One of the frovatriptan side chains forms an additional ring with the indole, resulting in a carbazole ring system.
Triptan structures were designed from the structure of 5-HT to attain affinity to 5-HT receptors, hence the identical indole structure. The hydroxyl group (-OH) on the hexane of the indole core and the alkyl-amine side chain on position C3 on 5-HT have been replaced with other compounds, such as sulfonamides or azol-ring structured derivatives and different amine-alkyl side chains. An electro-negative group can form a hydrogen bond with Thr in the pocket of the receptor. Sulfonamide derivatives attached to the hexane ring of the indole structure have electro-negative properties, as well as the triazole and 2-oxazolidone on rizatriptan and zolmitriptan respectively. This can increase binding ability of the compound and the efficacy, especially with the 5-HT1D receptor.
A schematic drawing of the binding of sumatriptan to 5-HT1D receptor can be seen in figure 4. One study showed that sumatriptan fits better in the binding site of the receptor when the side chain with the protonated nitrogen atom is folded back over the indole structure. This alignment contributes to the hydrogen bonding between the nitrogen in the sulfonamide and the Ser138 in the binding site. It is also favorable to the formation of the hydrogen bond between the oxygen of the sulfonamide and Thr202. Other binding in the pocket of the binding site occurs with the nitrogen atom in the pentene ring of the indole structure of the triptan and the amino acid Ser352. This energetically favorable position of the agonist makes it possible for additional binding of the ligand to other Ser in the binding site, along with additional anchoring between Phe in the pocket of the binding site and the indole of the agonist. The binding of Phe and the triptan is caused by π stacking interactions of the indole and amino acid and an additional effect on this interaction is because of dispersive effect of amino acid leucine (Leu; not shown in figure 4). The amino acids Trp343 and Tyr346 both have electron rich π-systems in their aromatic structures. With their position in the binding site they create a sort of aromatic cage around the protonated nitrogen atom of the side chain on position C3 on the triptans (this nitrogen atom is protonated at physiological condition), and thereby stabilizes the ion bond the nitrogen atom has formed with a carboxylate on aspartic acid. Side chains of the surrounding amino acids can have an effect on the binding of the nitrogen atom, mainly three Phe can affect the methyl groups bound to the nitrogen atom (not shown in figure 4).
By placing an electron-withdrawing group or large group on position C2 on the indole structure the 5-HT agonist is conversed into an antagonist. This is thought to be because the indole ring is unable to occupy the aromatic part of the binding site.
Sumatriptan was the pioneer drug in this class. The second generation's triptans such as zolmitriptan, naratriptan, rizatriptan, almotriptan, eletriptan and frovatriptan soon became available.
Different triptans are available in different formulations and in different strengths (see table 2). They have been formulated as subcutaneous injections, oral tablets, orally disintegrating tablets, nasal spray and as rectal suppositories.
Delivery system of the triptans may play an important role in the onset of action. The selection of anti-migraine drug for patients depends on their symptoms. The first selective 5-HT1B/1D agonist, sumatriptan, was first synthesized as a subcutaneous injection, then as an oral tablets and more recently as a nasal spray, it is also available in some countries as suppositories. The subcutaneous injection is the fastest way to stop a rapidly progressing migraine attack. The sumatriptan nasal spray provides faster onset of action than the tablets but it produces a similar headache response at 2 hours. Some patients prefer the nasal spray as it works more rapidly than the tablets and does not have as many adverse effects as the subcutaneous injection. Nasal spray is although not suitable for all patients, because some patients experience bad taste and lack of consistency of response. Zolmitriptan was developed with the strategy to create a more lipophilic compound, with faster absorption and better ability to cross the blood brain barrier than sumatriptan. It is available as tablets, orally disintegrating tablets and as nasal spray in some countries. Rizatriptan is available as tablets and orally disintegrating tablets but naratriptan, almotriptan, eletriptan and frovatriptan are only available in tablets, for now.
