sumatriptan, Imitrex
Chromosomal localization of the 5-HT1F receptor gene: no evidence for involvement in response to sumatriptan in migraine patients.

Maassen VanDenBrink A, Vergouwe MN, Ophoff RA, Naylor SL, Dauwerse HG, Saxena PR, Ferrari MD, Frants RR.

Department of Pharmacology, Erasmus University Rotterdam, The Netherlands.

The 5-HT1F receptor, which is present in both human vascular and neuronal tissue, may mediate the therapeutic effect and/or side-effects of sumatriptan. We investigated the chromosomal localization of the 5-HT1F receptor gene and the relation between eventually existing polymorphisms and the clinical response to sumatriptan in migraine patients. The 5-HT1F receptor gene was localized using a monochromosomal mapping panel, followed by a radiation-reduced hybrid mapping and fluorescent in situ hybridization. The results of these techniques show that the 5-HT1F receptor gene is localized at 3p12. We investigated the presence of polymorphisms by single strand conformation polymorphism analysis in 14 migraine patients who consistently responded well to sumatriptan, 12 patients who consistently experienced recurrence of the headache after initial relief, 12 patients with no response to sumatriptan, and in 13 patients who consistently experienced chest symptoms after use of sumatriptan. No polymorphisms were detected in any of the patients. We therefore conclude that genetic diversity of the 5-HT1F receptor gene is most probably not responsible for the variable clinical response to sumatriptan.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9632173&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Validation of a liquid chromatographic tandem mass spectrometric method for the determination of sumatriptan in human biological fluids.

Cheng KN, Redrup MJ, Barrow A, Williams PN.

Department of Mass Spectrometry, Huntingdon Life Sciences, Cambridgeshire, UK.

A liquid chromatographic tandem mass spectrometric method for the quantitative determination of sumatriptan base in human plasma and urine has been developed and validated over the concentration range 0.2-20 ng base ml-1. Sumatriptan is a 5-HT1 receptor agonist which has found widespread use in the treatment of migraine. Sumatriptan and its internal standard (D3-sumatriptan) were extracted from human matrices using C2 solid phase cartridges. The extracts were chromatographed on a C18 column, ionised using a heated nebuliser assisted atmospheric pressure ionisation (API) interface and detected by MS/MS in the multiple reaction monitoring mode. The completed validation demonstrated the method to be robust, accurate, precise and specific for the direct quantification of sumatriptan in human fluids. The method was used on a routine basis to determine the levels of sumatriptan in human volunteers following the oral administration of a 25 mg dose of sumatriptan succinate.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9656150&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Coronary side-effect potential of current and prospective antimigraine drugs.

MaassenVanDenBrink A, Reekers M, Bax WA, Ferrari MD, Saxena PR.

Department of Pharmacology, Erasmus University Rotterdam, The Netherlands.

BACKGROUND: The antimigraine drugs ergotamine and sumatriptan may cause angina-like symptoms, possibly resulting from coronary artery constriction. We compared the coronary vasoconstrictor potential of a number of current and prospective antimigraine drugs (ergotamine, dihydroergotamine, methysergide and its metabolite methylergometrine, sumatriptan, naratriptan, zolmitriptan, rizatriptan, avitriptan). METHODS AND RESULTS: Concentration-response curves to the antimigraine drugs were constructed in human isolated coronary artery segments to obtain the maximum contractile response (Emax) and the concentration eliciting 50% of Emax (EC50). The EC50 values were related to maximum plasma concentrations (Cmax) reported in patients, obtaining Cmax/EC50 ratios as an index of coronary vasoconstriction occurring in the clinical setting. Furthermore, we studied the duration of contractile responses after washout of the acutely acting antimigraine drugs to assess their disappearance from the receptor biophase. Compared with sumatriptan, all drugs were more potent (lower EC50 values) in contracting the coronary artery but had similar efficacies (Emax <25% of K+-induced contraction). The Cmax of avitriptan was 7- to 11-fold higher than its EC50 value, whereas those of the other drugs were <40% of their respective EC50 values. The contractile responses to ergotamine and dihydroergotamine persisted even after repeated washings, but those to the other drugs declined rapidly after washing. CONCLUSIONS: All current and prospective antimigraine drugs contract the human coronary artery in vitro, but in view of low efficacy, these drugs are unlikely to cause myocardial ischemia at therapeutic plasma concentrations in healthy subjects. In patients with coronary artery disease, however, these drugs must remain contraindicated. The sustained contraction by ergotamine and dihydroergotamine seems to be an important disadvantage compared with sumatriptan-like drugs.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9665056&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
How does sumatriptan nasal spray perform in clinical practice?

