Frovatriptan: a review of pharmacology, pharmacokinetics and clinical potential in the treatment of menstrual migraine

Influence of metabolic state and body composition on the action of pharmacological treatment of migraine

Migraine is a disabling neurovascular disorder among people of all ages, with the highest prevalence in the fertile years, and in women. Migraine impacts the quality of life of affected individuals tremendously and, in addition, it is associated with highly prevalent metabolic diseases, such as obesity, diabetes mellitus and thyroid dysfunction. Also, the clinical response to drugs might be affected in patients with metabolic disease due to body composition and metabolic change. Therefore, the efficacy of antimigraine drugs could be altered in patients with both migraine and metabolic disease. However, knowledge of the pharmacology and the related clinical effects of antimigraine drugs in patients with metabolic disease are limited. Therefore, and given the clinical relevance, this article provides a comprehensive overview of the current research and hypotheses related to the influence of metabolic state and body composition on the action of antimigraine drugs. In addition, the influence of antimigraine drugs on metabolic functioning and, vice versa, the influence of metabolic diseases and its hormonal modulating medication on migraine activity is outlined. Future exploration on personalizing migraine treatment to individual characteristics is necessary to enhance therapeutic strategies, especially given its increasing significance in recent decades.

Identification of Novel High-Affinity Substrates of OCT1 Using Machine Learning-Guided Virtual Screening and Experimental Validation

OCT1 is the most highly expressed cation transporter in the liver and affects pharmacokinetics and pharmacodynamics. Newly marketed drugs have previously been screened as potential OCT1 substrates and verified by virtual docking. Here, we used machine learning with transport experiment data to predict OCT1 substrates based on classic molecular descriptors, pharmacophore features, and extended-connectivity fingerprints and confirmed them by in vitro uptake experiments. We virtually screened a database of more than 1000 substances. Nineteen predicted substances were chosen for in vitro testing. Sixteen of the 19 newly tested substances (85%) were confirmed as, mostly strong, substrates, including edrophonium, fenpiverinium, ritodrine, and ractopamine. Even without a crystal structure of OCT1, machine learning algorithms predict substrates accurately and may contribute not only to a more focused screening in drug development but also to a better molecular understanding of OCT1 in general.

Spotlight on frovatriptan: a review of its efficacy in the treatment of migraine

Migraine is a common neurovascular disorder, affecting millions of people worldwide. Current guidelines recommend triptans as first-line treatment for moderate-to-severe migraine attacks. Frovatriptan is a second-generation triptan with a longer terminal elimination half-life in blood than other triptans (~26 hours). Three double-blind, randomized crossover preference studies have been recently conducted, assessing efficacy and safety of frovatriptan versus rizatriptan, zolmitriptan, and almotriptan, respectively. Frovatriptan showed favorable tolerability and sustained effect, with a significantly lower rate of relapse over 48 hours versus the other triptans. These findings were confirmed in a series of analyses of patient subsets from the three studies, including patients with menstrually related and oral contraceptive-induced migraine, hypertension, obesity, weekend migraine, as well as patients with migraine with aura. In all patient subsets analyzed, lower headache recurrence rates were observed versus the comparator triptans, indicating a more sustained pain-relieving effect on migraine symptoms. A further randomized, double-blind study demonstrated that frovatriptan given in combination with the fast-acting cyclooxygenase inhibitor dexketoprofen provided improved migraine pain-free activity at 2 hours, and gave more sustained pain-free activity at 24 hours, versus frovatriptan alone. These benefits were observed both when the combination was administered early (<1 hour after symptom onset) or late (>1 hour after onset). Different pharmacokinetic, but synergistic, properties between frovatriptan and dexketoprofen may make the combination of these agents particularly effective in migraine treatment, with rapid onset of action and sustained effect over 48 hours. These benefits, together with potential cost-effectiveness advantages versus other triptans could drive selection of the most appropriate treatment for acute migraine attacks.

