CNS part 1 Flashcards
Opioids work by binding to the ____ and _______ receptors that we have around our body.
mu and kappa
Pure Opioid Agonists (______, codeine, meperidine), bind with…
Pure Opioid Agonists (morphine, codeine, meperidine), bind with mu and kappa receptors (agonist for both).
Agonist-Antagonist Opioids (pentazocine, nalbuphine, butorphanol, buprenorphine), don’t bind so much with ___ (________ & partial ________) which is good because binding with mu could cause respiratory depression and it may not cause the euphoria that could happen. They still bind with ______ (except for buprenorphine)
Agonist-Antagonist Opioids (pentazocine, nalbuphine, butorphanol, buprenorphine), don’t bind so much with mu (antagonist & partial antagonist) which is good because binding with mu could cause respiratory depression and it may not cause the euphoria that could happen. They still bind with kappa (except for buprenorphine)
Pure Opioid Antagonists (naloxone, naltrexone), does not bind with ____ or ______; like an ________ to the other drugs
Pure Opioid Antagonists (naloxone, naltrexone), does not bind with mu or kappa; like an antidote to the other drugs
Opioid/Morphine adverse effects that do not go away with time
Sedation, Miosis, Constipation
Other opioid/morphine adverse effects
- Euphoria/dysphoria
- Pruritus: itching but does subside with time
- Sedation: side effect that will not go away
- Miosis (constricted pupils): side effect that will not go away
- Neurotoxicity (delirium, agitation, hyperalgesia)
- Renal impairment
- Birth defects
- Constipation: side effect that will not go away; most patients require meds to prevent (stool softeners, laxative)- they will not build up a tolerance to the constipation.
- Orthostatic hypotension: will go away with time
- Cough suppression
- Emesis (N/V)- will go away with time/meds
- Urinary retention- will go away with time
What are the immediate concerns for the patient who is opioid naïve?
Respiratory depression- which is the most serious adverse effect of opioids, “especially for those who are opioid naïve, they have never been on opioids”
Tolerance to respiratory depression can develop over time (usually 72 hrs), so risk ________ over that period.
When you start adding other drugs that are CNS depressants (eg, _______, barbiturates, benzodiazepines)- _____ risk for respiratory depression
Tolerance to respiratory depression can develop over time (usually 72 hrs), so risk decreases over that period.
When you start adding other drugs that are CNS depressants (eg, alcohol, barbiturates, benzodiazepines)- higher risk for respiratory depression
ii. What is one of the potential side effects that continue as long as the patient is taking an opioid? Why does this occur (underlying physiology)
Constipation- occurs due to a decreased/suppressed peristalsis, increased tone of anal sphincter, and reduced secretion of fluids into intestinal lumen
Know the advantages to around the clock (ATC) dosing compared to PRN dosing with opioids.
The research shows that patients on ATC get better _____ _____ and require less ____ _______. ATC dosing has more of a ____ state. So, ATC is better, esp. with chronic pain. Typically used w sustained/extended release drugs.
PRN: Usually end up requiring _____ pain medicine and not _______ with pain management
Basically, the more we can keep them in a steady state, the better pain is managed, the less pain medicine they require, and the more ______ they are with pain management (for ATC)
The research shows that patients on ATC get better pain relief and require less pain medicine. ATC dosing has more of a steady state. So, ATC is better, esp. with chronic pain. Typically used w sustained/extended release drugs.
PRN: Usually end up requiring more pain medicine and not satisfied with pain management
Basically, the more we can keep them in a steady state, the better pain is managed, the less pain medicine they require, and the more satisfied they are with pain management (for ATC)
What drugs are considered opioid antagonists?
Naloxone and Naltrexone
Opioid antagonists (Naloxone and Naltrexone) are used for:
-treatment of opioid overdose
-relief of opioid-induced constipation
-reversal of postoperative opioid effects
-management of opioid addiction
Drug of choice for complete or partial reversal of opioid-induced respiratory depression?
