Pharmacokinetics and tolerability of rizatriptan in pediatric migraineurs in a randomized study

Objective.— To evaluate the pharmacokinetic profile and tolerability of single doses of rizatriptan oral disintegrating tablets (ODTs) in pediatric migraineurs. Background.— Acute migraine treatment options for children are limited despite a rising migraine prevalence. No triptans are approved in those under 12, and only sumatriptan nasal spray (European Union) and almotriptan tablets (USA) are approved for those aged 12‐17. Appropriate dose selection based on body weight may be a factor in establishing treatment efficacy in this population. Methods.— Randomized, double‐blind, placebo‐controlled, parallel group, single‐dose study in 6‐ to 17‐year‐old migraineurs. The study was performed between acute migraine attacks. Subjects were allocated to 1 of 2 groups based on body weight: (1) those weighing <40 kg received rizatriptan ODT 5 mg or placebo; (2) those weighing ≥40 kg received rizatriptan 10 mg ODT or placebo. Pharmacokinetic data were compared with historical data on rizatriptan ODT 10 mg in healthy adults. Results.— The geometric mean area under the plasma concentration‐time curve from time 0 to infinity (AUC_(0‐∞)) (hours·ng/mL) and maximum peak plasma concentration (C_max) (ng/mL) were 56.68 (95% confidence interval [CI]: 48.60, 66.09) and 22.39 (95% CI: 17.90, 28.02), respectively, for the <40 kg group and 78.49 (95% CI: 68.93, 89.38) and 22.27 (95% CI: 18.43, 26.92), respectively, for the ≥40 kg group. For the comparison of children vs adults, the geometric mean ratios for rizatriptan AUC_(0‐∞) and C_max were 0.85 (90% CI: 0.73, 0.98) and 1.07 (90% CI: 0.86, 1.34), respectively, for the <40 kg group vs historical adult data and 1.17 (90% CI: 1.02, 1.34) and 1.06 (90% CI: 0.87, 1.30), respectively, for the ≥40 kg group vs historical adult data. There were no serious adverse events, and rizatriptan was generally well tolerated. Conclusions.— In pediatric migraineurs, a weight‐based dosing scheme generated plasma rizatriptan AUC_(0‐∞) and C_max values that were generally similar to those historically observed in adults administered a 10‐mg dose of rizatriptan ODT (a proven effective dose). The data support further evaluation of the safety, tolerability, and efficacy of this rizatriptan dosing scheme in larger scale clinical trials in the pediatric migraineur population.     

Long-term tolerability of telcagepant for acute treatment of migraine in a randomized trial

(Headache 2011;51:73‐84) Objective.— To evaluate the long‐term tolerability of telcagepant for acute treatment of intermittent migraine attacks. Background.— Telcagepant is a calcitonin gene‐related peptide (CGRP) receptor antagonist being investigated for the acute treatment of migraine. Methods.— Migraine patients were randomized 2:1 to double‐blind treatment with telcagepant 280/300 mg or rizatriptan 10 mg for an acute mild, moderate, or severe migraine. Patients could administer a second dose within 2‐24 hours for nonresponse or migraine recurrence. Patients could treat up to 8 attacks per month for up to 18 months. Safety assessments included spontaneous reports of adverse events and collection of vital signs, electrocardiograms, and laboratory assessments. The primary endpoint was the percentage of patients with ≥1 triptan‐related adverse events in the 14‐day period post dose. Results.— Of 1068 patients randomized, 641 (90%) patients treated ≥1 attack with telcagepant and 313 (88%) treated ≥1 attack with rizatriptan. A total of 19,820 attacks were treated with telcagepant (mean per patient = 31) and 10,981 with rizatriptan (mean per patient = 35). Fewer triptan‐related adverse events (difference: ?6.2%; 95% CI ?10.4, ?2.6; P < .001) and drug‐related adverse events (difference: ?15.6%; 95% CI ?22.2, ?9.0) were reported for telcagepant vs rizatriptan. The most common adverse events appeared to have generally similar incidence proportions between the treatment groups. Those with an incidence >5% in the telcagepant group were dry mouth (9.7%, rizatriptan = 13.7%), somnolence (9.2%, rizatriptan = 16.6%), dizziness (8.9%, rizatriptan = 10.2%), and nausea (9.0%, rizatriptan = 6.4%). Conclusions.— Telcagepant was generally well tolerated when administered for the acute intermittent treatment of migraine for up to 18 months. The incidences of triptan‐related and drug‐related adverse events favored telcagepant over rizatriptan.     

