Peripheral vascular effects and pharmacokinetics of the antimigraine compound, zolmitriptan, in combination with oral ergotamine in healthy volunteers

Members of the new class of antimigraine compounds, 5HT1B/1D agonists, as well as ergotamine, may cause vasoconstriction through stimulation of 5HT receptors on peripheral vessels. The cardiovascular effects of 20 mg oral zolmitriptan (Zomig, formerly 311C90), 2 mg oral ergotamine and the combination were assessed in a randomized double-blind, placebo-controlled crossover study in 12 healthy subjects. Pharmacodynamic measures included oscillometric blood pressure, systolic blood pressure at the toe and arm using a strain gauge technique, stroke volume and cardiac output using bioimpedance cardiography, high-resolution ultrasound to measure brachial arterial diameter and a novel Doppler method to measure blood flow velocity. Both drugs produced small degrees of peripheral vasoconstriction, including increases in diastolic blood pressure and blood flow velocity and decreases in arterial diameter and toe-arm systolic pressure gradient. These effects were generally additive with the combination but of no clinical importance. There were no significant changes in cardiac output, stroke volume heart rate or ECG. Zolmitriptan, at eight times the likely therapeutic dose, was generally well tolerated both alone and in combination with ergotamine. Ergotamine had no clinically important effects on zolmitriptan pharmacokinetics.

Potential drug interactions with the novel antimigraine compound zolmitriptan (Zomig, 311C90)

Seven randomized studies in healthy volunteers have investigated interactions between zolmitriptan (Zomig, formerly 311C90), a 5HT1B/1D agonist for acute migraine therapy, and selected drugs with which there was a possibility of interaction or a likelihood of concurrent use. Co-administration of oral dihydroergotamine, ergotamine, pizotifen, fluoxetine, paracetamol (acetaminophen)/metoclopramide or selegiline had no clinically significant effects on the pharmacokinetics of zolmitriptan or its metabolites, although small changes were observed in some cases. Co-administration of propranolol resulted in a 56% increase in the area under the plasma concentration-time curve (AUC) of zolmitriptan and a 11% decrease in the AUC of the active metabolite 183C91. However, these pharmacokinetic changes are unlikely to be relevant at lower clinical doses. Moclobemide, a monoamine oxidase A (MAO-A) inhibitor, decreased the clearance of zolmitriptan and, in particular, 183C91. This suggests that MAO-A is involved in the metabolism of 183C91 and it may be prudent to limit the daily zolmitriptan dose in migraine patients maintained on a MAO-A inhibitor. The clinically insignificant blood pressure increases produced by zolmitriptan, and the tolerability profile of this agent, were unaffected by any of the concomitant medications. Clinically significant interactions between zolmitriptan and commonly co-prescribed antimigraine therapies are unlikely.

Tolerability profile of zolmitriptan (Zomig; 311C90), a novel dual central and peripherally acting 5HT1B/1D agonist. International clinical experience based on > 3000 subjects treated with zolmitriptan

