No overdoses of MAXALT were reported during clinical trials.
Rizatriptan 40 mg (administered as either a single dose or as two doses with
a 2-hour interdose interval) was generally well tolerated in over 300 patients;
dizziness and somnolence were the most common drug-related adverse effects.
In a clinical pharmacology study in which 12 subjects received rizatriptan,
at total cumulative doses of 80 mg (given within four hours), two subjects
experienced syncope and/or bradycardia. One subject, a female aged 29 years,
developed vomiting, bradycardia, and dizziness beginning three hours after
receiving a total of 80 mg rizatriptan (administered over two hours); a third
degree AV block, responsive to atropine, was observed an hour after the onset of
the other symptoms. The second subject, a 25 year old male, experienced
transient dizziness, syncope, incontinence, and a 5-second systolic pause (on
ECG monitor) immediately after a painful venipuncture. The venipuncture occurred
two hours after the subject had received a total of 80 mg rizatriptan
(administered over four hours).
In addition, based on the pharmacology of rizatriptan, hypertension or other
more serious cardiovascular symptoms could occur after overdosage.
Gastrointestinal decontamination, (i.e., gastric lavage followed by activated
charcoal) should be considered in patients suspected of an overdose with MAXALT.
Clinical and electrocardiographic monitoring should be continued for at least 12
hours, even if clinical symptoms are not observed.
The effects of hemo- or peritoneal dialysis on serum concentrations of
rizatriptan are unknown.
MAXALT should not be given to patients with
ischemic heart disease (e.g., angina pectoris, history of myocardial infarction,
or documented silent ischemia) or to patients who have symptoms or findings
consistent with ischemic heart disease, coronary artery vasospasm, including
Prinzmetal's variant angina, or other significant underlying cardiovascular
Because MAXALT may increase blood pressure, it should not be
given to patients with uncontrolled hypertension (see
MAXALT should not be used within 24 hours of treatment with
another 5-HT1 agonist, or an ergotamine-containing or
ergot-type medication like dihydroergotamine or methysergide.
MAXALT should not be administered to patients with
hemiplegic or basilar migraine.
Concurrent administration of MAO inhibitors or use of
rizatriptan within 2 weeks of discontinuation of MAO inhibitor therapy is
CLINICAL PHARMACOLOGY, Drug
MAXALT is contraindicated in patients who are hypersensitive
to rizatriptan or any of its inactive ingredients.
DRUG ABUSE AND DEPENDENCE
Although the abuse potential of MAXALT has not been specifically assessed, no
abuse of, tolerance to, withdrawal from, or drug-seeking behavior was observed
in patients who received MAXALT in clinical trials or their extensions. The
5-HT1B/1D agonists, as a class, have not been associated
with drug abuse.