WARNINGS
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should only be used where a clear diagnosis of migraine headache has been established.
CYP 3A4 Inhibitors (e.g. Macrolide Antibiotics and Protease Inhibitors)
There have been rare reports of serious adverse events in connection with the coadministration of dihydroergotamine and potent CYP 3A4 inhibitors, such as protease inhibitors and macrolide antibiotics, resulting in vasospasm that led to cerebral ischemia and/or and ischemia of the extremities. The use of potent CYP 3A4 inhibitors with dihydroergotamine should therefore be avoided (see CONTRAINDICATIONS ). Examples of some of the more potent CYP 3A4 inhibitors include: anti-fungals ketoconazole and itraconazole, the protease inhibitors ritonavir, nelfinavir, and indinavir, and macrolide antibiotics erythromycin, clarithromycin, and troleandomycin. Other less potent CYP 3A4 inhibitors should be administered with caution. Less potent inhibitors include saquinavir, nefazodone, fluconazole, grapefruit juice, fluoxetine, fluvoxamine, zileuton, and clotrimazole. These lists are not exhaustive, and the prescriber should consider the effects on CYP3A4 of other agents being considered for concomitant use with dihydroergotamine.
Fibrotic Complication
There have been reports of pleural and retroperitoneal fibrosis in patients following prolonged daily use of injectable dihydroergotamine mesylate. Rarely, prolonged daily use of other ergot alkaloid drugs has been associated with cardiac valvular fibrosis. Rare cases have also been reported in association with the use of injectable dihydroergotamine mesylate; however, in those cases, patients also received drugs known to be associated with cardiac valvular fibrosis.
Administration of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP, should not exceed the dosing guidelines and should not be used for chronic daily administration (see DOSAGE AND ADMINISTRATION ).
Risk of Myocardial Ischemia and/or Infarction and Other Adverse Cardiac Events
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should not be used by patients with documented ischemic or vasospastic coronary artery disease. (See CONTRAINDICATIONS .) It is strongly recommended that D.H.E. 45® (dihydroergotamine mesylate) Injection, USP not be given to patients in whom unrecognized coronary artery disease (CAD) is predicted by the presence of risk factors (e.g., hypertension, hypercholesterolemia, smoker, obesity, diabetes, strong family history of CAD, females who are surgically or physiologically postmenopausal, or males who are over 40 years of age) unless a cardiovascular evaluation provides satisfactory clinical evidence that the patient is reasonably free of coronary artery and ischemic myocardial disease or other significant underlying cardiovascular disease. The sensitivity of cardiac diagnostic procedures to detect cardiovascular disease or predisposition to coronary artery vasospasm is modest, at best. If, during the cardiovascular evaluation, the patient’s medical history or electrocardiographic investigations reveal findings indicative of or consistent with coronary artery vasospasm or myocardial ischemia, D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should not be administered. (See CONTRAINDICATIONS .)
For patients with risk factors predictive of CAD who are determined to have a satisfactory cardiovascular evaluation, it is strongly recommended that administration of the first dose of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP take place in the setting of a physician’s office or similar medically staffed and equipped facility unless the patient has previously received dihydroergotamine mesylate. Because cardiac ischemia can occur in the absence of clinical symptoms, consideration should be given to obtaining on the first occasion of use an electrocardiogram (ECG) during the interval immediately following D.H.E. 45® (dihydroergotamine mesylate) Injection, USP, in those patients with risk factors.
It is recommended that patients who are intermittent long-term users of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP and who have or acquire risk factors predictive of CAD, as described above, undergo periodic interval cardiovascular evaluation as they continue to use D.H.E. 45® (dihydroergotamine mesylate) Injection, USP.
The systematic approach described above is currently recommended as a method to identify patients in whom D.H.E. 45® (dihydroergotamine mesylate) Injection, USP may be used to treat migraine headaches with an acceptable margin of cardiovascular safety.
Cardiac Events and Fatalities
The potential for adverse cardiac events exists. Serious adverse cardiac events, including acute myocardial infarction, life-threatening disturbances of cardiac rhythm, and death have been reported to have occurred following the administration of dihydroergotamine mesylate injection. Considering the extent of use of dihydroergotamine mesylate in patients with migraine, the incidence of these events is extremely low.
Drug-Associated Cerebrovascular Events and Fatalities
Cerebral hemorrhage, subarachnoid hemorrhage, stroke, and other cerebrovascular events have been reported in patients treated with D.H.E. 45® (dihydroergotamine mesylate) Injection, USP; and some have resulted in fatalities. In a number of cases, it appears possible that the cerebrovascular events were primary, the D.H.E. 45® (dihydroergotamine mesylate) Injection, USP having been administered in the incorrect belief that the symptoms experienced were a consequence of migraine, when they were not. It should be noted that patients with migraine may be at increased risk of certain cerebrovascular events (e.g., stroke, hemorrhage, transient ischemic attack).
Other Vasospasm Related Events
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP, like other ergot alkaloids, may cause vasospastic reactions other than coronary artery vasospasm. Myocardial, peripheral vascular, and colonic ischemia have been reported with D.H.E. 45® (dihydroergotamine mesylate) Injection, USP.
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP associated vasospastic phenomena may also cause muscle pains, numbness, coldness, pallor, and cyanosis of the digits. In patients with compromised circulation, persistent vasospasm may result in gangrene or death. D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should be discontinued immediately if signs or symptoms of vasoconstriction develop.
