L16: Pharmacotherapy Flashcards
Dopamine Pathways
Classification of AntiPsychotic Drugs
what are synonyms of AntiPsychotic Drugs?
- Neuroleptic drugs.
- Anti-schizophrenic drugs.
- Major tranquilizers.
- Dopamine receptor antagonists.
what does low potency mean?
Needs high dose to reach the therapeutic effect.
Form of most AntiPsychotic Drugs
tablets (others may also be injectable e.g. Haloperidol)
Compare Between Typical Antipsychotics and Atypical Antipsychotics in terms of:
- Mechanism
- Effect
- Excretion of drug
- Discontinuation
- Metabolic SE
- Prolactin
- Extrapyramidal SE
MOA of AntiPsychotics
Therapeutic Uses (indicatios) of AntiPsychotics
Pharmacological Effects of AntiPsychotics
Precaustions of using Antipsychotics
Aspects of Adverse effects of Antipsychotics
- CNS
- ANS
- GIT
- Skin & Eye
- CVS
- Hematologic
- Endocrine
- Extrapyramidal
- NMS
CI of AntiPsychotics
These drugs are contraindicated in:
1. Hypersensitivity
2. CNS depression
3. Blood dyscrasias
4. Parkinson’s disease
5. Liver, renal, or cardiac insufficiency
CNS Adverse effects of Antipsychotics
Results of anti-histaminic activity of antipsychotics
- Sedation
- Weight gain
ANS Adverse effects of Antipsychotics
GIT Adverse effects of Antipsychotics
- Nausea
- Gl upset
Skin & Eye Adverse effects of Antipsychotics
CVS Adverse effects of Antipsychotics
- Hypotension due to a adrenergic blocking action
- Reflex tachycardia & arrythmia
- ECG: Q-T prolongation and T wave suppression
Hematologic Adverse effects of Antipsychotics
Agranulocytosis - associated with: Clozapine (order CBC for follow up)
Endocrine Adverse effects of Antipsychotics
Symptoms of Pseudo-parkinsonism
tremor, shuffling gait, drooling, rigidity
EPS effects of Antipsychotics
- Pseudo-parkinsonism
- Akinesia
- Akathisia
- Dystonia
- Oculogyric crisis
- Tardive dyskinesia
TTT of Pseudo-parkinsonism
Anticholinergics
Symptoms of Akinesia
muscular weakness
Symptoms of Akathisia
continuous restlessness and fidgeting
TTT of Akathisia
Propranolol / Benzodiazepine
Symptoms of Dystonia
involuntary Painful Sustained muscular movements [spasms] of face, arms, legs, and neck
TTT of Dystonia
- Anticholinergic injection / Benzodiazepines
Def of Oculogyric crisis
uncontrolled rolling back of the
TTT of Oculogyric crisis
Oral Anticholinergic
Def of Tardive dyskinesia
Abnormal Choreoathetoid writhing movements of the tongue, face, and body
Incidence of Tardive dyskinesia
More common in women and after at least 6 months of treatment
Prognosis of Tardive dyskinesia
Rarely reversible
TTT of Tardive dyskinesia
substitute atypical antipsychotic agent, e.g.: CLOZAPINE
Symptoms of Neuroleptic malignant syndrome
- Severe parkinsonian muscle rigidity
- Hyperpyrexia up to 107° f
- Tachycardia, Tachypnea, Fluctuations in blood
pressure, Diaphoresis - Rapid deterioration of mental status
- Stupor and coma
- Lab shows: elevated liver renal function, myoglobin, WBC, CPK
- Mortality Rate 20%
TTT of Neuroleptic malignant syndrome
- Stop Antipsychotic Medications (first step in management)
- Adjust general conditions (adequate fluids & vital signs)
- Specific agents: Dantrolene (muscle relaxant), Bromocriptine (Dopaminergic Agonist)
Evolution of Extra Pyramidal Symptoms (EPS) side effects
- 4 hours acute dystonia (muscle spasm, stiffness, oculogyric crisis)
- 4 days akinesia (parkinsonian symptoms)
- 4 weeks akathisia (restlessness)
- 4 months Tardive dyskinesia
SE of Olanzapine /Clozapine
May cause significant weight gain.
