Muscles, Ligaments and Tendons Flashcards
What is contained within robaxacet?
acetaminophen and methocarbamol
What is contained in robaxisal?
ASA and methocarbamol
What is contained within robax platinum?
ibuprofen and methocarbamol
What products is chlorzoxazone in?
- parafon forte, tylenol aches and strains and acetazone
What products is orphenadrine in?
- solo or in combination - norflex (mainly over the counter)
What is methocarbamol?
central acting skeletal muscle relaxant , but does not work directly on the contractile mechanism of the striated muscle, motor endplate or nerve fiber
What is the MOA of methocarbamol?
unknown, but it is thought to cause skeletal muscle relaxation due to general CNS depression
What is methocarbamol used to treat?
- used to treat acute, painful, musculoskeletal muscle spasms
What is the onset of action of methocarbamol?
12-24 hours
What is the MOA of orphenadrine?
- works by mechanisms related to analgesic and anti-cholinergic properties Exact mechanism of action have not been determined
What is orphenadrine used to treat?
- used to treat painful muscle spasm due to acute musculoskeletal conditions
What is the onset of orphenadrine?
24 hours
What is the mechanism of chlorzoxazone?
- muscle relaxant due to its central acting properties
- does not act directly on the muscles, but it works on the spinal cord and brain level to decrease skeletal muscle spasm, provide pain relief and increase mobility of the muscle
What is the main SE of chlorzoxazone?
hepatotoxicity
What is the onset of cholzoxazone?
within 12-24 hours
What are the main SE of methocarbamol?
- drowsiness, dizziness, light headedness, headaches, urine discolouration (black, blue, green or brown)
What are the main SE of orphenadrine?
CNS SE, constipation, dry mouth and blurred vision
What are the main SE of chlorzoxazone?
CNS SE, urine discoloration (orange-red), impaired hepatic function
What are the main contraindications of skeletal muscle relaxants?
- pregnancy, anticholinergic activity, narrow angle glaucoma, prostate hypertrophy, arrhythmias
What are the drug interactions associated with skeletal muscle relaxants?
- other Ach agents, CNS depressants, MAO inhibitors, increase CNS AE, alcohol
What are the effects that topical analgesics exert?
- analgesic effects (raise pain threshold at terminal nerve ending)
- anesthetic (block pain receptors to numb the area)
- antipruritic (relieve itching)
- counterirritant effects (stimulate cutaneous sensory receptors)
What is an counterirritant?
a substance that is rubbed into the skin over a painful joint, tendon, ligament or muscle to relieve pain
- other agents are often needed as an adjuvant (oral analgesics, support bandages, rest, ice compression)
When are counterirritants of particular use?
- for patients that cannot tolerate AE associated with other oral analgesics
What is the MOA of counterirritants?
- paradoxical pain- relieving effect achieved by producing a less severe pain to counter a more intense one
- produces mild, local inflammatory reaction. Does this by producing redness (methyl salicylate, turpentine oil, strong ammonia solution), by producing a rolling effect (camphor and menthol), by vasodilation (methyl nicotinate)
- there can also be a placebo effect associated with a counterirritant (pleasant warmess, coolness or smell associated)