Total migraine freedom, a potential primary endpoint to assess acute treatment in migraine: comparison to the current FDA requirement using the complete rizatriptan study database

Objective.— To examine total migraine freedom (TMF), defined as pain freedom and absence of associated symptoms, using rizatriptan clinical trial data and to explore advantages of TMF as a single primary composite efficacy endpoint. Background.— The FDA has set a higher regulatory hurdle for registration of new migraine agents requiring both pain freedom (or relief) and absence of each associated symptom (phonophobia, photophobia, and nausea). Methods.— Twelve studies representing phase III + efficacy/safety studies of rizatriptan 10 mg in adults treating migraine were included in the meta‐analysis. The percentage of patients achieving TMF at 2 hours by study and combined by treatment group was summarized by treatment paradigm (early/mild pain, moderate/severe, menstrual migraine). To demonstrate the impact of the strict migraine regulatory hurdle on clinical trial design and to compare it to TMF, simulation via bootstrap sampling was used. Results.— Odds ratios (rizatriptan vs placebo, all P < .001) for TMF were 6.2 (95% CI: [4.9, 7.7]) for moderate/severe, 2.7 (95% CI: [1.8, 4.0]) for menstrual, and 3.1 (95% CI: [2.4, 4.0]) for early/mild. Most with moderate/severe migraine reported photophobia and/or phonophobia at baseline, but only half had nausea. Simulation results showed a substantial loss of power analyzing absence of pain and each symptom compared with the composite TMF endpoint across all treatment paradigms. Conclusion.— Rizatriptan 10 mg was superior to placebo in achieving TMF at 2 hours post‐dose across all treatment paradigms. Given that the majority of patients with migraine do not exhibit all 3 associated symptoms, the TMF endpoint has significant advantages vs establishing efficacy on pain and each symptom individually.     

Pharmacokinetics and tolerability of oral rizatriptan in healthy male and female volunteers

AIMS: The pharmacokinetics and dose proportionality of rizatriptan single oral doses from 2.5 to 15 mg administered as solutions to healthy volunteers were studied. METHODS: In a randomized, crossover study with four periods, twenty-four healthy volunteers (12 males and 12 females) took single oral doses of 2.5, 5, 10, and 15 mg rizatriptan in Periods 1-4. In a fifth period, subjects received 4 mg intravenous (i.v.) rizatriptan as a reference. Plasma and urine rizatriptan concentrations were determined at several timepoints/intervals for 12 and 24 h, respectively. RESULTS: The arithmetic mean AUC values following single oral doses of 2.5, 5, 10, and 15-mg rizatriptan were 16, 33, 72, and 127 ng ml-1 h, respectively, in males; and 19, 42, 97, and 161 ng ml-1 h, respectively, in females. The overall bioavailability (F ) of rizatriptan was approximately 40% in males. Following the 4 mg reference i.v. dose, the apparent plasma clearance (CL) and renal clearance (CLr ) were 1042 and 225 ml min-1, respectively, in males; and 821 and 174 ml min-1, respectively, in females. CONCLUSIONS: The disposition kinetics of oral rizatriptan were linear for doses of 2. 5-10 mg in males, and for doses of 2.5-5 mg in females. However, the degree of nonlinearity for higher doses was minor for both genders. The plasma concentrations of rizatriptan were slightly greater in women compared to men but the difference was not considered to be clinically meaningful. Also, the clearance of rizatriptan appeared to be mainly nonrenal.     

