STOP 101: A Phase 1, Randomized, Open-Label, Comparative Bioavailability Study of INP104, Dihydroergotamine Mesylate (DHE) Administered Intranasally by a I123 Precision Olfactory Delivery (POD® ) Device, in Healthy Adult Subjects.

OBJECTIVE: Investigate the safety and pharmacokinetics (PK) of INP104, intranasal dihydroergotamine mesylate (DHE) administered via a Precision Olfactory Delivery (POD® ) device, (Impel NeuroPharma, Seattle, WA) vs intravenous (IV) DHE and DHE nasal spray (Migranal® ) in healthy adult subjects. METHODS: This was a Phase 1, open-label, randomized, single-dose, 3-period, 3-way crossover study. Subjects received a single dose of A) INP104 1.45 mg (a drug-device combination product composed of DHE and the I123 POD device); B) DHE 45® Injection (IV) 1.0 mg; and C) DHE by Migranal® Nasal Spray 2.0 mg. Plasma levels of DHE and the major bioactive metabolite, 8'OH-DHE, were measured, and PK parameters were determined for both. Comparative bioavailability (BA) was assessed by calculating the ratio of the geometric means between treatments for Cmax and AUC0-inf on the ln-transformed data. Safety was assessed from adverse events, vital signs, electrocardiograms, and clinical laboratory values. RESULTS: Thirty-eight subjects were enrolled, 36 were dosed with at least 1 IP and 27 were included in the evaluation of PK and comparative BA. DHE plasma levels following INP104 1.45 mg administration reached 93% of Cmax by 20 minutes and were comparable to IV DHE 1.0 mg by 30 minutes (1219 ng/mL for INP104 vs 1224 ng/mL for IV DHE), which was the Tmax for INP104. From 30 minutes onward, DHE levels for INP104 closely matched those of IV DHE to 48 hours, the last time point measured. In comparison, the Cmax for Migranal was 299.6 pg/mL (approximately 4-fold less than INP104) and occurred at 47 minutes, 17 minutes later than INP104. Plasma DHE AUC0-inf were 6275, 7490, and 2199 h*pg/mL for INP104, IV DHE, and Migranal, respectively. Variability (coefficient of variation [CV%]) for Cmax and AUC0-inf for INP104 compared to Migranal indicated more consistent delivery with INP104. In the BA comparison using the PK population (subjects who had received all 3 treatments), the ratios of geometric means (percent) for Cmax and AUC0-inf were 7.9% and 74.2%, respectively, for INP104: IV DHE, and 445% and 308% for INP104: Migranal. Mean plasma concentration profiles for 8'-OH-DHE were proportionately lower and followed a similar profile to the parent compound, regardless of route of administration (IN vs IV) or delivery system (Migranal vs INP104). Treatment emergent AEs (TEAEs), of mostly mild intensity, were reported by 15/31 (48.4%), 21/32 (65.6%), and 14/34 (41.2%) subjects after INP104, IV DHE, and Migranal, respectively. Treatment-related TEAEs occurred in 6/31 (19.4%), 16/32 (50.0%), and 4/34 (11.8%) subjects after INP104, IV DHE, and Migranal, respectively. CONCLUSION: INP104 met the predefined statistical criteria for comparative bioavailability with IV DHE and Migranal. The shorter time to reach Cmax and at 4 times the plasma concentration of DHE in comparison to Migranal combined with a favorable tolerability profile support further investigation of INP104 as an effective, well tolerated, and non-invasive treatment for acute episodic migraine.

Sensitive and specific liquid chromatographic-tandem mass spectrometric assay for dihydroergotamine and its major metabolite in human plasma.

A sensitive and specific procedure for the simultaneous determination of dihydroergotamine (DHE) and its 8'-hydroxylated metabolite (8'-OH-DHE) in human plasma was developed and validated. The analytes were extracted from plasma samples by liquid-liquid extraction, separated through a Zorbax C18 column (50x2.1 mm I.D.) and detected by tandem mass spectrometry with an electrospray ionization interface. Caroverine was used as the internal standard. The method has a lower limit of quantitation (LOQ) of 10.0 and 11.0 pg/ml for DHE and 8'-OH-DHE, respectively. The intra- and inter-run precision was measured to be below 9.1% for both DHE and 8'-OH-DHE. The inter-run accuracy was within 4% for the analytes. The overall extraction recoveries of DHE and 8'-OH-DHE were determined to be about 58 and 52% on average, respectively. The chromatographic run time was approximately 2.5 min. More than 120 samples could be assayed daily with this method, including sample preparation, data acquisition and processing. The method developed was successfully used to investigate plasma concentrations of DHE and 8'-OH-DHE in a pharmacokinetic study of volunteers who received DHE orally.

