Granisetron and Beta-agonists may be prescribed together under the supervision of your health care provider. Examples of Beta-agonists include: Advair, Combivent, Foradil, Proventil, Serevent, and Ventolin. Although rare, Granisetron can increase the risk of a dangerous change in heartbeat or heart rhythm. Very rarely, Beta-agonists have also caused changes in heart rate or rhythm. Additional risk factors for this rare interaction include females, patients with certain pre-existing heart conditions (such as prior heart attack, angina, heart failure, heart rhythm disturbances), patients receiving certain Diuretics (water pills such as Hydrochlorothiazide) which can decrease the level of potassium in the blood, patients with a low potassium level in the blood due to excessive vomiting or diarrhea, or patients with congenital Long QT syndrome (a rare genetic syndrome). Seek medical attention immediately if you notice side effects like chest pain, dizziness, fainting or falling spells, palpitations, shortness of breath, or a change in your heart beat (such as a fast or irregular heart beat) while taking these drugs together.

Limit excessive Caffeine intake (examples: coffee, teas, colas, chocolate and some herbal supplements) while taking Sympathomimetics and avoid medicines containing additional Caffeine whenever possible. Examples of Sympathomimetics include medicines used to treat asthma and other breathing problems like Albuterol, Arformoterol, Formoterol, Salmterol and others. Taking a high amount of Caffeine with the listed drugs can increase the risk of nausea, nervousness, palpitations, problems with sleep, rapid heartbeat, or other side effects.

Side effects from Tolterodine may get worse if you take grapefruit juice. Do not significantly alter your intake of grapefruit or grapefruit juice while taking Tolterodine. Discuss any new or worsening side effects, such as constipation, dizziness, difficulty with urination, dry mouth and eyes, changes in vision, fast heartbeat, or confusion, with your health care provider.

The intake of Alcoholic beverages may decrease the actions of Tolterodine because Alcohol may increase urination. You may wish to limit your intake of Alcoholic beverages while taking Tolterodine. Do not drive or operate machinery until you know how these drugs affect you.

The intake of beverages containing caffeine may decrease the actions of Tolterodine because Caffeine may increase urination. You may wish to limit your caffeine intake (including intake of coffee, colas, teas, or herbal supplements) while taking Tolterodine.

Although Vasopressin, ADH (Pitressin) and Ethanol (Alcohol) can interact, generally, these drugs are only used together in a hospital or clinic. While Alcohol might reduce the effectiveness of Vasopressin, it is rare to see these two drugs given together.