Gender and triptan efficacy: a pooled analysis of three double-blind, randomized, crossover, multicenter, Italian studies comparing frovatriptan vs. other triptans

Migraine is three times as common in females as in males, and attacks may be more severe and difficult to treat in women. However, no study specifically addressed possible gender differences in response to antimigraine therapy. The objective of this study was to review the efficacy of frovatriptan vs. other triptans, in the acute treatment of migraine in subgroups of subjects classified according to gender (men vs. women) through a pooled analysis of three individual randomized Italian studies. 414 patients suffering from migraine with or without aura were randomized to frovatriptan 2.5 mg or rizatriptan 10 mg (study 1), frovatriptan 2.5 mg or zolmitriptan 2.5 mg (study 2), frovatriptan 2.5 mg or almotriptan 12.5 mg (study 3). All studies had a multicenter, randomized, double-blind, crossover design. After treating 1–3 episodes of migraine in no more than 3 months with the first treatment, patients switched to the other treatment for the next 3 months. In this analysis, traditional migraine endpoints were compared between the 66 men and 280 women of the intent-to-treat population. At baseline, long-term and debilitating migraine attacks were more frequently reported by women than men. During the observation period, the proportion of pain-free attacks at 2 h did not significantly differ between frovatriptan and the comparators in either men (32 vs. 38 %, p = NS) or women (30 vs. 33 %, p = NS). Pain relief was also similar between treatments for both genders (men: 56 % frovatriptan vs. 57 % comparators; women: 55 vs. 57 %; p = NS for both). The rate of relapse was significantly lower with frovatriptan than with the comparators in men (24 h: 10 vs. 30 %; 48 h: 21 vs. 39 %; p < 0.05) as well as in women (24 h: 14 vs. 23 %; 48 h: 28 vs. 40 %; p < 0.05). The rate of adverse drug reactions was significantly larger with comparators, irrespectively of gender. Although migraine presents in a more severe form in women, frovatriptan seems to retain its good efficacy and favorable sustained antimigraine effect regardless of the gender.

Frovatriptan vs. other triptans for the acute treatment of oral contraceptive-induced menstrual migraine: pooled analysis of three double-blind, randomized, crossover, multicenter studies

Oral contraceptive-induced menstrual migraine (OCMM) is a particularly severe form of migraine triggered by the cyclic hormone withdrawal. To review the efficacy of frovatriptan vs. other triptans, in the acute treatment of OCMM through a pooled analysis of three individual randomized Italian studies. With or without aura migraineurs were randomized to frovatriptan 2.5 mg or rizatriptan 10 mg (study 1), frovatriptan 2.5 mg or zolmitriptan 2.5 mg (study 2), frovatriptan 2.5 mg or almotriptan 12.5 mg (study 3). All studies had a multicenter, randomized, double-blind, crossover design. After treating 1-3 episodes of migraine in 3 months with the first treatment, patients switched to the other treatment for the next 3 months. In this analysis, the subset of 35 of the 280 women of the intention-to-treat population taking combined oral contraceptives and experiencing a migraine attack during the withdrawal phase, were analyzed. The proportion of pain free and pain relief at 2 h were 25 and 51 % with frovatriptan and 28 and 48 % with comparators (p = NS). At 24 h, 71 and 83 % of frovatriptan-treated patients and 60 and 76 % of comparator-treated patients were pain free (p < 0.05 between treatments) and had pain relief (p = NS), respectively. Relapse at 24 and 48 h was significantly (p < 0.05) lower with frovatriptan (17 and 21 %) than with the comparators (27 and 31 %). Our results suggest that, due to its sustained antimigraine effect, frovatriptan may be particularly suitable for the management of OCMM than other triptans.

A review of the use of frovatriptan in the treatment of menstrually related migraine

Menstrual migraine (MM) is a highly prevalent condition associated with considerable disability. Migraine attacks occur exclusively around the menstrual period in approximately 10% of women with migraine, that is, pure menstrual migraine, while at least 50% of them also experience migraine at other times of the month, that is, menstrually related migraine (MRM). The therapeutic approach to patients with MRM is based on treatment of the attack, or prophylactic strategies. Triptans are recommended as first-line treatments for moderate to severe migraine attacks, including MM. Frovatriptan is one of the newest triptans. Its high affinity for 5-HT1B/1D receptors and long half-life contribute to its distinctive clinical effect, characterized by a more sustained and prolonged effect than other triptans. Indeed, frovatriptan proved to be effective in treating the acute attack, but was particularly effective in the short-term preventive therapy of MM. In addition, frovatriptan is one of the safest triptans, with the lowest risk of treatment-emergent adverse events. Following extensive evidence from randomized pharmacological trials, frovatriptan has now gained a grade A recommendation from the guidelines for short-term prophylaxis of MM. Recent post-hoc analyses of direct comparative trials also suggest that frovatriptan might have an important role in the acute treatment of MRM. In these studies, frovatriptan showed pain relief and pain-free rates similar to those of zolmitriptan, rizatriptan, and almotriptan, but with significantly lower recurrence rates. More well-designed, randomized, prospective studies, specifically enrolling women with MM, will be needed in the near future to confirm the efficacy of frovatriptan in this migraine subtype.