Table 2: Properties of triptan formulationsa Specific enzyme not yet reported.
Most triptans were developed and introduced in the 1990s. Further studies have not shown much promise regarding the development of new triptans with better duration of action, efficacy and safety profile. Therefore, it is unlikely that further variations will be developed and new anti-migraine drugs are likely to have another mechanism of action.
Ferrari, M. D.; Goadsby, P.J.; Roon, K. I.; Lipton, R.B. (2002), "Triptans (serotonin, 5-HT1B/1D agonists) in migraine: detailed results and methods of a meta-analysis of 53 trials", Cephalalgia, 22 (8): 633–658, doi:10.1046/j.1468-2982.2002.00404.x, PMID 12383060, S2CID 2368571, archived from the original on 2012-12-17 https://archive.today/20121217205236/http://www3.interscience.wiley.com/cgi-bin/fulltext/118953152/PDFSTART
Goadsby, Peter J. (2006), "Recent advances in understanding migraine mechanism, molecules and therapeutics", Trends in Molecular Medicine, 13 (1): 39–44, doi:10.1016/j.molmed.2006.11.005, PMID 17141570 /wiki/Doi_(identifier)
Ferrari, M. D.; Goadsby, P.J.; Roon, K. I.; Lipton, R.B. (2002), "Triptans (serotonin, 5-HT1B/1D agonists) in migraine: detailed results and methods of a meta-analysis of 53 trials", Cephalalgia, 22 (8): 633–658, doi:10.1046/j.1468-2982.2002.00404.x, PMID 12383060, S2CID 2368571, archived from the original on 2012-12-17 https://archive.today/20121217205236/http://www3.interscience.wiley.com/cgi-bin/fulltext/118953152/PDFSTART
Humphrey, Patrick P.A. (2007), "The Discovery of a New Drug Class for the Acute Treatment of Migraine", Headache, 47 [Suppl 1]: 10–19, doi:10.1111/j.1526-4610.2007.00672.x, PMID 17425704[dead link] http://www3.interscience.wiley.com/cgi-bin/fulltext/118518307/PDFSTART
"Imigran Tablets 50mg Imigran Tablets 100mg". Archived from the original on 2007-12-18. Retrieved 2008-11-09. https://web.archive.org/web/20071218074211/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=751
"Zomig Tablets 2.5mg". Archived from the original on 2005-08-10. Retrieved 2008-11-09. https://web.archive.org/web/20050810082713/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=5905
"Maxalt 5mg, 10mg Tablets, Maxalt Melt 10mg Oral Lypophilisates". Archived from the original on 2008-05-02. Retrieved 2008-11-09. https://web.archive.org/web/20080502015348/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=1183
"Naramig Tablets 2.5mg". Archived from the original on 2007-04-30. Retrieved 2008-11-09. https://web.archive.org/web/20070430013518/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=759
"Axert". Retrieved 2008-11-09. http://www.rxlist.com/axert-drug.htm
"Migard". Archived from the original on December 24, 2012. Retrieved 2008-11-09. https://archive.today/20121224074545/http://emc.medicines.org.uk/emc/assets/c/html/DisplayDoc.asp?DocumentID=15216
"Relpax – 20 mg and 40 mg". Archived from the original on 2004-06-20. Retrieved 2008-11-09. https://web.archive.org/web/20040620163458/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=8195
