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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biological profile of naratriptan (N-methyl-3-(1-methyl-4-piperidinyl)-1H-indole-5-ethane-sulphonamide), a novel 5HT1B/1D receptor agonist, was investigated in a variety of experimental models of relevance to migraine. Naratriptan has high affinity for human recombinant 5HT1B and 5HT1D receptors (pKi = 8.7 +/- 0.03 and 8.3 +/- 0.1, respectively) and causes contractions of dog isolated basilar and middle cerebral artery (EC50 values of 0.11 and 0.07 microM, respectively). Naratriptan causes small contractions of human isolated coronary arteries (EC50 value of 0.17 microM; maximum contraction equivalent to 33% of 5HT maximum). In anaesthetized dogs, naratriptan causes selective vasoconstriction of the carotid arterial bed (CD50 dose = 19 +/- 3 micrograms kg-1) and, in anaesthetized rats, naratriptan selectively inhibits neurogenic plasma protein extravasation in the dura (ID50 = 4.1 micrograms kg-1). In a variety of antinociceptive tests, naratriptan has no effect even at high doses. In conscious rats and dogs, naratriptan has high oral bioavailability (71% and 95%, respectively). The data show that naratriptan is a selective agonist at 5HT1B/1D receptors, with a pharmacological profile very similar to that of sumatriptan, albeit 2-3 fold more potent. These observations, coupled with high oral bioavailability in animals, suggest that naratriptan has the profile of an orally effective anti-migraine drug.
Cephalalgia 1997 May
PMID:Naratriptan: biological profile in animal models relevant to migraine. 923 91

The efficacy and tolerability of naratriptan tablets (2.5 mg, 1 mg, and 0.25 mg) compared with placebo in the acute treatment of migraine were evaluated in a randomized, double-blind, four-period crossover study. Five hundred eighty-six assessable patients received naratriptan 2.5 mg, 595 received 1 mg, 591 received 0.25 mg, 602 received placebo. Headache relief (moderate or severe pain reduced to mild or none) 4 hours postdose was reported in 68% of patients after treatment with naratriptan 2.5 mg compared with 57% after 1 mg, 39% after 0.25 mg, and 33% after placebo (p < 0.001 naratriptan 2.5 mg and 1 mg versus placebo and 1 mg and 2.5 mg versus 0.25 mg). Headache relief was maintained 8, 12, and 24 hours postdose with no use of rescue medication or a second dose of study medication by significantly (p < 0.001) greater percentages of patients after treatment with naratriptan 2.5 mg or 1 mg compared with naratriptan 0.25 mg or placebo. Naratriptan was also more effective than placebo in reducing clinical disability and the incidences of nausea, photophobia, and phonophobia. The overall incidence of adverse events and the incidences of specific adverse events did not differ in the naratriptan groups compared with placebo. No clinically relevant changes in ECG, blood pressure, or laboratory findings were reported. These data demonstrate that naratriptan is effective and well tolerated for the acute treatment of migraine. The 2.5-mg dose was associated with superior efficacy, whereas its adverse event profile was similar to that of placebo.
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PMID:Naratriptan is effective and well tolerated in the acute treatment of migraine. Results of a double-blind, placebo-controlled, crossover study. The Naratriptan S2WA3003 Study Group. 1021 71

In vivo electrophysiological assays in anesthetized rats have been used to compare the effects of the 5HT1B/1D receptor agonist, naratriptan, on central trigeminal nociceptive processing from dural and cutaneous inputs with its effects on nociceptive processing in the spinal cord. Naratriptan inhibited responses of single trigeminal neurons, to noxious electrical and mechanical stimulation of the dura and face, dose dependently by a maximum of 67+/-3% and 70+/-18%, respectively, at 3 mg kg(-1) i.v. In contrast, naratriptan did not affect spinal dorsal horn neuronal responses to noxious mechanical stimulation of the hind-paw. These findings suggest that 5HT1B/1D receptors have differential effects on nociceptive processing in the trigeminal versus spinal dorsal horns and provide a potential explanation for the lack of general analgesic effects of brain penetrant 5HT(1B/1D) agonist antimigraine drugs.
Cephalalgia 1998 Dec
PMID:Differential effects of the 5HT1B/1D receptor agonist naratriptan on trigeminal versus spinal nociceptive responses. 995 Jun 21