Symptomatic or prophylactic treatment of weekend migraine: an open-label, nonrandomized, comparison study of frovatriptan versus naproxen sodium versus no therapy

BACKGROUND

Migraine often occurs during weekends. The efficacy of frovatriptan, naproxen sodium, or no therapy for the acute or prophylactic treatment of weekend migraineurs was tested in an open-label, nonrandomized pilot study.

METHODS

Twenty-eight subjects (mean age 36 ± 12 years, including 18 females) suffering from migraine without aura were followed up for six consecutive weekends. No treatment was administered during the first two weekends. On the third and fourth weekends, patients were given frovatriptan 2.5 mg and on the fifth and sixth weekends naproxen sodium 500 mg. Treatment was taken on Saturday and Sunday morning, regardless of the occurrence of migraine. Efficacy was evaluated through a diary, where patients reported the severity of migraine on a scale from 0 (no migraine) to 10 (severe migraine) and use of rescue medication.

RESULTS

The migraine severity score was significantly lower with frovatriptan (4.8 [95% confidence interval (CI) 3.8-5.9]) than with naproxen sodium (5.7 [CI 5.1-6.4], P< 0.05 versus frovatriptan) or no therapy (6.6 [6.2-7.0], P< 0.01 versus frovatriptan). The difference in favor of frovatriptan was more striking in patients not taking rescue medication (frovatriptan, 1.9 [1.5-2.3]) versus naproxen sodium 3.6 [3.0-4.2], P< 0.001) and versus no therapy (5.1 [4.4-5.8], P< 0.001) and on the second day of treatment. The rate of use of rescue medication was significantly (P< 0.05) lower on frovatriptan (12.5%) than on naproxen sodium (31.3%) or no therapy (56.3%).

CONCLUSION

This pilot study provides the first evidence of the efficacy of a second-generation triptan as symptomatic or prophylactic treatment for weekend migraine.

Frovatriptan versus almotriptan for acute treatment of menstrual migraine: analysis of a double-blind, randomized, cross-over, multicenter, Italian, comparative study

The objective of the study was to compare the efficacy and safety of frovatriptan and almotriptan in women with menstrually related migraine (IHS Classification of Headache disorders) enrolled in a multicenter, randomized, double-blind, cross-over study. Patients received frovatriptan 2.5 mg or almotriptan 12.5 mg in a randomized sequence: after treating 3 episodes of migraine in no more than 3 months with the first treatment, the patient was switched to the other treatment. 67 of the 96 female patients of the intention-to-treat population of the main study had regular menstrual cycles and were thus included in this subgroup analysis. 77 migraine attacks classified as related to menses were treated with frovatriptan and 78 with almotriptan. Rate of pain relief at 2 and 4 h was 36 and 53 % for frovatriptan and 41 and 50 % for almotriptan (p = NS between treatments). Rate of pain free at 2 and 4 h was 19 and 47 % with frovatriptan and 29 and 54 % for almotriptan (p = NS). At 24 h, 62 % of frovatriptan-treated and 67 % of almotriptan-treated patients had pain relief, while 60 versus 67 % were pain free (p = NS). Recurrence at 24 h was significantly (p < 0.05) lower with frovatriptan (8 vs. 21 % almotriptan). This was the case also at 48 h (9 vs. 24 %, p < 0.05). Frovatriptan was as effective as almotriptan in the immediate treatment of menstrually related migraine attacks. However, it showed a more favorable sustained effect, as shown by a lower rate of migraine recurrence.

Pharmacokinetic evaluation of frovatriptan

INTRODUCTION

Migraine is the most common painful neurological disorder, affecting 13% of the general population. Triptans represent a powerful pharmacological tool in acute migraine treatment, however, a significant portion of treated patients cannot have access to this class due to possible adverse affects. Today, a total of seven triptan molecules are available, representing a commonly prescribed migraine treatment. Although there is a need of extensive use of triptans, only 25% of migraine patients are using triptans.