Ferrari, M. D.; Goadsby, P.J.; Roon, K. I.; Lipton, R.B. (2002), "Triptans (serotonin, 5-HT1B/1D agonists) in migraine: detailed results and methods of a meta-analysis of 53 trials", Cephalalgia, 22 (8): 633–658, doi:10.1046/j.1468-2982.2002.00404.x, PMID 12383060, S2CID 2368571, archived from the original on 2012-12-17 https://archive.today/20121217205236/http://www3.interscience.wiley.com/cgi-bin/fulltext/118953152/PDFSTART
Bremner, DH; Ringan, NS; Wishart, G (1997), "Modeling of the agonist binding site of serotonin human 5-HT1A, 5-HTDα and 5-HTDβ receptors", European Journal of Medicinal Chemistry, 32 (1): 59–69, doi:10.1016/S0223-5234(97)84362-0 /wiki/Doi_(identifier)
Bojarski, Andrzej J. (2006), "Pharmacophore Models for Metabotropic 5-HT Receptor Ligands", Current Topics in Medicinal Chemistry, 6 (18): 2005–2026, doi:10.2174/156802606778522186, PMID 17017971 /wiki/Doi_(identifier)
Terzioglu, Nalan; Höltje, Hans-Dieter (2005), "Receptor-based 3D QSAR Analysis of Serotonin 5-HT1D receptor agonists", Collection of Czechoslovak Chemical Communications, 70 (9): 1482–1492, doi:10.1135/cccc20051482 /wiki/Doi_(identifier)
Bremner, DH; Ringan, NS; Wishart, G (1997), "Modeling of the agonist binding site of serotonin human 5-HT1A, 5-HTDα and 5-HTDβ receptors", European Journal of Medicinal Chemistry, 32 (1): 59–69, doi:10.1016/S0223-5234(97)84362-0 /wiki/Doi_(identifier)
Buckingham, Janet; Glen, Robert C.; Hill, Alan P.; Hyde, Richard M.; Martin, Graeme R.; Robertson, Alan D.; Woollard, Patrick M. (1995). "Computer-Aided Design and Synthesis of 5-Substituted Tryptamines and Their Pharmacology at the 5-HT1D Receptor: Discovery of Compounds with Potential Anti-Migraine Properties". Journal of Medicinal Chemistry. 38 (18): 3566–3580. doi:10.1021/jm00018a016. PMID 7658443. /wiki/Doi_(identifier)
Buckingham, Janet; Glen, Robert C.; Hill, Alan P.; Hyde, Richard M.; Martin, Graeme R.; Robertson, Alan D.; Woollard, Patrick M. (1995). "Computer-Aided Design and Synthesis of 5-Substituted Tryptamines and Their Pharmacology at the 5-HT1D Receptor: Discovery of Compounds with Potential Anti-Migraine Properties". Journal of Medicinal Chemistry. 38 (18): 3566–3580. doi:10.1021/jm00018a016. PMID 7658443. /wiki/Doi_(identifier)
Jandu, K. S.; Barrett, V.; Brockwell, M.; Cambridge, D.; Farrant, D. R.; Foster, C.; Selwood, D. L. (2001). "Discovery of 4-[3-(trans-3-Dimethylaminocyclobutyl)-1H-indol-5-ylmethyl]- (4S)-oxazolidin-2-one (4991W93), a 5HT1B/1D Receptor Partial Agonist and a Potent Inhibitor of Electrically Induced Plasma Extravasation". Journal of Medicinal Chemistry. 44 (5): 681–693. doi:10.1021/jm000956k. PMID 11262079. https://figshare.com/articles/Discovery_of_4-_3-_i_trans_i_-3-Dimethylaminocyclobutyl_-1_i_H_i_-indol-5-ylmethyl_-_4_i_S_i_-oxazolidin-2-one_4991W93_a_5HT_sub_1B_1D_sub_Receptor_Partial_Agonist_and_a_Potent_Inhibitor_of_Electrically_Induced_Plasma_Extravasation/3679944
