This is an overview of drugs used to treat migraine with an emphasis on serotonergic drugs. This presentation was for 2nd year pharmacy students as part of a pharmacology & toxicology course and accompanies Goodman & Gilman's (12e) chapter 46. A bit of general background on 5-HT is also included.

1. Serotonin & Migraine
Brian J. Piper, Ph.D., M.S.

2. Goals
• Serotonin
– Biosynthesis & elimination
– Receptors
• Migraine
– ergotamines
– triptans

3. Serotonin in Different Species
C. Elegans (roundworm) Betta splendens (Siamese fighting fish) lobster
C57 mouse Long-Evans rat marmoset

4. Biosynthesis: Tryptophan
• Essential amino acid
Food g tryptophan / 100 g food
salami 0.253
lentils 0.251
turkey (breast) 0.194
almonds 0.192
walnuts 0.17
asparagus 0.027
USDA National Nutrient Database for Standard Reference, Release 19 (2006).

5. Biosynthesis of 5-Hydroxytryptamine
• Tryptophan hydroxylase: found in axons, rate limiting
step
• L-aromatic amino acid decarboxylase (AACD): not rate
limiting step, also important for catecholamine
General Rule:
Depleting 5-HT: easy
Increasing 5-HT: not easy

6. Where is 5-Hydroxytryptamine
(Serotonin) localized?
• Enterochromaffin cells (90%)
• Platelets: thombosis
• Central nervous system (10%)
– Dorsal raphe: forebrain (lateral)
– Medial raphe: forebrain (medial)
– Nucleus raphe magnus: spinal
cord
Kranz et al. (2012). PNAS, 109(29), e2000.

7. 5-HT & Aggression
• Para-chlorophenylalanine (PCPA): irreversible
tryptophan hydroxylase inhibitor
• PCPA treated rats were tested for muricide
• Inverse relationship between 5-HT &
aggression
Killers Non-killers
Control 0 13
PCPA 14 4
Paxinos et al. (1977). Pharmacology, Biochemistry, Behavior, 6, 439-447.

8. Serotonin Transporter
• SERT removes 5-HT from synapse
• Localized at cleft, along axon, & on
soma
Stahl (2008). Essential Psychopharmacology. p. 93.

9. Serotonin Transporter (SERT) Reflects
Axon Integrity
• High dose 3,4-methylenedioxymethamphetamine (MDMA or
“ecstasy”) damages 5-HT axons
• SERT can be measured with immunocytochemistry

10. Serotonin fibers in the caudate nucleus of a control squirrel monkey
(A), a monkey that received 5 mg/kg MDMA 2 weeks (B), or 7 years
(C) previously.
Hatzidimitriou et al. (1999). Journal of Neuroscience, 19, 5096-5107.

11. Breakdown of 5-Hydroxytryptamine
Monoamine Oxidase (MAO): target of older
antidepressant drugs
5-HIAA: found in Cerebral Spinal Fluid
NADH: nicotine adenine dinucleotide, reduced;
increased by ethanol!
Sanders-Bush & Hazelwood (2012). In Pharmacological Basis of Therapeutics, p. 336.

12. Ergot Poisoning
• Fungus (Claviceps purpurea) found on grain contains
ergotamine
• Antiquity: Saint Anthony’s fire (convulsions & gangerine)
• Modern Case: Pont St. Espirit, France 1951
– Early Symptoms (6-48 hours): diffuse abdominal pain
(burning sensation throughout whole digestive tract),
nausea, vomiting, insomnia lasting several days
– Middle Symptoms ( ≈2 days – 1 week): cold extremities,
cramps of calves, logorrhea, visual hallucinations (themes =
animal & self-accusation)
– Late Symptoms (≈post 1 week): muscular spasm &
cardiovascular collapse (4 died)
Summarized from Gabbai et al. (1951). British Medical Journal, Sept 15, 650-651.

13. History of LSD
• Lysergic acid diethylamide was synthesized by Hoffman (1938)
from ergotamine
• CIA explored use (1950s)
• Counter-culture use (1960s) Albert Hoffman, Ph.D.
• 5-HT2A antagonist
• Schedule I
• Adjunct to psychotherapy?
1906 - 2008

14. History of LSD
• Lysergic acid diethylamide was synthesized by Hoffman (1938)
from ergotamine
• CIA explored use (1950s)
• Counter-culture use (1960s)
• 5-HT2A antagonist/5-HT1A agonist
• Schedule I
• Adjunct to psychotherapy?
1st 3 min: http://www.youtube.com/watch?v=HBOPFWmZCdM&list=LPNw1MNHLBky4&index=2&feature=plcp

15. 5-HT Receptor Tissue Post-Receptor Agonist (Ag) or
Mechanism Antagonist (Ant)
1A Raphe, hippocampus Gi Ag: 8-OH-DPAT
1B substantia nigra (SN) Gi Ag: Sumatriptan
1C (oops, 2C)
1D brain Gi Ag: Sumatriptan
1E cortex, putamen Gi
1F cortex, hippocampus Gi
1P enteric nervous system Go Ant: Ranzapride
2A platelets, smooth muscle Gq Ag: DOI; Ant: Ketanserin
2B stomach fundus Gq Ag: DOI
2C Hippocampus, SN Gq Ag: DOI
3 area postrema Na+ channel Ag: ondansetron
Based on Katzung et al. (2012). Basic & Clinical Pharmacology, p. 282.