AREAS COVERED

This review includes triptans and evidence for the use of frovatriptan. A systematic approach is used to discuss the pharmacodynamic and pharmacokinetic aspects of frovatriptan, considering the emerging data on the clinical efficacy of frovatriptan in the treatment of migraine and cluster headaches. The data were obtained by searching the following key words in MEDLINE: pharmacokinetic, pharmacodynamic, triptans, frovatriptan, migraine, menstrual migraine, relatively to the period 1988 - 2011.

EXPERT OPINION

Frovatriptan has been developed in order to improve safety and efficacy of triptans. It shows a favorable tolerability and efficacy profile, limited to 24/48-h headache recurrence, when compared with other triptans. Preclinical data suggest that the pharmacokinetic profile of frovatriptan may differ from other available triptans. In fact, among triptans, frovatriptan showed the highest potency at the 5-HT1B receptor (8.2) and the longer half-life (26 h). These parameters determine the clinical properties of frovatriptan; in particular the lowest rate of headache recurrence in comparison with other triptans.

Efficacy of frovatriptan in the acute treatment of menstrually related migraine: analysis of a double-blind, randomized, cross-over, multicenter, Italian, comparative study versus rizatriptan

The objectives of this study are to assess the efficacy and safety of frovatriptan, and rizatriptan in the subgroup of women with menstrually related migraine of a multicenter, randomized, double blind, cross-over study. Each patient received frovatriptan 2.5 mg or rizatriptan 10 mg in a randomized sequence: after treating 3 episodes of migraine in not more than 3 months with the first treatment, the patient had to switch to the other treatment. Menstrually related migraine was defined according to the criteria listed in the Appendix of the last IHS Classification of Headache disorders. 99 out of the 125 patients included in the intention-to-treat analysis of the main study were of a female gender: 93 had regular menstrual cycles and were, thus, included in this analysis. A total of 49 attacks classified as menstrually related migraine were treated with frovatriptan and 59 with rizatriptan. Rate of pain relief at 2 h was 58% for frovatriptan and 64% for rizatriptan (p = NS), while rate of pain free at 2 h was 31 and 34% (p = NS), respectively. At 24 h, 67 and 81% of frovatriptan-treated, and 61 and 74% of rizatriptan-treated patients were pain free and had pain relief, respectively (p = NS). Recurrence at 24 h was significantly (p < 0.01) lower with frovatriptan (10 vs. 32% rizatriptan). Frovatriptan was as effective as rizatriptan in the immediate treatment of menstrually related migraine attacks while showing a favorable sustained effect with a lower rate of migraine recurrence. These results need to be confirmed by randomized, double-blind, prospective, large clinical trials.

The Migraine Intervention Score - a tool to improve efficacy of triptans in acute migraine therapy: the ALADIN study

BACKGROUND

The 'Migraine Intervention Score' (MIS) is a new self-administered scale that can be used to quantify the severity of specific migraine symptoms. The objective of this study was to determine if MIS could be used to improve the efficacy of frovatriptan 2.5 mg in the early treatment of migraine attacks for clinical practice.

METHODS

In this prospective observational study, patients suffering from migraines with or without aura were enrolled and permitted to choose the time of self-medication with frovatriptan 2.5 mg. At the time of intake of medication, patients evaluated the severity of individual migraine symptoms using MIS. The scores for each symptom were then totalled to provide an overall level of symptom severity. A total of 1620 patients completed the treatment of three migraine attacks with frovatriptan. A total of 1518 patients could be analysed with respect to the documented efficacy parameters of the third attack. Patients initiating treatment at low symptom severity levels were compared with those initiating treatment at high symptom severity levels.

RESULTS

Time to the achievement of the primary endpoint (headache response) was significantly lower in patients who initiated treatment at low vs. high symptom severity levels (42.06 ± 32.33 vs. 49.25 ± 34.92 min; p = 0.0023). Likewise, patients who initiated treatment at low symptom severity levels achieved complete headache relief more rapidly (79.37 ± 65.33 vs. 96.05 ± 100.85 min; p = 0.0109) and required escape medication less frequently (3.88% vs. 13.73%; p < 0.0001).