Cheng, Ziqiang; Liu, Houfu; Yu, Na; Wang, Fei; An, Gang; Xu, Yan; Ayrton, Andrew (2012). "Hydrophilic anti-migraine triptans are substrates for OATP1A2, a transporter expressed at human blood-brain barrier". Xenobiotica. 42 (9): 880–890. doi:10.3109/00498254.2012.675455. PMID 22509823. S2CID 6478226. /wiki/Doi_(identifier)
Bremner, DH; Ringan, NS; Wishart, G (1997), "Modeling of the agonist binding site of serotonin human 5-HT1A, 5-HTDα and 5-HTDβ receptors", European Journal of Medicinal Chemistry, 32 (1): 59–69, doi:10.1016/S0223-5234(97)84362-0 /wiki/Doi_(identifier)
Bremner, DH; Ringan, NS; Wishart, G (1997), "Modeling of the agonist binding site of serotonin human 5-HT1A, 5-HTDα and 5-HTDβ receptors", European Journal of Medicinal Chemistry, 32 (1): 59–69, doi:10.1016/S0223-5234(97)84362-0 /wiki/Doi_(identifier)
Bremner, DH; Ringan, NS; Wishart, G (1997), "Modeling of the agonist binding site of serotonin human 5-HT1A, 5-HTDα and 5-HTDβ receptors", European Journal of Medicinal Chemistry, 32 (1): 59–69, doi:10.1016/S0223-5234(97)84362-0 /wiki/Doi_(identifier)
Bojarski, Andrzej J. (2006), "Pharmacophore Models for Metabotropic 5-HT Receptor Ligands", Current Topics in Medicinal Chemistry, 6 (18): 2005–2026, doi:10.2174/156802606778522186, PMID 17017971 /wiki/Doi_(identifier)
Terzioglu, Nalan; Höltje, Hans-Dieter (2005), "Receptor-based 3D QSAR Analysis of Serotonin 5-HT1D receptor agonists", Collection of Czechoslovak Chemical Communications, 70 (9): 1482–1492, doi:10.1135/cccc20051482 /wiki/Doi_(identifier)
Cheng, Ziqiang; Liu, Houfu; Yu, Na; Wang, Fei; An, Gang; Xu, Yan; Ayrton, Andrew (2012). "Hydrophilic anti-migraine triptans are substrates for OATP1A2, a transporter expressed at human blood-brain barrier". Xenobiotica. 42 (9): 880–890. doi:10.3109/00498254.2012.675455. PMID 22509823. S2CID 6478226. /wiki/Doi_(identifier)
Street, Leslie J.; Baker, Raymond; Castro, Jose L.; Chambers, Mark S.; Guiblin, Alexander R.; Hobbs, Sarah C.; Beer, Margaret S. (1993). "Synthesis and serotonergic activity of 5-(oxadiazolyl)tryptamines: potent agonists for 5-HT1D receptors". Journal of Medicinal Chemistry. 36 (11): 1529–1538. doi:10.1021/jm00063a003. PMID 8496922. /wiki/Doi_(identifier)
Cheng, Ziqiang; Liu, Houfu; Yu, Na; Wang, Fei; An, Gang; Xu, Yan; Ayrton, Andrew (2012). "Hydrophilic anti-migraine triptans are substrates for OATP1A2, a transporter expressed at human blood-brain barrier". Xenobiotica. 42 (9): 880–890. doi:10.3109/00498254.2012.675455. PMID 22509823. S2CID 6478226. /wiki/Doi_(identifier)
Jandu, K. S.; Barrett, V.; Brockwell, M.; Cambridge, D.; Farrant, D. R.; Foster, C.; Selwood, D. L. (2001). "Discovery of 4-[3-(trans-3-Dimethylaminocyclobutyl)-1H-indol-5-ylmethyl]- (4S)-oxazolidin-2-one (4991W93), a 5HT1B/1D Receptor Partial Agonist and a Potent Inhibitor of Electrically Induced Plasma Extravasation". Journal of Medicinal Chemistry. 44 (5): 681–693. doi:10.1021/jm000956k. PMID 11262079. https://figshare.com/articles/Discovery_of_4-_3-_i_trans_i_-3-Dimethylaminocyclobutyl_-1_i_H_i_-indol-5-ylmethyl_-_4_i_S_i_-oxazolidin-2-one_4991W93_a_5HT_sub_1B_1D_sub_Receptor_Partial_Agonist_and_a_Potent_Inhibitor_of_Electrically_Induced_Plasma_Extravasation/3679944