Zolmitriptan (Zomig, formerly 311C90) at doses of 0.5-50 mg was administered to 316 unique volunteers in clinical pharmacology studies and 2,750 unique patients in eight clinical studies of acute migraine treatment. Overall, subjects received almost 50,000 doses; 97% of exposures were at doses > or = 2.5 mg. In the clinical pharmacology studies, the overall incidence of subject exposures experiencing at least one adverse event was 52% with zolmitriptan 2.5 mg (28% with placebo). In placebo-controlled studies, the overall incidence of patients with at least one adverse event was dose-dependent for zolmitriptan over the 1-15 mg dose range, e.g. 42% and 46% with 1 and 2.5 mg, respectively and 58% with 5 mg (29% with placebo). Only four serious adverse events attributable to zolmitriptan were reported. In a long-term study, during which 2,058 outpatients treated a total of 31,579 migraine attacks with either one or two zolmitriptan 5 mg doses over a period of up to 1 year, the number of attacks associated with at least one adverse event was similar after one (26%) and two (24%) doses. The majority (59%) of the adverse events reported in this study (59%) occurred within 2 h of dosing, were predominantly mild (59%) or moderate (35%) in intensity, of < or = 4 h duration (58%), required no further action (94%). In placebo-controlled studies, the percentage of patients who reported severe adverse events was similar with zolmitriptan 2.5 mg (4%) and placebo (5%). The most frequently reported adverse events with zolmitriptan in the placebo-controlled clinical studies were asthenia, heaviness (other than chest or neck), dry mouth, nausea, dizziness, somnolence, paresthesia and warm sensations. The type and severity of the adverse events was not influenced by gender (although the frequency of reported adverse events was higher in females, as was the case in the placebo group), age, presence of aura prior to the attack, association of migraine with menstruation, concurrent medication, or by the addition of a second zolmitriptan dose. Zolmitriptan showed a similar tolerability profile in the long-term study, in which a low withdrawal rate due to adverse events of 8% was observed. Zolmitriptan was not associated with an increased frequency of central nervous system-related adverse events in a comparative study of sumatriptan, despite pre-clinical and neurophysiological evidence of a dual peripheral and central action of zolmitriptan. Moreover, zolmitriptan doses of 5-20 mg produced no statistically significant effects on objective assessments of psychometric function. Zolmitriptan had no clinically significant effects on blood pressure (even in patients with controlled mild to moderate hypertension or impaired renal function), ECGs (e.g. there was no evidence of ischemic events) or clinical chemistry, hematological or urinalysis measurements. In summary, zolmitriptan is well tolerated, particularly at the recommended dose of 2.5 mg. Zolmitriptan has a well-defined dose-response with 2.5 mg proving highly effective and optimizing the benefit/risk ratio of treatment. Thus, zolmitriptan is well suited as an acute oral treatment for migraine in the outpatient setting.

Clinical applications of zolmitriptan (Zomig, 311C90)

Zolmitriptan (Zomig, formerly 311C90) is a novel, oral antimigraine drug that is consistently effective and well tolerated in the acute treatment of migraine headache and its associated symptoms. The purpose of this article is to review data available from pharmacological and clinical trials with zolmitriptan and to summarize the clinically relevant features that distinguish this agent. We will review the attributes desirable in a migraine drug and use this as a template for assessing zolmitriptan. Zolmitriptan provides a new oral treatment option for physicians which should help improve patient outcomes.

311C90: increasing the options for therapy with effective acute antimigraine 5HT1B/1D receptor agonists

The novel antimigraine drug 311C90 (Zomig; zolmitriptan) has a high selectivity for serotonin (5HT)1 receptors, mainly 5HT1B and 5HT1D subtypes, and in preclinical studies it has been shown to act on four different sites within the trigemino-vascular system (blockade of neurogenic inflammation by inhibition of peptide release, vasoconstriction, inhibition of neuronal depolarization at peripheral sites, and effects at central sites). Oral 311C90 has a favorable pharmacokinetic profile. It is rapidly absorbed, with 75% of maximal plasma concentration (Cmax) attained within 1 hour and good absolute oral bioavailability (approximately 40%). Clinical studies have shown 311C90 to be rapidly and consistently effective in relieving migraine headache, with initial doses of between 2.5 and 5 mg providing an optimal balance between efficacy and safety considerations. Moreover, the good tolerability of 311C90 is supported by clinical data showing that doses up to 10-fold the therapeutic dose (2.5 mg) did not raise any serious safety concerns, highlighting the favorable safety profile of this drug.