Determination of dihydroergotamine in human plasma by high-performance liquid chromatography with fluorescence detection.

Dihydroergotamine, a 5-hydroxytryptamine antagonist, is used for the treatment of vascular headaches. A high-performance liquid chromatography assay with fluorescence detection is described for the determination of dihydroergotamine in plasma. The assay was validated over the concentration range 0.1-10 ng/ml plasma and applied to the analysis of plasma samples from subjects treated intramuscularly and intranasally with 2 mg of dihydroergotamine.

Bioavailability of intranasal formulations of dihydroergotamine.

OBJECTIVE: A comparison of the pharmacokinetic properties of two novel intranasal preparations of dihydroergotamine mesilate (DHEM) with a commercially available intranasal preparation. METHODS: Two intranasal formulations of DHEM in combination with randomly methylated beta-cyclodextrin (RAMEB) were prepared. Subsequently, in an open, randomised, crossover study in nine healthy volunteers, the following medication was administered: 2 mg DHEM/2% RAMEB nasal spray (= two puffs of 100 microliters); 2 mg DHEM/4 mg RAMEB nasal powder; 2 mg Diergo nasal spray (= four puffs of 125 microliters); 0.5 mg DHEM i.m., and 2 mg DHEM solution p.o. RESULTS: No statistically significant differences were found in maximum plasma concentration (Cmax), time to reach Cmax (tmax), area under plasma concentration-time curve (AUC0-8 h), Frel(t = 8 h) and Cmax/AUC(t = 8 h) for the three intranasal preparations. The relative bioavailabilities of the DHEM/RAMEB nasal spray, the DHEM/RAMEB nasal powder and the commercially available DHEM nasal spray were 25%, 19% and 21%, respectively, in comparison with i.m. administration. The relative bioavailability after oral administration was 8%. CONCLUSION: The pharmacokinetic properties of the novel intranasal preparations are not significantly different from the commercially available nasal spray. Advantages of the DHEM/RAMEB nasal spray are (1) less complicated handling, (2) reduction of the number of puffs and (3) a preference by the volunteers.

Simplified solid-phase extraction method for determination of dihydroergotamine in rabbit and human serum using high-performance liquid chromatography with fluorescence detection.

A rapid, selective and sensitive method for the determination of dihydroergotamine (DHE) in serum was developed. Dihydroergocristine (DHEC) was used as an internal standard. Human and rabbit serum samples were extracted using commercial solid-phase cyano (CN) columns. Proteins were washed from these columns with pure acetonitrile, resulting in clean extracts. Extracts were subsequently separated by HPLC in an isocratic way, using a reversed-phase C18 analytical column. Fluorometric detection was performed at excitation and emission wavelengths of 277 and 348 nm, respectively. Calibration curves with amounts of DHE ranging from 2 to 32 ng, were linear. The limit of detection found for DHE was 0.2 ng, extracted from 0.5 ml rabbit or from 2.5 ml human serum. The limit of quantification in serum of both species was 0.7 ng. The method has been shown to be suitable for monitoring DHE in serum during pharmacokinetic studies in rabbits.

Human pharmacokinetics of dihydroergotamine administered by nasal spray.

