Table 1. International Headache Society clinical end-points used to assess efficacy of medication in patients with migraine^[5]

Parameter	Definition
Headache response	Reduction of migraine intensity from moderate or severe to none or mild at a point in time
Therapeutic gain	Percentage of patients who respond to active drug therapy minus percentage of patients who respond to placebo (30% suggests good drug response, 40% excellent, 50% superb)
Pain-free state	Decrease in migraine severity from moderate or severe to no pain at a given time after medication administrationa
Relief of associated symptoms	Effect of medication on symptoms such as nausea, phono- and photophobia a
Time of pain relief	Chance of obtaining headache relief over time. Calculated using a sliding scale or survivor curve
Time to headache relief	Survival of the headache
Recurrence	The return of moderate to severe headache within 24 hours of treatment following initial headache response at 2 hours
Complete or sustained pain-free response	Patient is pain-free at 2 hours with no recurrence or use of rescue medications within 24 hours

 

a	Preferably measured at 2 hours post-administration.

Table 2. Selected features of various triptans which are still undergoing development^[1,12-15]

Feature	Almotriptan	Eletriptan	Frovatriptan
Usual dose (mg)	12.5	40	2.5
Pharmacokinetic parameters
tmax (h)	1.4-3.8	1-2	2-4
t1/2 (h)	3.2-3.7	3.6-5.5	25
Lipophilicity	?
Bioavailability (%)	70-80	50	24-30
Efficacy
Headache response at 2h (%)	57-65	65	36-46
Therapeutic gain (%)a	15	41	13-19
Recurrence rate (%)	18	19-23	7-25

 

a	Percentage of patients who respond to active drug therapy minus percentage of patients who respond to placebo.
Abbreviations and symbols: h = hours; tmax = time to achieve maximum plasma concentration; t1/2 = elimination half-life; = low; = high; ? = unknown.

Differential features

Comparison of various features of selected triptans for the treatment of acute migraine^[1-3]

Feature	Naratriptan	Rizatriptan†	Sumatriptan				Zolmitriptan
	Tablet	Tablet and water (melt)	Tablet	SC injection	Nasal spray	Suppository†	Tablet
Dosage information
Usual dose (mg)a	2.5	10b	50	6	20c	25	2.5
Time when repeat dose can be given (h)	4	2	2	1	2	NS	2
Maximum dose in 24h (mg)	5	30 (US) 20 (EU)	200 (US) 300 (EU)	12	40	50	10-15
Pharmacokinetic parameters
tmax (h)	2-3	1.3d	2.5	0.2	1 (range 0.08-4)	-	2
t1/2 (h)	5-6.3	2-3	2			-	2.5-3
Lipophilicity
Bioavailability (%)	63 (men) 74 (women)	45	14	97	17	-	40-48
Efficacy
Headache response at 2h (%)	48	67-77	61	77e	64	68	62-65
Therapeutic gain (%)f	18	27-40	33	48	34	43	28-29
Recurrence rate (%)f	17-28	30-47	32	34-38	32-34	44	30
Consistency (mean % of attacks aborted over 1 year)	70 at 4h	80 at 2h	84 at 2 (100mg dose)	70 at 1h	77 at 2h	-	95 with 1-2 doses of 2.5-5mg
Tolerability
Common adverse effects	Paraesthesia, heaviness, tightness in any part of the body (especially throat and chest)g , flushing, heat sensations, dizziness, feeling of weakness, fatigue, nausea and vomiting
Drug interactions:
avoid concurrent    use	§	Ergotamine, MAOIs	Ergotamine, MAOIs, SSRIs				Ergotamine
dosage adjustment    required	§	Propranolol	-				Cimetidine, fluvoxamine, MAOIs, quinolones
Acquisition costh
In the UK (£)	4.00	4.46	4.70	19.57	6.00	†	4.00
In the US ($)	16.74	11.93	16.00	48.61	20.81	†	14.17

 

†	Rizatriptan is not available in Australia and France; sumatriptan suppositories are not available in Australia, Canada, France, Spain, the UK and the US.
a	Oral dosage listed, unless otherwise specified.
b	Also available in a 'melt' formulation, a wafer which dissolves rapidly when placed on the tongue and is then swallowed for gastrointestinal absorption.
c	Use 1 spray in 1 nostril only.
d	tmax for tablet is 1.3h; water (melt) has similar pharmacokinetic properties.
e	Response at 1h.
f	See table 1 for definition.
g	Discontinue drug if sensation intense as it may be due to coronary vasoconstriction or anaphylaxis.
h	For a single dose at the usual dosage.
Abbreviations and symbols: EU = European Union; h = hour(s); MAOIs= monoamine oxidase inhibitors; NS = not specified; SC = subcutaneous; SSRIs = selective serotonin (5-hydroxytriptamine, 5-HT) reuptake inhibitors; tmax = time to achieve maximum plasma concentration; t1/2 = elimination half-life; = low; = moderate; = high; § = there are currently no recognised drug interactions with naratriptan.