311C90: long-term efficacy and tolerability profile for the acute treatment of migraine. International 311C90 Long-Term Study Group

311C90 (Zomig; zolmitriptan) is a novel, selective serotonin (5HT)1B/1D receptor agonist with both central and peripheral activity, now in late-stage clinical development for acute oral treatment of migraine. Several studies have demonstrated the tolerability and efficacy of 311C90 in the treatment of a single migraine headache. The objectives of this open-label study were to assess the tolerability and efficacy of repeated doses of 5 mg of 311C90 for acute treatment of multiple attacks for up to 1 year. Patients were allowed to treat as many migraine headaches (mild, moderate, or severe) as desired with an initial dose. A second 5-mg dose could be used to treat recurrence should it develop. Safety assessments included ECG, the frequency, intensity, and duration of adverse experiences, and routine hematology, urinalysis, and clinical chemistry parameters. Efficacy assessments included headache severity at 2 hours (i.e., severe, moderate, mild, or none), the proportion of patients pain-free at 2 hours, the use of a second tablet to treat headache recurrence if it developed, and the consistency of these findings over time. The efficacy profile and the nature/incidence of adverse events reported appear to be consistent with previous 311C90 studies. The dosing regimen was well tolerated during multiple exposures. Notably, headache response rates were consistently good after both initial and repeated exposure (> 80% across 1 to 30 attacks). For 67% of patients who treated at least five attacks, 311C90 was effective 80 to 100% of the time.

311C90, a new central and peripherally acting 5-HT1D receptor agonist in the acute oral treatment of migraine: a double-blind, placebo-controlled, dose-range finding study

311C90 is a novel, centrally and peripherally, acting 5-hydroxytryptamine1D receptor agonist. We investigated the efficacy and safety of 1, 5, and 25 mg of oral 311C90 in the acute treatment of migraine in a randomized, double-blind, placebo-controlled, parallel-group clinical trial involving 84 patients. The proportion of patients in whom the headache improved within 2 hours from moderate or severe to mild or no pain (primary efficacy measure) was 15% for placebo-treated patients and 27% (1 mg), 62% (5 mg), and 81% (25 mg) for patients treated with 311C90. Treatment differences compared with placebo were 12% (95% CI - 12, 37; p = 0.460) for 1 mg 311C90, 47% (CI 21, 73; p < 0.005) for 5 mg 311C90, and 66% (CI 43,89; p < 0.001) for 25 mg 311C90. Photophobia and nausea also showed improvement after 311C90. Adverse events were generally mild and transient in all treatment groups. There were no clinically significant changes in ECG recordings, blood pressure, or laboratory tests. Oral 311C90 (5 and 25 mg) is highly effective and well tolerated in the acute treatment of migraine. The response rates and treatment differences compared with placebo in this study suggest possible superiority over existing antimigraine therapies. This needs to be confirmed in formal comparative trials.

The tolerability and pharmacokinetics of the novel antimigraine compound 311C90 in healthy male volunteers

1. 311C90 is a novel and selective agonist at 5-HT1D receptors, with central and peripheral actions, currently in development for the acute oral treatment of migraine. 2. The pharmacokinetic and tolerability profiles of single oral doses from 1-50 mg 311C90 were investigated in 12 healthy male volunteers in a double-blind, placebo-controlled, dose-escalating study. 3. 311C90 was well tolerated with most adverse experiences of mild and transient nature. 4. Absorption was rapid with dose-independent kinetics. Median tmax was 2-4 h although 50-85% of eventual Cmax was attained within 1 h. The t1/2 was 2.5-3 h with a high apparent plasma clearance (CL/F > 2000 ml min-1) and apparent volume of distribution (Vz/F) of 400-500 l. 5. Three metabolites were detected in plasma and urine, one of which, the N-desmethyl metabolite, has 5-HT1D agonist activity. 6. 311C90 showed no clinically significant effects on blood pressure, heart rate, ECG or laboratory variables at any dose and demonstrated a tolerability and pharmacokinetic profile compatible with an acute oral migraine treatment.

Can oral 311C90, a novel 5-HT1D agonist, prevent migraine headache when taken during an aura?

