Before Using This Medicine

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 ritodrine, the following should be considered:

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

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. When you are taking or receiving ritodrine, it is especially important that your health care professional know if you are taking any of the following:

• Beta-adrenergic blocking agents (acebutolol [e.g., Sectral], atenolol [e.g., Tenormin], betaxolol [e.g., Kerlone], bisoprolol [e.g., Zebeta], carteolol [e.g., Cartrol], labetalol [e.g., Normodyne], metoprolol [e.g., Lopressor], nadolol [e.g., Corgard], oxprenolol [e.g., Trasicor], penbutolol [e.g., Levatol], pindolol [e.g., Visken], propranolol [e.g., Inderal], sotalol [e.g., Sotacor], timolol [e.g., Blocadren])—Ritodrine may be less effective if it is used with any of these medicines

• Corticosteroids (cortisone-like medicines)—These medicines are often given together to the mother to help her baby's lungs develop. If you are taking corticosteroids, your dose may need to be changed if ritodrine is also taken or injected. Sometimes the combination of these medicines increases the chance of side effects occurring in the mother.

• Medicine for asthma or breathing problems—Because these products have some effects that are similar to those of ritodrine, the chance of side effects developing is increased when these medicines are used with ritodrine

Other medical problems—The presence of other medical problems may affect the use of ritodrine. Make sure you tell your doctor if you have any other medical problems, especially:

• Diabetes mellitus (sugar diabetes)—Ritodrine may make this condition worse

• Heart or blood vessel disease or
• Overactive thyroid, uncontrolled—Use of ritodrine may cause serious effects of the heart, including irregular heartbeat

• High blood pressure (hypertension), uncontrolled, or
• Migraine headaches (or history of)—Ritodrine may make these conditions worse. Rarely, use of ritodrine during a migraine headache may cause problems with blood circulation in the brain