat with legs raised. Restart infusion if BP returns to normal in 5 min.
Patient & Family Education
- Know and understand adverse effects.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug