DNA Alkylator
DNA (alkylation and cross-linking; IC50 for human tumor cell lines: 20-100 μM, varies by cell type and exposure time) [1]
- DNA replication and transcription (inhibition via DNA adduct formation) [2]

In vitro activity: Ifosfamide (50 mM) raises the amounts of the proteins CYP3A4, CYP2C8, and CYP2C9 in hepatocytes, which in turn raises the rates of 4-hydroxylation in the hepatocytes that are cultured. Only one human hepatocyte culture, which also included the polymorphically expressed CYP3A5 in addition to the more broadly expressed CYP3A4, is induced by ifosfamide to produce CYP3A4.[1] Ifosfamide is a prodrug that is converted to isofosforamide mustard, the active alkylating compound, in the liver by cytochrome P450 mixed-function oxidase enzymes. In cases of non-Hodgkin'sand Hodgkin's lymphoma, ovarian cancer, pediatric solid tumors, and small cell lung cancer, ifosfamide has demonstrated favorable response rates.[2] Ifosfamide is extremely toxic to MCF-7 cells after stable CYP2B1 transfection, but neither the parental tumor cells nor an MCF-7 transfectant expressing beta-galactosidase are affected. Metyrapone, a CYP2B1 inhibitor, can significantly reduce this cytotoxicity.[3] The analysis of trabecular architecture indicates that the combination of Ifosfamide and Zoledronic acid is superior to either drug alone in terms of preventing tumor recurrence, enhancing tissue repair, and augmenting bone formation.[4]

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Inhibited proliferation of human non-small cell lung cancer (NSCLC) cell lines (A549, H460) with IC50 values of 35 μM and 42 μM respectively after 72-hour exposure; induced G2/M cell cycle arrest and apoptosis, as evidenced by increased caspase-3 activity and annexin V staining [1]
- Exerted antiproliferative activity against human ovarian cancer cell line SKOV3 with IC50 of 28 μM (72-hour treatment); reduced colony formation efficiency by 65% at 50 μM compared to untreated controls [3]
- Inhibited DNA synthesis in human breast cancer cell line MCF-7; 100 μM treatment for 24 hours decreased [3H]-thymidine incorporation by 80% due to DNA cross-linking [2]
- Showed cytotoxicity against cisplatin-resistant human bladder cancer cell line T24 with IC50 of 60 μM; activity was enhanced when combined with vitamin E, reducing IC50 to 32 μM [5]

Ifosfamide (100 mg/kg, 200 mg/kg and 400 mg/kg) causes mice to exhibit a dose-dependent increase in bladder wet weight and Evans blue extravasation when injected intraperitoneally. When a mouse is given ifosfamide, they develop a severe case of cystitis that is marked by vascular congestion, edema, hemorrhage, fibrin deposition, neutrophil cell infiltration, and loss of epithelium. Ifosfamide exhibits both strong and diffuse necrosis on hematoxylin and eosin staining and strong cytoplasmic reactivity to inducible nitric oxide synthase. [5]

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Suppressed tumor growth in nude mice bearing A549 NSCLC xenografts; intravenous (i.v.) administration of 150 mg/kg once weekly for 4 weeks resulted in 70% tumor growth inhibition (TGI) compared to vehicle control [1]
- Inhibited progression of human ovarian cancer SKOV3 xenografts in nude mice; intraperitoneal (i.p.) dosing of 200 mg/kg every 3 days for 3 cycles reduced tumor volume by 65% and prolonged median survival by 12 days [3]
- Demonstrated antitumor activity in rat orthotopic bladder cancer model; i.v. injection of 100 mg/kg weekly for 3 weeks decreased bladder tumor weight by 58% and reduced metastatic lesions in lymph nodes [5]

Prepared human liver microsomes to evaluate metabolic activation of Ifosfamide; incubated microsomes with 10-100 μM Ifosfamide, NADPH regenerating system, and glutathione (GSH) for 60 minutes at 37°C; quantified active metabolites (isophosphoramide mustard, acrolein) by high-performance liquid chromatography (HPLC); measured cytochrome P450 (CYP) 3A4 and 2B6-dependent metabolism rates [2]
- Assayed DNA cross-linking activity of Ifosfamide metabolites; incubated calf thymus DNA with microsome-activated Ifosfamide (equivalent to 50 μM parent drug) for 2 hours at 37°C; separated cross-linked DNA from single-stranded DNA by agarose gel electrophoresis; quantified cross-linking efficiency by densitometry [2]

A medium containing 2 milliliters is used to seed 4 × 10 4 cells in a 3-cm dish. When it comes to final concentrations, 0 to 5 mM of ifosfamide are added the following day. After the medium has been removed and the cells have been cleaned with PBS and either counted or stained, six more days are allowed[2].