Naratriptan is a novel, potent agonist at the 5HT1B/1D receptor. A total of 335 migraine patients were treated in this randomized, double-blind, placebo-controlled, dose-ranging, in-clinic study, to evaluate the efficacy, safety and tolerability of five doses of subcutaneous (sc) naratriptan (0.5, 1, 2.5, 5 or 10 mg) in comparison with sc sumatriptan (6 mg) and placebo in the acute treatment of a moderate/severe migraine attack. Headache relief [reduction of headache severity from moderate or severe (grade 2/3) to mild or none (grade 1/0)] at 1 and 2 h after each dose, was reported by a statistically significantly higher proportion of patients for all doses of sc naratriptan and sc sumatriptan (6 mg) than for placebo. The percentages of patients with headache relief at 2 h post-dose were: naratriptan (0.5 mg) 65%, (1 mg) 75%, (2.5 mg) 83%, (5 mg) 94% and (10 mg) 91%; sumatriptan (6 mg) 89%; placebo 41%, (P < 0.005). The earliest report of a statistically significant difference compared with placebo for the times assessed was with sc naratriptan (10 mg) at 10 min post-dose (P = 0.023). The percentages of patients reporting adverse events were dose-related; sc naratriptan (0.5 mg) 33%, (1 mg) 29%, (2.5 mg) 43%, (5 mg) 59% and (10 mg) 71%; sc sumatriptan 53%; placebo 22%. There were no clinically significant changes in electrocardiogram (ECG), vital signs or laboratory parameters. Systemic exposure increased proportionally to the dose, the absorption of sc naratriptan was rapid (tmax = 10 min) and the half-life was 5 h. In conclusion, sc naratriptan was an effective and well-tolerated acute treatment for migraine. Copyright 1998 Lippincott Williams & Wilkins
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PMID:Early clinical experience with subcutaneous naratriptan in the acute treatment of migraine: a dose-ranging study. 1021 Aug 76

This review summarizes data on the effectiveness of various symptomatic migraine pharmacotherapies and makes recommendations for treatment. A wide variety of agents are available for the symptomatic treatment of migraine headache, including over-the-counter analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), combination products, opiates, ergot alkaloids, corticosteroids, dopamine antagonists, and triptans. In the stepped-care approach, simple analgesics and NSAIDs are the recommended first step for the treatment of mild-to-moderate migraine headaches. Patients who do not respond to first-step treatments may be given ergots, combination products, dopamine antagonists, or triptans as the second step. Corticosteroids or opiates may be used as rescue treatment in patients who do not respond to second-step treatment. A stratified approach to care individualizes treatment based on the severity of the headache and other patient-specific factors. In a stratified approach, dihydroergotamine or triptans may be the first-step treatment for patients who present with a history of severe migraines that have responded poorly to previous treatments. Sumatriptan was the first triptan approved for the symptomatic treatment of migraine headache; newer triptans include zolmitriptan, naratriptan, and rizatriptan. Since sumatriptan is rapidly absorbed by the subcutaneous route, its time to onset of effect is shortest. Among triptan drugs that are administered orally, the relative time to onset may be shorter with rizatriptan than sumatriptan. Naratriptan has a longer time to onset but is associated with a lower rate of migraine recurrence than other triptans. graine headache, ergot alkaloids, triptans,
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PMID:Symptomatic pharmacotherapy of migraine. 1046 12

Because the "intensity dependence" of cortical auditory evoked potentials (IDAP) is under serotonergic control, it can be used to assess central antimigraine effects of 5HT1B/1D agonists. We measured IDAP before and 2 h after naratriptan (5 mg, n = 19) and zolmitriptan (5 mg, n = 19) in healthy volunteers. IDAP was expressed as the amplitude-stimulus intensity function ("ASF slope"). Naratriptan tended to increase ASF slope (mean difference 0.23 +/- 0.62 microV/10 dB, p = 0.06) while zolmitriptan (0.08 +/- 0.95 microV/10 dB, p = 0.35) did not. We assessed the suitability of IDAP for measuring central antimigraine drug effects using repeatability data (see companion paper). We calculated the trade-off between the size of the expected drug effects (ASF slope difference) and the necessary sample size. Because of poor repeatability 36 to 80 subjects are required to detect ASF slope changes in the 0.25-0.5 microV/10 dB range. These data can be used to design trials using IDAP.
Cephalalgia 1999 Dec
PMID:Auditory evoked potentials in the assessment of central nervous system effects of antimigraine drugs. 1066 7

In the last two years, a number of 5-HT1B/1D agonist triptans with enhanced lipophilicity (TELs) relative to the first drug of this class, sumatriptan, have been approved for marketing in most countries of the world (naratriptan, rizatriptan and zolmitriptan). In addition, at least three others are in advanced stage of clinical development (almotriptan, eletriptan, and frovatriptan). This paper sets out to review the recent data with the aim of identifying: 1) What are the critical differences between the TELs and sumatriptan? 2) How do the currently licensed TELs compare? 3) Is it possible to provide a rational approach to migraine therapy based on objective differences in the clinical profile of these new drugs? Recent randomised controlled and comparator data were reviewed, including the independent FDA assessment of rizatriptan. Critical differences for the new TELs (naratriptan, rizatriptan and zolmitriptan) which may lead to more rational migraine management: Both rizatriptan (10 mg) and zolmitriptan (2.5 mg and 5.0 mg) have demonstrated superior efficacy to sumatriptan 100 mg, and 25 and 50 mg respectively. Therefore, for first line use either rizatriptan or zolmitriptan would be appropriate for moderate and severe headache. Rizatriptan has a more rapid onset of action than sumatriptan 100 mg. Both rizatriptan and zolmitriptan have a more rapid onset of action than naratriptan. Therefore, for a rapid onset of action either rizatriptan or zolmitriptan would be appropriate. Naratriptan would appear to have a lower recurrent headache rate than sumatriptan, rizatriptan or zolmitriptan. However, 24-hour efficacy rates for zolmitriptan 2.5 mg were significantly greater than for sumatriptan 25 mg and 50 mg and were not significantly different from naratriptan. Therefore, for headaches of long duration and with a tendency to recur (e.g. menstrual headaches) either naratriptan or zolmitriptan would be appropriate. Naratriptan has lower reported adverse event rates comparable with placebo. This would support the use of naratriptan 2.5 mg in patients who have demonstrated poor tolerance to the "triptan type" adverse events.
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PMID:Rational migraine management: optimising treatment with the triptans. 1120 Jul 89

