Pharmacology Specifics – First Generation Antipsychotics Flashcards
What are the 11 FDA approved indications for the use of antipsychotics?
Schizophrenia bipolar disorder major depressive disorder (adjunctive therapy) Tourette's syndrome severe behavioral problems hyperactivity anxiety hiccups acute intermittent porphyria Nausea/vomiting Tetanus
What are the seven non-FDA approved uses for antipsychotics?
Dementia (behavioral disturbances)
substance use disorder (reduction in use)
anorexia nervosa (increase body weight) obsessive-compulsive disorder
posttraumatic stress disorder
generalized anxiety disorder
What is the mechanism of action for both first and second generation antipsychotics with regard to dopamine receptors?
They block post-synaptic D2 dopamine receptors in the mesolimbic system, which has been associated with their antipsychotic effect
What is another name for antipsychotics?
Neuroleptics
How do the first generation and second generation antipsychotics differ in their mechanism of action on serotonin receptors?
First generation antipsychotics minimally antagonize serotonin receptors; whereas the second-generation antipsychotics have greater antagonism of serotonin receptors
The side effects associated with first and second generation antipsychotics are due to antagonism at which three types of receptors?
Histaminic, muscarinic, and Alpha-adrenergic receptors
Which generation of antipsychotics are more frequently associated with significant adverse side effects, such as extrapyramidal symptoms (EPS)? What is this due to?
First generation antipsychotics
This is due to their higher antagonism of D2 dopamine receptors
Thorazine
Chlorpromazine
Who makes all first generation antipsychotics?
Multiple generic manufacturers
Except Orap (pimozide) which is manufactured by Teva and brand-name only
What is the route and form of Thorazine? What is the recommended dosage per day?
PO, tablets
200-1000 mg per day
BID or TID
Prolixin
Fluphenazine
What is the route and form of Prolixin?
PO, IM
Tablets, liquid IM, acute IM, depot
What is the recommended PO, IM acute, and IM depot doses of Prolixin?
PO
0.5-20 mg per day,
Often given BID with doses larger than 10 mg
IM acute
5-10 mg Q6-8 hrs PRN
IM depot
12.5-25 mg Every 2 weeks
Haldol
Haloperidol
What route and forms does Haldol come in?
PO, IM
Tablets, liquid IM, acute IM, depot
What are the recommended PO, intramuscular acute, and intramuscular depot doses of Haldol?
PO: 0.5-20 mg per day
Intramuscular, acute: 5-10 mg Q6-8 hrs PRN
Intramuscular, depot: 50-200 mg given once monthly
What’s the difference between the intramuscular depot shot for Prolixin, and that for Haldol?
The dose for Prolixin is 12.5-25 mg, while the dose for Haldol is 50-200 mg
Haldol is given once monthly, while Prolixin is given every two weeks
Loxitane
Loxapine
Navane
Thiothixene
Which two first generation antipsychotics can be dispensed in capsule form?
Navane and Loxitane
What is the route of administration for Loxitane? What is the recommended daily dose?
PO
25-250 mg per day
What is the route of administration for Navane? What is the recommended daily dose?
PO
15-30 mg per day
Which is more expensive, Loxitane or Navane?
Loxitane
Trilafon
Perphenazine
Orap
Pimozide
Mellaril
Thioridazine
Stelazine
Trifluoperazine
What route and form are Trilafon, Orap, Mellaril, and Stelazine dispensed in?
PO; tablets
What is the recommended daily dose for Trilafon?
16-64 mg per day
What is the recommended daily dose for Orap?
1-10 mg per day
What is the recommended daily dose for Stelazine?
2-40 mg per day
What is the recommended daily dose for Navane?
15-30 mg per day
What is the recommended daily dose for Mellaril?
200-800 mg per day
Which first generation antipsychotic in tablet form is the cheapest?
Haldol
Which first generation antipsychotics in the tablet form is the second cheapest?
Prolixin
Which 2 first generation antipsychotic in the tablet form is the most expensive?
Orap and Trilafon
How should first generation antipsychotics be adjusted in patients with renal insufficiency or renal failure?
No dosage adjustment needed
With regard to pregnancy, what category are the first generation antipsychotics in?
Category C
How should the dosage of first generation antipsychotics be adjusted for patients with liver failure or liver disease?
They should be used with caution in patients with liver disease, especially chlorpromazine and perphenazine because they are both metabolized by the liver
What are the two options for the starting recommended dose of Thorazine?
10 mg
3-4 times per day
25 mg
2-3 times per day
How should Thorazine be increased?
One can increase by 20-50 mg per day
What is the maximum recommended dose of Thorazine per day?
400 mg
What is the recommended intramuscular dose of Thorazine?
Intramuscular dose is 25 mg
It can be repeated in 1 hour if needed
What’s the recommended starting oral dose of Haldol? How much should it be increased per day?
1 mg per day or twice daily
It should be increased by 1-2 mg per day
What’s the maximum recommended dose of Haldol per day?
