PSYCHOPHARMACOLOGY.docx

PSYCHOPHARMACOLOGY:

AUTONOMIC NERVOUS SYSTEM Sympathetic Nervous S ystem (SNS)  “Fight” or aggression response  Also termed adrenergic or parasympatholytic response  The neurotransmitter for the SNS is norepinephrine Al l b o d y a c t i vi t i e s a r e I N C R E AS E D except GIT!  increased blood flow to brain, heart and skeletal muscles: These are the most important organs during times of stress  increased BP, increased heart rate: To maintain perfusion to vital organs  bronchodilation and increased RR: To increase oxygen intake  urinary retention  FLUID VOLUME EXCESS Fluids are withheld by the body to maintain circulating volume  pupillary dilation: MYDRIASIS: To increase environmental awareness during aggression  decreased GIT activity: CONSTIPATION and DRY MOUTH: Blood flow is decreased in the GIT because it is the least important area in  times of stress DRUGS WITH SNS effects:  Adrenergic/Parasympatholytic agents:  Epinephrine [Adrenalin]  Antipsychotics:  Haloperidol [Haldol], Chlorpromazine [Thorazine], etc.  Side effect of Thorazine: Atopic Dermatitis (eczema) and foulsmelling odor [recall: patients in NCMH are smelly]  Side effect of all antipsychotics: Sx of PARKINSON’S DISEASE, therefore antipsychotics are given together with antiparkinson drugs

Parasympathetic Nervous S ystem (PNS)  “Flight” or withdrawal response  Also termed cholinergic or sympatholytic response  The neurotransmitter for the PNS is acetylcholine (Ach) Al l b od y ac ti vi ties are D E C R E AS E D e x c e p t G I T !  normalized blood flow to vital organs  decreased BP, decreased heart rate  bronchoconstriction, decreased RR  urinary frequency  FLUID VOLUME DEFICIT  pupillary constriction: MIOSIS [this is the correct spelling, not meiosis ]  Increased GIT: DIARRHEA and INCREASED SALIVATION

DRUGS WITH PNS effects:  Anti-hypertensives:  Methyldopa – for pregnancy induced hpn (PIH)  -blockers (-olol):  Propranolol [Inderal], atenolol, metoprolol  ACE inhibitors (-pril):  Enalapril, Ramipril, Lisinopril, Benazepril, Captopril  Side effect of ACE inhibitors: AGRANULOCYTOSIS and NEUTROPENIA (blood dyscracias… always asked in

 Anti-parkinsonians:

 Cogentin, Artane, etc. drug:  Atropine Sulfate (AtSO4) – given before surgery to decrease salivary and mucus secretions

 Pre-operative



board!)  Calcium channel blockers (Calcium antagonists)  Nifedipine [Procardia], Verapamil [Isoptim], Dialtiazem [Cardizem]  NURSING ALERT: Antihypertensives are not given to patients with CHF or cardiogenic shock (Drug will cause a further decrease in heart rate  Death)  Rx for Myasthenia Gravis:  Pyridostigmine [Mestinon]  Neostigmine [Prostigmin]

ANTIPSYCHOTIC DRUGS:  Antipsychotic Drugs, also known as neuroleptics, are used to treat symptoms of psychosis such as delusions and hallucinations.  Mechanism of action: They work by blocking receptors of neurotransmitter dopamine. CATEGORIES OF ANTIPSYCHOTIC DRUGS: Typical Antipsychotic  are potent antagonists  Target the positive signs of schizophrenia, such as delusion, hallucinations, disturbed thinking and other psychotic symptoms, but have no observable effect on the negative signs  Produces many EPS Atypical Antipsychotics  Both dopamine and serotonin antagonists.  Atypical antipsychotics not only diminish psychotic symptoms, but for many clients they also lessen the negative signs such as lack of motivation, social withdrawal and anhedonia  Has a lower incidence of EPS Side Effects:  EXTRAPYRIMIDAL SYMPTOMS (EPS) - are serious neurologic symptoms that are major side effects of antipsychotic drugs. Therapy for EPS includes lowering the dosage, changing to different antiosychotic meds or administering anticholinergic medication.









 Dystonia – includes muscles rigidity and cramping, a stiff or thick tongue with difficulty swallowing, and in severe cases laryngospasm and respiratory difficulties.  Pseudoparkinsonianism – symptom resemble those of Parkinson’s disease.  Akathasia – reported by client as an intense need to move out. Client appears agitated, restless, anxious, with rigid posture and lack of spontaneous gesture. NEUROLEPTIC MALIGNANT SYNDROME – potentially fatal, idiosyncratic reaction to an antipsychotic drug. Major symptoms of NMS are - rigidity, high fever, autonomic instability, such as unstable blood pressure, diaphoresis and pallor, delirium and elevated level of enzymes particularly CPK. TARDIVE DYSKINESIA – a syndrome of permanent, involuntary movements, is most commonly caused by the long – term use of typical antipsychotics.  It includes involuntary movements of tongue, facial and neck muscles, upper and lower extremities and truncal musculature. Anticholinergic side effects often occur with the use of antipsychotics and include orthostatic hypotension, dry mouth, constipation, urinary hesitance or retention, blurred near vision, dry eyes, photophobia, nasal congestion and decreased memory. Clozapine - agrunolocytosis Sympathetic increase dilate decrease decrease dilate constrict increase Epinephrine/ Norepinephrine

Pulse rate Bronchus GI GU Pupils Blood Vessels BP

Anticholinergic: Cholinergic:

symphatetic effects parasymphatetic effects

ANTICHOLINERGIC SIDE EFFECTS ANTI

A – nxiety P – sychosis C – holinergic D – epressant D - opaminergic

Parasympathetic decrease constrict increase increase constrict dilate decrease Acetylcholine