Naloxone Hydrochloride (Narcan)
Naloxone Hydrochloride (Narcan):
- Drug of choice for complete or partial reversal of opioid-induced _______ ________
- Failure of the drug to significantly reverse effects of a presumed opioid overdose indicate the condition may ____be related to opioid overdose
- Remember that it also reverses ____ ______
- Has a half life of ___ hrs- only lasts for a _____ time (__ hrs); still need to go to ER
- ___ mg cumulative dose should see response
- Drug of choice for complete or partial reversal of opioid-induced respiratory depression
- Failure of the drug to significantly reverse effects of a presumed opioid overdose indicate the condition may not be related to opioid overdose
- Remember that it also reverses pain control
- Has a half life of 2 hrs- only lasts for a short time (2 hrs); still need to go to ER
- 10 mg cumulative dose should see response
Naltrexone (ReVia): drug of choice with…
pure opioid agonist overdose; blocks euphoria that they get
Naltrexone (ReVia)
- _______ ________ with physical dependence
- Reverses ____ _____ (analgesia), resp. depression, coma, euphoria, and sedation
- Half life of __ hrs; __ mg cumulative dose should see response
- Titrated cautiously with physical dependence
- Reverses pain control (analgesia), resp. depression, coma, euphoria, and sedation
- Half life of 2 hrs; 10 mg cumulative dose should see response
a. Know signs and symptoms of opioid withdrawal: CNS related symptoms would be:
- Diuresis
- Miosis
- Seizures
- N/V
- Respiratory depression
a. Know signs and symptoms of opioid withdrawal: Non-CNS related (due to release of histamine) symptoms would be:
- Hypotension
- Spasms of the colon- diarrhea
- Urinary retention
- Dilation of blood vessels- sweating, pruritus
Altogether- s/s of opioid withdrawal
- Diuresis
- Miosis
- Seizures
- N/V
- Respiratory depression
- Hypotension
- Spasms of the colon- diarrhea
- Urinary retention
- Dilation of blood vessels- sweating, pruritus
b. Review video on how to administration naloxone:
- Put on gloves
- Remove vial’s cap
- Pull plunger on syringe to bring air into it
- Remove cap on needle
- Insert needle into vial and inject air into it
- Pull plunger up to fill syringe w entire content of vial
- Slightly press down on plunger to remove air bubbles
- Hold syringe at ___ degrees and inject into ______ (___)
- Remove needle at same angle and firmly press down on plunger to pull the needle back into the syringe
- Put on gloves
- Remove vial’s cap
- Pull plunger on syringe to bring air into it
- Remove cap on needle
- Insert needle into vial and inject air into it
- Pull plunger up to fill syringe w entire content of vial
- Slightly press down on plunger to remove air bubbles
- Hold syringe at 90 degrees and inject into muscle (IM)
- Remove needle at same angle and firmly press down on plunger to pull the needle back into the syringe
What is the purpose of using Naltrexone to prevent relapse opioid use?
They use this drug because it blocks the euphoria effect
Know signs and symptoms of alcohol withdrawal
- Elevated blood pressure, pulse rate, and temperature
- Insomnia
- Tremors
- Agitation
What class of medication is used to manage alcohol withdrawal?
Benzodiazepines
The drugs for migraines end with
-triptan or -tripta
Migraine: Know how the class of drugs work (-triptan or -tripta) (mechanism of action)
The migraine causes a drop in serotonin, which causes the blood vessels in the brain to vasodilate. The rush of blood through those dilated cerebral arteries is what causes the pain/headache.
So, the drug’s MOA:
Triptans work as a ______ agonist; they ____ with receptors on _____ ______ leading to _______ and inhibition of ________
Triptans work as a serotonin agonist; they bind with receptors on blood vessels leading to constriction and inhibition of inflammation
Migraines-
What are the contraindications to taking the medications?