The recent clinical development of a number of migraine specific 5-HT1B/1D agonist triptans with enhanced lipophilicity (TELs), relative to the first drug of this class sumatriptan, and with a range of different metabolic, pharmacokinetic and receptor affinity profiles, provides the potential for critically different clinical profiles. Eletriptan, naratriptan, rizatriptan and zolmitriptan display both increased stability to first pass metabolic inactivation by monoamine oxidase (MAO-A) and enhanced lipophilicity (4- to > 120-fold more than sumatriptan), leading to increased oral bioavailability (2- to 5-fold more than the 14% reported for oral sumatriptan). Central penetration and increased receptor affinity and selectivity for the neuronal (5-HT1D) receptor also combine to allow for lower total oral dosing (i.e., unit doses of 15 mg or less compared with 50-300 mg doses of sumatriptan) and reduced peripheral exposure to the coronary vasoconstrictor (5-HT1B) receptor. The notable exception being eletriptan, where an active P-glycoprotein blood-brain barrier efflux system effectively negates these benefits and requires an 80 mg oral dose. Differences in the metabolic balance between hepatic P450 (especially CYP 1A2) and MAO-A inactivation lead to potential drug interactions for all TELs with the oral contraceptive pill (OCP), fluvoxamine and the quinilone antibiotics (with increased triptan levels). An important but complex MAO-A interaction between a metabolite of propranolol and rizatriptan mandates dosage reduction (to 5 mg) for rizatriptan in the presence of propranolol treatment. There is also an absolute contraindication for the concurrent administration of the MAO-A inhibitor moclobemide and rizatriptan. All the new-marketed TELs have potential clinical benefits and were well-tolerated relative to sumatriptan. Both rizatriptan (10 mg) and zolmitriptan (2.5 mg and 5 mg) demonstrate at least equivalent efficacy to sumatriptan 25, 50 and 100 mg, respectively, making them suitable first line agents for moderate or severe migraine headaches. Rizatriptan has the fastest onset of effect of the TELs. Naratriptan would appear to have lower recurrent headache rate than sumatriptan, rizatriptan or zolmitriptan. Therefore, for headaches of long duration and with a tendency to recur naratriptan may be the most appropriate treatment. Thus, knowledge of the metabolic, pharmacokinetic and clinical profiles of the TELs facilitates the selection of a triptan which allows optimisation of the clinical benefits for individual patients, minimising the risk of drug interactions and a minimally effective dose to reduce potential adverse events (AEs).
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PMID:Migraine pharmacotherapy with oral triptans: a rational approach to clinical management. 1124 25

We report three patients with transformed migraine, previously refractory to a wide variety of traditional preventive pharmacologic and nonpharmacologic interventions. Naratriptan 2.5 mg given each morning, with a second tablet allowed for breakthrough headache, at least 4 hours later, demonstrated a remarkable reduction in frequency and intensity of daily headache. In addition, a subjective improvement in quality of life and restoration of functioning including a decrease in missed workdays was noted. All three patients had previously experienced good responses to sumatriptan or zolmitriptan, but were limited in frequency of use by the authors. The patients were not experiencing rebound phenomena at the onset of treatment with naratriptan. Clinical responses were noted within 3 to 7 days of initiation of treatment. Traditional risk factor analysis and screening were performed. Naratriptan was extremely well tolerated, with no cardiovascular adverse events reported or observed. Possible mechanisms of action are discussed.
Headache
PMID:Naratriptan in the prophylaxis of transformed migraine. 1097 Jan 77

A 36-year-old man with cluster headache refractory to trials of standard prophylactic treatment and only partially responsive to parenteral sumatriptan and inhaled oxygen was admitted to an inpatient pain unit. The diagnosis of cluster headache was confirmed by direct observation of a typical attack. Despite efforts at prophylaxis, the patient continued to experience three to four severe headaches per day. Attempts to control his headaches with scheduled parenteral dihydroergotamine were successful, but headaches recurred when the medication was tapered, and continuous or intermittent use of parenteral dihydroergotamine was not felt to be a practical option for the patient. Naratriptan 2.5 mg twice daily completely abolished his headaches, which recurred when the medication was discontinued. No electrocardiographic or laboratory abnormalities were observed during treatment, and the patient reported no side effects.
Headache 2002 Jan
PMID:Naratriptan in the prophylaxis of cluster headache. 1200 76


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