The purpose of this pilot study was to determine whether 20 mg oral 311C90 can prevent the development of migraine headache when taken during the aura phase of a migraine attack. The study also aimed to provide an initial safety profile for 311C90 when taken during the aura. Forty patients (31 females, 9 males) were entered into this outpatient, double-blind, placebo-controlled, 2-period crossover trial. They all almost invariably experienced a migraine headache after the aura phase. Patients treated two migraine attacks during the aura phase in a random order, one with 311C90 20 mg and the other with placebo. Efficacy assessments were recorded on standard diary cards completed by each patient. A primary response was defined as the complete absence of headache pain in the 24 hour period following administration of the first dose of study medication. Safety assessments included ECGs, laboratory tests and the recording of adverse experiences. Twenty patients completed the study by treating 2 attacks, 16 of these were fully adherent to the study protocol. Three of the 16 patients responded to 311C90 whereas all patients developed a migraine headache after taking placebo. Two patients who did not respond to 311C90 described the developing headache as being "non-migraine'. Adverse experiences reported were similar to those experienced by patients in previous studies when 311C90 was taken during a migraine headache. There were no reports of 311C90-related adverse effects on the aura. These preliminary results suggest that oral 311C90 may be of value in preventing a migraine headache and is safe when taken during the aura phase. This intriguing possibility therefore warrants further investigation possibly utilising formulations that would deliver meaningful plasma levels of drug more rapidly.

Clinical safety of 311C90: aggregated data from patients and volunteers to date

The tolerability of 311C90, a novel, selective and highly effective 5-HT1D receptor agonist in development for the acute treatment of migraine, has been evaluated in a number of clinical pharmacology and patient studies across the dose range 1-50 mg. 311C90 has been well tolerated across the entire dose range and no clinically relevant changes in routine laboratory parameters, blood pressure or ECG recordings have been observed. Adverse experiences reported are generally dose related, mild to moderate and resolve spontaneously. Chest-related symptoms occur infrequently and the cardiovascular safety profile of 311C90 is considered particularly favourable. 311C90, therefore, possesses a desirable safety profile which is well suited to broad-based outpatient administration.

Evaluation of the long-term safety and efficacy of 311C90 in the treatment of migraine

311C90 is an orally active 5-HT1D agonist with both central and peripheral actions that is currently being developed as an acute antimigraine treatment. Several studies have demonstrated the safety and efficacy of 311C90 in the treatment of a single migraine headache. The objectives of this open study are to assess the safety and efficacy of 311C90 when used for a period of up to one year. Patients can treat as many migraine headaches as desired with an oral treatment regimen of 311C90. An initial 5 mg dose for treatment of the migraine headache may be followed with a second 5 mg dose to treat recurrence should it develop. Safety assessments include electrocardiograms, the frequency, intensity and duration of adverse experiences, and routine haematology, urinalysis and clinical chemistry measures. Data presented here are an interim view of the database as of August 1995 and should be considered as preliminary observations. No clinically significant serious adverse experiences have been reported. The adverse experience and efficacy profile appears to be consistent with previous 311C90 studies and this dosing regimen of 311C90 was well tolerated during multiple exposures. Notably, response rates are as good after both initial and repeated exposure (up to 5 migraines).

[Pharmaco-epidemiologic evaluation of rilmenidine in 18,235 hypertensive patients]

OBJECTIVES

Assess the effects of rilmenidine in routine clinical practice.

METHODS

18,235 patients with high blood pressure--mean age 61.2 years, arterial systolic pressure in supine position (SSP) over arterial diastolic pressure in supine position (SDP) at day 0: 174.58 +/- 0.12/101.51 +/- 0.06 mmHg--were followed by 2,072 general physicians. Treatment was initiated with a daily dose of 1 mg rilmenidine which was adapted as needed at different times in the study. At inclusion, diastolic pressure was between 90 and 115 mmHg in 84.5% of the patients; 1,126 patients had severe hypertension (SDP > or = 115 mmHg); 16,496 of these patients (81.5%) were followed for one year.

