Botulinum Toxin Flashcards
What are the absolute contraindications to Botox?
- Prev allergy to BT
- Psychological (BDD)
- Infection at treatment site
- NM disorders e.g. myasthenia, AL, eaton-lambert
- Dysphagia/aspiration history
- Pregnant or breastfeeding
What are the relative contraindications to botox?
- Less than 18yrs old
- Anticoagulants, antiplatelets, vit E
- Aminoglycosides (enhance effects of botox)
- Calcium antagonists (antagonise effect of botox)
What has gone wrong in glabellar treatment if there is medial brow ptosis?
injection points too high
What has gone wrong in glabellar treatment if there is lateral brow ptosis?
injections too lateral
When can brow ptosis happen with frontalis treatment?
Low product placement
Overtreatment of frontalis
Poor patient selection = low set eyelids, hooding or hyperkinetic frontalis
How can patients get spock brow (mephisto sign)?
If frontalis placement is too medial - caused by active lateral frontalis
Can also happen in tails of corrugator if product is placed too deep/lateral
Why can crows feet treatment cause diplopia?
medial migration of toxin to lateral rectus
How can OO injections affect the smile?
Deep injections of inferior point can cause paralysis of zygomaticus muscles
How can OO treatment cause dry eye?
Deep injections of superior point
Due to affecting the lacrimal gland
What are the cautions to be aware of when treating upper lip lines?
Risk using straw or eating from spoon could be difficult
Lengthening of upper lip
Administer close to vermillion border to prevent zygomaticus minor
Superficial injections means deep fibres remain intact preserving function
What is the history of botulinum toxin?
1985: Emile van Ermengem isolates clostridium botulinum
1944: Schantz isolates BT Type A
1973: Scott treats strabismus with Type A
1987: Jean Carruthers notices skin effects
1990: Alastair Carruthers publishes studies for aesthetic use
How does botulinum toxin work to cause muscle paralysis?
Inhibits release of acetylcholine at NMJ
To become active, the molecule is endogenously cleaved by bacterial proteases into 2 fragments
- light chain (50kDa) and heavy chain (100 kDa)
Botox binds presynaptically to cholinergic nerve terminals halting release of ACh
What type of toxin is preferred for aesthetics and why?
Type A
Longer duration of action and ease of production
Why is botox only temporary?
SNAP 25 gradually regenerates = restoring muscular contractility over time
What is the duration of action of botulinum toxin?
Effects begin within 3-4 days and peak at 14-30 days
Lasts approx. 3-4 months
Metabolised by body within 28 days
Top ups should be 2-4 weeks after initial treatment