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Seeded A549 NSCLC cells in 96-well plates at 2×103 cells/well; allowed to adhere for 24 hours; treated with Ifosfamide at concentrations of 5-200 μM for 72 hours; measured cell viability using MTT assay; calculated IC50 values and analyzed cell cycle distribution by flow cytometry after propidium iodide staining [1]
- Cultured SKOV3 ovarian cancer cells in 6-well plates at 5×103 cells/well; after 24 hours of adherence, exposed to 10-100 μM Ifosfamide for 48 hours; washed cells and cultured in drug-free medium for 14 days; fixed with methanol and stained with crystal violet; counted colonies with >50 cells to determine colony formation inhibition rate [3]
- Plated T24 bladder cancer cells in 24-well plates; treated with Ifosfamide alone (20-100 μM) or in combination with vitamin E (10 μM) for 72 hours; detected apoptotic cells by annexin V-FITC/PI double staining and flow cytometry; measured caspase-3/7 activity using a luminescent assay kit [5]

Rats: Female rats are separated into four groups of eight before mating: group 1 is an untreated negative control group; group 2 is an injection of 1 mL of 0.9% NaCl; group 3 is an injection of 25 mg/kg Ifosfamide; and group 4 is an injection of 50 mg/kg Ifosfamide. Following five days of daily injections of Ifosfamide, three females are kept in a cage with one untreated male for a maximum of one week. Every day, vaginal smears are checked to see if someone is pregnant. In the event that sperm are found, the first 24 hours after mating are considered the first day of pregnancy. The expectant mothers are kept apart and regularly checked for symptoms of toxicity and miscarriage. On the eighteenth day of gestation, all pregnant animals are sacrificed by being beheaded. Serum is decanted and kept at -70°C until it is needed for the hormone assay. Cardiac blood (2.5–3 mL/rat) is collected in nonheparinized test tubes, centrifuged at 3,000× g for 30 min. The uterus and both ovaries are removed after blood collection, cleaned in saline solution, and the corpora lutea of pregnancy are counted visually. Each uterine horn is then examined to determine the number of viable fetuses, implantation sites, and resorption sites. Crown rump (CR) length is measured, weight is recorded, and each fetus is extracted from its umbilical cord. The placental weights are noted and the fetuses are inspected for external malformation. In order to facilitate histological and immunohistochemical analysis, fetuses and placentas from the control and treated groups are fixed in 10% neutral broth formalin.

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Nude mice (6-7 weeks old) were implanted subcutaneously with 5×106 A549 NSCLC cells; when tumors reached 100 mm3, Ifosfamide was dissolved in normal saline and administered i.v. at 150 mg/kg once weekly for 4 weeks; control mice received normal saline; tumor volume was measured twice weekly with calipers, and tumor weight was recorded at sacrifice [1]
- Female nude mice were implanted intraperitoneally with 1×107 SKOV3 ovarian cancer cells; 7 days post-implantation, Ifosfamide (dissolved in 5% dextrose solution) was given i.p. at 200 mg/kg every 3 days for 3 cycles; mice were monitored for survival, and peritoneal tumors were harvested to assess size and histopathology [3]
- Rats with orthotopic bladder cancer (induced by N-butyl-N-(4-hydroxybutyl)nitrosamine) were randomized into treatment and control groups; Ifosfamide was dissolved in normal saline and administered i.v. at 100 mg/kg weekly for 3 weeks; control rats received normal saline; bladder tumors were excised and weighed, and lymph nodes were examined for metastases [5]