Bojarski, Andrzej J. (2006), "Pharmacophore Models for Metabotropic 5-HT Receptor Ligands", Current Topics in Medicinal Chemistry, 6 (18): 2005–2026, doi:10.2174/156802606778522186, PMID 17017971 /wiki/Doi_(identifier)
Mathew, Ninan T.; Loder, Elizabeth W. (2005), "Evaluating the triptans", The American Journal of Medicine, 118 (12): 28–35, doi:10.1016/j.amjmed.2005.09.014, PMID 16356805 /wiki/Doi_(identifier)
Bigal, Marcelo E.; Bordini, Carlos A.; Antoniazzi, Ana L.; Speciali, José G (2003), "The triptan formulations, A critical evaluation" (PDF), Arquivos de Neuro-Psiquiatria, 61 (2A): 313–320, doi:10.1590/s0004-282x2003000200032, PMID 12806521 http://www.scielo.br/pdf/anp/v61n2A/15707.pdf
Bigal, Marcelo E.; Bordini, Carlos A.; Antoniazzi, Ana L.; Speciali, José G (2003), "The triptan formulations, A critical evaluation" (PDF), Arquivos de Neuro-Psiquiatria, 61 (2A): 313–320, doi:10.1590/s0004-282x2003000200032, PMID 12806521 http://www.scielo.br/pdf/anp/v61n2A/15707.pdf
Bigal, Marcelo E.; Bordini, Carlos A.; Antoniazzi, Ana L.; Speciali, José G (2003), "The triptan formulations, A critical evaluation" (PDF), Arquivos de Neuro-Psiquiatria, 61 (2A): 313–320, doi:10.1590/s0004-282x2003000200032, PMID 12806521 http://www.scielo.br/pdf/anp/v61n2A/15707.pdf
Bigal, Marcelo E.; Bordini, Carlos A.; Antoniazzi, Ana L.; Speciali, José G (2003), "The triptan formulations, A critical evaluation" (PDF), Arquivos de Neuro-Psiquiatria, 61 (2A): 313–320, doi:10.1590/s0004-282x2003000200032, PMID 12806521 http://www.scielo.br/pdf/anp/v61n2A/15707.pdf
"Drug class review: Oral 5HT1 Receptor agonists" (PDF). U.S. Department of Veterans Affairs. Archived from the original (PDF) on 2009-01-14. Retrieved 2008-11-03. https://web.archive.org/web/20090114135602/http://www.pbm.va.gov/reviews/5ht1review.pdf
"Drug class review: Oral 5HT1 Receptor agonists" (PDF). U.S. Department of Veterans Affairs. Archived from the original (PDF) on 2009-01-14. Retrieved 2008-11-03. https://web.archive.org/web/20090114135602/http://www.pbm.va.gov/reviews/5ht1review.pdf
Armsterong, Scott C.; Cozza, Kelly L. (2002), "Triptans", Psychosomatics, 43 (6): 502–504, doi:10.1176/appi.psy.43.6.502, PMID 12444236 /wiki/Doi_(identifier)
"Drug class review: Oral 5HT1 Receptor agonists" (PDF). U.S. Department of Veterans Affairs. Archived from the original (PDF) on 2009-01-14. Retrieved 2008-11-03. https://web.archive.org/web/20090114135602/http://www.pbm.va.gov/reviews/5ht1review.pdf
Rapoport, Alan M.; Tepper, Stewart J.; Sheftell, Fred D.; Kung, Edna; Bigal, Marcelo E. (2006), "Which triptan for which patient?", Neurological Sciences, 27: 123–129, doi:10.1007/s10072-006-0586-y, PMID 16688615, S2CID 22223822 /wiki/Doi_(identifier)
