What special precautions should I follow?  

Before using dihydroergotamine,

• tell your doctor and pharmacist if you are allergic to dihydroergotamine, other ergot alkaloids such as bromocriptine (Parlodel), ergonovine (Ergotrate), ergotamine (Cafergot, Ercaf, others), methylergonovine (Methergine), and methysergide (Sansert), or any other medications.
• do not take dihydroergotamine within 24 hours of taking ergot alkaloids such as bromocriptine (Parlodel), ergonovine (Ergotrate), ergotamine (Cafergot, Ercaf, others), methylergonovine (Methergine), and methysergide (Sansert); or other medications for migraine such as frovatriptan (Frova), naratriptan (Amerge), rizatriptan (Maxalt), sumatriptan (Imitrex), and zolmitriptan (Zomig).
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking. Be sure to mention any of the following: beta blockers such as propranolol (Inderal); cimetidine (Tagamet); clotrimazole (Lotrimin); cyclosporine (Neoral, Sandimmune); danazol (Danocrine); delavirdine (Rescriptor); diltiazem (Cardizem, Dilacor, Tiazac); epinephrine (Epipen); fluconazole (Diflucan); isoniazid (INH, Nydrazid); medications for colds and asthma; metronidazole (Flagyl); nefazodone (Serzone); oral contraceptives (birth control pills); selective serotonin reuptake inhibitors (SSRIs) such as citalopram (Celexa), fluoxetine (Prozac, Sarafem), fluvoxamine (Luvox), paroxetine (Paxil ), and sertraline (Zoloft); saquinavir (Fortovase, Invirase); verapamil (Calan, Covera, Isoptin, Verelan); zafirlukast (Accolate); and zileuton (Zyflo). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have a family history of heart disease and if you have or have ever had high blood pressure; high cholesterol; diabetes; Raynaud's disease (a condition that affects the fingers and toes); any disease that affects your circulation or arteries; sepsis (a severe infection of the blood); surgery on your heart or blood vessels; a heart attack; or kidney, liver, lung, or heart disease.
• tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking dihydroergotamine, call your doctor immediately.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking dihydroergotamine.
• tell your doctor if you use tobacco products. Smoking cigarettes while taking this medication increases the risk of serious side effects.

What special dietary instructions should I follow?   

Talk to your doctor about drinking grapefruit juice while taking this medicine.