DEXTROTHYROXINE

Brand & Generic Names

Choloxin

Basic Information

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

Uses

Lowers blood cholesterol and low-density lipoprotein in patients who don't respond to low-fat diet and weight loss alone.

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 your doctor's instructions.

If you forget a dose:
Take as soon as you remember up to 2 hours late. If more than 2 hours, wait for next scheduled dose (don't double this dose).

What drug does:
Increases breakdown of LDL (low-density lipoprotein).

Time lapse before drug works:
1 to 2 months.

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:

None expected.

Common:

• Tremor, headache, irritability, insomnia.
• Appetite change, diarrhea, leg cramps, menstrual irregularities, fever, heat sensitivity, unusual sweating, weight loss.

Infrequent:

Hives, rash, vomiting, chest pain, rapid and irregular heartbeat, shortness of breath.

Rare:

None expected.

Warnings & Precautions

Don't take if:

• You have had a heart attack within 6 weeks.
• You have no thyroid deficiency, but want to use this to lose weight.

Before you start, consult your doctor:

• If you have heart disease or high blood pressure.
• If you have diabetes.
• If you have Addison's disease, have had adrenal gland deficiency or use epinephrine, ephedrine or isoproterenol for asthma.

Over age 60:
More sensitive to thyroid hormone. May need smaller doses.

Pregnancy:
Considered safe if for thyroid deficiency only.

Breast-feeding:
Present in milk. Considered safe if dose is correct.

Infants & children:
Use only under medical supervision.

Prolonged use:

• No problems expected, if dose is correct.
• Talk to your doctor about the need for follow-up medical examinations or laboratory studies to check serum cholesterol and triglycerides.

Skin & sunlight:
No problems expected.

Driving, piloting or hazardous work:
No problems expected.

Discontinuing:
Don't discontinue without consulting doctor. Dose may require gradual reduction if you have taken drug for a long time. Doses of other drugs may also require adjustment.

Others:

• Digestive upsets, tremors, cramps, nervousness, insomnia or diarrhea may indicate need for dose adjustment.
• Advise any doctor or dentist whom you consult that you take this medicine.
• May affect results in some medical tests.
• Stay on a low-fat diet.

Possible Interaction with Other Drugs

GENERIC NAME OR DRUG CLASS	COMBINED EFFECT
Amphetamines*	Increased amphetamine effect.
Anticoagulants, oral*	Increased anticoagulant effect.
Antidepressants,	Increased antidepressant effect.
tricyclic (TCA)*	Irregular heartbeat.
Antidiabetics*	Antidiabetic may require
	adjustment.
Aspirin (large doses,	Increased dextrothyroxine effect.
Barbiturates*	Decreased barbiturate effect.
Beta-adrenergic blockers*	Possible decreased beta blockers
	effect.
Cholestyramine	Decreased dextrothyroxine effect.
Colestipol	Decreased dextrothyroxine effect.
Contraceptives,	Decreased dextrothyroxine effect.
Cortisone drugs*	Requires dose adjustment to prevent
	cortisone deficiency.
Digitalis preparations*	Decreased digitalis effect.
Ephedrine	Increased ephedrine effect.
Epinephrine	Increased epinephrine effect.
Estrogens*	Decreased dextrothyroxine effect.
Methylphenidate	Increased methylphenidate effect.
Phenytoin	Possible decreased dextrothyroxine
	effect.

Possible Interaction with Other Substances

INTERACTS WITH	COMBINED EFFECT
---------------	---------------
Alcohol:	None expected.
Beverages:	None expected.
Cocaine:	Excess stimulation. Avoid.
Soybeans.	Heavy consumption interferes with
	thyroid function.
Marijuana:	None expected.
Tobacco:	None expected.