100 mg per day
What’s the initial, recommended long-acting intramuscular dose of Haldol?
10-20 times the total oral dose
What should be done if the initial long-acting intramuscular dose of Haldol is greater than 100mg?
It should be administered in separate doses one week apart
After giving the initial dose, the following month, what dose of long-acting intramuscular Haldol should be given?
10-15 times the total oral dose
What’s the maximum, recommended, long-acting intramuscular dose of Haldol?
450 mg
What is the recommended starting dose of Orap? How should the dose be gradually increased?
The recommended initial dose is 1-2 mg per day in divided doses
The dose should be gradually increased every other day
What is the maximum recommended dose per day of Orap?
10 mg
What type of biogenetic testing should be done for doses greater than 4 mg with the use of Orap?
CYP2D6 genotyping should be done
What is the recommended starting oral dose for Navane? What is the maximum recommended dose per day?
1-2 mg per day in divided doses
The maximum dose is 60 mg per day
What is the intramuscular dose of Navane?
4 mg, 2-3 times per day
Maximum dose of 60 mg per day
What is the recommended starting oral dose of Stelazine? What is the maximum dose per day?
2-5 mg twice per day
The maximum dose is 40 mg per day divided doses
What is the recommended intramuscular dose of Stelazine? What is the maximum dose given per day?
An intramuscular dose of 1-2 mg can be given every 4-6 hours as needed
The maximum dose is 6 mg per day
What is the recommended starting dose of Prolixin? What is the maximum dose per day?
2.5-10 mg per day in divided doses every 6-8 hours
The maximum dose is 40 mg per day
What is the conversion from oral dosing to intramuscular dosing for Prolixin?
The intramuscular dose is 1.25 times the oral dose every 2-4 weeks
What is the recommended starting oral dose for Trilafon? What is the maximum recommended dose per day
4 mg, 2-4 times per day
The maximum dose is 64 mg per day
What is the recommended starting dose for Loxitane? How much should this medication be increased per day? What is the maximum recommended dose?
Starting dose is 10 mg twice per day
It should be increased by 10 mg per day
The maximum dose is 250 mg per day
What is the recommended starting dose for Mellaril? How much should it be gradually increased per day? What is the maximum dose recommended?
Starting dose is 50 mg, 3x per day
It should be gradually increased by 50 mg per day
The maximum dose per day is 800 mg
What are the 6 doses for the tablet option of Haldol?
0.5 mg, 1 mg, 2 mg, 5 mg, 10 mg, 20 mg
What is the dosage for the liquid form of Haldol?
2 mg/mL
120 mL bottle
What is the dose for acute intramuscular, depot Haldol administration?
5 mg/mL
1 milliliter vial
What are the dosing options for intramuscular, depot administration of Haldol?
50 mg/mL
5 mL multidose vial
100 mg/mL
1 mL vials
What are the 4 tablet options for the administration of Prolixin?
1 mg, 2.5 mg, 5 mg, 10 mg
What are the 2 options for liquid administration of Prolixin?
2.5 mg/5 mL
480 mL
5 mg/mL
120 mL
What is the acute dose of intramuscular administration of Prolixin?
2.5 mg/mL
10 mL vial
What is the dose for intramuscular, depot administration of Prolixin?
25 mg/mL
5 mL vial
What are the 2 tablet options for Orap?
1 mg, 2 mg
What are the 4 tablet options for, both, Stelazine and Navane?
1 mg, 2 mg, 5 mg, 10 mg
What are the 4 tablet dosing options for Trilafon?
2 mg, 4 mg, 8 mg, 16mg
What are the 4 tablet dosing options for Loxitane?
5 mg, 10 mg, 25 mg, 50 mg
What are the 4 tablet dosing options for Mellaril?
10 mg, 25 mg, 50 mg, 100 mg
What are the 5 tablet dosing options for Thorazine?
10 mg, 25 mg, 50 mg, 100 mg, 200 mg
Which are the two cheapest antipsychotic options for tablets?
Mellaril and Haldol
Which are the two relatively most expensive antipsychotic tablet options?
Orap and Trilafon
What is the recommended course of action for the use of chlorpromazine, loxapine, Pimozide, thioridazine, thiothixene, and Trifluoroperazine in geriatric patients?
Start a low dose, and gradually increase as needed while monitoring for side effects
What is the recommended course of action for the use of haloperidol in geriatric patients?
Start at 0.5 mg daily-twice per day
gradually increase to 2 mg, 3x per day if needed
The initial IM dose is 10-15 times the total oral daily dose
What is the recommended course of action for the use of Fluphenazine in geriatric patients?
Start at 1-2.5 mg per day and increase gradually
What is the recommended course of action for the use of perphenazine in geriatric patients?
Start at 2 mg, 2x per day and gradually increase as needed/tolerated
How should the first generation neuroleptics be adjusted for patients with renal insufficiency or renal failure?