Rapoport, Alan M.; Tepper, Stewart J.; Sheftell, Fred D.; Kung, Edna; Bigal, Marcelo E. (2006), "Which triptan for which patient?", Neurological Sciences, 27: 123–129, doi:10.1007/s10072-006-0586-y, PMID 16688615, S2CID 22223822 /wiki/Doi_(identifier)
Rapoport, Alan M.; Tepper, Stewart J.; Sheftell, Fred D.; Kung, Edna; Bigal, Marcelo E. (2006), "Which triptan for which patient?", Neurological Sciences, 27: 123–129, doi:10.1007/s10072-006-0586-y, PMID 16688615, S2CID 22223822 /wiki/Doi_(identifier)
Rapoport, Alan M.; Tepper, Stewart J.; Sheftell, Fred D.; Kung, Edna; Bigal, Marcelo E. (2006), "Which triptan for which patient?", Neurological Sciences, 27: 123–129, doi:10.1007/s10072-006-0586-y, PMID 16688615, S2CID 22223822 /wiki/Doi_(identifier)
Färkkilä, M.; Dalhlöf, C.; Stovner, L.J.; Bruggen, J.P ter; Rasmussen, S.; Muirhead, N.; Sikes, C.; Sikes, C (2003), "Eletriptan for the treatment of migraine in patients with previous poor response or toletance to oral sumatriptan", Cephalalgia, 23 (6): 463–471, doi:10.1046/j.1468-2982.2003.00554.x, PMID 12807526 /wiki/Doi_(identifier)
"press release - Treximet (sumatriptan and naproxen sodium) tablets approved by FDA for acute treatment of migraine". GlaxoSmithKline. Archived from the original on 2008-12-04. Retrieved 2008-11-09. https://web.archive.org/web/20081204230212/http://www.gsk.com/media/pressreleases/2008/2008_us_pressrelease_10034.htm
Smith, Timothy R.; Sunshine, Abraham; Stark, Stuart R.; Littlefield, Diane E.; Spruill, Susan E.; Alexander, W. James (2005), "Sumatriptan and Naproxen Sodium for the Acute Treatment of Migraine", Headache, 45 (8): 983–991, doi:10.1111/j.1526-4610.2005.05178.x, PMID 16109111, S2CID 43314572, archived from the original on 2012-12-18 https://archive.today/20121218074659/http://www3.interscience.wiley.com/cgi-bin/fulltext/118644412/PDFSTART
Jhee, Stanford S.; Shiovitz, Thomas; Crawford, AAron W.; Cutler, Neal R. (2001), "Pharmacokinetics and pharmacodynamics of the triptan antimigraine agents", Clinical Pharmacokinetics, 40 (3): 189–205, doi:10.2165/00003088-200140030-00004, PMID 11327198, S2CID 31937163 /wiki/Doi_(identifier)
Mathew, Ninan T.; Loder, Elizabeth W. (2005), "Evaluating the triptans", The American Journal of Medicine, 118 (12): 28–35, doi:10.1016/j.amjmed.2005.09.014, PMID 16356805 /wiki/Doi_(identifier)
Jhee, Stanford S.; Shiovitz, Thomas; Crawford, AAron W.; Cutler, Neal R. (2001), "Pharmacokinetics and pharmacodynamics of the triptan antimigraine agents", Clinical Pharmacokinetics, 40 (3): 189–205, doi:10.2165/00003088-200140030-00004, PMID 11327198, S2CID 31937163 /wiki/Doi_(identifier)
Bigal, Marcelo E.; Bordini, Carlos A.; Antoniazzi, Ana L.; Speciali, José G (2003), "The triptan formulations, A critical evaluation" (PDF), Arquivos de Neuro-Psiquiatria, 61 (2A): 313–320, doi:10.1590/s0004-282x2003000200032, PMID 12806521 http://www.scielo.br/pdf/anp/v61n2A/15707.pdf