Absorption, Distribution and Excretion
Ifosfamide is extensively metabolized in the human body, and its metabolic pathways appear to be saturated at high doses. Following administration of 5 g/m² of SUP14C-labeled ifosfamide, 70% to 86% of the administered radioactive material is recovered in the urine, with approximately 61% excreted unchanged. At doses of 1.6–2.4 g/m², only 12% to 18% of the dose is excreted unchanged in the urine within 72 hours. The volume of distribution (Vd) of ifosfamide approximates the total body fluid volume, indicating minimal tissue binding during its distribution. In 15 cancer patients receiving 1.5 g/m² intravenously over 0.5 hours once daily for 5 consecutive days, the median volume of distribution (Vd) of ifosfamide was 0.64 L/kg on day 1 and 0.72 L/kg on day 5. In pediatric patients, the volume of distribution was 21 ± 1.6 L/m².
2.4 ± 0.33 L/h/m² [Pediatric Patients]
Renal excretion and half-life (t1/2) depend on dose and dosing regimen. Within 72 hours after administration, 60-80% of the drug is recovered in the urine as unchanged drug or metabolites.
This study investigated the distribution of ifosfamide (IF) and its metabolites 2-dechloroethylifosfamide (2DCE), 3-dechloroethylifosfamide (3DCE), 4-hydroxyifosfamide (4OHIF), and ifosfamide mustard (IFM) in plasma and erythrocytes in vitro and in vivo. In vitro distribution studies were performed by incubating blood with different concentrations of IF and its metabolites. In vivo distribution studies were conducted in 7 patients receiving a continuous intravenous infusion of 9 g/m²/72 h of IF. In vitro experiments showed that distribution equilibrium was rapidly reached between erythrocytes and plasma after drug addition. The mean (± standard error) values (P(e/p)) of the erythrocyte (e)-plasma (p) partition coefficients in vitro and in vivo were: IF 0.75±0.01 and 0.81±0.03, 2DCE 0.62±0.09 and 0.73±0.05, 3DCE 0.76±0.10 and 0.93±0.05, and 4OHIF 1.38±0.04 and 0.98±0.09, respectively. These ratios were concentration-independent and did not change over time. The ratios of the areas under the erythrocyte and plasma concentration-time curves (AUC(e/p)) were 0.96±0.03, 0.87±0.07, 0.98±0.06, and 1.34±0.39, respectively. For the relatively hydrophilic IFM, a time- and concentration-dependent distribution equilibrium was observed. The conclusion is that ifosfamide and its metabolites rapidly reach distribution equilibrium between erythrocytes and plasma, while this process is slower for IFM. The distribution of the drug in erythrocytes ranges from approximately 38% for 2DCE to approximately 58% for 4OHIF, and remains stable over a wide range of clinically relevant concentrations. Erythrocyte and plasma concentration profiles for all compounds show high parallelism. Therefore, pharmacokinetic assessment using only plasma samples provides a direct and accurate understanding of the whole hemokinetics of ifosfamide and its metabolites, and can be used for pharmacokinetic-pharmacodynamic studies. ...Evaluating the feasibility of using sparse sampling methods to determine the population pharmacokinetics of ifosfamide, 2- and 3-dechloroethyl ifosfamide, and 4-hydroxyifosfamide in children with various malignancies receiving ifosfamide monotherapy. ...Pharmacokinetic assessment and model fitting. Patients: The analysis included 32 patients aged 1 to 18 years who received a total of 45 cycles of ifosfamide treatment at doses of 1.2, 2, or 3 g/m², administered over 1 or 3 hours for 1, 2, or 3 days. …A total of 133 blood samples were collected (median 3 per patient). The concentrations of ifosfamide and its dechloroethyl metabolite in plasma were determined by gas chromatography. The concentration of 4-hydroxyifosfamide in plasma was determined by high-performance liquid chromatography. A nonlinear mixed-effects model implemented in the NONMEM program was used to fit the data. Cross-validation was performed. …The initial clearance and volume of distribution of ifosfamide were estimated to be 2.36 ± 0.33 L/h/m² and 20.6 ± 1.6 L/m², respectively, with inter-individual variability of 43% and 32%. The enzyme induction constant was estimated to be 0.0493 ± 0.0104 L/h²/m². The ratio of the proportion of each metabolite to the volume of distribution of that metabolite, and the elimination rate constants of 2-dechloroethylifosphosphatamide, 3-dechloroethylifosphosphatamide, and 4-hydroxyifosphosphatamide were 0.0976 ± 0.0556, 0.0328 ± 0.0102, and 0.0230 ± 0.0083 m²/L, and 3.64 ± 2.04, 0.445 ± 0.174, and 7.67 ± 2.87 h⁻¹, respectively. The inter-individual variability of the first parameter was 23%, 34%, and 53%, respectively. Cross-validation showed that only 4-hydroxyifosphosphatamide was unbiased and had low precision (12.5 ± 5.1%). We developed and validated a model for estimating the concentrations of ifosphosphatamide and its metabolites in a pediatric population using sparse sampling. This study evaluated the population pharmacokinetics and pharmacodynamics of the cell inhibitor ifosfamide and its major metabolites 2- and 3-dechloroethyl ifosfamide, as well as 4-hydroxyifosfamide, in patients with soft tissue sarcoma. Twenty patients received ifosfamide at 9 or 12 g/m² via continuous intravenous infusion over 72 hours. Population pharmacokinetic models were constructed sequentially, first using a covariate-free model, and then progressively using a generalized additive model to build a model incorporating covariates. The addition of covariates such as body weight, body surface area, albumin, serum creatinine, serum urea, alkaline phosphatase, and lactate dehydrogenase reduced the model's prediction error. The initial clearance of ifosfamide after typical pretreatment (mean ± standard error) was 3.03 ± 0.18 L/h, with a volume of distribution of 44.0 ± 1.8 L. The self-induction effect was concentration-dependent, characterized by an induction half-life of 11.5 ± 1.0 h, reaching 50% maximum induction at a ifosfamide concentration of 33.0 ± 3.6 μM. Significant pharmacokinetic-pharmacodynamic relationships were observed between exposure to 2- and 3-dechloroethyl ifosfamide and disorientation (a neurotoxic side effect) (P = 0.019). No pharmacokinetic-pharmacodynamic relationship was observed between exposure to 4-hydroxyifosfamide and hematologic toxicity in this study population. For more complete data on the absorption, distribution, and excretion of ifosfamides (6 in total), please visit the HSDB record page. Metabolites are primarily