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Related to Lanvis: thioguanine


(thye-oh-gwon-een) ,


(trade name),


(trade name)


Therapeutic: antineoplastics
Pharmacologic: antimetabolites
Pregnancy Category: D


Induction and consolidation of remission in acute nonlymphocytic leukemia (in combination with other agents).


Incorporated into DNA and RNA, subsequently disrupting synthesis (cell-cycle S phase–specific).

Therapeutic effects

Death of rapidly replicating cells, especially malignant ones.
Immunosuppressive properties.


Absorption: Variable and incomplete (average, 30%) following oral administration.
Distribution: Probably does not enter the CSF. Crosses the placenta.
Metabolism and Excretion: Highly metabolized by the liver; undergoes methylation via thiopurine methyltransferase (TPMT).
Half-life: 11 hr.

Time/action profile (effect on blood counts)

PO7–10 days14 days21 days


Contraindicated in: Hypersensitivity; Obstetric / Lactation: Pregnancy or lactation; Tumors with demonstrated resistance to thioguanine or mercaptopurine (usually complete cross-resistance).
Use Cautiously in: Patients with childbearing potential; Infections; ↓ bone marrow reserve; Other chronic debilitating illnesses; genetic implication Patients with TPMT enzyme deficiency (substantial dosage reductions are required to avoid hematologic adverse events).

Adverse Reactions/Side Effects

Ear, Eye, Nose, Throat

  • loss of vibratory sense


  • diarrhea
  • hepatotoxicity
  • jaundice
  • nausea
  • stomatitis
  • vomiting
  • anorexia
  • hepatic veno-occlusive disease


  • gonadal suppression


  • dermatitis
  • rash


  • anemia (most frequent)
  • leukopenia (most frequent)
  • thrombocytopenia (most frequent)
  • pancytopenia (most frequent)


  • hyperuricemia (most frequent)


  • unsteady gait


Drug-Drug interaction

↑ bone marrow depression with other antineoplastics or radiation therapy.Sulfasalazine, olsalazine and mesalamine may ↓ metabolism and ↑ effects.


Many other protocols are used
Oral (Adults and Children) Induction—2 mg/kg (75–100 mg/m2) per day, rounded off to nearest 20 mg given as single dose; after 4 wk may ↑ to 3 mg/kg.Maintenance—2–3 mg/kg (100 mg/m2) per day.


Tablets: 40 mg

Nursing implications

Nursing assessment

  • Monitor for bone marrow depression. Assess for bleeding (bleeding gums, bruising, petechiae, guaiac stools, urine, and emesis) and avoid IM injections and rectal temperatures if platelet count is low. Apply pressure to venipuncture sites for 10 min. Assess for signs of infection during neutropenia. Anemia may occur. Monitor for increased fatigue, dyspnea, and orthostatic hypotension.
  • Monitor intake and output, appetite, and nutritional intake. Administration of an antiemetic and adjustment of diet as tolerated may help maintain fluid and electrolyte balance and nutritional status.
  • Monitor for symptoms of tumor lysis syndrome (increased uric acid, phosphorous, and potassium that may lead to organ failure). Encourage patient to drink at least 2 L of fluid/day. Allopurinol may be used to decrease uric acid levels.
  • Lab Test Considerations: Monitor CBC and differential at least weekly, daily in patients with elevated leukocyte counts. Bone marrow suppression usually occurs in 2–4 wk, but rapid ↓ in leukocyte count may occur in 1–2 wk. Notify health care professional of any rapid or severe drop in blood counts; therapy may need to be withheld until values stabilize. Bone marrow aspiration may be required to detect thioguanine-induced hypoplasia.
    • Monitor for ↑ uric acid, creatinine, and BUN.
    • Monitor for hepatotoxicity evidenced by ↑ AST, ALT, LDH, serum bilirubin, and alkaline phosphatase.

Potential Nursing Diagnoses

Risk for infection (Side Effects)
Risk for injury (Side Effects)


  • high alert: Fatalities have occurred with chemotherapeutic agents. Before administering, clarify all ambiguous orders; double check single, daily, and course-of-therapy dose limits; have second practitioner independently double check original order and dose calculations.
  • Administration of live-virus vaccines to immunocompromised patients should be avoided.
  • Oral: Administer daily dose at bedtime. May also be divided into 2 doses and given 12 hr apart.
    • If patient has difficulty swallowing tablets, confer with pharmacist regarding preparation of syrup.

Patient/Family Teaching

  • Instruct patient to take thioguanine as directed, even if nausea and vomiting occur. If vomiting occurs shortly after dose is taken, consult health care professional. Take combinations of drugs at prescribed times. If a dose is missed, do not take at all.
  • Instruct patient to notify health care professional if decreased urine output; swelling of lower extremities; yellowing of skin; nausea; vomiting; severe diarrhea; mouth sores; fever; chills; sore throat; signs of infection; bleeding gums; bruising; petechiae; or blood in urine, stool, or emesis occurs.
  • Caution patient to avoid crowds and persons with known infections. Instruct patient to use soft toothbrush and electric razor. Caution patient not to drink alcoholic beverages or take products containing aspirin or NSAIDs.
  • This medication may cause gonadal suppression; however, patient should still use birth control. Advise patient to inform health care professional immediately if pregnancy is suspected.
  • Instruct patient to inspect oral mucosa for redness and ulceration. If ulceration occurs, advise patient to use sponge brush and rinse mouth with water after eating and drinking. Topical agents may be used if pain interferes with eating. Stomatitis pain may require treatment with opioid analgesics.
  • Instruct patient not to receive any vaccinations without advice of health care professional.
  • Advise patient of need for medical follow-up and frequent lab tests.

Evaluation/Desired Outcomes

  • Achievement of remission in patients with leukemia.
Drug Guide, © 2015 Farlex and Partners


A brand name for THIOGUANINE (tioguanine).
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005