Lecture 2 (Rheum)-Exam 1 Flashcards
Extended-Release Products:
* Who is it reserved for?
* What does it decrease?
* Allow for what?
* What is there a high risk of?
- Reserved for patients with severe chronic pain – usually cancer patients
- Decreased dosing frequency
- Allow for more even steady state with less peaks and troughs
- High risk for overdose of accidently ingested or breach of extended-release mechanism (e.g., crushing, cutting, chewing)
What is a muscle spasm vs muscle spasiticity?
Muscle Spasm
* Sudden / involuntary
* Secondary to fatigue or injury
Muscle Spasticity
* Sustained contraction
* Decreased dexterity from the CNS
* Multiple sclerosis
* Cerebral palsy
* Stroke
* Spinal cord damage
What are approved muscle relaxants for muscle spasms?
- Carisoprodol (Soma)
- Chlorzoxazone (Parafon)
- Cyclobenzaprine (Flexeril)
- Metaxalone (Skelaxin)
- Methocarbamol (Robaxin)
- Orphenadrine (Norflex)
- Tizanidine (Zanaflex)
- Diazepam (Valium)
What are approved muscle relaxants for muscle spasticity?
- Baclofen
- Dantrolene
- Tizanidine
- Diazepam
How does a muscle contract happen?
Action potentials travel down the UMN from the central nervous system
* Cause release of excitatory neurotransmitters (glutamate, norepinephrine)
* Synapse with the LMN
* Activate muscle contraction
What is the inhibitory interneuron?
Regulates excitation of the LMN
Central inhibition of muscle contraction:
* How does Gaba work?
GABA – inhibitory neurotransmitter
* Binds to GABA receptors
* Causes cell hyperpolarization
* Decrease frequency of cell depolarization
* Decreasing muscle contraction
How does Benzodiazepines (diazepam, et al ) work?
- Bind to GABA A receptors
- Increases of Cl- influx
- Hyperpolarization and decreased excitation
Work on CNS
How does baclofen work?
Binds to GABA B receptors
* Postsynaptic – increased K+ efflux
* Hyperpolarization
-
Presynaptic – decrease release of excitatory neurotransmitters (NE and glutamate)
* Less action potentials
Work on CNS
How does Tizanidine work?
- Alpha-2 agonist
- Binds to alpha-2 receptors on presynaptic neurons of the UMN
- Results in less release of exitatory neurotransmitters
Work on CNS
What are the four anti spasticity agents?
Baclofen, dantrolene, diazepam and tizinidine
What is the MOA of baclofen?
Binds GABAb receptors on:
1. LMN increasing K+ efflux, hyperpolarization, decreased action potential
2. Presynaptic UMN inhibiting release of excitatory NT glutamate and norepinephrine
What is the MOA of Dantolene?
Inhibits ryanodine receptors on the skeletal muscle cells; prevents Ca2+ release from SR preventing contraction
WORKS ON SKELETAL MUSCLE SO MORE PNS
What is the MOA of diazepam (Valium)?
Binds BDZ receptor on inhibitory GABAa receptor on LMN; increasing Cl- influx, hyperpolarization, decreased action potentials
What is the MOA Tizanidine (Zanaflex)?
Alpha-2 receptor agonist; binds to presynaptic UMN inhibiting release of excitatory NT glutamate and norepinephrine
What is unique about Dantrolene (Dantrium)?
Hepatotoxicity with high doses
What are the 6 antispasmodics medicine?
- Carisoprodol (soma)
- Chlorzoxazone (parafon)
- Cyclobenzaprine (flexeril)
- Metaxalone (Skelaxin)
- Methocarbamol (Robaxin)
- Orphenadrine (norflex)
What drug is a schedule IV that is antispasmodics?
Carisoprodol (soma)
What are the side effects of central muscle relaxants?
What are the Unique SE of central muscle relaxants?