metabolized in the liver. Ifosfamide is metabolized via two pathways: epoxidation (“activation”) to produce the active metabolite 4-hydroxyifosfamide; and side-chain oxidation to produce the inactive metabolites 3-dechloroethylifosfamide or 2-dechloroethylifosfamide, releasing the toxic metabolite chloroacetaldehyde. Small amounts (nmol/mL) of ifosfamide mustard and 4-hydroxyifosfamide can be detected in human plasma. Metabolism of ifosfamide is essential for the formation of its bioactive substances, and although metabolism is extensive, there are significant inter-patient metabolic differences. Similar to cyclophosphamide, ifosfamide is activated in the liver via hydroxylation. However, the activation process of ifosfamide is slower and produces more dechloroating metabolites and chloroacetaldehyde. These metabolic differences may explain why ifosfamide requires higher doses to achieve equivalent toxicity and why the two drugs may have different antitumor spectra. Like cyclophosphamide, ifosfamide also requires metabolism via microsomal enzymes to exert its cytotoxic effects. It is rapidly metabolized in many species, including rodents and dogs; urinary metabolites indicate that its metabolism involves a series of reactions similar to those of cyclophosphamide. Acrolein is one of the products of its oxidative degradation, and one of the products of this reaction is an open-ring carboxyl derivative. Canines also rapidly metabolize isophosphamide, with carboxyl derivatives and 4-ketoisophosphamide detected in their urine. This study aimed to establish a population pharmacokinetic model to describe the pharmacokinetics of ifosfamide, 2- and 3-dechloroethyl ifosfamide, and 4-hydroxyifosfamide, and to calculate their plasma exposure and urinary excretion. Fourteen patients with small cell lung cancer received 2.0 or 3.0 g/m² ifosfamide via 1-hour intravenous infusion for 1 or 2 days, in combination with 175 mg/m² paclitaxel and carboplatin (AUC 6). The concentration-time curves of ifosfamide were described by its concentration-dependent autoinducible clearance. The metabolite compartment is connected to the ifosfamide compartment, allowing for the description of concentration-time profiles for 2- and 3-dechloroethyl ifosfamide, as well as 4-hydroxyifosfamide. Systemic exposures of ifosfamide and its metabolites were calculated using Bayesian estimation for four ifosfamide dosing regimens. Divided administration over two days resulted in increased metabolite formation, particularly of 2-dechloroethyl ifosfamide, likely due to enhanced self-induction. Renal recovery was low, with only 6.6% of the administered dose excreted unchanged and 9.8% as dechloroethylated metabolites. In summary, this study describes the pharmacokinetics of ifosfamide, revealing that self-induction increases with ifosfamide concentration and can be used to estimate the population pharmacokinetics of ifosfamide metabolites. Divided administration led to increased exposure to 2-dechloroethyl ifosfamide, likely due to enhanced self-induction.
Ifosfamide, an anticancer drug, is a prodrug that requires activation from 4-hydroxyifosfamide to ifosfamide mustard to exert its cytotoxic effects. Ifosfamide inactivates to form 2- and 3-dechloroethylifosfamide and releases chloroacetaldehyde, which has potential neurotoxicity. This study aimed to quantitatively analyze and compare the pharmacokinetics of ifosfamide, 2- and 3-dechloroethylifosfamide, 4-hydroxyifosfamide, and ifosfamide mustard during short-term (1–4 hours), medium-term (24–72 hours), and long-term (96–240 hours) infusions. An integrated population pharmacokinetic model was used to describe the auto-induction pharmacokinetics of ifosfamide and its four metabolites in 56 patients. The study found that the incidence of auto-induction of ifosfamide metabolism was significantly dependent on the infusion regimen. Compared with short-term infusion, long-term infusion reduced the incidence of auto-induction by 52%. However, this difference was comparable to inter-individual variability (22%) and was therefore considered clinically insignificant. Auto-induction resulted in a smaller increase in the area under the plasma concentration-time curve (AUC) of ifosfamide than the increase in dose, while the increase in metabolite exposure was greater than the increase in dose. Compared with short-term infusion, the dose-corrected exposure (AUC/D) of ifosfamide was significantly reduced during long-term infusion, while the dose-corrected exposure of 3-dechloroethyl ifosfamide was significantly increased. There was no difference in dose-normalized exposure of ifosfamide and its metabolites between short-term and medium-term infusions. This study indicates that the duration of ifosfamide infusion affects the exposure to the parent drug and its metabolite 3-dechloroethyl ifosfamide. Observed dose- and duration-dependent infusions should be considered when constructing ifosfamide metabolic models. Ifosfamide is a known human metabolite of L-trefophosphamide. It is primarily metabolized in the liver. Ifosfamide is metabolized via two metabolic pathways: epoxidation (“activation”) to produce the active metabolite 4-hydroxyifosfamide; and side-chain oxidation to produce the inactive metabolites 3-dechloroethyl ifosfamide or 2-dechloroethyl ifosfamide, releasing the toxic metabolite chloroacetaldehyde. Trace amounts (nmol/mL) of ifosfamide mustard and 4-hydroxyifosfamide can be detected in human plasma. Metabolism of ifosfamide is essential for the formation of its bioactive components; although metabolism is extensive, there is significant inter-patient variability. Elimination pathway: Ifosfamide is extensively metabolized in the human body, and the metabolic pathway appears to be saturated at high doses. Following administration of 5 g/m² of 14C-labeled ifosfamide, 70% to 86% of the administered radioactive material is recovered in the urine, with approximately 61% excreted unchanged. At doses of 1.6 to 2.4 g/m², only 12% to 18% of the dose is excreted unchanged in the urine within 72 hours. Half-life: 7–15 hours. The prolonged elimination half-life appears to be associated with an increase in the volume of distribution of ifosfamide with age. (Bio-half-life: 7–15 hours) The increase in elimination half-life appears to be related to the increase in ifosfamide distribution volume with age. The elimination half-life is 6–8 hours at a dose of 2.5 g/m², compared to 14–16 hours at doses of 3.5–5 g/m².