OBJECTIVES: A nasal spray of dihydroergotamine was developed for the treatment of migraine headaches, and pharmacokinetic studies were scheduled to evaluate the bioavailability of dihydroergotamine by this new route of administration. METHODS: Nine studies were performed with dihydroergotamine administered by nasal spray to evaluate the bioavailability of the nasal route versus the intramuscular route, the linearity of the kinetics, the interindividual and intraindividual variations, and the influence of different factors. RESULTS: Nasally administered dihydroergotamine (1 mg) becomes rapidly available to the systemic circulation, with peak plasma levels of 1 ng/ml achieved in 0.9 hour. The relative bioavailability versus intramuscular route is 38.4%. Dihydroergotamine administered by the nasal route exhibits linear dose proportionality (1 to 4 mg). Intraindividual variations of bioavailability evaluated for a 1-year period were higher (29%) than those found for the intramuscular route (20%) but comparable to the oral route. Interindividual variations for bioavailability were greater (25% versus 14% by the intramuscular route) but comparable to the oral route. Caffeine contained in the nasal solution (1%) had no effect on the absorption. Vasomotor phenomena, which could also affect the nasal mucosa during a migraine headache, do not modify the bioavailability. The constriction of the nasal mucosa by fenoxazoline leads to a slight decrease (-15%) in the bioavailability. The presence of acute viral rhinitis did not result in any change in dihydroergotamine nasal absorption compared with the normal state of the nasal mucosa. From a pharmacokinetic point of view, nasally administered dihydroergotamine can be given, without risk of overdose, to patients receiving long-term oral dihydroergotamine medication. CONCLUSION: These results show the reliability and reproducibility of this route of dihydroergotamine administration adapted for the treatment of migraine headaches.

Effect of ponsinomycin on the pharmacokinetics of dihydroergotamine administered orally.

Ponsinomycin is a new macrolide antibiotic. Its effect on DHE pharmacokinetics was investigated in this study. Twelve young healthy volunteers received a single 9 mg oral dose of DHE before and on the 8th day of treatment (800 mg twice daily) with ponsinomycin. DHE was assayed in plasma by RIA. Because of low plasma levels, only peak concentrations could be accurately compared for a ponsinomycin effect. We observed a 3-40-fold increase in maximum DHE plasma levels in the majority of cases and a much more important effect on one occasion, when DHE was administered in the presence of ponsinomycin. These data are consistent with an increase of DHE bioavailability in the presence of ponsinomycin, probably related to a reduction of its first-pass elimination. This pharmacokinetic interaction is likely to have clinical consequences and administration of ponsinomycin should be avoided in patients treated orally with DHE.

Pharmacodynamics and pharmacokinetics of dihydroergotamine (DHE) in conscious beagle dogs.

Dihydroergotamine (DHE) elicits selective and longlasting venoconstrictor activity though the drug disappears rapidly from the blood. Changes in the diameter of the saphenous vein were determined in conscious beagle dogs and compared to plasma level-time curves of DHE and its metabolites. After both intravenous and oral administration of DHE the venoconstrictor response is of markedly longer duration than would be expected on the basis of the half life for elimination of DHE from blood. Furthermore, 3 out of 5 of the main metabolites of DHE elicited considerable constrictor effects when infused locally into the vein. It is suggested that the long duration of the DHE-induced venoconstriction is due to an extremely slow dissociation of the drug from its receptor sites on the venous smooth muscle cell and to the formation of active metabolites.

Determination of sub-nanogram amounts of dihydroergotamine in plasma and urine using liquid chromatography and fluorimetric detection with off-line and on-line solid-phase drug enrichment.

A highly sensitive and selective high-performance liquid chromatographic method, involving sample pre-treatment, column switching and fluorimetric detection, is described for the determination of dihydroergotamine in plasma and urine samples. The pre-chromatographic sample treatment consists of extraction by means of an Extrelut column for plasma samples, and pre-separation with enrichment steps on a Sep-Pak column for urine samples. The samples are then injected onto a pre-separation column (Aquapore), and the fraction containing dihydroergotamine are automatically diverted onto an analytical column (ODS reversed phase). An acetonitrile-ammonium carbamate gradient is used as the mobile phase. High recovery of dihydroergotamine from both plasma (87%) and urine (100%) and a detection limit as low as 100 pg/ml were achieved, with a linear response up to 5 ng/ml. The assay demonstrated a high degree of selectivity with regard to the extensive metabolism of dihydroergotamine especially to the main metabolite 8'-hydroxydihydroergotamine. The assay was successfully applied for more than one year to the determination of plasma and urine concentrations of dihydroergotamine after parenteral administration.

Dihydroergotamine: pharmacokinetics, pharmacodynamics, and mechanism of venoconstrictor action in beagle dogs.