CONCLUSIONS

The initiation of attack treatment with frovatriptan at low severity of migraine symptoms is more effective than starting therapy at higher symptom levels. Together with the low recurrence headache rate, the decreased necessity for escape medication and the low number of tablets needed, these data demonstrate that operationalised intervention with frovatriptan 2.5 mg is a valuable method for improving the treatment of migraine attacks.

A double-blind, randomized, multicenter, Italian study of frovatriptan versus almotriptan for the acute treatment of migraine

The objective of this study was to evaluate patients’ satisfaction with acute treatment of migraine with frovatriptan or almotriptan by preference questionnaire. One hundred and thirty three subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or almotriptan 12.5 mg, treating 1–3 attacks. The study had a multicenter, randomized, double blind, cross-over design, with treatment periods lasting <3 months. At study end patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain free and pain relief episodes at 2 and 4 h, and recurrent and sustained pain free episodes within 48 h. Of the 133 patients (86%, intention-to-treat population) 114 of them expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (3.1 ± 1.3) and almotriptan (3.4 ± 1.3). The rates of pain free (30% frovatriptan vs. 32% almotriptan) and pain relief (54% vs. 56%) episodes at 2 h did not significantly differ between treatments. This was the case also at 4 h (pain free: 56% vs. 59%; pain relief: 75% vs. 72%). Recurrent episodes were significantly (P < 0.05) less frequent under frovatriptan (30% vs. 44%), also for the attacks treated within 30 min. No significant differences were observed in sustained pain free episodes (21% vs. 18%). The tolerability profile was similar between the two drugs. In conclusion, our study suggests that frovatriptan has a similar efficacy of almotriptan in the short-term, while some advantages are observed during long-term treatment.

A double-blind, randomized, multicenter, Italian study of frovatriptan versus rizatriptan for the acute treatment of migraine

The objective of this study was to assess patient satisfaction with acute treatment of migraine with frovatriptan or rizatriptan by preference questionnaire. 148 subjects with a history of migraine with or without aura (IHS 2004 criteria), with at least one migraine attack per month in the preceding 6 months, were enrolled and randomized to frovatriptan 2.5 mg or rizatriptan 10 mg treating 1-3 attacks. The study had a multicenter, randomized, double-blind, cross-over design, with treatment periods lasting <3 months. At the end of the study, patients assigned preference to one of the treatments using a questionnaire with a score from 0 to 5 (primary endpoint). Secondary endpoints were pain-free and pain relief episodes at 2 h, and recurrent and sustained pain-free episodes within 48 h. 104 of the 125 patients (83%, intention-to-treat population) expressed a preference for a triptan. The average preference score was not significantly different between frovatriptan (2.9±1.3) and rizatriptan (3.2±1.1). The rates of pain-free (33% frovatriptan vs. 39% rizatriptan) and pain relief (55 vs. 62%) episodes at 2 h were not significantly different between the two treatments. The rate of recurrent episodes was significantly (p<0.001) lower under frovatriptan (21 vs. 43% rizatriptan). No significant differences were observed in sustained pain-free episodes (26% frovatriptan vs. 22% rizatriptan). The number of patients with adverse events was not significantly different between rizatriptan (34) and frovatriptan (25, p=NS). The results suggest that frovatriptan has a similar efficacy to rizatriptan, but a more prolonged duration of action.

Inhibition and induction of human cytochrome P450 enzymes: current status

Variability of drug metabolism, especially that of the most important phase I enzymes or cytochrome P450 (CYP) enzymes, is an important complicating factor in many areas of pharmacology and toxicology, in drug development, preclinical toxicity studies, clinical trials, drug therapy, environmental exposures and risk assessment. These frequently enormous consequences in mind, predictive and pre-emptying measures have been a top priority in both pharmacology and toxicology. This means the development of predictive in vitro approaches. The sound prediction is always based on the firm background of basic research on the phenomena of inhibition and induction and their underlying mechanisms; consequently the description of these aspects is the purpose of this review. We cover both inhibition and induction of CYP enzymes, always keeping in mind the basic mechanisms on which to build predictive and preventive in vitro approaches. Just because validation is an essential part of any in vitro-in vivo extrapolation scenario, we cover also necessary in vivo research and findings in order to provide a proper view to justify in vitro approaches and observations.