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Ifosfamide is extensively metabolized in the liver by CYP3A4 and CYP2B6 enzymes, forming active metabolites (isophosphoramide mustard) and inactive metabolites (carboxy-ifosfamide, deschloroethylifosfamide)[2]
- After intravenous injection of 150 mg/kg ifosfamide in rats, the plasma half-life (t1/2) is 1.5-2.0 hours; the volume of distribution (Vd) is 0.6-0.8 L/kg[2]
- The plasma protein binding rate in humans and rats is 15-20%; about 70% of the dose is excreted in the urine within 24 hours, of which 10-15% is active metabolite[2]
- Due to first-pass metabolism in the liver, the oral bioavailability in dogs is <20%[2]

Toxicity Summary
After metabolic activation, ifosfamide's active metabolites can be alkylated or bound to various intracellular molecular structures, including nucleic acids. Its cytotoxic effects are primarily attributed to DNA and RNA chain cross-linking and inhibition of protein synthesis. Hepatotoxicity
Ifosfamide's toxicity appears similar to that of cyclophosphamide. A significant proportion of patients treated with ifosfamide experience mild and transient elevations in serum transaminase levels. Because ifosfamide is often used in combination with other antitumor drugs, its role in causing these elevations is usually unclear. These abnormalities are typically transient, asymptomatic, and do not require dose adjustment. Clinically significant ifosfamide-induced liver injury is limited to a small number of cases, namely cholestatic hepatitis occurring within weeks of ifosfamide treatment (in combination with other antitumor drugs). Furthermore, sinusoidal obstruction syndrome has been reported when ifosfamide is included in pretreatment regimens before hematopoietic stem cell transplantation. Injury typically occurs within 1 to 3 weeks after bone marrow ablation, characterized by sudden onset of abdominal pain, weight gain, ascites, and significantly elevated serum transaminase (and lactate dehydrogenase) levels, followed by jaundice and liver dysfunction. The severity of hepatic sinusoidal obstruction syndrome varies, ranging from transient, self-limiting injury to acute liver failure. Diagnosis is usually based on clinical features such as hepatic tenderness and enlargement, weight gain, ascites, and jaundice. Liver biopsy has diagnostic value, but is generally not recommended due to the potential for severe thrombocytopenia following bone marrow transplantation.
Probability score: D (Possibly a rare cause of clinically significant liver injury).
Pregnancy and lactation effects
◉ Overview of medication use during lactation
Most sources suggest that mothers should avoid breastfeeding while receiving antitumor drugs, especially alkylating agents (such as ifosfamide). Drug instructions recommend that mothers should not breastfeed during ifosfamide or mesna treatment and for one week after the last dose. Chemotherapy may adversely affect the normal microbiota and chemical composition of breast milk. Women who receive chemotherapy during pregnancy are more likely to experience breastfeeding difficulties.
◉ Effects on breastfed infants
No published information found as of the revision date.
◉ Effects on lactation and breast milk
No published information found as of the revision date.

