SCOTTSDALE, ARIZONA—Dihydroergotamine (DHE) remains underused in the treatment of migraine and daily severe headaches, especially in inpatient settings, according to an overview presented at the American Headache Society’s 2014 Scottsdale Headache Symposium.
The drug offers several clinical advantages, said Priyanka Chaudhry, MD, a neurologist specializing in headache treatment at the University of Texas Southwestern Medical Center in Dallas.
When used in combination with an antiemetic such as metoclopramide, DHE is as effective as opiates, valproate, and ketorolac in relieving migraine headache and preventing relapses, said Dr. Chaudhry. Its bioavailability is 100% when given intramuscularly or IV and about 40% when given as a nasal spray, she added.
With its relatively long half-life of 10 to 13 hours, DHE also poses less risk of physical dependence than does ergotamine, Dr. Chaudhry noted. In a 2011 uncontrolled retrospective study, its cumulative positive effects persisted for as long as one month after patient discharge, she said.
Dr. Chaudhry typically starts patients on an infusion of 0.3 mg of DHE given over 45 minutes. If the patient tolerates this dose, she increases it to 0.5 mg, then 0.75 mg, and then 1 mg every six to eight hours, she said. When the patient is free of headaches, Dr. Chaudhry reduces the dose to 0.5 mg. She prefers that patients be headache-free for 24 hours before discontinuing DHE, although this goal is not always achievable, she noted.
Treatment with DHE for five days seems to be more effective than shorter courses, added Dr. Chaudhry. She therefore will admit patients to the infusion clinic for five days and readmit them later for follow-up treatment with lidocaine.
DHE is associated with several potentially serious adverse effects. “It can be very harsh on veins, so if you’re admitting somebody in an inpatient setting, it is preferable to order a midline catheter or a peripherally inserted central catheter line,” said Dr. Chaudhry. Patients also can have chest pain or warmth or pressure in the neck during DHE infusion, especially during the first time they are exposed to a given dose of the drug, she noted. “This side effect is not a contraindication for use,” Dr. Chaudhry emphasized. “But consider a slow infusion and do not [give a] bolus.” She orders electrocardiograms for patients who have these side effects, but sees no need to monitor cardiac enzymes.
Nausea is the most common side effect of DHE and can be treated with 8 mg of odansetron, said Dr. Chaudhry. She adds a second antiemetic such as promethazine as needed, decreases the rate of DHE infusion, and reduces the dose if nausea persists, she said. Clinicians also may consider adding 50 mg of hydroxyzine orally or intramuscularly every six hours, starting at 25 mg if patients are relatively small or sensitive to medications, she said. DHE also can cause light-headedness, diarrhea, abdominal cramping, and leg cramps, noted Dr. Chaudhry. Patients who are pregnant or have renal or hepatic failure, uncontrolled hypertension, sepsis, or vascular disease should not take DHE, she cautioned.