- History of heart-related problems like Prinzmetal angina
- Dyslipidemia
- Hypertension
- History of stroke
- Peripheral arterial disease
- Seizure disorder
- History of hepatitis, cirrhosis, liver failure
Review the common presenting symptoms of Parkinson’s disease.
Resting tremor, bradykinesia (slow movement), rigidity (stiffness of limbs/trunk), postural instability, and hypotension
Review the underlying pathophysiology of Parkinson’s disease.
Dopamine in the substantia nigra is not sufficiently produced to bind to receptor
Review the relationship between dopamine and acetylcholine neurotransmitters:
Dopamine ______/_______acetylcholine, and acetylcholine works with ____________ NS. Decrease in dopamine means acetylcholine works __________ because there is an ________ between the dopamine and acetylcholine.
Goal is to balance out these neurotransmitters
Dopamine counters/balances acetylcholine, and acetylcholine works with parasympathetic NS. Decrease in dopamine means acetylcholine works unopposed because there is an imbalance between the dopamine and acetylcholine.
Know how the drug levodopa works to manage Parkinson’s disease:
Levodopa is the drug of choice for
the symptomatic treatment of bradykinesia
MOA of Levodopa:
Relieves _____ symptoms by ________to _______ in surviving nerve ______ in the brain- increases _______ __________ and enhances the __________ of dopamine.
Relieves motor symptoms by conversion to dopamine in surviving nerve terminals in the brain- increases dopamine concentration and enhances the neurotransmission of dopamine.
Limitations of Levodopa:
- It can take ______to get to a full_____ _____
- Highly effective, but benefits _______ ____ _____
- ____ _____ are needed to get to the CNS (except it increases adverse effects; BUT if levodopa is given with carbidopa, it prevents enzyme in the gut from breaking down levodopa so there isn’t any need to increase dose )
- Can’t eat _____ _____ meals/ avoid _______/ spread it out (dietary issue)
- It can take months to get to a full therapeutic effect
- Highly effective, but benefits diminish over time
- High doses are needed to get to the CNS (except it increases adverse effects; BUT if levodopa is given with carbidopa, it prevents enzyme in the gut from breaking down levodopa so there isn’t any need to increase dose )
- Can’t eat high protein meals/ avoid proteins/ spread it out (dietary issue)
Levodopa must be taken on a
empty stomach because food delays absorption
Food interaction of Levodopa:
high protein meals -> slows absorption -> reduces therapeutic effect
Vitamin B6 (fish, beef liver)
Levodopa has something called an ___ ___ syndrome- what does this mean?
- “On-off” syndrome: it works for 2-5 yrs, but you get a loss of response over time. Gradual “wearing off” at end of dose; and abrupt loss of effect (“on-off” phenomenon) can happen at any time in dosing
Drug holidays with Levodopa:
- With long-term use of levodopa, adverse effects tend to increase and therapeutic effects tend to diminish. For some patients, taking time off from treatment, say, 10 days, may produce a beneficial effect with lower doses. This is a dangerous time.
- Drug holidays must take place in the ______, because drug withdrawal _________ the patient. The patient is at risk for all of the physical and psychological effects of this stress.
- Drug holidays must take place in the hospital, because drug withdrawal immobilizes the patient. The patient is at risk for all of the physical and psychological effects of this stress.
Class – dopamine agonists.
Primary drug used in practice is
levodopa/carbidopa
Drug Therapy for Parkinson’s Disease:
- Achieved by correcting the _____ of neurotransmitters by
Dopamine and Ach:
imbalance
Dopamine agonists: two types-
Derivatives of ergot and Nonergot derivatives
Derivatives of ergot –____ selective for ______ (Bromocriptine – rarely used, SE) Not reliant on ______conversion. Less likely to cause _______
Derivatives of ergot – less selective for Dopamine (Bromocriptine – rarely used, SE) Not reliant on enzyme conversion. Less likely to cause dyskinesias.
