Neurological Drugs and Disorders

• Neurological disorders result in physical, cognitive, emotional, and behavioral symptoms, for example, pain, confusion, mood changes, and/or coordination difficulties.
• The goal of therapy is to correct nervous system alterations, manage symptoms with nervous system medications

The Nervous System

• The nervous system is divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
• The CNS is the body's master control unit, while the PNS links the body to the outside world.

The Central Nervous System

• The CNS is composed of the spinal cord and the brain.
• The spinal cord is a column of nerves located between the brain and the peripheral nervous system.
• The brain connects to the spinal cord through the brainstem.
• The brain is divided into three major parts: the hindbrain (lower part), midbrain, and forebrain.

The Peripheral Nervous System

• The autonomic nervous system (ANS) and the somatic nervous system (SNS) make up the PNS
• The autonomic nervous system regulates involuntary bodily processes like heart rate, respiration, digestion, and pupil contraction, which operates automatically without conscious direction.
• The somatic nervous system carries sensory information from sensory organs to the CNS, relays motor commands to muscles, and controls voluntary movements.
• The autonomic nervous system includes the sympathetic and parasympathetic nervous systems.
• The sympathetic nervous system prepares the body for action and stress, also known as the "fight or flight" response.
• The parasympathetic nervous system calms the body and helps conserve energy.
• The parasympathetic stimulation constricts pupils, stimulates saliva flow, slows heart rate, constricts bronchi, stimulates stomach, pancreas, intestines, stimulates bile release and contracts bladder.
• The sympathetic stimulation dilates pupils, inhibits saliva flow, accelerates heart rate, dilates bronchi, stimulates stomach, pancreas, intestines, converts glycogen to glucose, secretes adrenaline and inhibits bladder contraction.

Medications for Neuro Conditions

• Muscle Relaxants
• Seizure Disorders
• ADHD
• Parkinson's
• Alzheimer's
• Multiple Sclerosis
• Migraines

Muscle Relaxants

• Muscle relaxants are classified into centrally acting types and peripherally acting types.
• Muscle relaxants are used for relief of painful conditions like back spasms, trauma, spinal cord injury, as well as control of spasticity of chronic conditions like multiple sclerosis and cerebral palsy.

Centrally Acting Relaxants

• Baclofen is the prototype for centrally acting relaxants.
• Centrally acting relaxants work in the CNS to reduce muscle hyperactivity by acting as a Gamma-aminobutyric acid (GABA) agonist
• Centrally acting relaxants have CNS depressant effects like dizziness, drowsiness, and orthostatic hypotension.
• Baclofen can be administered intrathecally (into the spine), through a pump
• Clients should not take Baclofen with MAOIs, alcohol, or other CNS depressants due to hypotension and CNS depression.

Peripherally Acting Relaxants

• Dantrolene is the prototype for peripherally acting relaxants.
• Peripherally acting relaxants act directly on skeletal muscles by inhibiting calcium release, which is needed for muscle contraction.
• Peripherally acting relaxants have a high potential for liver toxicity.
• Clients taking peripherally acting relaxants should avoid alcohol and other CNS depressants.
• Peripherally acting relaxants are contraindicated for clients older than 35 taking estrogen and clients taking a calcium channel blocker.

Seizure Disorders

• Seizure disorders medications are classified as traditional antiepileptic drugs (AEDs) and new AEDs.

AEDs: Hydantoins

• Phenytoin is the prototype for hydantoin AEDs.
• Phenytoin suppresses the sodium intake in hyperactive neurons to control tonic-clonic seizures (grand mal).
• Phenytoin has CNS depressant effects.
• Gingival hyperplasia is an expected side effect of Phenytoin
• An adverse reaction to Phenytoin is a skin rash, which may indicate Stevens-Johnson Syndrome (SJS).
• Phenytoin reduces the effectiveness of oral contraceptives.
• Phenytoin IV injections should be administered slowly, and blood levels should be monitored (10-20 mcg/ml).

AEDs: Other

• Carbamazepine (Tegretol) is the prototype medication.
• Carbamazepine has the same mode of action as Phenytoin.
• Carbamazepine is used for partial seizures and also as a mood stabilizer for bipolar disorder.
• Side effects of carbamazepine include neurological issues such as visual disturbances, headache, ataxia, nystagmus, and blurred vision, as well as fluid retention and skin rash.
• Monitor for bone marrow suppression by checking CBC, fever, sore throat, easy bruising.
• Carbamazepine decreases the effectiveness of oral contraceptives.

ADHD

• Attention Deficit Hyperactivity Disorder (ADHD) classifications include Amphetamines and Methylphenidate.
• ADHD is a neurodevelopmental disorder affecting both children and adults.
• ADHD is characterized by signs such as difficulty with focus, hyperactivity, and impulsivity.

Amphetamines/ADHD

• Amphetamine/dextroamphetamine is the prototype medication
• Amphetamines increase the release of norepinephrine and dopamine.
• Amphetamines act as CNS stimulants to improve mood, focus, attention span, and reduce impulsivity and distractibility.
• Side effects of amphetamines include weight loss, tolerance/dependence, and risk of toxicity (psychosis). Closely monitor weight in children.
• Amphetamines are classified as Schedule II controlled substances.
• Abruptly stopping amphetamines can lead to abstinence syndrome, characterized by severe exhaustion, hypersomnia, and depression.
• Amphetamines are contraindicated with MAOIs due to the risk of hypertensive crisis.

