Skeletal Muscle Relaxants Flashcards
Antispasticity Agents (4)
- Baclofen
- Tizanidine
- Dantrolene
- Diazepem
Antispasmodics (8)
- Tizanidine
- Benzos
- Methocarbamol
- Cyclobenzaprine
- Carisoprodol
- Orphenadrine
- Metaxalone
- Chlorzoxazone
Baclofen
4 important things
9 ADRs
- GABA(b) mimetic
- PO or intrathecal (helpful in controlling severe spasticity and pain in patients not responsive to other meds)
- Inhibits release of substance P
- For spinal spasticity, MS
- ADRs: drowsiness, may decrease seizure control in epileptics, impairs motor coordination, nausea, vertigo, hypotonia, weakness, depression, headache
Botulinum Toxin
3 important things
- IM injection
- Blocks pre-synaptic release of ACh from nerve terminal
- For strabismus, blepharospasm, stroke spasticity
Carisoprodol
4 important things
8 ADRs
- PO tablet
- For relief of spasm, acute musculoskeletal pain relief
- NOT effective for chronic condition
- Schedule IV
- ADRs: drowsiness, increased HR, flushing, CNS depression, trembling, headache, angioedema, hiccups
Chlorzoxazone
3 important things
3 ADRs
- PO, take with food or milk (GI irritant)
- For rapid relief
- Superior to diazepam
- ADRs: hepatocellular toxicity (monitor fatigue, anorexia, N/V, rash, jaundice, dark urine)**, drowsiness, similar to carisoprodol
Clonidine
2 important things
7 ADRs
- Adjunct, rarely used
- a-Agonist (decreases sympathetic outflow)
- ADRs: bradycardia, hypotension, dry mouth, constipation, drowsiness, dizziness, depression
Cyclobenzaprine
4 important things
6 ADRs
- Related to TCA
- For trauma, acute musculoskeletal pain, spasm, local pain, and ROM
- As effective or better than diazepam
- Long DOA
- ADRs: dry mouth, edema of face/lips, syncope, blurred vision, muscle weakness, urination problems
Dantrolene
3 important things
2 ADRs
- Chemically unique
- Interferes directly with excitation-contraction coupling in muscle fibers
- DOC for malignancy hyperthermia: interferes with calcium release from sarcoplasmic reticulum
- ADRs: dose dependent muscle weakness and increased LFTs
Diazepam
4 important things
2 ADRs
- Gold standard
- GABAa receptor
- IV, PO
- Schedule IV
- ADRs: very sedating, ataxia
Metaxalone
2 important things
7 ADRs
- Sedative properties (not skeletal muscle relaxation)
- Not for long term
- ADRs: very sedating, nausea, headache, dry mouth, urinary retention, nervousness and exacerbates seizures
Methocarbamol
3 important things
8 ADRs
- Doesn’t directly relax skeletal muscle
- Adjunctive for tetanus
- IV and enteral
- ADRs: drowsiness, dizziness, nystagmus, congestion, facial flushing, bradycardia, nausea, vomiting
Orphenadrine
3 important things
1 ADR
- Related to diphenhydramine (antihistamine)
- Doesn’t directly relax skeletal muscle
- Anticholinergic, antihistaminic, local anesthetic, slight CNS stimulation
- ADRs: propoxyphene interaction (additive CNS, confusion, anxiety, tremor)
Tizanidine
3 important things
7 ADRs
- a-Agonist
- Similar efficacy and better tolerated than baclofen or diazepam
- Interacts with cipro
- ADRs: insomnia, weakness, dry mouth, drowsiness, dizziness, hallucinations, increased LFTs
A sudden, violent, involuntary contraction of a muscle, attended by pain and interference with function, producing involuntary movement and distortion.
Spasm
A state of increased tone of muscle, with heightened deep tendon reflexes. Characterized by muscle hypertonicity and involuntary jerks. Often accompanied by muscle weakness.
Spasticity