Increase In Blood Pressure
Significant elevation in blood pressure has been reported on rare occasions in patients with and without a history of hypertension treated with dihydroergotamine mesylate injection. D.H.E. 45® (dihydroergotamine mesylate) Injection, USP is contraindicated in patients with uncontrolled hypertension. (See CONTRAINDICATIONS .)
An 18% increase in mean pulmonary artery pressure was seen following dosing with another 5-HT1 agonist in a study evaluating subjects undergoing cardiac catheterization.
PRECAUTIONS
General
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP may cause coronary artery vasospasm; patients who experience signs or symptoms suggestive of angina following its administration should, therefore, be evaluated for the presence of CAD or a predisposition to variant angina before receiving additional doses. Similarly, patients who experience other symptoms or signs suggestive of decreased arterial flow, such as ischemic bowel syndrome or Raynaud’s syndrome following the use of any 5-HT agonist are candidates for further evaluation. (See WARNINGS .)
Fibrotic Complications: see WARNINGS: Fibrotic Complications
Information for Patients
The text of a patient information sheet is printed at the end of this insert. To assure safe and effective use of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP, the information and instructions provided in the patient information sheet should be discussed with patients.
Patients should be advised to report to the physician immediately any of the following: numbness or tingling in the fingers and toes, muscle pain in the arms and legs, weakness in the legs, pain in the chest, temporary speeding or slowing of the heart rate, swelling, or itching.
Prior to the initial use of the product by a patient, the prescriber should take steps to ensure that the patient understands how to use the product as provided. (See Patient Information Sheet and product packaging .)
Administration of D.H.E. 45® (dihydroergotamine mesylate) Injection USP, should not exceed the dosing guidelines and should not be used for chronic daily administration (See DOSAGE AND ADMINISTRATION ).
Drug Interactions
Vasoconstrictors
D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should not be used with peripheral vasoconstrictors because the combination may cause synergistic elevation of blood pressure.
Sumatriptan
Sumatriptan has been reported to cause coronary artery vasospasm, and its effect could be additive with D.H.E. 45® (dihydroergotamine mesylate) Injection, USP. Sumatriptan and D.H.E. 45® (dihydroergotamine mesylate) Injection, USP should not be taken within 24 hours of each other. (See CONTRAINDICATIONS .)
Beta Blockers
Although the results of a clinical study did not indicate a safety problem associated with the administration of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP to subjects already receiving propranolol, there have been reports that propranolol may potentiate the vasoconstrictive action of ergotamine by blocking the vasodilating property of epinephrine.
Nicotine
Nicotine may provoke vasoconstriction in some patients, predisposing to a greater ischemic response to ergot therapy.
CYP 3A4 Inhibitors (e.g. Macrolide Antibiotics and Protease Inhibitors) See CONTRAINDICATIONS and WARNINGS .
SSRI’s
Weakness, hyperreflexia, and incoordination have been reported rarely when 5-HT1 agonists have been co-administered with SSRI’s (e.g., fluoxetine, fluvoxamine, paroxetine, sertraline). There have been no reported cases from spontaneous reports of drug interaction between SSRI’s and D.H.E. 45® (dihydroergotamine mesylate) Injection, USP.
Oral Contraceptives
The effect of oral contraceptives on the pharmacokinetics of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP has not been studied.
Carcinogenesis, Mutagenesis, Impairment of Fertility
Carcinogenesis
Assessment of the carcinogenic potential of dihydroergotamine mesylate in mice and rats is ongoing
Mutagenesis
Dihydroergotamine mesylate was clastogenic in two in vitro chromosomal aberration assays, the V79 Chinese hamster cell assay with metabolic activation and the cultured human peripheral blood lymphocyte assay. There was no evidence of mutagenic potential when dihydroergotamine mesylate was tested in the presence or absence of metabolic activation in two gene mutation assays (the Ames test and the in vitro mammalian Chinese hamster V79/HGPRT assay) and in an assay for DNA damage (the rat hepatocyte unscheduled DNA synthesis test). Dihydroergotamine was not clastogenic in the in vivo mouse and hamster micronucleus tests.
Impairment of Fertility
Impairment of fertility was not evaluated for D.H.E. 45® (dihydroergotamine mesylate) Injection, USP. There was no evidence of impairment of fertility in rats given intranasal doses of Migranal® Nasal Spray up to 1.6 mg/day (associated with mean plasma dihydroergotamine mesylate exposures [AUC] approximately 9 to 11 times those in humans receiving the MRDD of 4 mg).
Pregnancy
Pregnancy Category X. See CONTRAINDICATIONS
Nursing Mothers
Ergot drugs are known to inhibit prolactin. It is likely that D.H.E. 45® (dihydroergotamine mesylate) Injection, USP is excreted in human milk, but there are no data on the concentration of dihydroergotamine in human milk. It is known that ergotamine is excreted in breast milk and may cause vomiting, diarrhea, weak pulse, and unstable blood pressure in nursing infants. Because of the potential for these serious adverse events in nursing infants exposed to D.H.E. 45® (dihydroergotamine mesylate) Injection, USP, nursing should not be undertaken with the use of D.H.E. 45® (dihydroergotamine mesylate) Injection, USP. (See CONTRAINDICATIONS .)
Pediatric Use
Safety and effectiveness in pediatric patients have not been established.
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