Methylphenidate/ADHD, narcolepsy

• Methylphenidate (Ritalin, Concerta) is the prototype medication.
• Methylphenidate has the same action and effects as amphetamine as a CNS stimulant.

Parkinson's Disease (PD)

• Classifications for Parkinson's Disease medications include Dopamine replacement, Dopamine receptor agonists, and MAO-B inhibitors.
• Parkinson's disease (PD) occurs when brain cells that produce dopamine stop working or die.
• Parkinson's disease can cause tremors, slowness, stiffness, and walking and balance problems, therefore it is called a movement disorder; it is a lifelong and progressive disease.

Dopamine Replacement Drugs (PD)

• Levodopa/carbidopa is the prototype medication
• Levodopa is absorbed in the intestine; the brain converts it to dopamine, which powers normal movement.
• The decrease in dopamine causes Parkinson's disease (PD).
• Carbidopa prevents levodopa from turning into dopamine before it reaches the brain and limits levodopa's side effects.
• Adverse effects of levodopa/carbidopa may darken sweat/urine and cause dyskinesias (early on).
• Orthostatic hypotension is also an adverse effect of levodopa/carbidopa
• It can take up to 6 months to achieve a response.
• Clients must avoid high-protein foods.

Dopamine Receptor Agonists (PD)

• Pramipexole is the prototype medication.
• Dopamine receptor agonists bind to dopamine receptors to mimic dopamine.
• Side effects are similar to levodopa/carbidopa, also causing drowsiness ("sleep attacks").
• Muscle weakness can also occur, creating a risk for falls.

Monoamine Oxidase Type B (MAO-B) inhibitors (PD)

• Selegiline is the prototype medication.
• MAO-B inhibitors are used as an adjunct to L/C to manage the symptoms of Parkinson's disease.
• MAO-B inactivates domaine, so MAO-B inhibitors makes more dopamine available to the brain, therefore enhancing the effectiveness of L/C.
• Major adverse effects of MAO-B includes insomnia, ingesting foods that contain tyramine (aged cheeses, processed meats) can cause hypertensive crisis when high doses are given.
• MAO-B inhibitors interacts with many different types of drugs.

Alzheimer's (AZ)

• Classifications for Alzheimer's disease medications include Cholinesterase inhibitors and NMDA receptor agonists.
• Alzheimer's disease (AZ) begins building of proteins in the form of amyloid plaques and neurofibrillary tangles.
• AZ is the most common cause of dementia, and it causes brain cells to die over time, leading to serious memory loss and the inability to do everyday tasks.
• There is no cure for Alzheimer's disease.

Cholinesterase Inhibitors/AZ

• Donepezil (Aricept) is the prototype medication
• Cholinesterase inhibitors increases the amount of acetylcholine available in the brain with low levels of acetyl
• Side effects of cholinesterase inhibitors include GI symptoms (including GI bleeding) and CNS effects like insomnia, dizziness, and headache.
• Syncope and bradycardia are adverse effects; monitor HR.
• Ensure caregiver is present when giving instructions.

NMDA receptor antagonist/AZ

• Memantine is the prototype medication
• NMDA receptor antagonists reduce intracellular calcium, which restores normal nerve transmissions and prevents damage from high levels of CA
• CNS effects include dizziness, headache, confusion, and constipation.
• Ensure caregiver is present when giving instructions.

Multiple Sclerosis (MS)

• Immunomodulators are the only class of drugs for Multiple Sclerosis (MS)
• MS is an autoimmune disease that causes breakdown of the protective covering (myelin sheath) of nerves
• Can cause numbness, weakness, trouble walking, vision changes and other symptoms
• There is no cure for MS, other drugs are used to manage symptoms

Immunomodulators/MS

• Interferon beta-1a (Avonex, Rebif) and interferon beta-1b (Betaseron) are the prototype medications
• Immunomodulators inhibit the movement of leukocytes across the blood-brain barrier, which protects the myelin sheath from further damage
• Given by injection
• Monitor blood counts for thrombocytopenia and neutropenia.
• Should not be given with any other drug that suppresses the immune system like prednisone.

Migraines

• Serotonin agonists (triptans) are used for migraine
• Other drugs include beta blockers, tricyclic antidepressants, antiepileptics, estrogens and analgesics

Serotonin Agonists/Migraine

• Sumatriptan (Imitrex)are the prototype medications
• Promotes vasoconstriction and suppression of the inflammatory response that occurs with migraines
• Chest heaviness and anginal pain are common side effects
• Monitor vitals because of the risk of vasospasm of the coronary arteries
• Should never give for clients with coronary artery disease, MI, severe hypertension, peripheral vascular disease (because of the vasoconstriction action)
• St. John's wart may cause sumatriptan toxicity

This content covers neurological disorders, their symptoms (physical, cognitive, and behavioral), and treatment, especially the use of neurological drugs like levodopa/carbidopa. It also addresses nursing interventions for medication management.