"Drug class review: Oral 5HT1 Receptor agonists" (PDF). U.S. Department of Veterans Affairs. Archived from the original (PDF) on 2009-01-14. Retrieved 2008-11-03. https://web.archive.org/web/20090114135602/http://www.pbm.va.gov/reviews/5ht1review.pdf
Jhee, Stanford S.; Shiovitz, Thomas; Crawford, AAron W.; Cutler, Neal R. (2001), "Pharmacokinetics and pharmacodynamics of the triptan antimigraine agents", Clinical Pharmacokinetics, 40 (3): 189–205, doi:10.2165/00003088-200140030-00004, PMID 11327198, S2CID 31937163 /wiki/Doi_(identifier)
Rapoport, Alan M.; Tepper, Stewart J.; Sheftell, Fred D.; Kung, Edna; Bigal, Marcelo E. (2006), "Which triptan for which patient?", Neurological Sciences, 27: 123–129, doi:10.1007/s10072-006-0586-y, PMID 16688615, S2CID 22223822 /wiki/Doi_(identifier)
Saxena, Pramod R.; Tfelt-Hansen, Peer (2001), "Success and failure of triptans", The Journal of Headache and Pain, 2 (1): 3–11, doi:10.1007/s101940170040, PMC 3611827 /wiki/The_Journal_of_Headache_and_Pain
Pascual, Julio; Muñoz, Pedro (2005), "Correlation between lipophilicity and triptan outcomes", Headache, 45 (1): 3–6, doi:10.1111/j.1526-4610.2005.05003.x, PMID 15663606, S2CID 37808880[dead link] http://www3.interscience.wiley.com/cgi-bin/fulltext/118644161/PDFSTART
"Drug class review: Oral 5HT1 Receptor agonists" (PDF). U.S. Department of Veterans Affairs. Archived from the original (PDF) on 2009-01-14. Retrieved 2008-11-03. https://web.archive.org/web/20090114135602/http://www.pbm.va.gov/reviews/5ht1review.pdf
"Relpax – 20 mg and 40 mg". Archived from the original on 2004-06-20. Retrieved 2008-11-09. https://web.archive.org/web/20040620163458/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=8195
"Relpax – 20 mg and 40 mg". Archived from the original on 2004-06-20. Retrieved 2008-11-09. https://web.archive.org/web/20040620163458/http://emc.medicines.org.uk/emc/assets/c/html/displaydoc.asp?documentid=8195
Mathew, Ninan T.; Loder, Elizabeth W. (2005), "Evaluating the triptans", The American Journal of Medicine, 118 (12): 28–35, doi:10.1016/j.amjmed.2005.09.014, PMID 16356805 /wiki/Doi_(identifier)
Jhee, Stanford S.; Shiovitz, Thomas; Crawford, AAron W.; Cutler, Neal R. (2001), "Pharmacokinetics and pharmacodynamics of the triptan antimigraine agents", Clinical Pharmacokinetics, 40 (3): 189–205, doi:10.2165/00003088-200140030-00004, PMID 11327198, S2CID 31937163 /wiki/Doi_(identifier)
"Migard". Archived from the original on December 24, 2012. Retrieved 2008-11-09. https://archive.today/20121224074545/http://emc.medicines.org.uk/emc/assets/c/html/DisplayDoc.asp?DocumentID=15216
Lambert, Geoffrey A. (2005), "Preclinical Neuropharmacology of Naratriptan", CNS Drug Reviews, 11 (3): 289–316, doi:10.1111/j.1527-3458.2005.tb00048.x, PMC 6741765, PMID 16389295[dead link] /wiki/Doi_(identifier)
Lambert, Geoffrey A. (2005), "Preclinical Neuropharmacology of Naratriptan", CNS Drug Reviews, 11 (3): 289–316, doi:10.1111/j.1527-3458.2005.tb00048.x, PMC 6741765, PMID 16389295[dead link] /wiki/Doi_(identifier)