Pentostatin Injection
Pentostatin is a chemotherapy drug used to treat hairy cell leukemia, given intravenously as Nipent.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Pentostatin (Nipent) is a chemotherapy given into a vein for hairy cell leukemia, new or after alpha-interferon fails, and blocks the enzyme adenosine deaminase so toxic byproducts poison the cancer cells; around since about 1991 and available as a generic, it is one of two standard first choices alongside cladribine. It is a real chemotherapy, and nausea, tiredness, rash and fever or chills are the usual complaints. A high fever needs a call right away, since infection-fighting white cells can drop sharply in early courses, and the boxed warning rules out higher-than-recommended doses (kidney, liver, lung and brain damage) and pairing with fludarabine (severe or fatal lung toxicity).
Clinical pearls
- Expect IV fluids before and after every dose to protect your kidneys, so clinic visits run longer than the injection.
- If you take allopurinol for gout, tell your oncologist, since the pair has been linked to rare serious allergic reactions.
- Use effective birth control throughout treatment, because pentostatin can seriously harm a developing baby.
- Kidney blood tests are checked through treatment, and decreased urination or new swelling should be reported promptly.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Nipent must be given by a doctor who is experienced in cancer chemotherapy. Using higher doses than recommended can cause severe — and potentially fatal — damage to the kidneys, liver, lungs, and brain. Do not exceed the recommended dose. Importantly, Nipent should never be combined with fludarabine phosphate: in a clinical study, 4 out of 6 patients who received this combination developed severe or fatal lung toxicity. This combination is not recommended under any circumstances.
Patient information guide A plain-language walkthrough of Pentostatin Injection, written from its FDA label.
What Pentostatin Injection is used for
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Pentostatin injection (brand name Nipent) is a chemotherapy approved for one specific cancer:
- Hairy cell leukemia — Nipent intravenous injection is indicated for both untreated patients and those whose disease did not respond to alpha-interferon, when the disease is active (causing low blood counts or symptoms)
How Pentostatin Injection works
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Pentostatin is a potent blocker of an enzyme called adenosine deaminase (ADA). Lymphoid cells — especially cancerous ones like hairy cell leukemia — rely heavily on ADA. When pentostatin shuts it down, toxic substances (particularly a compound called dATP) accumulate inside the cancer cells and interfere with DNA production, ultimately killing them. Pentostatin can also disrupt RNA production and cause additional DNA damage in cancer cells.
Hairy cell leukemia cells are especially vulnerable to this mechanism because they have very high ADA activity, making them a precise target for pentostatin's action.
Pentostatin Injection dosage
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Nipent is given intravenously (into a vein) by a healthcare provider, typically every other week. It may be given as a short bolus injection or infused over 20 to 30 minutes. Before each dose, IV fluids are administered to protect the kidneys; additional fluids are given after the dose as well.
- Treatment continues until a complete response is achieved or the best possible response is reached
- Response is assessed at 6 months; if there is no response at all, treatment is stopped
- Doses may be held or skipped if serious side effects occur — your doctor will guide this
- No specific milligram doses should be self-adjusted; always follow your prescriber's plan
Dosing details from the FDA-approved label
From the Pentostatin Injection prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Hairy cell leukemia
- 4 mg/m 2 every other week, given intravenously by bolus injection or diluted in a larger volume and given over 20 to 30 minutes
- Hydration with 500 to 1,000 mL of 5% Dextrose in 0.5 Normal Saline or equivalent before administration and an additional 500 mL of 5% Dextrose or equivalent after
- Maximum: Higher doses are not recommended
- Patients who have elevated serum creatinine should have their dose withheld and a CL cr determined; insufficient data to recommend a starting or subsequent dose for patients with impaired renal function
Read the label’s full dosing text
DOSAGE AND ADMINISTRATION It is recommended that patients receive hydration with 500 to 1,000 mL of 5% Dextrose in 0.5 Normal Saline or equivalent before NIPENT administration. An additional 500 mL of 5% Dextrose or equivalent should be administered after NIPENT is given. The recommended dosage of NIPENT for the treatment of hairy cell leukemia is 4 mg/m 2 every other week. NIPENT may be administered intravenously by bolus injection or diluted in a larger volume and given over 20 to 30 minutes (See Preparation of Intravenous Solution ). Higher doses are not recommended. No extravasation injuries were reported in clinical studies. The optimal duration of treatment has not been determined. In the absence of major toxicity and with observed continuing improvement, the patient should be treated until a complete response has been achieved. Although not established as required, the administration of two additional doses has been recommended following the achievement of a complete response. All patients receiving NIPENT at 6 months should be assessed for response to treatment. If the patient has not achieved a complete or partial response, treatment with NIPENT should be discontinued. If the patient has achieved a partial response, NIPENT treatment should be continued in an effort to achieve a complete response. At any time thereafter that a complete response is achieved, two additional doses of NIPENT are recommended. NIPENT treatment should then be stopped. If the best response to treatment at the end of 12 months is a partial response, it is recommended that treatment with NIPENT be stopped. Withholding or discontinuation of individual doses may be needed when severe adverse reactions occur. Drug treatment should be withheld in patients with severe rash, and withheld or discontinued in patients showing evidence of nervous system toxicity. NIPENT treatment should be withheld in patients with active infection occurring during the treatment but may be resumed when the infection is controlled. Patients who have elevated serum creatinine should have their dose withheld and a CL cr determined. There are insufficient data to recommend a starting or a subsequent dose for patients with impaired renal function (CL cr <60 mL/min). Patients with impaired renal function should be treated only when the potential benefit justifies the potential risk.
