Brands, Medical Use, Clinical Data
Drug Category
- Immunosuppressive Agents
- Antibiotics
- Antineoplastic Agents
Dosage Forms
Brands / Synonyms
2'-DCF; 2'-Deoxycoformycin; 2'-Dexoycoformycin; Co-V; Co-Vidarabine; Covidarabine; Dcf; Deaminase Inhibitor; Deoxycoformycin; Nipent; PD-ADI; Vidarbine; Vira a Deaminase Inhibitor
Indications
For the treatment of hairy cell leukaemia refractory to alpha interferon.
Pharmacology
Pentostatin is an antineoplastic anti-metabolite used in the treatment of several forms of leukemia including acute nonlymphocytic leukemia and hairy cell leukemia. Anti-metabolites masquerade as purine or pyrimidine - which become the building blocks of DNA. They prevent these substances becoming incorporated in to DNA during the "S" phase (of the cell cycle), stopping normal development and division. It is a 6-thiopurine analogue of the naturally occurring purine bases hypoxanthine and guanine. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Cytotoxicity is cell cycle phase-specific (S-phase).
Mechanism of Action
Pentostatin is a potent transition state inhibitor of adenosine deaminase (ADA), the greatest activity of which is found in cells of the lymphoid system. T-cells have higher ADA activity than B-cells, and T-cell malignancies have higher activity than B-cell malignancies. The cytotoxicity that results from prevention of catabolism of adenosine or deoxyadenosine is thought to be due to elevated intracellular levels of dATP, which can block DNA synthesis through inhibition of ribonucleotide reductase. Intracellular activation results in incorporation into DNA as a false purine base. An additional cytotoxic effect is related to its incorporation into RNA. Cytotoxicity is cell cycle phase-specific (S-phase).
Absorption
Not absorbed orally, crosses blood brain barrier.
Toxicity
LD50=128 mg/kg (mouse), side effects include lethargy, rash, fatigue, nausea and myelosuppression.
Biotrnasformation / Drug Metabolism
Primarily hepatic, but only small amounts are metabolized.
Contraindications
Patients with severe pre-existing infections should not receive this drug.
Contraindicated in patients with severe renal impairment
Drug Interactions
Interactions with cylcopholsphamide, fludarabine and vidarabine
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