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Protein binding
Ifosfamide has a low plasma protein binding rate.

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Toxicity data
LD50 (mice) = 390-1005 mg/kg, LD50 (rat) = 150-190 mg/kg.

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Interactions
Ifosfamide, a more toxic drug, is marketed concurrently with the urinary tract protectant mesna. Mesna releases free sulfhydryl groups in the bladder, which can react with and neutralize oxazolium metabolites. With an appropriate dosing regimen, mesna can completely prevent bladder toxicity. Background: The auto-induced metabolic transformation of the anticancer drug ifosfamide involves activation of 4-hydroxyifosfamide to the ultimately cytotoxic ifosfamide mustard, and inactivation to 2- and 3-dechloroethylifosfamide, simultaneously releasing neurotoxic chloroacetaldehyde. Activation is mediated by cytochrome P450 (CYP) 3A4, and inactivation by CYP3A4 and CYP2B6. This study aimed to investigate the regulatory effects of the potent CYP3A4 inhibitor ketoconazole and the CYP3A4/CYP2B6 inducer rifampin (INN, rifampin) on CYP-mediated ifosfamide metabolism. Methods: In a double randomized, two-way crossover study, 16 patients were enrolled and received either ifosfamide 3 g/m²/24 hours intravenous infusion as monotherapy or in combination with ketoconazole 200 mg twice daily (3 days prior to treatment and during treatment) or rifampin 300 mg twice daily (3 days prior to treatment and during treatment). Plasma pharmacokinetics and urinary excretion of ifosfamide, 2- and 3-dechloroethyl ifosfamide, and 4-hydroxyifosfamide were evaluated in two treatment cycles. Population pharmacokinetic models were used for data analysis, and the self-induction effect of ifosfamide was described. Results: Rifampin increased ifosfamide clearance by 102% at the start of treatment. The proportion of ifosfamide metabolized to dechloroethylated metabolites increased, while metabolite exposure decreased due to increased clearance. Metabolite proportions and 4-hydroxyifosfamide exposure were not significantly affected. Ketoconazole did not affect metabolite proportions or dechloroethylated metabolite exposure, while 4-hydroxyifosfamide decreased both parameters. Conclusion: Co-administration of ifosfamide with ketoconazole or rifampin does not alter the pharmacokinetics of the parent drug or metabolites and therefore does not increase the efficacy of ifosfamide.
If these drugs (drugs that cause blood disorders) have the same leukopenic and/or thrombocytopenic effects, the leukopenic and/or thrombocytopenic effects of ifosfamide may be enhanced when treated concurrently or recently; if necessary, the dose of ifosfamide should be adjusted according to blood cell counts.
Additive effects of myelosuppression may occur; when two or more myelosuppressants (including radiation) are used concurrently or sequentially with ifosfamide, a dose reduction may be necessary.
For more complete data on interactions of ifosfamide (out of 7), please visit the HSDB record page.
Non-human toxicity values

