sumatriptan, Imitrex
The anti-migraine agent sumatriptan induces a calcium-dependent discharge in meningeal sensory neurons.

Strassman AM, Levy D.

Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center and Harvard Medical School, 330 Brookline Ave, Boston, MA 02215, USA. Andrew.Strassman bidmc.harvard.edu

The anti-migraine agent sumatriptan constricts cerebral blood vessels, and also blocks neuropeptide release from meningeal sensory neurons. We investigated whether sumatriptan can also affect neuronal discharge, by recording the activity of dural primary afferent neurons during dural application of sumatriptan in anesthetized rats. Sumatriptan (0.24-24 microM) induced a concentration-dependent increase in ongoing discharge. The discharge occurred only in the presence of calcium. The suppressive effect of calcium removal was not a result of a general decrease in excitability, because calcium removal produced a pronounced increase in mechanically evoked discharge. The excitatory effect on dural afferent discharge might underlie the initial worsening of the headache that can occur following sumatriptan administration, prior to the subsequent onset of headache relief.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15194863&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Patterns of use of triptans and reasons for switching them in a tertiary care migraine population.

Sheftell FD, Feleppa M, Tepper SJ, Volcy M, Rapoport AM, Bigal ME.

Department of Psychiatry, New York Medical College, NY, USA.

OBJECTIVE: To assess the reasons for switching triptans within migraine patients presenting to a specialty clinic. DESIGN AND METHODS: We reviewed data of migraineurs who (1) were currently using a triptan as acute treatment medication for migraine, and (2) had previously used at least one other triptan, or a different triptan formulation. All subjects were followed for at least 1 year. For every triptan/formulation used, the reasons for discontinuation were obtained. RESULTS: Our sample consisted of 386 patients, 339 of whom (87.8%) were females. Sumatriptan was first used by 349 (90.4%); zolmitriptan, by 238 (61.5%); rizatriptan, by 195 (50.5%); naratriptan, by 137 (35.4%); and almotriptan, by 31 (8.0%). Almotriptan was excluded from this analysis because of our small sample. We found significant differences among those who wanted to try another triptan to see if it would be better in those who first used sumatriptan 25 mg, compared to those first using sumatriptan 50 mg (P = .01), sumatriptan 100 mg (P < .001), sumatriptan nasal spray (NS) (P < .001), sumatriptan subcutaneous (SC) (P < .001), zolmitriptan 5 mg (P < .001), rizatriptan 10 mg (P < .001), and naratriptan (P = .001). Patients using rizatriptan, sumatriptan NS, and sumatriptan SC had significantly lower rates of reporting this answer. Subjects first using naratriptan were less likely to report recurrence than those using sumatriptan 25 mg (P = .004), sumatriptan 50 mg (P = .0005), sumatriptan 100 mg (P = .003), zolmitriptan (P = .02), and rizatriptan (P = .006). Incomplete relief was more frequently reported by those first using sumatriptan 25 mg and naratriptan. Inconsistency was a reason for switching in those initially using sumatriptan NS, sumatriptan 25 mg, and naratriptan and less frequently reported in those using zolmitriptan and sumatriptan SC. Side effects were major factors for those first using sumatriptan 100 mg, NS, and SC, and less for those using naratriptan and sumatriptan 25 mg. From those subjects that initially used sumatriptan SC and were switched to a different triptan or formulation, 19.5% returned to sumatriptan SC; for the other triptans/formulations, the percentages were: sumatriptan 25 mg, 7.8%; sumatriptan 50 mg or 100 mg, 42.3%; sumatriptan NS, 17.7%; zolmitriptan, 17.6%; rizatriptan, 16.5%; naratriptan, 9.4%. For those who used more than three triptans/formulations, the last triptan used was: sumatriptan, 29.5%; zolmitriptan, 31.8%; rizatriptan, 25.0%; naratriptan, 12.5%. CONCLUSIONS: A variety of treatment attributes are important in determining the reasons involved in switching a triptan. To assess this attributes can provide additional information to supplement the traditional tests of efficacy provided by randomized clinical trials.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15209687&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Predicting the response to sumatriptan: the Sumatriptan Naratriptan Aggregate Patient Database.