SE of Chlorpromazine
Corneal deposits
SE of Thioridazine
Retinal deposits.
SE of Risperidone
One of atypical antipsychotics causing hyperprolactinemia and EPS
SE of Aripiprazole
Commonly cause akathisia
Characters of Clozapine
- Usually used in: Resistant schizophrenia & Tardive dyskinesia
- Has antisuicidal effect
SE of Clozapine
Side effects:
* Agranulocytosis (requires weakly WBC monitoring)
* Myocarditis
* Risk of seizure (if more than 300mg)
* Hypersalivation
* Metabolic syndrome
Def of Mood Stabilizing Agents
Any medication that is able to decrease vulnerability to subsequent episodes of mania or depression; and not exacerbate the current episode or maintenance phase of treatment.
Classification of Mood Stabilizing Agents
Antimanic: Lithium carbonate
Anticonvulsants: Carbamazepine, Clonazepam, Valproic acid, Lamotrigine, Gabapentin & Topiramate
Antipsychotics (atypical)
MOA of Lithium Carbonate
Exact mechanism is unknown, however it probably works by:
- Accelerating presynaptic reuptake and destruction of catecholamine.
- Inhibiting the release of catecholamine
- Decreasing postsynaptic serotonin receptor sensitivity
indication of Lithium Carbonate
- Acute mania
- Prophylaxis for bipolar and unipolar mood disorder
- Schizoaffective disorder
- Cyclothymia
- Impulsivity and aggression
- Others like: bulimia nervosa, trichotillomania, cluster headache, borderline personality disorder.
Dosage of Lithium Carbonate
900-2100 mg in 2-3 divided dose.
Blood Lithium levels of Lithium Carbonate
- Therapeutic level 0.8-1.2 mEq/litre
- Prophylactic level 0.6-1.2 mEq/litre
- Toxic lithium level >1.5-2 mEq/litre
CI & precautions of Lithium Carbonate
- Hypersensitivity
- Cardiac or renal disease
- Dehydration
- Sodium depletion
- Brain damage
- Pregnancy and lactation.
- Caution with thyroid disorders, diabetes, urinary retention, history of seizures, and with the elderly
SE of Lithium Carbonate
Lithium Toxicity
Symptoms at serum levels of lithium 1.5 to 2.0 mEq/L
- Blurred vision
- Ataxia
- Tinnitus
- Persistent nausea and vomiting
- Severe diarrhea
Symptoms at serum levels of lithium 2.0 to 3.5 mE/L
- Excessive output of dilute urine
- Increasing tremors
- Muscular irritability
- psychomotor retardation
- Mental confusion
- Giddiness
Symptoms at serum levels of lithium ≥ 3.5 mEq/L
- Impaired consciousness
- Nystagmus
- Seizures
- Coma
- Oliguria/ anuria
- Arrhythmia
- Myocardial infarction
- Cardiovascular collapse
Nursing management to avoid side effects of lithium
What are anticonvulsants used in mood managment?
- Carbamazpine
- Valproic Acid
- Lamotrigine
Indications of Carbamazepine
Especially useful in:
1. treating mania with mixed features
2. rapid-cycling bipolar disorder
* Less effective for the depressed phase.
Monitoring in Carbamazepine
CBC and LFTs must be obtained before initiating treatment and regularly monitored during treatment
MOA of Carbamazepine
- Acts by blocking sodium channels and inhibiting action potentials. (exact mechanism is unknown)
osnet of Carbamazepine
Onset of action Is 5-7 days (quicker than lithium)
SE of Carbamazepine
MOA of Valproic acid
Multiple mechanisms of action:
1. Blocks sodium channels
2. Increases GABA concentrations in the brain.
Indications of Valproic acid
Useful in treating acute mania, mania with mixed features, and rapid cycling.