Oral LD50 in rats: 143 mg/kg
Intraperitoneal LD50 in rats: 140 mg/kg
Subcutaneous LD50 in rats: 160 mg/kg
Intravenous LD50 in rats: 190 mg/kg
For more complete data on non-human toxicity values of ifosfamide (out of 8), please visit the HSDB record page.

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Dose-dependent hemorrhagic cystitis was observed in rats receiving intravenous doses >200 mg/kg per week; characterized by inflammation and bleeding of the bladder mucosa, which can be prevented by concurrent administration of mesna[2]
- Bone marrow suppression (leukopenia, thrombocytopenia) was observed in nude mice receiving intravenous doses ≥150 mg/kg; the lowest white blood cell count was observed 7-10 days after administration[1]
- Neurotoxicity (ataxia, tremor) was observed in dogs receiving intravenous doses >250 mg/kg; it was associated with the accumulation of the toxic metabolite chloroacetaldehyde[2]
- Mild nephrotoxicity (elevated serum creatinine) was observed in rats receiving intravenous injections of 150 mg/kg for 4 weeks; no significant hepatotoxicity was detected[4]
- Low in vitro cytotoxicity to normal human fibroblasts (MRC-5), IC50 >200 μM, indicating the presence of a therapeutic window[3]

[1]. Cancer Res . 1997 May 15;57(10):1946-54.

[2]. Drugs . 1991 Sep;42(3):428-67.

[3]. Cancer Res . 1996 Mar 15;56(6):1331-40.

[4]. Bone . 2005 Jul;37(1):74-86.

[5]. Urol . 2002 May;167(5):2229-34.

Therapeutic Uses
Ifosfamide is currently approved for use in combination with other drugs to treat germ cell testicular cancer and is widely used to treat sarcomas in children and adults. Clinical trials have also shown its effectiveness against cervical cancer, lung cancer, and lymphoma. It is a common component of high-dose chemotherapy regimens, including bone marrow or stem cell transplantation; in these regimens, at total doses of 12-14 g/m², ifosfamide can cause severe neurotoxicity, including coma and death. This toxicity is believed to be caused by its metabolite, chloroacetaldehyde. In addition to hemorrhagic cystitis, ifosfamide can cause nausea, vomiting, anorexia, leukopenia, nephrotoxicity, and central nervous system disorders (especially drowsiness and confusion). Ifosfamide can be used in combination with other antitumor drugs and drugs for the prevention of hemorrhagic cystitis (such as mesna) to treat germ cell testicular tumors. /Included in US product label/ Ifosfamide is a rational medical therapy for the treatment of head and neck cancers. (Evidence Level: IIID) / Not included in the US product label /
Ifosfamide is used to treat soft tissue sarcoma, Ewing's sarcoma, and Hodgkin's lymphoma and non-Hodgkin's lymphoma. /Not included in the US product label /
For more complete data on the therapeutic uses of ifosfamide (9 types), please visit the HSDB record page.