RESULTS

Mean fall in blood pressure between day 0 and month 12 was -28.7/-19.3 mmHg in the overall study population and -27.4/-18.9 mmHg in patients treated with 1 mg/day. Mean fall in blood pressure was comparable in the 8 risk populations identified. The percentage of patients who achieved normalized blood pressure status was 96.2% (SDP < or = 90 mmHg); 59.1% with a 1 mg daily dose, 23.7% with 2 mg/day, 11.6% with two-drug treatment and 1.8% with three-drug treatment. Acceptability, taking into account all possible imputabilities (more than 35,000 coprescriptions) and associated diseases, the incidence of undesirable side effects never exceeded 5.6% of the overall study population (5.2% in single-drug treatment, 8.3% in two- or three-drug treatment) and only 3.6% of the patients withdrew from the study due to an undesirable effect whether imputable to the treatment or not. There was little change in heart rate (mean--3 beats per minute between day 0 and month 12); variations observed depended on the rate at study onset. Laboratory tests (blood glucose, cholesterol, triglycerides, potassium, creatinine, uric acid) were not changed in any of the population groups.

CONCLUSIONS

This pharmaco-epidemiologic study showed that the benefit/acceptability ratio for rilmenidine is quite satisfactory and confirms the contribution of rilmenidine as first line treatment for hypertension.

Pressor effect of oral tyramine during treatment with befloxatone, a new reversible monoamine oxidase-A inhibitor, in healthy subjects

The interaction between tyramine and befloxatone, a new selective, reversible monoamine oxidase-A (MAO-A) inhibitor, was studied in a single-blind, parallel-group study in 30 healthy male volunteers whose fasting tyramine 30 dose (Tyr30) was 400 or 600 mg. Each subject completed a placebo run-in period followed by a befloxatone period. Befloxatone was given in repeated doses according to one of three regimens: befloxatone 20 mg once daily at the end of a meal rich in tyramine or befloxatone 10 or 20 mg twice daily 2 hours before a meal rich in tyramine. Subjects were given increasing daily doses of tyramine mixed with the meal, until a systolic blood pressure increase of at least 30 mm Hg was achieved (Tyr30). The mean Tyr30 decreased from 1220 mg (range, 600-1800 mg) during placebo to 290 mg (range, 150-500 mg) during befloxatone 20 mg once daily, 250 mg (range, 100-300) during befloxatone 10 mg twice daily, and 155 mg (range, 100-250 mg) during befloxatone 20 mg twice daily; corresponding to a potentiation factor of 5.2-, 6.5-, and 7.9-fold, respectively. The extent and the duration of the systolic blood pressure increase did not significantly differ between the placebo and the befloxatone regimens, except for a longer duration with the 20-mg twice daily regimen. These results are similar to those reported with the therapeutic dosage of other selective MAO-A inhibitors. They suggest that there would be little risk of hypertensive crisis in patients treated in clinical studies with befloxatone, and thus dietary restrictions appear to be unnecessary when the drug is given in a regimen of up to 20-mg once daily after meals.

Study of morbidity of personnel with potential exposure to vinclozolin

OBJECTIVES

To examine internal exposure and targeted health outcomes of employees exposed to 3-(3,5-dichlorophenyl)-5-methyl-5-vinyl-1,3-oxazolidine-2,4-dione; chemical abstracts service (CAS) number: 50471-44-8 (vinclozolin).

METHODS

A cross sectional study of 67 men exposed to vinclozolin for one to 13 years during synthesis and formulation operations and 52 controls. Biomonitoring was based on determination of urinary metabolites that contained a 3,5-dichloroaniline (3,5-DCA) moiety. Targeted health endpoints were the same as in previous subchronic and chronic animal studies--namely, reversible changes in the concentrations of hormones of the adrenocorticotrophic and gonadotrophic feedback systems, signs of liver injury, haemolytic anaemia, cataract formation (uniquely in rats), and hormonally induced hyperplasia and tumours at high doses. The clinical investigation consisted of a medical and occupational history questionnaire, physical examination, laboratory determinations (including testosterone, LH, and FSH measurements), ultrasonography of the liver and prostate, a detailed eye examination, and routine spirometry.