Evidence-based analysis of a migraine treatment drug comparison trial

Patients present with specific problems against a background of their particular situation. The applicability of a treatment to a specific case may be difficult to assess in the light of the information available on that treatment. Evidence-based medicine is a discipline developed to achieve the best informed treatment decisions in clinical situations. In this paper, we illustrate a logical approach to reaching a decision regarding which of two migraine treatments should be used in a clearly defined patient. The information evaluated is a comparative trial between sumatriptan (100 mg), rizatriptan (5 and 10 mg) and placebo. The use of the analytical tools of evidence-based medicine is demonstrated in this exercise. The example was chosen because this is an area of great current interest in the field of neurology.     

Expanding Access to Triptans: Assessment of Clinical Outcome

Objective.— To evaluate whether access to more liberal quantities of rizatriptan improves clinical outcome in patients with episodic migraine.
Background.— Currently many pharmacy benefit programs limit the number of triptan tablets/injections per month based on perceived cost savings and the belief that too-frequent use of triptans may lead to medication overuse headache and headache chronification.
Methods.— This observer-blind, randomized, parallel-group study enrolled 197 subjects with migraine with or without aura. Subjects completed a 3-month baseline period to establish migraine frequency and then were randomly assigned to receive 9 (formulary limit [FL]) or 27 (clinical limit [CL]) tablets of 10 mg rizatriptan orally disintegrating tablet (ODT) per month for 3 months. The primary endpoint was change in the mean number of migraine days from the baseline to treatment period.
Results.— There was no statistically significant difference between the FL and CL groups in mean number of migraine days (FL-CL LS mean: −0.08 [−0.39, 0.23]; P  = .613). Subjects in the CL group treated attacks at lower headache severity. No CL subjects were reported to have developed chronic migraine despite utilization of greater than 10 rizatriptan ODT tablets per month. Rizatriptan was generally well tolerated by both groups.
Conclusion.— Providing a greater quantity of rizatriptan ODT 10 mg did not reduce the number of migraine days compared with providing 9 tablets per month for this population with episodic migraine with a frequency of 3-8 migraines per month. Regardless of quantity provided, rizatriptan was generally well tolerated.     

Efficacy of Rizatriptan 10 mg administered early in a migraine attack

OBJECTIVE: To determine if administration of rizatriptan 10 mg is superior to placebo for the early treatment of acute migraine, while the pain is mild. BACKGROUND: Past studies have suggested that treatment outcomes can be improved if a triptan is administered early in the time course of a migraine attack. METHODS: Two randomized, parallel, placebo-controlled, double-blind studies. TAME (Treat A Migraine Early)1 was conducted at 46 centers in the United States; TAME2, at 48 centers in the United States. Totally, 1030 adult patients with at least a 6-month history of migraine were studied. Patients were instructed to treat within 1 hour of migraine onset, while pain was mild. Patients maintained a headache diary in which they rated their levels of pain and disability, and recorded other symptoms of migraine. Primary endpoints were pain freedom at 2 hours and sustained pain freedom at 24 hours post-dose. RESULTS: In TAME1, 57.3% versus 31.1% of patients reported pain freedom at 2 hours post-dose and 42.6% versus 23.2% reported 24-hour sustained pain freedom with rizatriptan versus placebo, respectively (P < .001 for both). In TAME2, 58.9% versus 31.1% of patients reported pain freedom at 2 hours post-dose and 48.0% versus 24.6% reported 24-hour sustained pain freedom with rizatriptan versus placebo, respectively (P < .001 for both). All other efficacy endpoints favored rizatriptan. Repeat doses of the medicine were not allowed; patients may have delayed treatment; non-migraine headaches may have been treated. CONCLUSIONS: Rizatriptan 10 mg was superior to placebo when treating migraine early, while pain is mild, as measured by pain freedom at 2 hours and 24-hour sustained pain freedom.     

