Anti-spasticity Agents

Question 1

What are the names of some common centrally-acting anti-spasticity agents?

Answer 1

Baclofen (Lioresal)
Diazepam (Valium)
Tizanidine (Zanaflex)

Question 2

What are the names of some common peripherally-acting anti-spasticity agents?

Answer 2

Dantrolene (Dantrium)

Question 3

What is a positive of centrally-acting anti-spasticity agents?

Answer 3

No ceiling effects

Question 4

Baclofen (Lioresal) - site of action

Answer 4

GABA-b receptors

Question 5

Baclofen (Lioresal) - side effects:

Answer 5

Sedation
Ataxia
Hypotension
Slurred speech
Respiratory depression
Hallucinations

Question 6

Baclofen (Lioresal) - drug interactions:

Answer 6

Drugs that also cause sedation
Methadone
Mirtazapine
Zolpidem
Azelastine
Buprenorphine

Question 7

Baclofen (Lioresal) - clinical considerations:

Answer 7

Effectiveness limited by systemic SEs
Limited ability to cross the BBB (where spasticity comes from)
May lower the seizure threshold
Withdrawal sx

Question 8

What is one way to combat Baclofen’s limited ability to cross the BBB?

Answer 8

It is also available intrathecally or via a pump (usually placed between T12/L1)

Question 9

Indications for intrathecal Baclofen (Lioresal):

Answer 9

Severe spasticity unresponsive to oral agents

Intolerable SEs at effective oral doses (systemic reactions)

Question 10

What is a positive of Baclofen (Lioresal)

Answer 10

Fewer systemic SEs because it is injected directly into the SC

Question 11

When can intrathecal Baclofen (Lioresal) be prescribed?

Answer 11

After an initial screening hospital admission trial of 1-3 days

Question 12

Is there a black box warning associated with intrathecal Baclofen (Lioresal)?

Answer 12

YES - abrupt discontinuation may lead to organ failure or death

Question 13

Intrathecal Baclofen (Lioresal) - complications:

Answer 13

Infection
Dislodged pump
Blocked or twisted catheter
Pump failure
OD

Question 14

Diazepam (Valium) - site of action:

Answer 14

Brainstem reticular formation

Spinal polysynaptic pathways

Question 15

Diazepam (Valium) - side effects:

Answer 15

Sedation
Decreased gait speed
Muscle weakness
Hypotension
Ataxia
Constipation

Question 16

Diazepam (Valium) - half-life:

Answer 16

20-80 hours

Question 17

How is the half-life of Diazepam (Valium) determined?

Answer 17

Age

Question 18

Diazepam (Valium) - side effects:

Answer 18

Antifungal agents
Azelastine 
CCBs
Azithromycin 
Methadone

Question 19

Diazepam (Valium) - clinical considerations:

Answer 19

Class IV controlled substance
Long half-life - not recommended in elderly (Beers)
Avoid alcohol - potentiates CNS depression

Question 20

What are common anticholinergic effects caused by antihistamines?

Answer 20

Flushing
Dry mouth
Difficulty urinating
Cognitive effects

Question 21

Tizanidine (Zanaflex) - site of action:

Answer 21

Alpha-2 adrenergic receptors

Question 22

Tizanidine (Zanaflex) - side effects:

Answer 22

Sedation
Dizziness
Dry mouth
Hypotension
Hepatotoxicity

Question 23

Tizanidine (Zanaflex) - clinical considerations:

Answer 23

Avoid in patients with liver disease

Withdrawal sx may occur if therapy stopped suddenly

Question 24

Dantrolene (Dantrium) - site of action:

Answer 24

Skeletal muscle Ca++ stores

Question 25

Dantrolene (Dantrium) - use:

Answer 25

For spasticity that limits rehab progression

Question 26

Dantrolene (Dantrium) - side effects:

Answer 26

``` Fatigue Dizziness Weakness Malaise Diarrhea Hepatotoxicity ```

Question 27

Dantrolene (Dantrium) - contraindications:

Answer 27

Patients who require spasticity to remain upright or balanced (SCI) Liver disease

Question 28

Dantrolene (Dantrium) - interactions:

Answer 28

Methadone Azelastine Mirtiazapine Zolpidem

Question 29

Dantrolene (Dantrium) - clinical considerations:

Answer 29

Fewer cognitive side effects | Alcohol enhances sedation

Question 30

For what is botulinum toxin (Botox) approved?

Answer 30

Treatment of UE spasticity

Question 31

For who is Botulinum toxin (Botox) indicated?

Answer 31

Patients with painful spasticity that limits skin hygiene and daily functioning (CP)

Question 32

Effects of botulinum toxin (Botox):

Answer 32

Decreased muscle tone | Increased ROM

Question 33

What is the black box warning associated with Botulinum toxin (Botox)?

Answer 33

Injected toxins may spread to distal sites and cause sx of botulism (can be fatal)

Question 34

Botulinum toxin (Botox) - side effects:

Answer 34

``` Fatigue Nausea Bronchitis Pain @ injection site Weakness ```