Dahlof CG, Boes-Hansen S, Cederberg CG, Hardebo JE, Henriksson A.

Gothenburg Migraine Clinic, Goteborg, Sweden.

Migraineurs (94F, 24M) with previous experience of subcutaneous sumatriptan and/or sumatriptan tablets were asked their opinion on sumatriptan nasal spray treatment particularly with respect to onset of action, total efficacy, tolerability, and user friendliness. The information was obtained by means of a self-administered questionnaire handed out at the time of prescription of the nasal spray. The results are based on the patients' cumulative experience of having treated at least two migraine attacks with the spray (20 mg). Sumatriptan nasal spray (20 mg) was perceived to have a faster onset of action and, with the exception of a bad taste, to have a better tolerability than the tablets. Compared with subcutaneous sumatriptan, the nasal spray was claimed to be less effective in reducing symptoms of migraine attacks but to cause fewer adverse events. A bitter taste was the most commonly reported side effect of sumatriptan nasal spray--reported by 68% (80 out of 118) of the migraineurs. The user friendliness of sumatriptan nasal spray was rated better than that of subcutaneous sumatriptan and/or sumatriptan tablets. The overall impression of sumatriptan nasal spray was reported to be better or equal to that of the tablet and the injection by 57% and 46%, respectively. It is concluded that the results obtained in clinical practice are very much in line with those obtained in controlled clinical trials. The overall impression of sumatriptan nasal spray is that it is user friendly and useful in the acute treatment of migraine attacks of moderate intensity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9673808&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
The 5-HT1-like receptors mediating inhibition of sympathetic vasopressor outflow in the pithed rat: operational correlation with the 5-HT1A, 5-HT1B and 5-HT1D subtypes.

Villalon CM, Centurion D, Rabelo G, de Vries P, Saxena PR, Sanchez-Lopez A.

Departamento de Farmacologia y Toxicologia, CINVESTAV, I.P.N., Mexico D.F., Mexico.

1. It has been suggested that the inhibition of sympathetically-induced vasopressor responses produced by 5-hydroxytryptamine (5-HT) in pithed rats is mediated by 5-HT1-like receptors. The present study has re-analysed this suggestion with regard to the classification schemes recently proposed by the NC-IUPHAR subcommittee on 5-HT receptors. 2. Intravenous (i.v.) continuous infusions of 5-HT and the 5-HT1 receptor agonists, 8-OH-DPAT (5-HT1A), indorenate (5-HT1A), CP 93,129 (5-HT1B) and sumatriptan (5-HT(1B/1D)), resulted in a dose-dependent inhibition of sympathetically-induced vasopressor responses. 3. The sympatho-inhibitory responses induced by 5-HT, 8-OH-DPAT, indorenate, CP 93,129 or sumatriptan were analysed before and after i.v. treatment with blocking doses of the putative 5-HT receptor antagonists, WAY 100635 (5-HT1A), cyanopindolol (5-HT(1A/1B)) or GR 127935 (5-HT(1B/1D)). Thus, after WAY 100635, the responses to 5-HT and indorenate, but not to 8-OH-DPAT, CP 93,129 and sumatriptan, were blocked. After cyanopindolol, the responses to 5-HT, indorenate and CP 93,129 were abolished, whilst those to 8-OH-DPAT and sumatriptan (except at the lowest frequency of stimulation) remained unaltered. In contrast, after GR 127935, the responses to 5-HT, CP 93,129 and sumatriptan, but not to 8-OH-DPAT and indorenate, were abolished. 4. In additional experiments, the inhibition induced by 5-HT was not modified after 5-HT7 receptor blocking doses of mesulergine. 5. The above results suggest that the 5-HT1-like receptors, which inhibit the sympathetic vasopressor outflow in pithed rats, display the pharmacological profile of the 5-HT1A, 5-HT1B and 5-HT1D, but not that of 5-HT7, receptors.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9692787&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Effects of the novel high-affinity 5-HT(1B/1D)-receptor ligand frovatriptan in human isolated basilar and coronary arteries.