Dihydroergotamine (DHE) elicits selective and long-lasting venoconstrictor activity, although the drug disappears rapidly from the blood. Therefore, a comparative study on the pharmacokinetic and pharmacodynamic properties of DHE was performed in beagle dogs. In addition, the mechanism of the venoconstrictor activity of DHE was investigated in vivo. Changes in the diameter of the saphenous vein and plasma level-time curves of DHE and its metabolites were determined in conscious beagle dogs. After both intravenous and oral administrations of DHE, the venoconstrictor response is of markedly longer duration than would be expected on the basis of the half-life for elimination of DHE from blood. The experimental data support the suggestion that the long duration of the DHE-induced venoconstriction is due to an extremely slow dissociation of the drug from its receptor sites on the venous smooth muscle cell, and to the formation of active metabolites. Using the antagonists ketanserin, pizotifen, and rauwolscine, evidence is presented that the venoconstrictor activity of DHE is mediated through stimulation of 5-HT receptors; there is no evidence of involvement of alpha-adrenoceptors.

Combination dihydroergotamine mesylate and heparin sodium with lidocaine HCl. Pharmacokinetics, mechanism of action, clinical efficacy, and adverse effects.

Dihydroergotamine(DHE)-heparin combination offers a unique treatment modality for the prevention of deep vein thrombosis. The combination appears to affect all 3 limbs of Virchow's triad: hypercoagulability, venous stasis, and endothelial damage. In most efficacy studies, data indicated that the combination of DHE 0.5 mg and heparin 5000 IU was superior to low-dose heparin alone. Even when the efficacy of DHE-heparin was the same as that of heparin alone, the use of the combination allowed for a decrease in the heparin dose required.

Venoconstrictor effects of dihydroergotamine after intranasal and intramuscular administration.

A parenteral formulation of dihydroergotamine (DHE) is the only galenical form now available for the treatment of acute attacks of migraine in which a rapid onset of action is required. A recently developed nasal spray of DHE has been compared with intramuscular DHE for its venoconstrictor activity. In a randomised double-blind, cross-over trial, 9 healthy male volunteers received a single dose of DHE 1 mg intranasally, DHE 0.5 mg i.m. or placebo (intranasally and i.m.) on three different occasions, with an interval of at least 1 week between doses. Both active treatments, but not placebo, produced marked venoconstriction as shown by reduced compliance of superficial hand veins. The effect persisted for more than 8 h. The maximum venoconstrictor effect of 1 mg DHE intranasally was 40 +/- 12% (mean +/- SEM) and after 0.5 mg i.m. it was 52 +/- 15%. The time course of the venoconstrictor effect was similar after both routes of administration. Blood pressure and heart rate changes in these normotensive subjects were almost identical after dihydroergotamine and placebo. The results suggest that the nasal spray could be used as an alternative to parenteral DHE, permitting self-administration of the drug for the treatment of acute attacks of migraine.

What is known about the action of dihydroergotamine on the vasculature in man?

The vasoconstrictor activity of dihydroergotamine is long-lasting and independent from continuously elevated plasma levels. There is evidence that dihydroergotamine accumulates at the vascular smooth muscle cells and elicits venoconstriction through both stimulation of 5-HT receptors as well as sensitization of the venous smooth muscle to the constrictor activity of biogenic amines. In vivo, the vasoconstrictor activity of dihydroergotamine is probably modulated through vasoactive metabolites, i.e., the vasoconstrictor profile and efficacy obviously varies with the ratio of the parent drug and dihydroergotamine metabolites in plasma.

[Treatment of morning migraine. Clinical and biokinetic correlation of programmed-release dihydroergotamine]. / Le traitement des migraines matinales. Corrélation clinique et biocinétique d'une dihydroergotamine à libération programmée.

The authors have tested a new preparation of dihydroergotamine (microgranules in a capsule) by comparing the clinical results obtained in 30 patients suffering from morning migraine with the plasma levels of the active substance measured in 8 healthy subjects. The microgranules were administered in doses of 30 mg/24 hours and compared with a similar dose of a dihydroergotamine solution. The close correlation observed between sustained plasma levels and prolonged therapeutic effects indicates a truly programmed delivery of dihydroergotamine by the microgranule preparation.