RESULTS

The mean 3,5-DCA concentration for two thirds of the study group exceeded an equivalent of the vinclozolin acceptable daily intake (ADI) used for consumer regulatory purposes. Even the highest concentrations were, however, at least 10 times below the no observable adverse effect level (NOAEL) based on animal studies. Analysis of physical examination and laboratory data provided no evidence of hormonal responses induced by vinclozolin. Furthermore, no evidence of liver injury, prostate changes, cataract formation, or haemolytic anaemia was found.

CONCLUSION

There was no evidence of any health effects induced by vinclozolin among employees with potential long term exposure. In particular, no antiandrogenic effects were found.

Pharmacologic effect of toloxatone on reactivity to the 35% carbon dioxide challenge: a single-blind, random, placebo-controlled study

The effect of a short treatment (7 days) with the reversible monoamine oxidase type A inhibitor toloxatone on the reactivity to the inhalation of 35% CO2 was evaluated in 18 panic patients who responded to 35% CO2 inhalation with panic before treatment. A single-blind, placebo-controlled design was applied. Panic patients were randomly assigned to the toloxatone (N = 10) or placebo (N = 8) groups and were given the 35% CO2 challenge on days 1 (before starting the treatment), 3, and 7. Patients on placebo did not report any significant changes in their reactivity to 35% CO2 during the three sessions, whereas patients on toloxatone reported a significant attenuation of the reactivity on day 7. These results indicate that (1) anxiety provoked by the inhalation of 35% CO2 is reproducible; (2) placebo has a negligible effect on 35% CO2 reactivity; and (3) reactivity to 35% CO2 is significantly attenuated by short treatment with toloxatone, possibly related to its antipanic activity.

Dose-effect relationship of rilmenidine after chronic administration

The antihypertensive efficacy and acceptability of 3 doses of rilmenidine (0.5, 1 and 2 mg, once daily) and a placebo over a 4 week period have been compared in a randomised, double-blind, parallel-group trial in 60 mild to moderate hypertensive patients. Six patients dropped out: 4 in the 2 mg-group and one in the 1 mg-group because of adverse events, and one in the placebo group for personal reason. The blood pressure was significantly decreased after the 1 and 2 mg doses with the maximum antihypertensive effect already being obtained after 1 mg. A significant dose-effect relationship was shown for supine systolic blood pressure (P = 0.05) but not for the supine diastolic blood pressure. The most beneficial efficacy/acceptability ratio was achieved at the dose of 1 mg once daily, which demonstrated the maximum antihypertensive effect associated with a low incidence of adverse events.

A pharmacokinetic and tolerance study of romazarit in patients with rheumatoid arthritis

Romazarit is a new drug for which animal pharmacology suggests a disease-modifying action in rheumatoid arthritis (RA). These animal studies predict that plasma romazarit concentrations within the range 50-100 mg l-1 may be required for efficacy in the clinic. Therefore, a pharmacokinetic study was designed to estimate the dosage required to achieve these concentrations in man. Twenty-four patients with RA entered a double-blind controlled assessment receiving either placebo, 100 mg t.i.d., 350 mg b.i.d., or 350 mg t.i.d., for 6 days. Pharmacokinetic profiles were measured after single doses and after the last of the multiple doses. Adverse events were mainly trival and were distributed almost equally between all three treatment and the placebo groups. Plasma romazarit concentrations were not dose-proportional after the single doses. Mean peak plasma drug concentrations were 11.8, 66.7, and 159 mg l-1 at steady state after 100 mg t.i.d., 350 mg b.i.d., and 350 mg t.i.d. The mean urinary recovery of drug-related material (mostly ester glucuronides) was 71 per cent of the dose during the dosage interval. The renal clearance of romazarit glucuronides correlated with creatinine clearance (p less than 0.01). Saturable tubular secretion of glucuronides coupled with reversible glucuronidation would explain these findings. It is predicted that oral doses of 450 mg romazarit given 12-hourly will result in plasma concentrations within the target range of 50-100 mg l-1.