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Pentostatin Injection side effects
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Most patients treated with Nipent experience at least one side effect, though many are mild to moderate and often lessen over time. Common ones include:
Common side effects
- Nausea and/or vomiting
- Fever or chills
- Skin rash or itching
- Fatigue or weakness
- Headache
- Diarrhea
- Cough or upper respiratory symptoms
- Decreased appetite
- Diarrhea or abdominal pain
- Low white blood cell counts (leukopenia), which raise infection risk
When to get medical help
- Call your doctor right away if you develop signs of severe infection — high fever, chills, or worsening illness
- Seek help immediately if you have trouble breathing or chest tightness (possible pulmonary/lung toxicity)
- Tell your doctor if you notice easy bruising, unusual bleeding, or extreme fatigue (signs of low blood counts)
- Report any signs of nerve or brain problems — confusion, numbness, or neurological changes
- Contact your doctor if you develop a severe or worsening skin rash
- Tell your doctor if you have decreased urination or swelling, which could signal kidney problems
Pentostatin Injection warnings and precautions
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- Bone marrow suppression: Nipent can cause dangerously low blood counts, especially early in treatment. Frequent blood count monitoring is essential.
- Infection risk: Patients with active infections before or during treatment are at risk of serious worsening. Treatment may need to be delayed until infection is controlled.
- Lung toxicity: Combining Nipent with fludarabine phosphate caused severe or fatal lung toxicity in clinical studies — this combination must be avoided.
- Kidney effects: Nipent is cleared mainly through the kidneys. If kidney function declines, doses may need to be withheld.
- Liver effects: Liver enzyme elevations can occur; these are usually reversible but should be monitored.
- Pregnancy: Pentostatin causes fetal harm in animal studies. Pregnancy must be avoided during treatment.
- Severe rash: Rashes can worsen with continued treatment. Severe rash requires withholding of doses.
Pentostatin Injection interactions
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Several medications can interact seriously with Nipent. Tell your entire care team about everything you take:
- Fludarabine phosphate — this combination is not recommended; it caused severe and fatal lung toxicity in a clinical study
- Vidarabine (an antiviral drug) — pentostatin boosts vidarabine's effects, increasing the risk of serious side effects from both drugs
- Allopurinol (a gout medication) — both drugs can cause skin rashes; at least one fatal allergic reaction has been reported with combined use
- Carmustine, etoposide, high-dose cyclophosphamide — when used with pentostatin as part of a bone marrow transplant regimen, fatal lung complications and severe low blood pressure have been reported
Interactions listed in the FDA-approved label
From the Pentostatin Injection prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Allopurinol: Both are associated with skin rashes; in 25 refractory patients who received both, the combination did not appear to produce a higher incidence of skin rashes than NIPENT alone, but one patient who received both drugs experienced a hypersensitivity vasculitis that resulted in death, and it was unclear whether the drug combination caused it.
- Vidarabine: Pentostatin enhances the effects of vidarabine, and the combined use may result in an increase in adverse reactions associated with each drug. The therapeutic benefit of the drug combination has not been established.
- Fludarabine phosphate: The combination may be associated with an increased risk of fatal pulmonary toxicity. The combined use of NIPENT and fludarabine phosphate is not recommended.
- Carmustine, etoposide and high dose cyclophosphamide: Acute pulmonary edema and hypotension, leading to death, have been reported in the literature in patients treated with pentostatin in combination with these drugs as part of the ablative regimen for bone marrow transplant.
Read the label’s full interactions text
Drug Interactions Allopurinol and NIPENT are both associated with skin rashes. Based on clinical studies in 25 refractory patients who received both NIPENT and allopurinol, the combined use of NIPENT and allopurinol did not appear to produce a higher incidence of skin rashes than observed with NIPENT alone. There has been a report of one patient who received both drugs and experienced a hypersensitivity vasculitis that resulted in death. It was unclear whether this adverse event and subsequent death resulted from the drug combination. Biochemical studies have demonstrated that pentostatin enhances the effects of vidarabine, a purine nucleoside with antiviral activity. The combined use of vidarabine and NIPENT may result in an increase in adverse reactions associated with each drug. The therapeutic benefit of the drug combination has not been established. The combined use of NIPENT and fludarabine phosphate is not recommended because it may be associated with an increased risk of fatal pulmonary toxicity (see WARNINGS ). Acute pulmonary edema and hypotension, leading to death, have been reported in the literature in patients treated with pentostatin in combination with carmustine, etoposide and high dose cyclophosphamide as part of the ablative regimen for bone marrow transplant.
