Overview
11 DESCRIPTION ETHYOL (amifostine) is an organic thiophosphate cytoprotective agent known chemically as 2-[(3-aminopropyl)amino]ethanethiol dihydrogen phosphate (ester) and has the following structural formula: Amifostine is a white crystalline powder which is freely soluble in water. Its empirical formula is C 5 H 15 N 2 O 3 PS and it has a molecular weight of 214.22.
Mechanism of Action
12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action ETHYOL is a prodrug that is dephosphorylated by alkaline phosphatase in tissues to a pharmacologically active free thiol metabolite. This metabolite is believed to be responsible for the reduction of the cumulative renal toxicity of cisplatin and for the reduction of the toxic effects of radiation on normal oral tissues. The ability of ETHYOL to differentially protect normal tissues is attributed to the higher capillary alkaline phosphatase activity, higher pH and better vascularity of normal tissues relative to tumor tissue, which results in a more rapid generation of the active thiol metabolite as well as a higher rate constant for uptake into cells.
Indications
- 1 INDICATIONS AND USAGE ETHYOL is a cytoprotective agent indicated for: – reduction of cumulative renal toxicity associated with repeated administration of cisplatin in patients with advanced ovarian cancer. ( 1.1 ) – reduction of the incidence of moderate to severe xerostomia in patients undergoing post-operative radiation treatment for head and neck cancer, where the radiation port includes a substantial portion of the parotid glands. ( 1.
Common Doses
- 910 mg
- 200 mg
- 20 mg
- 740 mg
Dosage
2 DOSAGE AND ADMINISTRATION – For reduction of cumulative renal toxicity with chemotherapy, the recommended starting dose is 910 mg/m 2 administered once daily as a 15-minute intravenous infusion, starting 30 minutes prior to chemotherapy. ( 2.1 ) – For reduction of moderate to severe xerostomia from radiation of the head and neck, the recommended dose is 200 mg/m 2 administered once daily as a 3-minute intravenous infusion, starting 15-30 minutes prior to standard fraction radiation therapy (1.8-2.0 Gy). ( 2.2 ) 2.
Contraindications
- 4 CONTRAINDICATIONS ETHYOL is contraindicated in patients with known hypersensitivity to aminothiol compounds. ETHYOL is contraindicated in patients with known hypersensitivity to aminothiol compounds. ( 4 )
Side Effects
- 6 ADVERSE REACTIONS The following serious adverse reactions are discussed in greater detail in other sections of the labeling: – Hypotension and Cardiovascular Events [see Warnings and Precautions (5.3) ] – Severe Cutaneous Reactions [see Warnings and Precautions (5.4) ] – Hypersensitivity [see Warnings and Precautions (5.5) ] – Nausea and Vomiting [see Warnings and Precautions (5.6) ] – Hypocalcemia [see Warnings and Precautions (5.7) ] Most common adverse reactions are hypotension, nausea and vomiting. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Legacy Pharma Inc.
Interactions
- 7 DRUG INTERACTIONS Closely monitor patients receiving anti-hypertensive medications or other drugs that could cause or potentiate hypotension. – Closely monitor patients receiving anti-hypertensive medications or other drugs that could cause or potentiate hypotension. ( 7 )