THIOGUANINE

Brand & Generic Names

Lanvis

Basic Information

• Habit forming? No
• Prescription needed? Yes
• Available as generic? Yes
• Drug class: Antineoplastic

Uses

Treats some forms of leukemia.

Dosage & Usage Information

How to take:
Tablets--Swallow with liquid. If you can't swallow whole, crumble tablet and take with liquid or food. Instructions to take on empty stomach mean 1 hour before or 2 hours after eating.

When to take:
According to doctor's instructions.

If you forget a dose:
Skip the missed dose and return to regular schedule. Don't double dose.

What drug does:
Interferes with growth of cancer cells.

Time lapse before drug works:
Varies greatly among patients.

Don't take with:
Any other medicines (including over-the-counter drugs such as cough and cold medicines, laxatives, antacids, diet pills, caffeine, nose drops or vitamins) without consulting your doctor.

Overdose

SYMPTOMS:
None expected.

WHAT TO DO:

Overdose unlikely to threaten life. If person takes much larger amount than prescribed, call doctor, poison-control center or hospital emergency room for instructions.

Possible Adverse Reactions or Side Effects

Life-threatening:

Black, tarry stools. Discontinue. Seek emergency treatment.

Common:

• Appetite loss, diarrhea, skin rash.
• Nausea.

Infrequent:

Bloody urine; hoarseness or cough; fever or chills; lower back or side pain; painful or difficult urination; red spots on skin; unusual bleeding or bruising; joint pain; swollen feet and legs; unsteady gait.

Rare:

Mouth and lip sores; jaundice (yellow skin and eyes).

Warnings & Precautions

Don't take if:

• You are allergic to thioguanine.
• You have chicken pox or shingles.

Before you start, consult your doctor:

• If you have gout.
• If you have an infection.
• If you have kidney or liver disease.
• If you have had radiation or cancer chemotherapy within 6 weeks.

Over age 60:
Adverse reactions and side effects may be more frequent and severe than in younger persons. You may need smaller doses for shorter periods of time.

Pregnancy:

• Risk to unborn child outweighs drug benefits. Don't use.
• Don't use birth control pills for contraception.

Breast-feeding:
Drug may pass into milk. Avoid drug or discontinue nursing until you finish medicine. Consult doctor for advice on maintaining milk supply.

Infants & children:
No special problems expected.

Prolonged use:

• Increased likelihood of side effects.
• Talk to your doctor about the need for follow-up medical examinations or laboratory studies to check kidney and liver function, serum uric acid, and complete blood counts (white blood cell count, platelet count, red blood cell count, hemoglobin, hematocrit).

Skin & sunlight:
No problems expected.

Driving, piloting or hazardous work:
No problems expected.

Discontinuing:
Report to your doctor any of these symptoms that occur after discontinuing: black, tarry stools; bloody urine; hoarseness or cough; fever or chills; lower back or side pain; painful or difficult urination; red spots on skin; unusual bleeding or bruising.

Others:

• Advise any doctor or dentist whom you consult that you take this medicine.
• May affect results in some medical tests.
• Don't use birth control pills for contraception.

Possible Interaction with Other Drugs

GENERIC NAME	COMBINED EFFECT
------------------------	-----------------------
Antithyroid agents*	More likelihood of toxicity of both
	drugs.
Azathioprine	More likelihood of toxicity of both
	drugs.
Chloramphenicol	More likelihood of toxicity of both
	drugs.
Clozapine	Toxic effect on bone marrow.
Colchicine	May need increased dosage of
	colchicine.
Flucytosine	More likelihood of toxicity of both
	drugs.
Interferon	More likelihood of toxicity of both
	drugs.
Levamisole	Increased risk of bone marrow
	depression.
Plicamycin	More likelihood of toxicity of both
	drugs.
Probenecid	More likelihood of toxicity of both
	drugs.
Sulfinpyrazone	May need increased dosage of
	sulfinpyrazone.
Tiopronin	Increased risk of toxicity to bone
	marrow.
Vaccines, live	Increased risk of toxicity or reduced
or killed	effectiveness of vaccine.
Zidovudine	More likelihood of toxicity of both
	drugs.

Possible Interaction with Other Substances

INTERACTS WITH	COMBINED EFFECT
---------------	---------------
Alcohol:	Increased side effects.
Beverages:	No special problems expected.
Cocaine:	Increased side effects.
Foods:	No special problems expected.
Marijuana:	No special problems expected.
Tobacco:	No special problems expected.