Neurological Drugs

1. Neurological Drugs Dr. Kathy Ham

2. Neurological Disorders Antiseizure Drugs Anorexiants Autonomic Nervous System Drugs Adrenergics Antiadrenergics Cholinergics Anticholinergics

3. Antiseizure Drugs Also called antiepileptic drugs or anticonvulsants The term seizure and convulsion may be used interchangeably Drugs can usually control the seizure activity but do not cure the underlying disorder

4. Mechanism of Action Decrease CNS stimulation and prevent the excessive electrical discharge of the seizure focus in the CNS Also exert a protective effect on surrounding cells to prevent their discharge

5. Indications Prevention or treatment of seizures, especially chronic recurring seizures of epilepsy Indications for particular drugs depend on the type of seizure Also used to stop acute tonic-clonic seizures and status epilepticus Some may be used to treat bipolar disorder and chronic neuropathic pain Prophylactic use in patients with injury or other neuro problem predisposing to seizures

6. Contraindications In patients with CNS depression Hypersensitivity reaction Caution in hepatic or renal dysfunction Caution in pregnancy due to teratogenic effect in animals

7. Side/Adverse Effects Slurred speech Ataxia Confusion Dizziness Drowsiness Nausea/vomiting Cardiac dysrhythmias

8. Classes of Drugs Barbiturates- CNS depressants Produce sedation, hypnosis, or respiratory depression Phenobarbital is the most useful as an anticonvulsant One of the safest for long-term use as an anticonvulsant

9. Classes of Drugs Hydantoins- used to prevent and treat seizures Reduce spontaneous electrical impulses in the brain Less sedation than barbiturates but have more adverse effects phenytoin (Dilantin) is the prototype Keep serum levels between 5-20 mcg/ml

10. Classes of Drugs Benzodiazepines- limit the spread of seizure electrical discharges from point of origin Cause CNS depression Drug interactions due to CNS depression diazepam (Valium) and lorazepam (Ativan)

11. Individual drugs phenytoin (Dilantin)-Prototype fosphenytoin (Cerebyx) carbamazepine (Tegretol) clonazepam (Klonopin) phenobarbital valproic acid (Depakene)

12. Nursing Care Assessment of seizure/seizure disorder Labs- serum drug levels Minimize seizures- teach patients to identify conditions and take precautions Teach about individual drugs, safety precautions, and adverse effects Always stress importance of not missing medication Teach to have MedicAlert bracelet or other ID Question closely about other medications/herbal therapy- may interact and alter effectiveness of anticonvulsant

13. Lifespan Considerations Pregnancy- all are considered teratogenic Use in children Rates of metabolism and excretion are higher so require higher doses Some are not approved in children Use in the elderly Assess for other meds and impaired liver or renal function May need to start with reduced dose and gradually increase to desired effect

14. Anorexiants (Stimulant Drugs) Sympathomimetics used to reduce appetite for weight loss Also used to treat narcolepsy and ADD/ADHD Chemically and pharmacologically related to amphetamine Long term use can result in addiction

15. Types of Stimulants Amphetamines- MoA- increase neurotransmitter levels- mood elevation, increased mental alertness, increased work productivity, and prolonged wakefulness methylphenidate (Ritalin), atomoxetine (Strattera), amphetamine mixture (Adderall) Amphetamine-related drugs- same MoA as above dexmethylphenidate (Focalin)

16. Types of Stimulants Analeptics- infrequently used- acts as respiratory stimulant doxapram (Dopram) Xanthines- stimulate cerebral cortex- increases mental alertness and decreases drowsiness and fatigue Caffeine theophylline (Aminophylline, Theodur)

17. Individual Drugs amphetamine- narcolepsy, ADHD dextroamphetamine (Dexedrine)- narcolepsy, ADHD methamphetamine (Desoxyn)- ADHD in children methylphenidate (Ritalin, Ritalin SR, Concerta)- ADHD amphetamine mixture (Adderall)- ADHD and narcolepsy atomoxetine- Strattera

18. Contraindications CNS stimulants can cause cardiac stimulation- may cause problems for patients with angina, dysrhythmias, hypertension Also contraindicated in anxiety disorders, glaucoma, or hyperthyroidism Usually contraindicated in history of drug abuse

19. Nursing Care Assess use of stimulant and depressant drugs Assess caffeine intake In child with suspected ADD/ADHD- assess behavior as thoroughly as possible Assess behavior for signs of tolerance and abuse of these drugs Assess for signs of toxicity- increased nervousness, hypertension, headache

20. Nursing Care For a child- assist parents in scheduling drug administration- send information to teacher Teach about side effects- suppressed appetite, insomnia, weight loss Schedule appointments to evaluate growth and nutritional information Lab tests- CBC, serum lead level

21. Lifespan Considerations Use in children Not recommended if under 6 yrs Patient/family/school teaching Use in the elderly Slowed metabolism and excretion may cause toxicity May have CV disease- could aggravate Reduced doses are recommended