- Dizziness/ lightheadedness
- Hypotension
- Arrythmias
What are anticholinergic side effects?
- Fever
- Dry mucous membranes
- Flushing
- Blurred vision
- mydriasis
- Hallucinations
- Sedation
- Tachycardia
How are steroids produced?
* Released when?
* What type of effects?
Endogenous steroids produced in the adrenal gland (MC cortisol)
* Released in response to stress and inflammation
* Anti-inflammatory and immunosuppressive effects
What is the MOA of steroids?
Inhibit the production of inflammatory cytokines
* Bind to glucocorticoid receptors inside cells
* Bind to sites on DNA
* Down regulate cytokine production
Inhibit the production of inflammatory mediators
* Inhibit phospholipase A2
* Prevents the production of arachidonic acid
* Decreasing prostaglandins, leukotrienes, thromboxane
Immunosuppression
For steroids effects, what happens to the inflammatory response?
Suppress inflammatory response to all noxious stimuli
* Pathogens
* Chemical / physical
* Immune mediated / hypersensitivity
For the effects of steroids, how is inflammation reduced?
Reduce inflammation by DECREASING:
* Cytokine production – including various interleukins, tumor necrosis factor alpha
* Recruitment of WBCs and monocytes to sites of inflammation (neutrophil demargination)
* Lymphocyte, monocytes, basophil, eosinophil, mast cell production / function
* T-lymphocyte activity
* Production of prostaglandins, bradykinins, leukotrienes (inhibition of phospholipase A2)
Underlying cause of disease NOT corrected-> just a bandage
What is the short term adverse effect of steroids?
- Increased appetite
- Acne
- Insomnia
- Hyperglycemia – induction of gluconeogenesis and insulin resistance-> Caution with diabetes
- Increased fluid retention, edema, and blood pressure
* Mineralocorticoid effects - Mood / Psychiatric changes
- Steroid psychosis
What is the long term adverse effect of steroids?
- Hypothalamic – pituitary-adrenal axis suppression
* Cushing syndrome – moon facies, buffalo hump, central obesity - Growth suppression (in younger people)
- Muscle wasting
- Skin atrophy
- Immunosuppression (issues with infection)
- Cataracts / glaucoma
- Decreased bone mineral density (need to watch closer)
- Gastrointestinal bleeding
What are the big effects of glucocorticoids and mineralocorticoids?
Glucocorticoids
* Glucose metabolism
* Anti-inflammatory
Mineralocorticoids
* Sodium retention
* Fluid retention
What drug is high glucocorticoid and no mineralocorticoids?
Dexamethasone
Tapering
What is the recommedation following prolonged use/higher doses of steroids?
Recommended following prolonged use / higher doses
* Prednisone ≥ 30 mg daily (or equivalent) for ≥ 2 weeks
* Any dose systemic steroid for ≥ 4 weeks
* Signs and symptoms of HPA suppression present
Why do you need to taper steriods?
Used to avoid disease flare or adrenal crisis/insufficiency (HPA suppression)
LOW YIELD
What is the general taper for steroids?
What is the signs and symptoms of adrenal insufficiency?
Osteoporosis:
* What is the mechanism?
* What is less?
* Who is at higher risk of fracture?
* What is thinning?
- Osteoclasts break down bone faster than osteoblasts rebuild it
- Fewer trabeculae
- Bones with higher percentage of trabecular bone at increased risk of fracture – spine, wrist, ribs
- Cortical bone thinning
What is the most common casues of osteoporosis?
- Postmenopausal dt decreased estrogen
- Age related
How does postmenopausal cause osteoporosis?
Postmenopausal - decreased estrogen
* Increased proliferation, differentiation, and activation of osteoclasts (more breakdown)
* Increased calcium excretion (increase Ca in pee)
* Decreased calcium absorption from the GI tract
How is age related issues cause osteoporosis?