16. 5-HT & Anxiety:
Light Dark Test
• Role of GABA or 5-HT in anxiety
--------------------------------- --------------------------------------------------

17. 5-HT & Depression
• Methods: 15 un-medicated women with a
history of 2+ episodes of depression were on a
low protein diet for 1 week, then randomly
assigned to receive:
– Tryptophan + : L-tryptophan (1.9 g), L-alanine (4.6
g) L-arginine (4.1 g)
– Tryptophan - : L-alanine (4.6 g) L-arginine (4.1 g)
Smith et al. (1997). Lancet, 349, 915-919.

18. Hamilton Depression Inventory
http://www.psy-world.com/online_hamd.htm

19. Ham-D
Max Hamilton
1912-1988
http://www.psy-world.com/online_hamd.htm

20. Smith et al. (1997). Lancet, 349, 915-919.

21. Migraine Terminology
• migraineurs: person who experiences migraines
• aura: collection of symptoms that may precede or
co-occur; typically visual, lasts less than 1 hour
– positive features
• scintillations: a rapidly oscillating pattern of visual distortions
• photopsia: perception of flashes of light
• teichopsia: spot of flickering light
– negative features
• scotoma: an area of diminished vision within the visual field
• hemianopsia: blindness in half of the visual field, may involve
one or both eyes
– hemiplegic aura: occurring on one side of body
– basilar type aura: aura is localized to the brainstem
DiPiro et al. (2008). Pharmacotherapy: A Pathophysiologic Approach. p. 1008.

22. George Cruikshank: The Head Ache (1819)
2:20: http://www.mayoclinic.com/health/migraine-aura/MM00659

23. International Headache Society Migraine Criteria
• Migraine with aura (classic migraine)
– At least 2 attacks
– Aura fulfills criteria for typical aura, hemiplegic aura, or basilar
type aura
– Not attributed to another disorder
• Migraine without aura
– At least 5 attacks
– Headache lasts 4 to 72 hours (untreated or successfully treated)
– Headache has at least 2 characteristics
• Unilateral location, pulsating quality, or moderate or severe intensity
– Aggravation by or avoidance of routine physical activity
(walking, climbing stairs)
– During headache, at least one of the following:
• Nausea, vomiting, or both
• Photophobia and phonophobia
– Not attributed to another disorder
http://ihs-classification.org/en/02_klassifikation/02_teil1/01.00.00_migraine.html

24. Epidemiology

25. Pathophysiology
• limited animal models
• theory: genetic (50% heritable) & neurovascular
• 2 min: http://www.youtube.com/watch?v=yZr9Joe85wg
• orthodromic: electrical potential following typical direction (soma
to axon)
• antidromic: electrical potential traveling in the reverse direction
(axon to soma)

26. Ergot Alkaloids
• Used for moderate to severe migraines (non-
prophylactic) but not other pain
• Vasoconstrictive agents with long history (1920s)
but dirty drugs (5-HT, dopamine, adrenergic)

27. Effects of ergot derivatives on contraction of isolated segments of human basilar artery strips
removed at surgery. All ergot derivatives are partial agonists, and all are more potent than
full agonists, norepinephrine (NE) and serotonin (5-HT). Dihydroergotamine (DHE), ergotamine
(ERG), methysergide (MS), and methylergometrine (MT).
Modified from Katzung (2012). Basic & Clinical Pharmacology. p. 289.

28. Diverse ROA
• ergotamine & caffeine (Cafergot): oral
• ergotamine & caffeine (Migerot):
suppositories
• ergotamine tartrate (Ergomar): sublingual
• dihydroxyergotamine mesylate (Migranol):
nasal spray or injections

29. Adverse Effects
• Route dependent nausea & vomiting (10-20%)
• weakness
• tingling of extremities (think history!)
• chest pain & temporary changes in heart rate
(↑↓ )

30. Contraindications
• pregnant women (miscarriage risk)
• coronary artery disease
• should not be used simultaneously with
triptans

31. Triptans
• Recently developed (1990s) 5-HT1B/1D agonists act
on neurons & blood vessels
• First line therapy for moderate to severe
migraines (non-prophylactic)
• Should not be used with SSRI

32. Example Trial Evaluating Triptans
*
* *
Effects of sumatriptan (6 mg injected subcutaneously, N=734) or placebo (N=370) on symptoms
of acute migraine 60 minutes after subcutaneous injection. From Cady et al. (1991). JAMA, 265,
2831-2835.

33. Summary
• “neurotransmitter for all seasons”
• Ergot alkaloids
• Triptans

34. Melatonin

35. Goodwin (13) & Related Terminology
Enterochromaffin cells (p. 335): a type of enteroendocrine cell occuring in the epithelia lining the
lumen of the digestive tract and the respiratory tract
tunicate (p. 335): marine filter feeders (image, lower right)
coelenterate (p. 335): outdated zoological term for 2 phyla including comb jellies (image, lower
left) and sea anemonies
psychotomimetic (p. 337): drug that mimics elements of mental illness (psychosis)
choroid plexus (p. 337): layer fo cells found in ventricles of brain that produce cerebral spinal fluid
superior colliculus (p. 340): Latin: upper hill , anatomical structure (image, middle, see arrow)
hyperacusis (p. 345): oversensitivity to certain frequencies of sound
paresthesias (p. 346): sensation of tingling or burning, aka “pins & needles”
asthenia (p. 346): weakness
precordial (p. 348): pertaining to the region over the heart/stomach
Horton’s syndome (p. 349): aka cluster headache, intense pain typically on one side of the head

36. Organic Chemistry (Refresher)