| Amifostine Pharmacology |
| Amifostine |
| About Amifostine |
| Cytoprotective agent (in DNA-binding chemotherapeutic agents), Antineoplastic adjunct. |
| Mechanism of Action of Amifostine |
| Amifostine is a pro-drug which is activated to the free thiol metabolite at the tissue site. The thiol metabolite has cytoprotective and radioprotective properties of amifostine. It is readily taken up by cells where it binds to and detoxifies reactive metabolites of platinum and alkylating agents as well as scavenges free radicals. |
| Pharmacokinets of Amifostine |
| Absorption- Rapidly absorbed after intravenous administration Distribution- Widely distributed in the body.4% bound to the plasma proteins Metabolism- It is metabolized in the tissues by alkaline phosphatase (which causes dephosphorylation of drug). Its active metabolite is Thiol and inactive metabolite is Disulfide Excretion- Excreted through urine |
| Onset of Action for Amifostine |
| N/A |
| Duration of Action for Amifostine |
| N/A |
| Half Life of Amifostine |
| Drug has plasma half life 8 min. and its active metabolite thiol has 7.3 hr |
| Side Effects of Amifostine |
| 1.Nausea 2 Vomiting 3.Flushing (feeling of warmth) 4.Chills ( feeling of coldness) 5.Fever 6.Dizziness 7.Drowsiness 8.Sneezing 9.Shortness of breath 10.Fainting 11.Seizures 12.Chest tightness 13.Skin rash 14.Hives 15.Swelling of the throat |
| Contra-indications of Amifostine |
| 1.Hypersensitivity to the drug or any other thiol containing compound 2. Low blood pressure 3. Dehydration 4. Renal impairment 5. Hepatic impairment |
| Special Precautions while taking Amifostine |
| 1. Cardiovascular disease 2. Cerebrovascular diseases. 3. Antihypertensive drug should be stopped 24 hrs before administration 4. Antiemetics should be administered before infusion |
| Pregnancy Related Information |
| Contraindicated. |
| Old Age Related Information |
| Contraindicated |
| Breast Feeding Related Information |
| Contraindicated |
| Children Related Information |
| Contraindicated |
| Indications for Amifostine |
| 1.Prevention of Xerostomia during radiotherapy for head and neck cancer 2. Myelodysplastic syndromes 3.Reduction of cumulative nephrotoxicity due to Cisplatin |
| Interactions for Amifostine |
| Antihypertensives: Concomitant use of Amifostine with antihypertensive produces severe hypotension. |
| Typical Dosage for Amifostine |
| Intravenous- Adult- 740-910mg/metre square once daily over 15 min, Drug to be taken 30min before starting chemotherapy treatment Prevention of Xerostomia: 200mg / metre square once daily over 3 minutes, starting 15- 30 minutes before radiotherapy. |
| Schedule of Amifostine |
| H |
| Storage Requirements for Amifostine |
| Stored at controlled room temperature (20 -25 degree C) |
| Effects of Missed Dosage of Amifostine |
| Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose. |
| Effects of Overdose of Amifostine |
| Give symptomatic and supportive treatment |