INTERVENTIONS FOR ANTICHOLINERGIC SIDE EFFECTS:  Dry mouth – use ice chips or hard candy for relief  Blurred vision – Assess side effect, which should be improve with time; report if no improvement  Costipation – Increase fluid and dietary fiber intake, may need a stool softener if unrelieved  Urinary retention – Instruct client to report any frequency or burning with urination; report if no improvement overtime  Orthostatic Hypotension – Instruct client to rise slowly from sitting or lying position; wait to ambulate if no longer dizzy or light headed INTERVENTIONS FOR OTHER SIDE EFFECTS:  Seizures – stop medication and notify the physician; protect client from injury during seizure; provide reassurance and privacy for the client after seizure  Sedation – Caution about activities requiring client to be fully alert, such as driving a car  Photosensitivity – avoid sun exposure; when in the sun, wear protective clothing and sun blocking lotion.  Agranulocytosis – drug must be discontinued immediately if WBC count drops from 50% or less than 3,000 -have blood samples taken weekly to monitor WBC ANTIDEPRESSANT DRUGS:  Antidepressant drugs are primarily used in the treatment of major depressive illness, panic disorder and other anxiety disorders, bipolar depression, and psychotic depression.  Mechanism of action: not completely understood, but somehow interact with two neurotransmitters – serotonin and norepinephrine.  Antidepressants are divide into four groups:  Tricyclic and related cyclic antidepressant  Selective serotonin reuptake inhibitors(SSRIs)  Monoamide oxidase inhibitors (MAOIs)  Other antidepressants sucha s venlafaxine, bupropion, trazodone and nefazodone.  Side effects of SSRIs: anxiety, agitation, akathasia, nausea, insomnia and sexual dysfunction, and specifically diminished sexual drive or difficulty achieving and erection or orgasm.  Less common side effects includes: sedation, sweating, diarrhea, hand tremors and headaches.  Side effects of MAOis: daytime sedation, insomnia, weight gain, dty mouth, orthostatic hypotension and sexual dysfunction.  Side effects of Cyclic Antidepressants: it blocks anticholinergic receptors resulting in anticholinergic effects such as dry mouth, constipation, urinary hesitancy or retention, dry nasal passages and blurred near vision.

MOOD STABILIZING DRUGS  Mood Stabilizing Drugs are used to treat bipolar affective disorder by stabilizing the clients mood, avoiding or minimizing the highs and lows that characterize bipolar illness, and by treating acute episode of mania.  Lithium is the most common used mood stabilizer.  Mechanism of action: lithium normalizes the reuptake of certain neurotransmitters such as serotonin, norepinephrine, acetylcholine and dopamine. It also reduces the release of norepinephrine through competition with calcium. Lithium produces its effects intracellularly rather than within neuronal synapses, acting directly on the G proteins and certain subenzymes.  Side effects: mild nausea, or diarrhea, anorexia, fine hand tremor, polydipsia, polyuria, a metallic taste in the mouth and fatigue or lethargy. Weight gain and acne are side effects that occur alter in lithium therapy.  Toxic effects includes: severe diarrhea, drowsiness, muscle weakness and lack of coordination. ANTIANXIETY DRUGS: (ANXIOLYTICS)  Antianxiety Drugs (anxiolytics), are used to treat anxiety and anxiety disorders, insomnia, OCD, depression, post traumatic stress disorder and alcohol withdrawal.  Benzodiazepines have proved to be the most effective in relieving anxiety and are the drugs most frequently prescribed.  Mechanism of action: Benzodiazepines mediate the action of the amino acid GABA, the major inhibitory neurotransmitter in the brain. Because GABA receptor channels selectively admit the anion chloride into neurons, activation of GABA receptor hyperpolarizes neurons and can lead to overuse of these drugs.  Side effects: CNS depression such as drowsiness, sedation, poor coordination and impairment of memory or clouded sensorium. When used for sleep, clients complain of next day sedation or hang over side effect. STIMULANTS:  Stimulants, specifically amphetamines were first used in the treatment of psychiatric disorders in the 1930s for their pronounced effects of CNS stimulation.  Dextroamphetamine (Dexedrine) have been widely abused to produce a high or to remain awake for a longer period of time.  Mechanism of action: amphetamine and methylphenidate are often termed indirectly acting amines because they act by causing release of the neurotransmitters from presynaptic nerve terminals, as opposed to having direct agonist effects on the postsynaptic receptors.  Today, the most common use of stimulants is for ADHD in children, residual attention deficit in older adults and narcolepsy  They also block the reuptake of these neurotransmitters. Methylphenidate produces milder CNS stimulation than amphetamines; pemoline primarily affects dopamine and therefore has less effect on the sympathetic nervous system.

 In ADHD, it was originally thought that it produce the reverse effect of most stimulants – a calming or slowing activity in the brain.  Side effects: anorexia, weight loss, nausea and irritabilty. Caffeine, sugar and chocolate should be avoided because they may worsen these symptoms.  Less common side effects are dizziness, dry mouth, blurred vision and palpitations. DISULFIRAM (ANTABUSE):  Disulfiram (Antabuse), is a sensitizing agent that causes an adverse reaction when mixed with alcohol in the body. These agents use is as a deterrent to drinking alcohol in persons receiving treatment for alcoholism.  Disulfiram inhibits the enzyme aldehyde dehydrogenase which is involve in the metabolism of ethanol. Side effects: fatigue, drowsiness, halitosis, tremor and impotence. It can also interfere with the metabolism of other drugs such as phenytoin, isoniazid, warfarin, barbiturates and long acting benzodiazepines.