Immunoassay of ergotamine and dihydroergotamine using a common 3H-labelled ligand as tracer for specific antibody and means to overcome experienced pitfalls.

A highly sensitive radioimmunoassay for the determination of ergotamine and dihydroergotamine is described. The limit of detection is about 9 pg/mL blood plasma for both compounds. The specificity of the gamma-globulin, which was prepared from rabbit antiserum, was investigated in the presence of compounds synthesized as possible metabolites. It was found that the tricyclic peptide moiety common to both molecules is an essential structural feature for binding to the gamma-globulin. From dilution experiments with the radioactively labelled compound it followed that ergotamine and to a lesser extent also its dihydro derivative are adsorbed on various tube wall materials using known buffer solutions. A practically insuperable obstacle is rearrangement of ergotamine under the experimental conditions, forming a stereoisomer by inversion at the C-8 position. The equilibrium of ergotamine in equilibrium ergotaminine found in human plasma remains stable under the incubation conditions of the radioimmunoassay.

Interspecies similarities in the disposition of 3H-dihydroergotamine following subcutaneous administration in man and rabbits.

The disposition of dihydroergotamine methanesulfonate following single subcutaneous doses was studied in man and the rabbit using radiotracer techniques. 3H-Dihydroergotamine was almost immediately and completely absorbed from the injection site; peak blood radioactivity levels were attained within 1 h of drug administration in both species. The disappearance of radioactivity from blood was biphasic, with t 1/2,alpha and t 1/2,beta values of 2.9 and 16.9 h, respectively, in man and 2.9 and 14.7 h, respectively, in the rabbit. Apparent volumes of distribution were 18.9 Liter/kg in man and 30.4 Liter/kg in the rabbit. The excretion pattern of dihydroergotamine and its metabolites was also similar for the two species, with biliary elimination being the predominant route. At 4-5 days postdosing, 80-85% of the administered radioactivity was recovered in the feces and urine. The rabbit appears to be an adequate animal model for the study of dihydroergotamine pharmacokinetics in man.

On the treatment of migraine. Pharmacokinetic-pharmacodynamic relationships for a programmed release formulation of dihydroergotamine administered orally in the human.

With the combined pharmacokinetic-pharmacodynamic approach, the bioavailability and venoconstrictor effects of two DHE formulations (programmed release capsules and oral solution) have been compared after acute oral dose administrations in the healthy volunteer subjects. The bioavailability of DHE from programmed release capsules has been significantly greater than that shown by the oral solution. DHE capsules formulation has seemed to provide appropriate plasma concentrations for at least 10 h after administration. That may well account for its efficacy in the treatment of morning migraine.

The pharmacokinetics and bioavailability of subcutaneously administered dihydroergotamine, heparin and the dihydroergotamine-heparin combination.

Subcutaneously administered dihydroergotamine (DHE) becomes rapidly and completely available to the human systemic circulation, with peak plasma levels of 1.4-3.5 ng/mL/mg achieved in less than 1 h. The elimination of DHE from plasma is biphasic, t 1/2 alpha = 1h, t 1/2 beta = 4-5 h. DHE exhibits linear dose proportionality. Coadministration of heparin results in a statistically significant increase of 25% in the area under the plasma level/time curve for DHE (bioavailability). Coinjection of DHE and heparin in the same subcutaneous site furthermore causes a decrease in the rate of DHE absorption by 63%, resulting in delayed time to peak (by 110%) and reduced peak levels (by 15%) of DHE. In contrast, there is no effect by coadministered DHE on heparin pharmacokinetic parameters. Heparin peak plasma levels (0.3 I.U./mL by activated factor X, 0.1 I.U./mL by protamine titration with a 15,000 I.U. s.c. bolus) are achieved in 3.6 h. Pharmacokinetic analysis suggests that the subcutaneous route of administration provides only 19% of the bioavailable heparin that would be obtained following administration of an equipotent intravenous dose. DHE-heparin formulated for injection in combination demonstrates systemic availability identical to that of the two components injected separately, but with a reduced rate of absorption for the DHE component and a corresponding attenuation of fluctuations in steady state DHE levels.