Non-ergot derivatives (_______ selective for Dopamine receptors & less S/E. (newer) ___ line motor drug
Ex drugs: _______ (Mirapex) ; ________ (Requip) also used for restless leg syndrome.
Non-ergot derivatives (highly selective for Dopamine receptors & less S/E. (newer) 1st line motor drug
Ex drugs: Pramipexole (Mirapex) ; Ropinirole (Requip) also used for restless leg syndrome.
Non-ergot derivatives S/E
nausea, dizziness, daytime somnolence- (“sleep attacks”) AKA narcolepsy, insomnia, constipation, weakness, and hallucinations
If non-ergot derivatives are combined w levodopa, you’ll see more (what S/E)
orthostatic hypotension, dyskinesias, and increase in hallucinations
Most common drugs for PD
Dopaminergic agents- they promote the activation of dopamine receptors
ex: levodopa
Another drug for PD
Anticholinergic agents
* Block receptors for ACh (prevent activation of
cholinergic receptors)
Non-ergot derivatives are a first line
motor drug
In rare instances, non-ergot derivatives may increases effects of
prior addictions (incr dopamine) such as gambling or alcoholism
Know the limitations of drug therapy in general with PD (hint – how long can the drugs manage the disease)
Lasts 2-5 years. Drug holidays can last up to 10 days and should be taken at the hospital since this is a dangerous time.
This would increase the amount of ach and then that would be real bad.
remember: “On and off” syndrome- works for 2-5 yrs; gradual weaning off at end of dose
Review the newer dopamine agonist drugs including their benefits and potential side effects. (non-ergot)
Disadvantage
* Less effective than levodopa
Advantages
* Not dependent on enzymatic conversion to be active
* Do not compete with dietary proteins
* Lower incidence of response failure and less likely to cause dyskinesia
S/E:
nausea, dizziness, daytime somnolence- (“sleep attacks”) AKA narcolepsy, insomnia, constipation, weakness, and hallucinations
Review the COMT inhibitors and what their role is in management. Know how they work
They inhibit the metabolism of levodopa in the periphery by blocking the enzyme COMT (Catechol Ortho-Methyltransferase) which breaks down dopamine. By itself it does nothing for Parkinson’s- it just enhances the levodopa; only for use with levodopa because it reduces the wearing off of levodopa.
Do not rapidly withdraw COMT inhibitors bc it may lead to
parkinsonian crisis
Review drugs that manage the acetylcholine in PD
What drug and MOA?
Amantadine – MOA: inhibit dopamine uptake, stimulate dopamine release, block cholinergic receptors.
Amantadine- Used for antiviral (flu), early mild/moderated Parkinson’s disease- ___________________________________________________
Used for antiviral (flu), early mild/moderated Parkinson’s disease- tremors, rigidity, and to treat dyskinesia associated w carbidopa/levodopa
Anticholinergic drugs like benztropine , biperiden, procyclidine, and trihexyphenidyl inhibit choleric effects, meaning it ____ ____ activity leading to a decrease in _________. Used for ______ and ______- (cogwheeling- resistance to passive movement) and to control _______ (______)
Anticholinergic drugs like benztropine, biperiden, procyclidine, and trihexyphenidyl inhibit choleric effects, meaning it blocks PNS activity leading to a decrease in acetylcholine. Used for tremors and rigidity- (cogwheeling- resistance to passive movement) and to control sialorrhea (drooling)
Anticonvulsant drugs
Phenytoin, Carbamazepine (Tegretol), Valproic acid, Fosphenytonin,
newer drugs including gabapentin, lamotrigine, topiramate, levetiracetam.
& ethosuximide
Pt. teaching with anticonvulsants (drugs for epilepsy/seizures)
1) consistent drug dosing; 2) will/may be monitoring of plasma drug level; 3) maintain seizure frequency chart!
Phenytoin (Dilantin)- The generic and the trade…
Cannot be interchanged
Phenytoin (Dilantin) uses
-Complex partial seizures
-Tonic-clonic seizures
Phenytoin (Dilantin) has a what therapeutic range
Narrow therapeutic range (10-20 mcg/mL)- outside of that causes CNS toxicity
Phenytoin (Dilantin)- symptoms seen with abnormal therapeutic ranges
20-30 = nystagmus
30-40 = ataxia
>40 = dec. level of consciousness
remember normal is 10-20 mcg/mL
What category is Phenytoin (Dilantin) for pregnancy
–Cat D (teratogenic)
Phenytoin (Dilantin) adverse effects
- Nystagmus - Diplopia
- Sedation - Cognitive impairment
- Ataxia
- Hirsutism
- Gingival hyperplasia – 20%
- to minimize: teach brushing, flossing, gum massage; dental visits
- Skin reactions: rash! Stevens-Johnson, toxic epidermal necrolysis (TEN) – higher in Asian population!
- Pregnancy –Cat D (teratogenic)
- CV effects: hypotension & dysrhythmias (Class III antiarrhythmic)
- Interferes with Vitamin D & K metabolism
What class is Phenytoin (Dilantin) for dysrhythmias
(Class III antiarrhythmic)
Phenytoin can cause what syndrome with IV push
- Can cause “purple glove syndrome” which is a discoloration that occurs if a nurse gives phenytoin by IV push- avoid IV push
Pt. teaching/ drug-drug interactions of Phenytonin
- Effect of drug is reduced when taken with: phenobarbital, carbamazepine, rifampin, antacids, gingko, ETOH, “azole” drugs (Recall Cytochrome P450)
- May reduce effectiveness of oral contraception pills, corticosteroids, anticoagulants, levodopa, thyroid hormone,
Teach to monitor for infection bc it could cause hematological disorders like thrombocytopenia or leukopenia
Don’t suddenly withdraw the drug- seizures may occur
Tegretol uses
- Partial & generalized tonic-clonic seizures (50% used)
- Mixed seizure types
- Complex partial seizures (DOC)
- Relieves pain r/t trigeminal neuralgia
- Bipolar disorder
Therapeutic blood level of Tegretol
8-12 mcg/ml
Considerations of Tegretol (one big one to focus on)
- Shake oral suspension well before measuring the dose
- NG tube – mix the dose w/ equal volume of H2O, NS, or D5W -> then flush w/ 100 of diluent
- Give with meals
- Monitor for S/E - diplopia, blurred vision, N/V, leukopenia which is checked q 3-6 mo.
- Can cause SIADH -> monitor Na+ (big thing to be aware of- otherwise the rest are like dilatin)
- Contraindication if glaucoma, cardiac or renal, or hepatic disease
Pt teaching of Tegretol
- Do not drink ETOH
- Do not drink grapefruit juice or eat grapefruit
- Can depress bone marrow – watch for s/s infection, bleeding
- Can cause photosensitivity – protect against sun burns, no tanning beds
- Watch for low sodium - headache, confusion, slurred speech, severe weakness, feeling unsteady
Valproic acid uses
- Absence seizures
- Myoclonic seizures
- Tonic-clonic seizures
- Partial seizures
- Neonatal seizures
- Prevent Migraine headaches
- Bipolar disorder (manic depression)
- Therapeutic blood level of valproic acid
50-100 mcg/ml
- valproic acid: pregnancy category…
Pregnancy category X
Review use of fosphenytoin
generalized seizures and status epilepticus
c. Review newer drugs including gabapentin, lamotrigine, topiramate, levetiracetam (will have individual cards for this- just overview)
Gabapentin- used widely for neuropathic pain
Lamotrigine- Used for bipolar disorder and seizures; black box warning for Steven Johnson syndrome
Topiramate- Used for prevention of migraines, weight loss, and seizures
A/E= memory loss
Levetiracetam- Used for partial seizures and adjuvant for generalized, partial, myoclonic seizures; MOA: works by suppressing calcium channels which prevents impulse conduction across synapses
Gabapentin is used widely for
neuropathic pain
Lamotrigine- Used for
bipolar disorder and seizures; black box warning for Steven Johnson syndrome
Topiramate- Used for; a/e?
Used for prevention of migraines, weight loss, and seizures
A/E= memory loss
Levetiracetam- Used for; MOA
works by suppressing _________ _________ which prevents ______ _____ across ___________
Levetiracetam- Used for partial seizures and adjuvant for generalized, partial, myoclonic seizures; MOA: works by suppressing calcium channels which prevents impulse conduction across synapses
used widely for neuropathic pain
Gabapentin
Used for bipolar disorder and seizures; black box warning for Steven Johnson syndrome
Lamotrigine
Used for prevention of migraines, weight loss, and seizures
A/E= memory loss
Topiramate
Used for partial seizures and adjuvant for generalized, partial, myoclonic seizures; MOA: works by suppressing calcium channels which prevents impulse conduction across synapses
Levetiracetam
Review use of ethosuximide and when it is used.
Drug of choice for absence seizures
OVERALL PT TEACHING for Anticonvulsants (but alr highlighted it in beginning)
- Take the drug exactly as prescribed & don’t stop drug w/out HCP approval.
- Take drug w/ food to reduce GI upset & loss of appetite
- Don’t change brands or dosage forms bc they’ll be dosed differently
- Avoid hazardous activities that require mental alertness
- Wear medical alert bracelet or necklace
- Record & report any seizure activity while on drug
- Try to space activities throughout the day & allow rest periods to avoid fatigue, weakness, drowsiness. Caution w/ driving & handling heavy machinery
- Report persistent or bothersome adverse effects
- Be aware phenytoin may discolor urine pink, red, or red-brown
- Be aware that heavy ETOH use may diminish drug’s benefit
- Follow up w/ HCP as scheduled
- Perform oral hygiene & see a dentist for regular exams esp. if taking phenytoin or it’s derivate
- Most are either category C or D -> pregnancy
- Loss of Drivers License in TX: seizure-free 3 months on or off meds (non-commercial drivers only)
a. Important to know the difference between muscle spasms and spasticity. They are different.
What is muscle spasm?
involuntary contraction of muscle or muscle group; usually self-limiting
Important to know the difference between muscle spasms and spasticity. They are different.
What is spasticity?
abnormal muscle tightness due to prolonged muscle contraction. It is a symptom associated with damage to the brain, spinal cord, or motor nerves, and is seen in neurological conditions such as: spinal cord injury, multiple sclerosis, cerebral palsy.
* Muscles become stiff, resist being stretched, usually seen with increased DTRs
Summary of muscle spasms vs spasticity:
Muscle spasms-_________; we’ve all had them- it goes ____
Spasticity- usually something going on w spinal cord; connected to an injury/condition- _____ _____ go _____
Muscle spasms- temporary; we’ve all had them- it goes away
Spasticity- usually something going on w spinal cord; connected to an injury/condition- does not go away.
- Two groups of drugs that cause skeletal muscle relaxation:
One group for localized muscle spasm (antispasmodic):
- Diazepam (Valium)
- Tizanidine (Zanaflex)
Two groups of drugs that cause skeletal muscle relaxation:
- Other group for spasticity (antispastics)
- _______ (Lioresal)
*_______(Valium) - _______(Dantrium)
- ALL produce their effects through actions in the CNS except ________
- Baclofen (Lioresal)
- Diazepam (Valium)
- Dantrolene (Dantrium)
- ALL produce their effects through actions in the CNS except dantrolene
- Two groups of drugs that cause skeletal muscle relaxation
- One group for localized muscle spasm (antispasmodics)
- Diazepam (Valium)
- Tizanidine (Zanaflex)
- Other group for spasticity (antispastics)
- Baclofen (Lioresal)
- Diazepam (Valium)
- Dantrolene (Dantrium)
- ALL produce their effects through actions in the CNS except dantrolene
- Groups are not interchangeable… EXCEPT
- Diazepam tx both spasm & spasticity
Drugs to Manage Muscle spasms/ Spasticity:
Know about the centrally acting muscle relaxers including usage
Therapeutic use:
* Relieve local muscle spasm
* Decrease local muscle pain
* Increase range of motion (ROM)
* Neither drug better than the others
* Drug selection prescriber preference and patient response
* NOT for spasticity
Centrally acting muscle relaxers are meant for
- Meant for short-term use; 2-3 weeks at most- not for chronic use
Centrally acting muscle relaxer side effects
Generalized CNS depression – safety issues
* Drowsiness, dizziness; Tizanidine - hypotension
Severe reactions include:
* Allergic reactions
* Arrhythmias & bradycardia
Hepatic toxicity
* Tizanidine (Zanaflex) and metaxalone (Skelaxin) can cause hepatic damage.
* Chlorzoxazone (Paraflex) can cause hepatitis and necrosis.
Long term use of drug can lead to Physical dependence
* Abstinence syndrome – with chronic high-dose therapy
* potentially life-threatening abstinence syndrome with abrupt cessation
Less common:
* Abdominal distress, N/V, constipation or diarrhea, heartburn, ataxia
c. Review the drug baclofen including use, side effects:
Baclofen is the DOC..
Baclofen is the DOC for spasticity
Uses of Baclofen
- Therapeutic uses:
- Spasticity associated w/ spinal cord injury (paraplegic or quadriplegic)
- Multiple sclerosis
- Trauma
A/E of Baclofen
- Avoid abrupt discontinuation of intrathecal baclofen ->
-
Baclofen withdrawal
Classic symptoms of baclofen withdrawal are a sudden increase or return of your spasticity or tone, profuse sweating, and itching without an associated rash. You can also have fever, high heart or respiratory rate, high or low blood pressure or even confusion. Severe withdrawal symptoms include hallucinations or delirium, seizures, rhabdomyolysis, organ failure and even death.
d. Review the drug dantrolene including how it works, side effects.
MOA?
- Acts directly on skeletal muscle
- Suppresses the release of calcium from the sarcoplasmic reticulum (SR)
More about how dantrolene works:
- Appears to reduce the number of Ca++ ions released from the sarcoplasmic reticulum.
- The lower the calcium level in the muscle plasma or myoplasm, the less energy produced when calcium prompts interaction of the muscle’s actin & myosin filaments.
- Less energy means a weaker muscle contraction
- Reducing rigidity, halting hyperthermia
- By promoting muscle relaxation, dantrolene prevents or reduces the rigidity that contributes to the life-threatening body temperature of malignant hyperthermia
Use of Dantolone- it treats…
- Tx for malignant hyperthermia- potentially fatal condition also caused by succinylcholine and general anesthetics
A/E of Dantolone
- Hepatic toxicity – can prolong half life
- Muscle weakness
- Drowsiness
- Diarrhea
- Acne-like rash
S/S of malignant hyperthermia:
(alot
- Dramatic rise in body temp
- Rigid or painful muscles, esp. in the jaw
- Flushed skin
- Sweating
- Rapid or irrgegukar HR
- Brown urine
- Very low BP (shock)
- Confusion
- Muscle weakness or swelling after the event
Risk for malignant hyperthermia
Many people who carry a gene for malignant hyperthermia will never develop symptoms
How is it managed? (malignant hyperthermia)
Termination of inhaled gas, Dantrolene IV, quick cooling w ice
Be aware that several anticonvulsants are used to manage bipolar disorder:
Bipolar depression- 3 drugs and psychotherapy (antipsychotic)
b. Carbamazepine
c. Valproic acid
d. Lithium
Lithium MOA
thought to regulate CNS catecholamine release by increasing norepinephrine & epinephrine uptake
Use of lithium (DOC for)
- Bipolar disorder: DOC for manic episodes & long-term prophylaxis & preventing suicide
As far as our kidneys are concerned, sodium and lithium are the ____. Lithium ___ When sodium is ____ (kidneys may confuse lithium for sodium and ___ when sodium is low)
As far as our kidneys are concerned, sodium and lithium are the same. Lithium decr. When sodium is decr. (kidneys may confuse lithium for sodium and hold when sodium is low)
Lithium- therapeutic range
Plasma levels – narrow therapeutic range, must monitor drug levels
* For the management of acute mania, a lithium serum level of ___ to ____mEq/L is usually required. Desirable long-term maintenance levels range between ___ and ___ mEq/L.
- Plasma levels – narrow therapeutic range, must monitor drug levels
- For the management of acute mania, a lithium serum level of 1 to 1.5 mEq/L is usually required. Desirable long-term maintenance levels range between 0.6 and 1.2 mEq/L.
Lithium- risk of toxicity increases when
when taking NSAIDS, thiazides, or loop diuretics: watch for diuretics that eliminate sodium, kidneys will keep lithium for ransom due to bodies release of sodium. Cause toxicity (keep Na range normal)
Pt. teaching: Lithium
- “Lithium is a simple salt and is similar to table salt. Salt consumption can cause fluctuations in serum lithium levels. While taking lithium, do not make sudden changes to your salt intake. A sudden decrease in sodium intake may result in higher serum lithium levels, while a sudden increase in sodium might prompt your lithium levels to fall. Discuss any changes to sodium intake with your doctor prior to making them.”
- Also – decreases in body fluid leading to
dehydration can result in lithium toxicity – so make sure to drink enough water
Adverse effects of Lithium:
- Early in tx: fatigue, HA, confusion, memory problems
_Poor conc.; impaired memory (HCP may need to titrate dose)
- Gastrointestinal - N/V
- Weight gain
- Hair loss
- Renal toxicity (diarrhea and dehydration)
- Acne
-Fine tremors, polyuria/thirst (teach to drink a lot of water), Goiter and hypothyroidism
Toxic effects of lithium
- Confusion, lethargy
- Slurred speech
- Increased reflex reactions (hyperreflexia)
- Seixures
Lithium pregnancy cat.
Tertogenesisis- Pregnancy Category D; discourage use in lactation
Abbreviation to remember lithium side effects
Leukocytosis
Insipidus (nephrogenic diabetes inspidius)
Tremor/Tertogenic (Epstein’s anomaly)
Hypothyroidism
Pt. teaching for lithium:
- Take the drug w/ 2-3 liters of _____/day & after meals to minimize GI upset
- Lithium has a narrow therapeutic margin of safety
- A blood level that’s even slightly high can be dangerous
- Watch for s/s of toxicity including diarrhea, vomiting, tremor, drowsiness, muscle weakness, & ataxia.
- _____ one dose of drug and call HCP if toxic symptoms appear. Don’t stop drug abruptly
- Expect transient nausea, polyuria, thirst, & discomfort the first few days of therapy
- Avoid ______ that require alertness & good psychomotor coordination until the drug’s CNS effects are known
- Don’t switch brands or take other prescription or OTC drugs w/out HCP approval
- Wear or carry medical identification
- Take the drug w/ 2-3 liters of water/day & after meals to minimize GI upset
- Lithium has a narrow therapeutic margin of safety
- A blood level that’s even slightly high can be dangerous
- Watch for s/s of toxicity including diarrhea, vomiting, tremor, drowsiness, muscle weakness, & ataxia.
- Withhold one dose of drug and call HCP if toxic symptoms appear. Don’t stop drug abruptly
- Expect transient nausea, polyuria, thirst, & discomfort the first few days of therapy
- Avoid activities that require alertness & good psychomotor coordination until the drug’s CNS effects are known
- Don’t switch brands or take other prescription or OTC drugs w/out HCP approval
- Wear or carry medical identification