Christoph-Diener H, Ferrari M, Mansbach H; SNAP Database Study Group.

Dept. of Neurology, University of Essen, Hufelandstr. 55, 45147 Essen, Germany. h.diener uni-essen.de

OBJECTIVE: The efficacy and tolerability profiles of sumatriptan and other 5HT(1B/1D) agonists (triptans) have been well established. However, the determinants for optimal response to sumatriptan are unknown. The Sumatriptan Naratriptan Aggregate Patient (SNAP) database contains data from 128 clinical trials including 28,407 migraine sufferers treating over 130,000 attacks. The authors analyzed these data to identify factors predicting response (headache relief and pain-free response) to sumatriptan. METHODS: The authors assessed 24 possible univariate predictors of headache response in 3,706 patients (18 years and older) receiving sumatriptan tablets 100 mg or placebo in a double-blind study using recursive partitioning and logistic regression techniques. RESULTS: The authors found seven predictors of headache relief 2 hours postdose. Moderate pain at baseline was the strongest predictor (adjusted p = 3.32 x 10(-35)), followed by absence of a disability requiring bedrest (adjusted p = 3.11 x 10(-18)). Other predictors included absence at baseline of vomiting, pulsating pain, nausea, or photophobia/phonophobia, and onset of headache during daytime hours. Logistic regression confirmed that treatment with sumatriptan was the strongest predictor of headache relief, with significant baseline covariates being pain severity, level of disability, and presence or absence of vomiting. A similar pattern of results was reported for predictors of pain-free response 2 hours after taking sumatriptan. CONCLUSIONS: Pretreatment pain severity is the most important predicting factor for response to sumatriptan in migraine attacks: the lower baseline severity, the better.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15304585&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Effect of sumatriptan in different models of pain in rats.

Ottani A, Ferraris E, Giuliani D, Mioni C, Bertolini A, Sternieri E, Ferrari A.

Department of Biomedical Sciences, University of Modena and Reggio Emilia, Section of Pharmacology, Via G. Campi 287, 41100 Modena, Italy. alessandraottani yahoo.it

The effect of sumatriptan in two standard algesimetric tests and in a model of cephalalgia was evaluated in rats. The pain threshold was measured by the hot-plate and the writhing tests; cephalalgia was produced by injecting bradykinin (10 microg in a volume of 10 microl) into a common carotid artery. Sumatriptan was subcutaneously (s.c.) injected at the doses of 4, 8, 24 or 42 mg/kg; morphine (5 or 10 mg/kg s.c.) and indomethacin (5 or 10 mg/kg s.c) were used as standard analgesic drugs. Sumatriptan had no analgesic activity either in the hot-plate test or in the writhing test. On the other hand, at 24 and 42 mg/kg it dose-dependently reduced the response to the intracarotid injection of bradykinin (vocalization and tachypnea), this effect being prevented by the 5-HT(1B) receptor antagonist, isamoltane. The 5-HT(1D) receptor antagonist BRL15572 prevented the effect of sumatriptan on bradykinin-induced tachypnea, but not the effect of sumatriptan on bradykinin-induced vocalization. These data demonstrate that sumatriptan is significantly effective in a reliable animal model of cephalalgia, while having no systemic analgesic activity.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15306203&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Effects of sumatriptan on capsaicin-induced carotid haemodynamic changes and CGRP release in anaesthetized pigs.

Arulmani U, Heiligers JP, Garrelds IM, Sanchez-Lopez A, Willems EW, Villalon CM, Saxena PR.

Department of Pharmacology, Cardiovascular Research Institute 'COEUR', Erasmus MC, University Medical Centre Rotterdam, Rotterdam, the Netherlands.

