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 aminophylline, oxtriphylline, or theophylline, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to aminophylline, ethylenediamine (contained in aminophylline), oxtriphylline, or theophylline.

Diet—Make certain your health care professional knows if you are on any special diet, such as a high-protein, low-carbohydrate or a low-protein, high-carbohydrate diet.

Pregnancy—Aminophylline, oxtriphylline, and theophylline are frequently used to treat asthma in pregnant women. Although there are no studies on birth defects in humans, problems have not been reported. Some studies in animals have shown that aminophylline, oxtriphylline, and theophylline can cause birth defects when given in doses many times the human dose.

Because your ability to clear theophylline from your body may decrease later in pregnancy, your doctor may want to take blood samples during your pregnancy to measure the amount of medicine in the blood. This will help your doctor decide whether the dose of this medicine should be changed.

Theophylline crosses the placenta. Use of aminophylline, oxtriphylline, or theophylline during pregnancy may cause unwanted effects such as fast heartbeat, irritability, jitteriness, or vomiting in the newborn infant if the amount of medicine in your blood is too high.

Breast-feeding—Theophylline passes into the breast milk and may cause irritability in nursing babies of mothers taking aminophylline, oxtriphylline, or theophylline.

Children—Very young children and newborn infants require a lower dose than older children. If the amount of theophylline in the blood is too high, side effects are more likely to occur. Your doctor may want to take blood samples to determine whether a dose change is needed.

Older adults—Patients older than 60 years of age are likely to require a lower dose than younger adults. If the amount of theophylline is too high, side effects are more likely to occur. Your doctor may want to take blood samples to determine whether a dose change is needed.

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 aminophylline, oxtriphylline, or theophylline, it is especially important that your health care professional know if you are taking any of the following:

• Beta-adrenergic blocking agents including those used in the eyes (acebutolol [e.g., Sectral], atenolol [e.g., Tenormin], betaxolol [e.g., Betoptic, Kerlone], bisoprolol [e.g., Zebeta], carteolol [e.g., Cartrol], labetalol [e.g., Normodyne], levobunolol [e.g., Betagan], metipranolol [e.g., OptiPranolol], 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, Timoptic])—These medicines may prevent aminophylline, oxtriphylline, or theophylline from working properly

• Cimetidine (e.g., Tagamet) or
• Ciprofloxacin (e.g., Cipro) or
• Clarithromycin (e.g., Biaxin) or
• Enoxacin (e.g., Penetrex) or
• Erythromycin (e.g., E-Mycin) or
• Fluvoxamine (e.g., Luvox) or
• Mexiletine (e.g., Mexitil) or
• Pentoxifylline (e.g., Trental) or
• Propranolol (e.g., Inderal) or
• Tacrine (e.g., Cognex) or
• Thiabendazole or
• Ticlopidine (e.g., Ticlid) or
• Troleandomycin (e.g., TAO)—These medicines may increase the effects of aminophylline, oxtriphylline, or theophylline

• Moricizine (e.g., Ethmozine) or
• Phenytoin (e.g., Dilantin) or
• Rifampin (e.g., Rifadin)—These medicines may decrease the effects of aminophylline, oxtriphylline, or theophylline

• Smoking tobacco or marijuana—Starting or stopping smoking may change the effectiveness of these medicines

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

• Convulsions (seizures)—Aminophylline, oxtriphylline, or theophylline may make this condition worse

• Heart failure or
• Liver disease or
• Underactive thyroid—The effects of aminophylline, oxtriphylline, or theophylline may be increased