Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018681 (headache)
 56,091 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Migraine is a common neurological disorder often treated with triptans. Triptan overuse can lead to increased frequency of headache in some patients, a phenomenon termed medication overuse headache. Previous preclinical studies have demonstrated that repeated or sustained triptan administration for several days can elicit persistent neural adaptations in trigeminal ganglion cells innervating the dura, prominently characterized by increased labelling of neuronal profiles for calcitonin gene related peptide. Additionally, triptan administration elicited a behavioural syndrome of enhanced sensitivity to surrogate triggers of migraine that was maintained for weeks following discontinuation of drug, a phenomenon termed 'triptan-induced latent sensitization'. Here, we demonstrate that triptan administration elicits a long-lasting increase in identified rat trigeminal dural afferents labelled for neuronal nitric oxide synthase in the trigeminal ganglion. Cutaneous allodynia observed during the period of triptan administration was reversed by NXN-323, a selective inhibitor of neuronal nitric oxide synthase. Additionally, neuronal nitric oxide synthase inhibition prevented environmental stress-induced hypersensitivity in the post-triptan administration period. Co-administration of NXN-323 with sumatriptan over several days prevented the expression of allodynia and enhanced sensitivity to stress observed following latent sensitization, but not the triptan-induced increased labelling of neuronal nitric oxide synthase in dural afferents. Triptan administration thus promotes increased expression of neuronal nitric oxide synthase in dural afferents, which is critical for enhanced sensitivity to environmental stress. These data provide a biological basis for increased frequency of headache following triptans and highlight the potential clinical utility of neuronal nitric oxide synthase inhibition in preventing or treating medication overuse headache.
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PMID:Triptan-induced enhancement of neuronal nitric oxide synthase in trigeminal ganglion dural afferents underlies increased responsiveness to potential migraine triggers. 2062 71

Background and aims NXN-188 is a combined neuronal nitric oxide synthase (nNOS) inhibitor and 5HT-1B/1D receptor agonist which has previously shown efficacy in the acute treatment of migraine. Nitric oxide (NO) is involved in the pathogenesis of migraine pain and is formed after cortical spreading depression. Therefore NXN-188 could perhaps prevent the development of the headache phase in migraine with aura if taken during the aura. The aims of the present study were to evaluate the efficacy and safety of 600mg NXN-188 in the acute treatment of migraine when dosed during the aura. Methods A single-centre, randomized, double-blind, placebo-controlled, two-way crossover trial. The study medication was taken during the aura and the patients kept a study diary for 48h post-dose. Results Of 615 patients screened, 50 patients were included in the study and randomized. Only 18 patients completed both treatments in compliance with the study procedures. 22% of patients reported freedom of headache at 2h after intake of NXN-188 compared with only 11% of patients after placebo. Conclusions The dual-action drug NXN-188 with 5HT-1B/1D agonism and nNOS inhibition, taken orally during the aura phase did not have a statistically substantial effect on migraine headache in this study. This study was limited by a high drop-out rate and small sample of included patients who were able to complete the cross-over protocol. Therefore, efficacy of the treatment cannot be refuted with certainty. Implications This study illustrates the difficulties of doing well controlled studies in migraine patients with aura. nNOS inhibition is expected to be effective mostly in the aura phase, i.e. the oral administration may have had too slow pharmacokinetics to have effect. Parenteral administration may overcome this obstacle. 5HT-1B/1D agonism is not effective when dosed during migraine aura. Repeated dosing of the NXN-188 during and immediately following the aura may have exploited more the dualaction. The high drop-out rate may be reduced in future studies by having the patients familiarize themselves with the study procedure by filling out the attack report form while treating one attack with their own medication before entering the trial. A parallel group comparison may be a more effective trial design for treatment during an aura.
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PMID:The nitric oxide synthase inhibitor and serotonin-receptor agonist NXN-188 during the aura phase of migraine with aura: A randomized, double-blind, placebo-controlled cross-over study. 2991 85