Parsons AA, Raval P, Smith S, Tilford N, King FD, Kaumann AJ, Hunter J.

Department of Neuroscience Research, SmithKline Beecham Pharmaceuticals, New Frontiers Science Park (North), Harlow, Essex, UK.

The contractile actions of the novel high-affinity 5-hydroxytryptamine (5-HT(1B/1D)) ligand, frovatriptan (formerly VML 251/SB-209509) were investigated in human isolated basilar and coronary arteries in which the endothelium had been removed. Basilar arteries were obtained post mortem, and coronary arteries were obtained from patients undergoing heart transplant (recipient) or from donor hearts that were not suitable for transplant. Frovatriptan was a potent contractile agent in isolated basilar artery with a -log mean effective concentration (EC50) value of 7.86 +/- 0.07 and intrinsic activity of 1.25 +/- 0.10 relative to 5-HT (n = 4). Frovatriptan was 8.5-fold more potent than sumatriptan, which produced a -log EC50 value of 6.93 +/- 0.09 and intrinsic activity 11.1 +/- 0.08 relative to 5-HT (n = 4). In coronary arteries, frovatriptan produced contraction with -log EC50 values of 7.38 +/- 0.12 and 7.81 +/- 0.2 in recipient (n = 7) and donor (n = 3) arteries, respectively. The relative degree of contraction of frovatriptan was lower than that of 5-HT, with relative intrinsic activities of 0.42 +/- 0.06 and 0.40 +/- 0.09, respectively. Sumatriptan produced contraction of human recipient and donor arteries with -log EC50 values (intrinsic activity) of 6.57 +/- 0.13 (0.79 +/- 0.27; n = 6) and 7.35 (1.41; n = 2), respectively. Furthermore, marked bell-shaped responses were apparent for frovatriptan in coronary arteries, with relaxation occurring at concentrations >6 microM in some tissues. In contrast, no bell-shaped concentration-response curves were apparent for sumatriptan or 5-HT. Threshold concentrations for frovatriptan-induced contractions were also different between basilar (>2 nM) and coronary arteries (>20 nM). No separation of threshold activity was observed with sumatriptan or 5-HT. These data show that frovatriptan produces constriction of human isolated basilar and coronary arteries. However, frovatriptan produces a complex pharmacologic response in the coronary artery, with threshold contractile activity requiring approximately 10-fold greater concentrations of agonist than in the basilar artery. Frovatriptan also shows a differential pharmacologic profile compared with sumatriptan in coronary arteries, with reversal of tone predominating at high concentration.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9700983&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Functional evaluation of 5-hydroxytryptamine receptor activity in rat resistance vessels.

Potenza MA, Serio M, Montagnani M, Mansi G, Rinaldi R, Genualdo M, Mitolo-Chieppa D.

Institute of Pharmacology, Medical School, University of Bari, Italy.

1. To characterize 5-hydroxytryptamine (5-HT) receptors in rat perfused mesenteric vascular bed (MVB), the effect of 5-HT and related compounds was investigated by functional assay. 2. In quiescent preparations, 5-HT elicited a concentration-dependent conctractile response. After addition of ketanserin, a 5-HT2 receptor antagonist, EC50 values were significantly higher than in controls. 3. In noradrenaline (NA)-precontracted preparations, under continuous infusion of ketanserin, 5-HT, 5-carboxamidotryptamine (5-CT) and sumatriptan produced relaxation. Their rank order of relaxant potency and maximum effect were sumatriptan > 5-HT > 5-CT. Methysergide (1 microM) and spiperone (20-100 nM) caused a rightward shift of the relaxation curve to sumatriptan. These data suggest that vasodilatation in rat MVB is mediated by an 'atypical' subtype of 5-HT1-like receptor, which reveals a pharmacological profile similar to that of the 5-HT1D receptor. The involvement of both 5-HT3 and 5-HT4 receptors can be ruled out, since tropisetron (up to 10 microM) was not able to antagonize the relaxant effect by sumatriptan. 4. Under granisetron infusion (3 microM), the contractile response evoked by perivascular nervous stimulation, but not exogenous NA contraction, was significantly reduced (P < 0.001). These data demonstrate the presence of 5-HT3 receptors in peripheral neurones, modulating neurotransmitters release.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9730261&dopt=Abstract sumatriptan Imitrex