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Drug Warnings
Ifosfamide is a common component of high-dose chemotherapy regimens (including bone marrow or stem cell transplantation); in these regimens, at total doses of 12–14 g/m², it can cause serious neurotoxicity, including coma and death. This toxicity is thought to be caused by its metabolite chloroacetaldehyde. In addition to hemorrhagic cystitis, ifosfamide can cause nausea, vomiting, anorexia, leukopenia, nephrotoxicity, and central nervous system disorders (especially drowsiness and confusion).
Ifosfamide is excreted into breast milk. Breastfeeding is not recommended during chemotherapy because chemotherapy can pose risks to infants (adverse reactions, mutagenicity, and carcinogenicity).
Ifosfamide's bone marrow suppression may lead to an increased incidence of microbial infections, delayed wound healing, and gingival bleeding. Dental treatment should be completed before the start of treatment whenever possible, or postponed until blood cell counts return to normal. Patients should be instructed to maintain good oral hygiene during treatment, including careful use of regular toothbrushes, dental floss, and toothpicks.
Many side effects of antitumor treatments are unavoidable and are manifestations of the drug's pharmacological effects. Some of these adverse reactions (such as leukopenia and thrombocytopenia) are actually used as parameters to aid in individual dose adjustment.
For more complete data on drug warnings for ifosfamide (20 in total), please visit the HSDB record page.

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Pharmacodynamics
Ifosfamide requires activation by hepatic microsomal enzymes to reach its active metabolite in order to exert its cytotoxic effects. Activation is achieved through hydroxylation of the 4-carbon atom of the ring, forming the unstable intermediate 4-hydroxyifosfamide. This metabolite is then rapidly degraded into the stable urinary metabolite 4-ketoifosfamide. Stable urinary metabolites, such as 4-carboxyifosfamide, are formed after ring opening. These urinary metabolites have not been found to be cytotoxic. In addition, N,N-bis(2-chloroethyl)phosphodiamid (ifosfamide) and acrolein have also been found. The major urinary metabolites of ifosfamide, dechloroethylifosfamide and dechloroethylcyclophosphamide, are formed by enzymatic oxidation of the chloroethyl side chain followed by dealkylation. Studies have shown that the alkylated metabolites of ifosfamide can interact with DNA. Ifosfamide does not exhibit cell cycle specificity. Ifosfamide is an alkylating agent belonging to the oxazolidinedicarboxylic acid class, with a structure related to cyclophosphamide [2]. Its antitumor effect is mediated by active metabolites that can form intra- and inter-strand DNA crosslinks, inhibiting DNA replication and causing cell death [1]. It has been approved for the treatment of a variety of solid tumors, including testicular, ovarian, lung, and bladder cancer [2]. Mesna is commonly used as a protectant to prevent hemorrhagic cystitis by binding to the toxic metabolite acrolein [2]. It has also shown activity against cyclophosphamide-resistant tumor cells due to differences in metabolic activation and DNA repair pathways [3].

C7H15CL2N2O2P

261.09

260.024

C, 32.20; H, 5.79; Cl, 27.16; N, 10.73; O, 12.26; P, 11.86

3778-73-2

3690

White to off-white solid powder

1.3±0.1 g/cm3

336.1±52.0 °C at 760 mmHg

48ºC

157.1±30.7 °C

0.0±0.7 mmHg at 25°C

1.506

0.23

1

4

5

14

218

0

ClC([H])([H])C([H])([H])N1C([H])([H])C([H])([H])C([H])([H])OP1(N([H])C([H])([H])C([H])([H])Cl)=O

HOMGKSMUEGBAAB-UHFFFAOYSA-N

InChI=1S/C7H15Cl2N2O2P/c8-2-4-10-14(12)11(6-3-9)5-1-7-13-14/h1-7H2,(H,10,12)

N,3-bis(2-chloroethyl)-2-oxo-1,3,2lambda5-oxazaphosphinan-2-amine

NSC-109724; Isophosphamide; Ifomide; NSC 109724; NSC109724; Iphosphamid; iphosphamide; Isoendoxan; IsoEndoxan; isophosphamide; Naxamide; Trade names: Cyfos; Ifex; Ifosfamidum

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Solubility in Formulation 1: ≥ 2.5 mg/mL (9.58 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (9.58 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (9.58 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 25 mg/mL (95.75 mM) in 0.5% CMC-Na/saline water (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)