- Osteoblasts lose ability to form bone
- Osteoclasts retain activity
What are the risk factors of osteoporosis?
- Decreased estrogen
- Decreased serum calcium
- Alcohol consumption
- Smoking
- Medications (steroids, heparin)
- Physical inactivity
What is the t-scores and diagnostic criteria for osteoporosis?
Who needs to be screened for osteoporosis?
- All adults ≥ 50 years with history of fracture
- USPSTF: all women ≥ 65 years
- Endocrine society: all men ≥ 70 years
What is a bone healthy lifestyle?
- Weight-bearing exercises with resistance training – 30 to 40 min, three times a week
- No Smoking
- Limited ETOH
- Fall prevention
How much calcium should women take pre and postmenopausal?
- 1000 mg daily – premenopausal women and men 50 to 70 years of age
- 1200 mg daily – postmenopausal women and men 71 years and older
How much vitamin D should women and men take? What does it do?
- 600 international units/ day men and women 51 to 70 years
- 800 international units / day – men and women > 70
* Reduce bone loss and fracture rate in older men and women taking adequate calcium
How much protein do you need to intake for osteoporosis prevention?
0.8 g/kg/day
What are the high risk patients of osteoporosis?
- Patients with osteopenia and a history of fragility fracture at the hip or spine
- Patients with a t-score of -2.5 or less in the lumbar spine, femoral neck, total hip
- Patients with a T-score between -1 and -2.5 if the FRAX 10-year probability of major osteoporotic fracture ≥ 20% and hip fracture ≥ 3%
What is the first line therapy of osteoporosis? How does it work?
Bisphosphonates
MOA:
* Reduce bone resorption by:
* Stimulating osteoclast apoptosis
* Decrease cholesterol synthetic pathway which decreases osteoclast function
Osteoclasts are either killed or unfunctional
What is the pharmacokinetics of bisphosphonates?
Bioavailability poor - < 1%
* Worse with concomitant food intake
Amount absorbed
* 50% eliminated renally
* 50% remains for months to years
What are the side effects of bisphosphonate?
- Esophagitis
- Esophageal irritation
- Heartburn
- Abdominal pain
- Diarrhea
- Hypocalcemia
- Renal dysfunction
- Osteonecrosis of the jaw – rare, prolonged, high doses, invasive dental procedures ⭐️
- Flu-like symptoms (fever, muscle aches) with IV therapy
Bisphosphonates:
* What are the oral medicine?
* What should you do to increase bioavailability and decrease SE?
Oral (alendronate, risedronate, ibandronate)
* Take on empty stomach in the morning – increases poor bioavailability
* Full glass of water
* Remain upright for at least 30 minutes
What are the IV bisphosphonates?
Intravenous
* Zoledronic acid
* Pamidronate
What are drug holidays for bisphosphonates?
- After 3 to 5 years treatment – patients mild to moderate fracture risk
- After 6 to 10 years – patients at high fracture risk
- ≤ 5 year holiday with BMD Q 2 to 4 years
You can stop taking the medicine
What are the second line treatments of osteoporosis?
- Denosumab
- Ralonifene
- Teriparatide
Patients who cannot tolerate or have contraindications bisphosphonates
How are specific agents determined for osteoporosis?
Specific agent depends on patient co-morbidities, T-scores, adverse effects, patient preference
What is densumab used for?
Patients at high risk for fracture (eg, osteoporosis by BMD in the absence of fragility fracture, T-score >-2.5 with a fragility fracture, single vertebral fracture)
Osteoporosis
What is raloxifene used for?
Patients with no history of fragility fractures, especially in women at high risk for breast cancer
osteoporosis
What is teriparatide used for
Patients at very high risk of fracture (eg, T-score of ≤-3.5, T-score of ≤-2.5 plus a fragility fracture, severe or multiple vertebral fractures)
osteoporosis
What is the mechanism of action and CI for denosumab, teriparatide and raloxifene?