31 - 216 -BOTULINUM TOXIN Flashcards
7 serotypes of Botulinum neurotoxins
A, B, C1, D, E, F, G
Type A toxin cleaves what protein?
**SNAP-25 **(synaptosome-associated protein of 25 kDa)
type B toxin cleaves what protein?
VAMP (vesicleassociated membrane protein), also called synaptobrevin
what protein complex is cleaved to inhibit exocytosis of the neurotransmitters such as acetylcholine?
SNARE (soluble N-ethylmaleimidesensitive factor attachment protein receptor) protein complex
When Botox is diluted with 1 mL NSS per 100 units, how many units are present in 0.1mL
10 units
When Botox is diluted with 2 mL NSS per 100 units, how many units are present in 0.1mL
5 units/ 0.1 mL
When Botox is diluted with 2.5 mL NSS per 100 units, how many units are present in 0.1mL
4 units/0.1 mL
this diluent appears to lessen the sting of injection with Botox ®and Dysport®
sterile saline with preservative (benzy alcohol)
what are the corrugator injection points?
(1) just at or above the medial brow and
(2) in or just medial to the midpupillary line, at least 1 cm above the bony orbital rim
The fifth injection is placed in the procerus at the midline at a point just above the horizontal creases created in the glabella at the bridge of the nose.
- patients have been instructed to remain upright for 2 to 3 hours to limit the incidence of eyelid ptosis, which occurs with diffusion of the toxin down into the levator muscles of the lid
treatment for eyelid ptosis secondary to toxin
- Temporary stimulation of Müller muscle in the lid can be achieved with 0.5% apraclonidine or
- 2.5% phenylephrine eyedrops or even
-
naphazoline hydrochloride 0.025%
* pheniramine maleate 0.3% eyedrops (Naphcon A ® available over the counter)
- These will produce 2 to 3 mm of elevation of the lash margin, and administration may be repeated at intervals of 4 to 6 hours as needed until the distant diffusion effect of the botulinum toxin on the levator muscle disappears, usually in** 2 to 3 weeks.**
toxin units on the horizontal forehead lines
- Twelve to 20 units of Botox ®or 20 to 50 units of Dysport ® are placed in 4 or 5 divided doses equidistantly along the forehead equator
- If too large a dose is applied or injection sites are placed too low, brow ptosis and loss of brow arch are produced, which leads to an unpleasant, heavy sensation in the brow as well as an aesthetically unattractive appearance in females
- Unlike in the treatment of eyelid ptosis, there is no comparable adrenergic agent available to reverse brow ptosis induced by botulinum, and the patient must wait several weeks for the effect to wear off.
In injecting the “smile lines”, what will happen when the toxin is placed at or below the malar eminence in an attempt to weaken these lines?
may lead to paralysis of the zygomaticus muscles and a drooping corner of the mouth that cannot spontaneously be raised, so that the patient may acquire a poststroke appearance
injection points of crow’s feet
toxin is usually placed at 1 to 3 injection points approximately 1 cm lateral to the lateral canthus
- Typical doses range from 10 to 18 units of Botox ® or 25 to 30 units of Dysport® depending on the estimate of muscle mass and activity
- Great care must be taken to make the injections into the skin only, raising wheals or blebs that can be gently massaged down.
- Intramuscular injection in this area will reliably produce unwanted bruising because of the rich venous plexus underlying the skin in this region.
botulinum-induced ptosis resolves spontaneously, usually how many weeks?
usually in 3 weeks or less
dose of toxin in axillary hyperhidrosis
Doses of **2.5 to 4.0 units of Botox ® are placed every 1 to 2 cm **as intradermal injections in axillary skin
Reliable anhidrosis is produced within how many hours of toxin injection on the axilla?
72 hours
axillary anhidrosis after toxin injection of 50 to 100 units of Botox will last for how many months?
8 to 12 months
- Aside from insignificant bruising from the needle trauma, there are no apparent side effects
in treating palmar hyperhidrosis, how many units of toxin are needed?
Approximately,** 100 to 150 units of Botox are needed to treat a single palm**, divided into 50 to 60 intradermal injections of 2 to 3 units each
Onset of anhidrosis peaks in how many days after toxin injection on the palms?
5 to 7 days
- accompanied by minor weakness of the intrinsic muscles of the hand, which makes tasks requiring strength and stability (eg, pushing a button through a buttonhole) difficult to perform
hand weakness after toxin injection usually subsides within how many weeks?
The weakness usually subsides within 3 weeks, whereas the anhidrosis persists for several months.
anhidrosis lasts for how many months after toxin injection on the palms?
There is wider variation in response to palmar treatment than to axillary treatment, with anhidrosis lasting from 4 to 12 months, which probably reflects the technical difficulties in achieving even dispersion of the toxin through the palmar skin
problematic complications of toxin
* eyelid ptosis - which can occur after injections in the glabellar brow
* brow ptosis - from overzealous treatment of the frontalis muscle
* transient lid edema - from periocular injections;
* headaches - after injections anywhere in the upper third of the face; and
* palmar weakness - after injections for hyperhidrosis
how can you avoid eyelid ptosis complication?
- Eyelid ptosis is thought to be best avoided by carefully placing the midbrow injections at a minimal distance of 1 cm from the superior orbital rim, keeping the injection rate **slow and gentle, and having the patient avoid prone positions and sleeping for 2 hours after injection**
how can you avoid brow ptosis?
- Restricting injections to the **upper two-thirds of the frontalis **and **reducing doses to the minimum necessary **to produce the desired clinical effect may minimize brow ptosis
- Unopposed muscle groups may trigger headaches as a rebound phenomenon after facial injections of botulinum toxin, but their etiology is unclear
At the present time, what the only FDA-approved indications for cosmetic botulinum toxin?
glabellar frown lines and the lateral canthal lines or crow’s feet
