Drug reference

Busulfan

Alkylating agent (bifunctional alkyl-sulfonate; antineoplastic) · Antineoplastic

Also known as Busulphan

START

0.8 mg/kg IV every 6 h × 16 doses (standard 4-day myeloablative); AUC monitoring

TYPICAL MAX

AUC-guided (typical target ~900–1500 µMol·min/dose)

STOP IF

Hepatic VOD/SOS signs, severe seizure, or pulmonary fibrosis

WATCH

AUC monitoring, LFTs, weight, abdominal pain (VOD), seizure prophylaxis (e.g., levetiracetam)

CDSCO approvedATC L01AB01

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 6min · infusion start
PEAK: 2h · end infusion
t½: 2.5h · t½
DURATION: 4d · 4-day cond

EXCRETION

Renal — mainly metabolites

route + CYP

INTERACTIONS

12 major

SEVERE in our sources

PREGNANCY

Contraindicated — fetal harm; effective contraception required.

FDA category + note

Top interactionssee all 12 →

AzolesSevereTextbookHarrison 22e · p1742
ImidazolesSevereTextbookG&G 14e · p1350
AdalimumabSevereDatabaseDDInter
BaricitinibSevereDatabaseDDInter

Mechanism

Bifunctional alkyl-sulfonate that crosslinks DNA via guanine N7 → cell-cycle non-specific apoptosis; high cytotoxicity for haematopoietic stem cells → used in HSCT myeloablative conditioning and chronic myeloid leukaemia.

Indications

Conditioning for allogeneic / autologous haematopoietic stem-cell transplant (myeloablative)Chronic myeloid leukaemia (largely superseded by TKIs)

Dosing

Adult: IV conditioning: 0.8 mg/kg every 6 h × 16 doses over 4 days (with cyclophosphamide / fludarabine). PO CML maintenance (historical): 4–8 mg/day until response, then maintain.
Pediatric: Weight-banded conditioning per protocol; therapeutic drug monitoring (AUC target) widely used.
Renal adjustment: No fixed adjustment; therapeutic drug monitoring guides dose.
Hepatic adjustment: Use with caution; AUC-guided dosing.
Geriatric: Lower-intensity protocols often used.
Max dose: AUC-guided; 0.8 mg/kg q6h × 16 doses in standard 4-day myeloablative protocol

Pharmacokinetics

Onset

Cytotoxicity over days

Peak effect

End of infusion (IV)

Duration

4-day conditioning cycle

Half-life

~2.5 h

Bioavailability

~80% (oral) — variable; IV preferred for AUC control

Protein binding

~32%

Metabolism

Hepatic GSH conjugation (mostly via GSTA1)

Excretion

Renal (mainly metabolites)

Contraindications

Severe hypersensitivity
Caution: significant cytopenias, hepatic impairment, prior cranial irradiation (seizure risk)

Side effects

Common

Severe myelosuppression (intended in HSCT)Nausea/vomitingMucositisDiarrhoeaSkin hyperpigmentation

Serious

Severe pancytopenia / aplasia
Hepatic veno-occlusive disease (sinusoidal obstruction syndrome — boxed)
Pulmonary fibrosis / 'busulfan lung'
Seizures (high-dose conditioning)
Secondary malignancies (MDS/AML)
Cardiac tamponade (IV)

Pregnancy & lactation

Pregnancy

Contraindicated — fetal harm; effective contraception required.

Lactation

Contraindicated during therapy.

Drug interactions

Azoles

Severe

Textbook

Increased plasma levels of busulfan.

Source: Harrison 22e · p1742

Imidazoles

Severe

Textbook

Increased incidence of veno-occlusive disease (VOD) and hepatotoxicity.

Not specified, but implies avoidance due to increased severe toxicities.

Source: G&G 14e · p1350

Adalimumab

Severe

Database