22. Autonomic System Drugs Adrenergics Antiadrenergics Cholinergics Anticholinergics

23. Adrenergics Also called sympathomimetics- produce effects similar to those produced by stimulation of the sympathetic nervous system Such as neurotransmitters (endogenous) Have multiple effects on body systems

24. Mechanism of Action Effect depends on the type of receptor activated- alpha, beta, or both Alpha stimulation- constricts vessels, raises BP, speeds heart rate, decreases nasal congestion Beta stimulation- increased cardiac output, increased heart rate, bronchodilation, vasodilation, uterine relaxation

25. Indications Used for effects they exert on heart, blood vessels, and bronchi Often used in emergency situations in the treatment of cardiovascular, respiratory, and allergic disorders May be used to decrease uterine contractions

26. Contraindications Cardiac dysrhythmias Angina pectoris Glaucoma Hyperthyroidism Second stage of labor

27. Individual Drugs epinephrine (Adrenalin) norepinephrine (Levophed) ephedrine pseudoephedrine (Sudafed) isoproterenol (Isuprel) phenylephrine (Neo-Synephrine) dopamine (Intropin)

28. Patient Teaching Alert doctor about taking these drugs- take no other drugs or herbal supplements until cleared by doctor Monitor vital signs and cardiac status Don�t use decongestants longer than 3 to 5 days EpiPen- learn to administer if needed Monitor glucose level carefully if diabetic

29. Antiadrenergic Drugs Also called sympatholytic drugs Decrease or block the effects of sympathetic nerve stimulation, endogenous catecholamines, and adrenergic drugs

30. Mechanism of Action Work at receptors to decrease or block sympathetic activity Alpha adrenergic blockers- inhibit the release of norepinephrine Beta adrenergic blockers- occupy beta receptor sites

31. Indications Alpha blockers- hypertension Beta blockers- angina pectoris, cardiac tachydysrhythmias, hypertension, myocardial infarction, congestive heart failure, and glaucoma

32. Contraindications Alpha blockers- Hypersensitivity to the drugs Active liver disease Beta blockers- Bradycardia Heart block Asthma, allergic responses with bronchoconstriction

33. Individual Drugs Alpha blockers- clonidine (Catapres) doxazosin (Cardura) Beta blockers- propranolol (Inderal) metoprolol (Lopressor)

34. Patient Teaching Based on therapeutic and side effects of various drugs Always alert doctor if on other drugs, even OTC or herbal therapy and dietary supplements Have BP checked regularly Report adverse effects Don�t stop abruptly Learn to count pulse and know norms

35. Cholinergic Drugs Stimulate the parasympathetic nervous system in the same manner as acetylcholine Also called parasympathomimetics

36. Mechanism of Action Combine with receptors in cardiac muscle, smooth muscle, exocrine glands, and the eye to: Decrease heart rate Vasodilate Increase tone and contractility in GI smooth muscle Relax sphincters Increase salivation and GI secretions Increase tone and contractility of bladder smooth muscle Increase tone and contractility of bronchial smooth muscle Increase respiratory secretions Constrict pupils

37. Indications Urinary bladder atrophy Abdominal distension due to paralytic ileus Myasthenia gravis diagnosis and treatment Alzheimer�s disease Reverse effects of neuromuscular blocking agents in surgery

38. Contraindications Urinary, GI tract obstruction Asthma Peptic ulcer disease Coronary artery disease Hyperthyroidism Pregnancy Inflammatory abdominal conditions

39. Individual Drugs bethanechol (Urecholine) neostigmine (Prostigmin) donepezil (Aricept)

40. Patient Teaching Cautions for specific drugs Atropine is the antidote Report increasing muscle weakness, difficulty breathing to physician- also abdominal cramps, diarrhea, excessive oral secretions If for bladder dysfunction, have bathroom available Wear MedicAlert bracelet

41. Anticholinergic Drugs Also called cholinergic blocking and parasympatholytic agents

42. Mechanism of Action Occupy receptor sites at parasympathetic nerve endings Blocks the ability of acetylcholine to bind at receptor sites Effects on the body: CNS stimulation followed by depression Increased heart rate Bronchodilation and decreased respiratory secretions Antispasmodic effects in GI tract Dilates pupils, paralyzes ciliary muscles Decreased body secretions, such as sweat and saliva Relaxation of bladder and ureters

43. Indications Reduce intestinal spasms Reduce urinary spasms For eye exams For bronchodilation To increase heart rate Parkinson�s disease to control salivation, spasticity, and tremors Before surgery to prevent vagal stimulation and reduce respiratory tract secretions

44. Contraindications Any condition that would be aggravated by the drug Hiatal hernia or reflux esophagitis

45. Individual Drugs atropine ipratropium (Atrovent) scopolamine oxybutynin (Ditropan)

46. Patient Teaching Alert doctor to other drugs or agents Prevent heat exhaustion and heat stroke Good dental hygiene Beware of blurred vision High fiber diet