Nervous System Disorder Treatment PDF

# Nervous system disorders - Pharmacological treatment ## Drug Therapy for Myasthenia Gravis, Alzheimer's Disease, and Other Conditions Treated with Cholinergic Agents **Myasthenia gravis** - Neuromuscular conditions characterized by disruptions in neurologic and autoimmune processes - Acetylchol...

# Nervous system disorders - Pharmacological treatment ## Drug Therapy for Myasthenia Gravis, Alzheimer's Disease, and Other Conditions Treated with Cholinergic Agents **Myasthenia gravis** - Neuromuscular conditions characterized by disruptions in neurologic and autoimmune processes - Acetylcholinesterase inhibitor drugs - **Prototype:** neostigmine - IV use only; also used as an antidote for tuborcurarine and skeletal muscle relaxants given during surgery; more commonly prescribed: pyridostigmine. - **Use:** diagnosis and treatment of Myasthenia gravis. - **Action:** acetylcholine builds up in the synapse; decreased heart rate, increased smooth muscle tone, increased salivary secretions. - **Adverse Effects:** cardiovascular effects, increased secretions. - **Contraindications:** renal and hepatic impairment, asthma, CV disease. **Alzheimer's Disease** - Most common form of dementia, deficiency in cholinergic function in the cortex and basal forebrain, neuropathologic hallmarks are neuritic plaques and neurofibrillary tangles, early symptom is difficulty remembering newly learned information, advanced symptoms: disorientation and mood and behavior changes; deepening confusion about events, time, and place; unfounded suspicions about family, friends, and professional caregivers; more serious memory loss and behavior changes; and difficulty speaking, swallowing, and walking. - **Alzheimer's Disease Drug Therapy** - Goal of therapy - Slow memory and cognition loss, preserve individual's independence for as long as possible. - **Cholinesterase inhibitors** - Reversible indirect-acting cholinergics. - **Prototype:** donepezil (Aricept); rivastigmine (Exelon). - **Action:** increases acetylcholine in the brain, slowing neuronal degradation. - **Uses:** delay progression of Alzheimers disease up to 55 weeks, enhances memory in MS. - **Adverse effects:** headache, dizziness, depression, vertigo, Gl disturbances, dyspnea in patients with past lung disease. - **Contraindications:** lung disease, or heart disease. - **N-methyl-d-aspartate receptor antagonist** - **Prototype:** memantine (Namenda). - **Action:** antagonizes the NMDA receptor. - **Uses:** slow progression of moderate to severe Alzheimer's disease. - **Contraindications:** renal failure. - **Urinary Retention** - **Causes:** Most common is a lack of nerve innervation (neurogenic bladder), others include diabetes, prostate enlargement, pregnancy, neurologic disorders such as multiple sclerosis or Parkinson's disease, and surgery with general anesthesia. - **Cholinergic agonist** - **Prototype:** bethanechol chloride (Urecholine). - **Action:** acts like acetylcholine, increase urinary and Gl muscle tone. - **Use:** acute postop for treatment of nonobstructive urinary retention, and neurogenic atony of the bladder. - **Adverse effects:** Heart block, orthostatic hypotension, Gl adverse effects, urinary urgency. - **Contraindications:** bladder neck surgery. ## Drug Therapy for Parkinson's Disease, Urinary Spasticity, and Disorders Requiring Anticholinergic Drug Therapy - **Parkinson's Disease:** A chronic, progressive, degenerative disorder of the CNS characterized by resting tremor, bradykinesia, rigidity, postural instability, Shuffling gait, stooped posture, masklike facial expression, soft-speaking voice. Initial: resting tremor that begins in fingers and thumb of one hand, pill-rolling movements. - **Dopamine Receptor Agonists:** Increase the amount of dopamine in the brain via various mechanisms. - **Prototype:** levodopa-carbidopa (Sinemet); Amantidine, pramipexole, ropinirole. - **Action:** increase dopamine in the synapse. - **Uses:** Parkinson's, Restless Leg Syndrome. - **Adverse effect:** headache, anxiety, hallucinations, drowsiness, CV effects. - **Contraindications:** glaucoma, severe hypertension, MAO inhibitors, severe cardiovascular, pulmonary, renal, hepatic, or endocrine disorders. - **Catechol-O-Methyltransferase Inhibitors** - **Prototype:** tolcapone - Increases dopamine levels in the brain. - **Action:** Inhibits levodopa metabolism. - **Use:** Treat s/s of idiopathic Parkinson's; Use only in conjunction with levodopa-carbidopa. Relieves symptoms effectively and consistently within 3 weeks or treatment is discontinued. - **Adverse Effects:** CNS, CV, GI, respiratory system. - **Contraindications:** liver disease, nontraumatic rhabdo. - **Anticholinergics** - Atropine, benztropine mesylate, glycopyrrolate, ipratropium bromide, dicyclomine hydrochloride, oxybutynin chloride, scopolamine hydrobromide. - **Action:** antispasmodic and antisecretory action. Effects in CNS, heart, smooth muscle, glands, eye. - **Use:** Idiopathic parkinsonism with minimal symptoms, patients intolerant of levodopa, used in combination therapy, relieve symptoms of extrapyramidal reaction, not effective for bradykinesia, decrease salivation, spasticity, and tremors. - **Contraindications:** Glaucoma, myasthenia gravis, Gl obstruction, prostatic hypertrophy, Urinary bladder neck obstruction, Cardiovascular disorders, Hepatic or renal disease, Elderly patients with cognitive impairments. - **Belladonna alkaloid** - **Atropine** - **Action:** depresses salivary and bronchial secretions. - **Use:** cardiac rate restoration. - **Adverse effects:** anticholinergic effects. - **Centrally acting anticholinergics** - **Benztropine mesylate (Cogentin)** - **Action:** suppresses secondary symptoms of parkinsonism - **Use:** Parkinsonian symptoms - **Adverse effects:** anticholinergic effects - **Contraindications:** glaucoma, GI & GU obstruction, CV disorders - **Gastrointestinal anticholinergics** - **Dicyclomine hydrochloride (Bentyl)** - **Action:** GI smooth muscle relaxant - **Use:** treat irritable bowel syndromes - **Adverse effects:** anticholinergic effects - **Contraindications:** glaucoma, asthma, GI & GU obstruction - **Urinary antispasmodics** - **Oxybutynin (Ditropan)** - **Action:** relaxes smooth muscle - **Use:** bladder instability, overactive bladder, incontinence, urgency, frequency. - **Adverse effects:** anticholinergic effects - **Contraindications:** ulcers, obstructions.