STEPTRACKERPHARMACOLOGY | NEUROLOGY | HIGH-YIELD REVIEW

Headache, Spasticity & Other Neuro Drugs

Migraine has abortive and preventive drugs; spasticity and myasthenia have their own short lists; a few odd ones out — vertigo, glaucoma, sleep — round out the neurology formulary.

FOCUS ON
Migraine abortive: NSAIDs/acetaminophen, triptans (5-HT1B/1D agonists → cranial vasoconstriction, ↓ CGRP release; avoid in CAD, Prinzmetal, uncontrolled HTN, pregnancy; serotonin syndrome), antiemetics (metoclopramide, prochlorperazine), gepants (ubrogepant, rimegepant — CGRP receptor), lasmiditan (5-HT1F, no vasoconstriction), ergots (dihydroergotamine; ergotism). Migraine prevention: propranolol, topiramate, amitriptyline, valproate, venlafaxine, candesartan, anti-CGRP antibodies (erenumab, fremanezumab), onabotulinumtoxinA (chronic). Cluster: 100% O₂, SC sumatriptan; verapamil prevention. Tension: NSAIDs. Medication-overuse headache. Spasticity: baclofen (GABA-B; withdrawal seizures), tizanidine (α2), dantrolene, botulinum toxin, diazepam. Muscle relaxants (cyclobenzaprine — TCA-like). Myasthenia: pyridostigmine, steroids, azathioprine, eculizumab, efgartigimod, IVIG/plasmapheresis for crisis. Glaucoma: prostaglandin analogs (latanoprost — brown iris), β-blockers (timolol), α2 agonists, CAIs, pilocarpine.
DRUG
MECHANISM
USE
ADVERSE · NOTES
Sumatriptan · rizatriptan
5-HT1B/1D agonists
Acute migraine, cluster (SC sumatriptan)
Chest tightness, coronary vasospasm; avoid in CAD, hemiplegic migraine, MAOI use
Ubrogepant · rimegepant · atogepant
CGRP receptor antagonists (gepants)
Acute (ubro-, rime-) and preventive (atogepant, rimegepant)
Nausea; no vasoconstriction
Lasmiditan
5-HT1F agonist
Acute migraine with CV risk
Dizziness, sedation — no driving 8 h
Ergotamine · dihydroergotamine
5-HT, α, D receptor agonists
Refractory migraine
Ergotism (limb ischemia), contraindicated with CYP3A4 inhibitors, pregnancy
Erenumab · fremanezumab · galcanezumab
Anti-CGRP (or receptor) monoclonal antibodies
Migraine prevention
Constipation, injection-site reactions
Preventive oral agents
Propranolol, topiramate, amitriptyline, valproate, venlafaxine
≥ 4 migraine days/month
Choose by comorbidity (HTN, obesity, insomnia)
Verapamil · oxygen
Ca²⁺ channel block · cerebral vasoconstriction
Cluster prevention · cluster abortive
ECG monitoring at high verapamil doses
Baclofen
GABA-B agonist in spinal cord
Spasticity (MS, cord injury); intrathecal
Sedation; abrupt stop → seizures, hallucinations, hyperthermia
Cyclobenzaprine · methocarbamol
Centrally acting relaxants
Acute musculoskeletal spasm
Cyclobenzaprine anticholinergic, sedating
Botulinum toxin A
Cleaves SNAP-25 → ↓ ACh release
Focal dystonia, spasticity, chronic migraine, hyperhidrosis, achalasia
Local weakness, dysphagia
Eculizumab · efgartigimod
C5 inhibitor · FcRn blocker (↓ IgG)
AChR-antibody myasthenia gravis
Eculizumab: meningococcal infection — vaccinate
Latanoprost · bimatoprost
PGF2α analogs → ↑ uveoscleral outflow
Open-angle glaucoma (first-line)
Darkened iris, eyelash growth
Timolol · brimonidine · dorzolamide · pilocarpine
↓ Aqueous production (β-block, α2, CAI) · ↑ trabecular outflow (pilocarpine)
Glaucoma
Timolol systemic β-block (asthma, bradycardia)
Meclizine · betahistine
H1 antagonist · H3 antagonist
Vertigo · Ménière disease
Sedation

Mechanism — triptans in migraine

Trigeminal activationCGRP, substance P released
→
Meningeal vasodilation, inflammation
→
Triptan (5-HT1B/1D)Vasoconstricts, blocks CGRP release

Gepants and CGRP antibodies target the same peptide without vasoconstriction.

Glaucoma drug choice

DRUG
ACTION
SIDE EFFECT
Latanoprost
↑ Outflow
Brown iris
Timolol
↓ Production
Bradycardia, wheeze
Brimonidine
↓ Production
Allergy
Acetazolamide
↓ Production
Acidosis, paresthesia
Pilocarpine
↑ Outflow
Miosis, brow ache

How it's tested

COMMON CONFUSIONMedication-overuse headache develops with frequent analgesics, triptans or opioids — treatment is withdrawal plus a preventive.
THE TRAPTriptan for migraine in a patient with coronary disease or Prinzmetal angina → coronary vasospasm; choose a gepant or lasmiditan.
YOUR APPROACHHeadache type → abortive vs preventive → contraindications (vascular disease, pregnancy, interactions).

If you see… think…

Chest pressure after migraine nasal spray → triptan vasospasm
Cluster headache, acute treatment → 100% oxygen, SC sumatriptan
Cluster headache prevention → verapamil
Seizures after intrathecal pump fails → baclofen withdrawal
Glaucoma drop that darkens the iris → latanoprost
Glaucoma drop worsening asthma → timolol
Cold, pale fingers after migraine drug + clarithromycin → ergotism
Migraine prevention in obese patient → topiramate
Myasthenia biologic requiring meningococcal vaccine → eculizumab
Toxin used for chronic migraine and hyperhidrosis → botulinum toxin A