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Pentostatin Injection
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- Tell your doctor if you have ever had an allergic (hypersensitivity) reaction to pentostatin or Nipent — it is contraindicated in those patients
- Tell your doctor if you have kidney problems; pentostatin is eliminated through the kidneys and dosing may need to be held
- Tell your doctor if you have an active infection before treatment begins
- Pentostatin can cause serious fetal harm — do not use during pregnancy; women who could become pregnant should use effective contraception
- Share your full medication list with your care team, especially fludarabine, vidarabine, or allopurinol
- Nipent must be administered under the supervision of a physician experienced in cancer chemotherapy
Pentostatin Injection overdose
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There is no specific antidote if too much Nipent is given. Higher-than-recommended doses have been associated with deaths from severe damage to the kidneys, liver, lungs, and brain. If an overdose occurs, treatment focuses on supportive care — managing symptoms and monitoring organ function through the period of toxicity.
What Pentostatin Injection does in the body
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Pentostatin's key measurable effect is the inhibition of adenosine deaminase (ADA) activity in lymphoid cells. By blocking ADA, it causes toxic levels of dATP — a DNA-building block — to build up inside cancer cells, which then blocks an enzyme called ribonucleotide reductase and halts DNA synthesis. Pentostatin also disrupts RNA synthesis and can directly increase DNA damage, all contributing to cancer cell death.
How your body processes Pentostatin Injection
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After a single intravenous dose, pentostatin distributes rapidly into the body — the distribution phase lasts about 11 minutes. The drug then clears more slowly, with an average terminal half-life (the time it takes for half the drug to leave the body) of about 5.7 hours in patients with normal kidney function. Approximately 90% of the dose is eliminated through the urine, mostly unchanged. In patients with reduced kidney function, the drug clears more slowly, which is why kidney function is monitored closely during treatment.
How to store Pentostatin Injection
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Store NIPENT vials under refrigerated storage conditions 2° to 8° C (36° to 46°F).
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Pentostatin Injection
17 supplements and herbal products have documented interactions with Pentostatin Injection in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Pentostatin Injection: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Pentostatin Injection — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is Nipent used for?
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How is Nipent given, and how often will I need to go in?
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What side effects should I expect, and which ones should make me call my doctor?
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Are there any medications I absolutely cannot take with Nipent?
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Is it safe to get pregnant or try to conceive while on Nipent?
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How will my doctor know if Nipent is working?
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Is Pentostatin Injection available over the counter?
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When was Pentostatin Injection first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Pentostatin Injection on HelloPharmacist
Pentostatin Injection forms and strengths (how it comes)
Pentostatin Injection is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Pentostatin Injection inactive ingredients by manufacturer.
Injection
How this form is used
- Nipent is used to treat active hairy cell leukemia in patients who have not previously been treated
- Nipent is used to treat hairy cell leukemia that did not respond to alpha-interferon therapy
- Nipent is given intravenously, either as a bolus injection or infused over 20 to 30 minutes — your care team will determine the method
- Nipent is typically administered every other week; your doctor will decide how long treatment continues based on your response
- Before each Nipent dose, IV fluids are given to hydrate you and protect your kidneys; more fluids are given after the dose as well
- Nipent doses may be withheld if you develop severe rash, active infection, nerve problems, or rising creatinine levels — follow your doctor's guidance
Pentostatin Injection on the U.S. market: products, makers and brands
How Pentostatin Injection appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 1 Pentostatin Injection product record with the FDA, mostly as injection; the earliest marketing or approval year on record is 1991. Brand names on the directory include Nipent; the rest are generics.
Compare Pentostatin Injection products
A representative set of FDA-listed product records for Pentostatin Injection — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Injection | ||||
| 2 mg/mL | Intravenous | Hospira, Inc. | NDA | View NDC → |
Showing 1 of 1 products — FDA National Drug Code Directory. See every product, package size and price: browse all 1 Pentostatin Injection NDCs →
Pentostatin Injection side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Pentostatin Injection — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Pentostatin Injection in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Pentostatin Injection FDA approval history
How Pentostatin Injection went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Pentostatin Injection recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Pentostatin recalls since July 2021.
✅No Pentostatin recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 8011 1 dose form · 1 strength
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Dose form (SCDF) Injection RxCUI 1794544In current FDA listingsClinical drug / strength (SCD) 10 MGRxCUI 240573
Look up RxCUI 8011 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
Pentostatin Injection supply and shortage status
Whether Pentostatin Injection is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Pentostatin Injection brand names
Pentostatin Injection is sold under one brand name in the FDA directory — Nipent. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Pentostatin Injection: manufacturers and labelers
One company lists Pentostatin Injection products with the FDA. By number of product records, the largest are Hospira, Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Pentostatin Injection drug class (RxNorm)
Pentostatin Injection belongs to the Nucleoside Metabolic Inhibitor class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Pentostatin Injection page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Hospira, Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →