Module 3: Neurologic and Neuromuscular Drugs Flashcards Preview

Introduction to Pharmacology > Module 3: Neurologic and Neuromuscular Drugs > Flashcards

Flashcards in Module 3: Neurologic and Neuromuscular Drugs Deck (20)
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1
Q

Types of Skeletal muscle relaxants

A
  • Centrally acting: through CNS

- Direct-acting: on muscle

2
Q

Types of Neuromuscular blocking drugs

A
  • Non-depolarizing

- Depolarizing

3
Q

Types of Anti-parkingsonian drugs

A
  • Anti-cholinergic
  • Dopaminergic
  • COMT inhibitors
4
Q

Anti-migraine drugs

A
  • 5-HT1-receptor agonists (triptans)

- Ergotamine preparations

5
Q

Skeletal Muscle Relaxants work to?

Name and describe the 2 Classes:
-Centrally acting?

-Direct-acting?

A

Relieve musculoskeletal pain, spasm, spasticity

  • Act as CNS depressants (diazepam, baclofen, cyclobenzaprine)
  • produce muscle weakness (dantrolene)
6
Q

Centrally Acting
-Mechanism?

-Adverse Effects

A
  • unknown; don’t directly relax skeletal muscle or depress neuronal conduction; are CNS depressants (sedatives, anti-anxiolytics ((antianxiety))
  • physical, psychological dependence; withdrawl symptoms
7
Q

Direct-acting

Drantrolene is the?

Mechanism:

A
  • most commonly used
  • interferes with calcium ions involved in skeletal muscle contraction➡muscle relaxation/ weakness; little effect on cardiac, smooth muscle
8
Q

Neuromuscular Blocking Drugs do what?

Name and describe the two classes:

  • Non-depolarizing:
  • Depolarizing:
A
  • relax skeletal muscles by disrupting transmission of nerve impulses at motor end plate
  • derived from curare alkaloids [atracurium, mivacurium, tubocurarine]
  • [succinylcholine]
9
Q

A Motor End Plate is?

A

a terminal nerve ending that innervates muscle (instead of another nerve). Nerve impulse releases acetylcholine (ACH) into synaptic cleft to bind receptors on adjacent MUSCLE.

10
Q

Non-depolarizing blocking
-Derived from?

-Compete with acetylcholine ➡ muscle contracted prevented➡

Antidote:

A
  • curare alkaloids (South American Indians used on arrow tips; paralyzes diaphragm (can’t breath, die)
  • prolonged muscle relaxation…but…doesn’t cross blood-brain barrier….so remain conscious, can feel pain, just paralyzed
  • anti-cholinesterase drugs [neostigmine, pyridostigmine]
11
Q

Adverse side effects of Non-depolarizing blocking

A
-non-depolarizing blockers adverse effects
apnea
hypotension
skin reactions
bronchospasm
excessive bronchial/salivary secretions
12
Q

Depolarizing Blocking
-act like acetylcholine, but not 4

  • Succinylcholine:
  • Adverse Effects:
A
  • but not inactivated by cholinesterase
  • Only therapeutic drug in this class; metabolized slower than acetylcholine➡ longer muscle paralysis
  • prolonged apnea, hypotension; genetic prediposition increases risk.
13
Q

Anti-Parkinsonian Drugs:

Parkinson’s disease:

Therapy:
-Anti-cholinergic inhibit?

-Dopaminergics: enhance?

A
  • dopamine deficiency, acetylcholine excess ➡ movement disorders (muscle rigidity, akinesia, temors at rest, posture/balance disturbances)
  • inhibit cholinergic effects (movement disorders) [benztropine, diphenhydramine]
  • enhance dopamine effects 9sustain motor activity) [levodopa, carbidopaomocriptine, amantadine]
14
Q

Parkinson’s drugs

  • Anti-cholinergic(parasympatholytic) drugs inhibit?
  • High acetylcholine excites?
  • Adverse Effects
A
  • inhibit acetylcholine action at parasympathetic receptors
  • CNS causing parkinsonian termor
  • confusion, restlessness, agitation and excitement, drowsiness and insomnia, tachycardia and palpitations, constipation, nausea, vomiting, urine retention, increased intraocular pressure, blurred vision, pupil dilation, photophobia
15
Q

Parkinson’s drugs: dopaminergic drugs

  • Dopaminergic drugs:
  • Levodopa:
  • Carbidopa:
A
  • act in brain to improve motor function
  • inactive until crosses blood-brain-barrier and converted to dopamine
  • enhances levodopa’s effectiveness by blocking peripheral conversion, increasing amount into brain.
16
Q

Dopaminergic adverse evects [levodopa]

A
  • nausea, vomiting
  • orthostatic hypotension
  • anorexia
  • neuroleptic malignant syndrome
  • arrhythmias
  • irritability
  • confuseion
17
Q

COMT Inhibitors

COMT =

-Used as?

Adverse effects:

Liver function test required?

A

=Catechol-O-methyltransferase

  • used as adjuncts to levodopa-carbidopa therapy in Parkinson patients who experience “wearing-off” symptoms at end of dosing interval
  • Life-threatening acute liver failure; rapid withdrawl may lead to parkinsonian crisis
  • Liver function test required every 2 weeks for 1st year, tapering thereafter.
18
Q

Anti-convulsant drugs:

Major drug names:

  • phenytoin:
  • phenobarbital:
  • carbamazepine
  • clonazepam, diazepam:
  • valproate:
  • Gabapentin:
  • Topiramate:
A

Inhibit neuromuscular transmission; prescribed for epilepsy, seizures; numerous adverse effects

  • phenytoin is a hydantoin, stabilizes nerves from over-excitement. Used to control seizures, called anticonvulsants, used after surgery to the brain or nervous system. Decreases abnormal electrical activity in the brain
  • phenobarbital is a barbiturate, elevates seizure threshold by decreasing post-synaptic excitation. treats insomnia and sedating antianxiety drug.
  • carbamazepine is an iminostilbene, inhibits neuromuscular transmission. treats seizures. is an anticonvulsant anti-epileptic drug
  • clonazepam is a benzodiazepine, safest, fewest side effects, has sedative pro[erties
  • valproate is a carboxylic acid derivative, thought to increase GABA (an inhibiory neurotransmitter). treats epilepsy and bipolar disorder and to prevent migraine headaches.
  • Gabapentin is an analogue of GABA; mechanism unknown. treat partial seizures, neuropathic pain, hot flashes, and restless legs syndrome.
  • topiramate thought to block voltage-dependent sodium channels, enhancing activity of GABA receptors and antagonizing glutamate receptors. control seizures, prevent migraine headache once occurs, off label to treat bulimia
19
Q

Anti-Migraine Drugs

2 types of treatment:

  • Abortive:
  • Prevention:

2 classes:
-5-HT1 -receptor agonists (triptans):

-Ergotamine preparations:

A
  • Abortive are for after migraine starts to relieve pain
  • Prevention are before migraines start
  • constrict ranial vessels, inhibit neuropeptide release, reduce neurogenic inflammatory process
  • less selective for 5-HT receptors; block neurogenic inflammation; effectivness increased with coffee [ergotamine]
20
Q

Triptans

  • Contraindications:
  • Safety?

Many?

A
  • not for use in patients with ischemic heart disease (angina, myocardial infarction), cerebro-vascular syndromes (stroke), coronary artery disease (hypertension, smoking, obesity, hypercholesterolemia, diabetes)
  • safety of treating 3+ migraines in 30-day period not established
  • Many drug interactions