It is suggested that during a migraine attack capsaicin-sensitive trigeminal sensory nerves release calcitonin gene related peptide (CGRP), resulting in cranial vasodilatation and central nociception. Hence, inhibition of trigeminal CGRP release may prevent the above vasodilatation and, accordingly, abort migraine headache. Therefore, this study investigated the effects of sumatriptan (100 and 300 microg/kg, i.v.) on capsaicin-induced carotid haemodynamic changes and on CGRP release. Intracarotid (i.c.) infusions of capsaicin (10 microg/kg/min, i.c.) increased total carotid, arteriovenous anastomotic and capillary conductances as well as carotid pulsations, but decreased the difference between arterial and jugular venous oxygen saturations. Except for some attenuation of arteriovenous anastomotic changes, the capsaicin-induced responses were not affected by sumatriptan. Moreover, i.c. infusions of capsaicin (0.3, 1, 3 and 10 microg/kg/min, i.c.) dose-dependently increased the jugular venous plasma concentrations of CGRP, which also remained unaffected by sumatriptan. The above results support the contention that the therapeutic action of sumatriptan is mainly due to cranial vasoconstriction rather than trigeminal (CGRP release) inhibition. Copyright 2004 Blackwell Publishing Ltd

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15315527&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Effects of sumatriptan on rat medullary dorsal horn neurons.

Jennings EA, Ryan RM, Christie MJ.

Department Pharmacology, University of Sydney, Sydney, NSW 2006, Australia. e.jennings unimelb.edu.au

This study examined the cellular actions of the anti-migraine drug sumatriptan, on neurons in the substantia gelatinosa of the spinal trigeminal nucleus pars caudalis. Sumatriptan inhibited the miniature EPSC (mEPSC) rate in a dose dependent fashion, with an EC(50) of 250 nM. Sumatriptan (3 microM) inhibited the mEPSC rate by 36%, without altering the mEPSC amplitude. This effect was partially reversed by the 5HT(1D) specific antagonist BRL15572 (10 microM). In contrast, the 5HT(1B) agonist CP93129 (10 microm) did not alter the mEPSC rate. Furthermore, sumatriptan (3 microM) decreased the amplitude of electrically evoked EPSCs (eEPSC) by 40%. After incubating the slices in ketanserin (an antagonist which shows selectivity for 5HT(1D) over 5HT(1B) receptors) sumatriptan had little effect on eEPSC amplitude. In control conditions paired stimuli resulted in paired pulse depression (PPD; the ratio eEPSC(2)/eEPSC(1)=0.7+/-0.01), whilst in the presence of sumatriptan the PPD was blocked (ratio eEPSC(2)/eEPSC(1)=0.9+/-0.1). Sumatriptan produced no post-synaptic membrane current and had no significant effect on membrane conductance over a range of membrane potentials (-60 to -130 mV). RT-PCR experiments revealed the presence of mRNA for both 5HT(1D) and 5HT(1B) receptor subtypes in the trigeminal ganglia and subnucleus caudalis. These data suggest that sumatriptan acts pre-synaptically on trigeminal primary afferent central terminals to reduce the probability of release of glutamate, and that this action is mediated through 5HT(1D) receptors.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15327806&dopt=Abstract sumatriptan Imitrex



sumatriptan, Imitrex
Switching patients with migraine from sumatriptan to other triptans increases primary care costs.

Savani N, Martin A, Browning D.

Colne House Surgery, Rickmansworth, Hertfordshire, UK. naren.savani gp-e82083.nhs.uk

Treatment of migraine with triptans is highly effective, although cost considerations may prompt a change in therapy. This retrospective database analysis of 3196 patients with migraine, established on sumatriptan therapy, found that 54% of the 292 experiencing a triptan switch returned to sumatriptan within 15 months, suggesting that the alternative was less acceptable. Excluding patients with unusually high use of triptans (> or = 208 tablets/year), switching therapy resulted in a significant increase of pounds sterling 53/patient in total costs, compared with patients continuing on sumatriptan (p = 0.014). Cost savings (pounds sterling 17/patient over 15 months) were observed only among the 41% of patients in whom the initial switch was successful and did not result in a further switch or return to sumatriptan. Among patients who were relatively low cost initially, switching resulted in increased costs, irrespective of the outcome. This study suggests that there is no economic justification for switching from sumatriptan to another triptan.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=15372848&dopt=Abstract sumatriptan Imitrex