In the U.S.—

In Canada—

• Antidysmenorrheal
• Labor (premature), inhibitor
• Senility symptoms treatment adjunct
• Vasospastic therapy adjunct

Isoxsuprine (eye-SOX-syoo-preen) belongs to the group of medicines called vasodilators. Vasodilators increase the size of blood vessels. Isoxsuprine is used to treat problems resulting from poor blood circulation.

It may also be used for other conditions as determined by your doctor.

Isoxsuprine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Tablets (U.S. and Canada)

Parenteral
• Injection (Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For isoxsuprine, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to isoxsuprine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Isoxsuprine has not been shown to cause birth defects in humans. However, isoxsuprine given shortly before delivery may cause fast heartbeat and other problems (low blood sugar, bowel problems, low blood pressure) in the newborn.

Breast-feeding—Isoxsuprine has not been reported to cause problems in nursing babies.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of isoxsuprine in the elderly with use in other age groups. However, isoxsuprine may reduce tolerance to cold temperatures in elderly patients.

Other medicines—Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Tell your health care professional if you are taking any other prescription or nonprescription (over-the-counter [OTC]) medicine, or if you smoke.

• Angina (chest pain) or
• Bleeding problems or
• Glaucoma or
• Hardening of the arteries or
• Heart attack (recent) or
• Stroke (recent)—The chance of side effects may be increased

If this medicine upsets your stomach, it may be taken with meals, milk, or antacids.

Dosing—

The dose of isoxsuprine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of isoxsuprine. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine.

• For oral dosage form (tablets):
  • For poor blood circulation:
    • Adults—10 to 20 milligrams (mg) three or four times a day.

Missed dose—

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

It may take some time for this medicine to work. If you feel that the medicine is not working, do not stop taking it on your own. Instead, check with your doctor.

The helpful effects of this medicine may be decreased if you smoke. If you have any questions about this, check with your doctor.

Dizziness may occur, especially when you get up from a lying or sitting position or climb stairs. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• Rare
  • Chest pain;  dizziness or faintness (more common for injection);  fast heartbeat (more common for injection);  shortness of breath;  skin rash 
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if the following side effects continue or are bothersome:

• Less common
  • Nausea or vomiting (more common for injection) 
  
  

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

Although this use is not included in U.S. product labeling, isoxsuprine is used in certain women to stop premature labor.

In addition to the above information, the following information applies when this medicine is used to stop premature labor:

• Before you begin treatment with this medicine, tell your doctor if you have any of the following medical problems:
  • Asthma
  • Diabetes mellitus (sugar diabetes)
  • Heart disease
  • High blood pressure
  • Overactive thyroid
• Check with your doctor immediately:
  • if your contractions begin again or your water breaks.
  • if you notice chest pain or shortness of breath while taking isoxsuprine.