Chapter 63 - Botulinum toxin, fillers

Question 1

brands other than Botox that contain botulinum toxin-A

Answer 1

Dysport, Xeomin
Botox has longest record of safety, efficacy, and most FDA-approved indications
Dysport is weaker, need 2-3 units to equal one unit of Xeomin/Botox

Myobloc is botulinum toxin-B

Question 2

how botulinum toxin acts

Answer 2

presynaptic NMJ
prevents ACh release
cleaves SNARE proteins which allow vesicles containing ACh to fuse with plasmalema of nerve terminal leading to exocytosis

Question 3

How to treat ptosis due to botox

Answer 3

a-adrenergic ophthalmic drops

Question 4

how hyaluronic acid fillers work, how long

Answer 4

bind water –> volumization, hydration of skin
Same in all species –> very low likelihood for allergic reaction –> no skin testing needed
Last 6-12 mo

Question 5

Sculptra’s MOA (poly-L-lactic acid filler)

Answer 5

gradual neocollagenesis, may last up to 3 yr

Question 6

Technical term for crows feet

Answer 6

lateral canthal lines

Question 7

Two areas where Botox is considered on-label

Answer 7

glabellar lines (Botox cosmetic, dysport, xeomin)
lateral canthal lines (botox cosmetic only)

Question 8

Other conditions treated with botulinum toxin

Answer 8

Cervical dystonia (botox, dysport, xeomin)
blepharospasm (botox, xeomin)
strabismus, upper limb spasticity, chronic migraine, urinary incontinence if overactive bladder, severe primary axillary hyperhidrosis (botox)

Off label, botox also used for facial tics, spasmodic dysphonia, myofascial pain syndrome, sialorrhea

Question 9

How long does botox work for with wrinkles

Answer 9

Takes 3-7 days for effect, max effect 2 wk
Effect lasts for 3 mo (4-6 if repeated since facial mm atrophy)

mm fxn returns due to axonal sprouting, production of new NMJ

Question 10

Lethal dose of botox, normal dose with cosmetic treatment

Answer 10

2500-3000 is the LD50

Normally use 40-60

Question 11

Doses of botox based on site

Answer 11

Glabella: 20-40u divide 5 sites
Forehead: 10-30u decide 4-8 sites, 2cm above eyebrow at least
Crow: 8-12u each side, divide 3-4 sites
Perioral: 4-10u, 2-6 sites
Chin: 2-8u, 1-2 sites
Neck (platysma band); 10-40u, 2-4 sites/band

Question 12

Depressors/elevators of brow

Answer 12

Dep: corrugator, procerus, depressor supercilii (part of orb)

EL: frontalis

Question 13

chemical brow lift

Answer 13

botox to superolateral orb just below eyebrow
1-2mm lift
weaken the depressor fxn

Question 14

AEs of botox

Answer 14

HA, dry mouth, tired, neck pain

difficulty breathing/swallow/speak/urinate, weakness…these very unlikely at cosmetic doses

Question 15

botox ptosis

Answer 15

inject less than 1cm from orbital rim…spreads to levator palp superiorus
Tx with apraclonidine (lopidine) and phenylephrine (mydfrin) to target a2/a1 receptors –> contract Muller (sup tarsal) mm –> elevate lid

Question 16

Can you develop resistance to botox?

Answer 16

Yes, can develop ABs

Avoid by small, spaced doses

Question 17

Post botox instructions

Answer 17

Don’t rub area
No vigorous sports for 1 week
No skin treatments that day

Question 18

4 filling injection strategies

Answer 18

Linear threat (inject while withdrawing)...good for lip, nasolabial fold
Fanning (one prick, 3 different angles) and cross-hatching (multiple pricks perpendicular to each other) good for large defects
May also do serial puncture

Question 19

Complications of fillers

Answer 19

bruise, red, edema at site
asymmetry, nodule, granuloma (inflam to filler)
skin necrosis, blindness due to intravascular inject

Question 20

Tyndall effect

Answer 20

inject HLA too superficially –> bluish bump in skin

Prevent with deeper inject, bevel needle away from skin

Question 21

How quickly does hyaluronidase work?

Answer 21

Within 24 hr