The effect of rizatriptan,ergotamine, and their combination on human peripheral arteries: a double-blind,placebo-controlled,crossover study in normal subjects

AIMS: To compare the peripheral vasoconstrictor effects of ergotamine, rizatriptan, and their combination, in normal subjects. METHODS: This was a double-blind, four-way, crossover study. Sixteen young male volunteers, selected as responders to the vasoconstrictor effect of 0.5 mg ergotamine i.v., were administered 10 mg oral rizatriptan, 0.25 mg i.v. ergotamine, 10 mg oral rizatriptan+0.25 mg i.v. ergotamine, and placebo. The vasoconstrictor effect on peripheral arteries was measured with strain gauge plethysmography up to 8 h after dosing. The 8 h assessment period was divided into two 4 h intervals to assess the immediate (0-4 h) vs sustained effect (4-8 h) of treatment. RESULTS: For the 0-4 h interval, the decreases in peripheral systolic blood pressure gradients were: placebo (-1 mmHg [95% CI: -3, 1])<rizatriptan (-5 mmHg [95% CI: -7, -3])rizatriptan+ergotamine (-15 mmHg [95% CI: -17, -13]). For the 4-8 h interval, the decreases were: placebo (-5 mmHg [95% CI: -8, -3])=rizatriptan (-8 mmHg [95% CI: -11, -5])rizatriptan+ergotamine (-28 mmHg [95% CI: -31, -26]). CONCLUSIONS: In normal subjects, rizatriptan 10 mg orally had only a small transient vasoconstrictor effect on peripheral arteries compared with the sustained and more pronounced effect of 0.25 mg i.v. ergotamine. Furthermore, rizatriptan exerted no additional effect on ergotamine-induced constriction of peripheral arteries when the two drugs were given in combination.     

Early treatment of migraine with rizatriptan: a placebo-controlled study

OBJECTIVE: To evaluate the efficacy of rizatriptan when administered early during a migraine attack. BACKGROUND: Several studies indicate that triptans are more efficacious when administered early during a migraine attack, when the pain is still mild. METHODS: One hundred and twelve rizatriptan-na?ve patients aged 20 to 64 years with a history of migraine with or without aura that progressively worsened when left untreated were instructed to treat a total of three migraine attacks with either rizatriptan 10 mg or placebo as early as possible during each attack. Seventy-four patients (68 women and 6 men) were assigned to use the active drug and 38 (35 women and 3 men) to placebo. The primary efficacy endpoint was pain-free response at 2 hours after administration of the study drug. Secondary efficacy measures were pain-free response at 1 hour and sustained pain-free response lasting between 2 and 24 hours. RESULTS: A total of 216 attacks were treated in the rizatriptan group and 109 in the placebo group. Pain-free response at 2 hours after early treatment was noted in 151 (70%) of attacks in the rizatriptan group and in 24 (22%) in the placebo group (P < .01). Pain-free response at 1 hour occurred in 97 (45%) and 9 (8%) attacks, respectively (P < .01). When the attacks were categorized by headache severity at the time of treatment, the pain-free response at 2 hours was higher for mild attacks than for moderate or severe attacks (P < .01). Sustained pain-free response after treatment was significantly higher for attacks treated with rizatriptan (60%) than for those treated with placebo (17%) (P < .001). Adverse events were observed in 62 patients in the rizatriptan group and 15 in the placebo group. Only 1 patient taking rizatriptan discontinued the study because of adverse events, and no serious adverse events were reported. CONCLUSIONS: Rizatriptan is significantly more likely than placebo to produce a pain-free response within 2 hours when the drug is administered early in the migraine attack, when pain is mild rather than moderate or severe.