No dosage adjustment needed
How should first generation antipsychotics be adjusted in patients with liver disease?
They should be used with caution in patients with liver disease
Which two first generation antipsychotics are known to be metabolized by the liver?
Chlorpromazine and perphenazine
What is the general recommendation for the use of first generation antipsychotics in a post partum mother who is breast-feeding?
Generally speaking, there is insufficient data for the use of first generation antipsychotics during nursing and breast-feeding should be avoided
Which two first generation antipsychotics are not recommended for patients less than 12 years of age?
Perphenazine and Thiothixene
Which medication has safety and efficacy that is not established in children?
Loxapine
What is the pediatric dosing for Haldol?
Starting dose is 0.05 mg per kilogram per day divided into 2-3 doses
increase by 0.5 mg per day weekly
What is the pediatric dosing for pimozide?
Starting dose is 0.05 mg per kilogram per day, which can be increased every third day with the maximum dose of 0.2 mg per kilogram per day not to exceed 10 mg per day
What is needed for doses of pimozide greater than 0.05 mg per kilogram in pediatric patients?
A GYP2D genotype
What is the pediatric dosing for fluphenazine?
0.25-0.75 mg,
1-4 times per day
What is the pediatric dosing for chlorpromazine?
Starting dose is 0.25 mg per pound Q4-6hrs PRN
Maximum dose is 200-400 mg per day
Intramuscular dose is 0.25 mg per pound every 6-8 hours PRN
What is the pediatric dosing for Trifluoroperazine?
Starting dose is 1 mg, 1-2 times per day
It can gradually increase to a maximum of 15 mg per day
Similar doses can be used for the intramuscular form
What type of adjustment needs to be made for first generation antipsychotic use in pediatric patients with renal disease?
No adjustment needed
Generally speaking, all the neuroleptics have a black box warning of increased mortality in elderly patients with what condition?
Dementia
Thioridazine and Pimozide also have a black box warning for what specific cardiac side effects?
QTC interval prolongation
Patients on IV haloperidol are at a higher risk for which two specific cardiac side effects?
QTC prolongation and torsades de pointes
What are the 15 most common side effects associated with first generation antipsychotic use?
EPS, orthostatic hypotension, dry mouth, increased sweating, photosensitivity, blurred vision, retinitis pigmentosa, epithelial keratopathy, constipation, tardive dyskinesia, akithesia, dizziness, sedation, parkinsonism, nasal congestion
What are 3 occasional side effects seen with first-generation antipsychotic use?
Prolonged QTC interval
Paralytic ileus
Obstipation
What are 12 rare side effects associated with first generation antipsychotic use?
Agranulocytosis, aplastic anemia, leukopenia, jaundice, neuroleptic malignant syndrome, priapism, seizure, lupus, torsades, jaundice, anaphylactic reaction, erythroderma photosensitivity, seizure
What is the bioavailability of fluphenazine in the oral form and intramuscular form?
Oral = 2.7%
Intramuscular = 100%
What is the bioavailability of chlorpromazine in the oral form and the intramuscular form?
Oral = 32%
Intramuscular = 100%
What is the bioavailability of perphenazine in the oral form and the intramuscular form?
Oral = 40%
Intramuscular = 100%
What is the bioavailability of pimozide in the oral form?
> 50%
What is the bioavailability of thioridazine in the oral form?
> 60%
What is the bioavailability of Haldol in the oral form and the intramuscular form?
Oral = 60-70%
Intramuscular = 100%
What is the bioavailability of loxapine, thiothixene, and trifluoperazine in the oral form?
100%
Where are all of the first generation antipsychotics metabolized?
In the liver
All of the first generation antipsychotics are excreted by the kidneys except for which specific one?
Trifluoperazine
It’s excreted via the feces
Aside from trifluoperazine, what two other first generation antipsychotics are also found to be excreted partially in the feces?
Loxapine and thioridazine
Which specific liver enzyme is responsible for metabolizing perphenazine?
CYP2D6
Pimozide, in addition to being metabolized by CYP2D6 is also metabolized in the liver by which two other specific enzymes?
CYP1A2
CYP3A4
What percentage of Haldol is bound to protein?
> 90%
What percentage of chlorpromazine is bound to protein?
90-99%
What percentage of fluphenazine and perphenazine is bound to protein?
91-99%
What percentage of Loxapine is bound to protein?
97%
What percentage of pimozide, thioridazine, thiothixene and trifluoperazine is bound to protein in the body?
99%
What is the half-life of chlorpromazine?
6 hours
What is the half-life of perphenazine?
9-12 hours
What is the half-life of trifluoperazine?
12 hours
What is the half-life of loxapine?
8 hours
What is the half-life of Haldol in the oral form?
14-37 hours
What is the half-life of thioridazine?
21-24 hours
What is the half-life of Fluphenazine in the oral form?
33 hours
What is the half-life of thiothixene?
34 hours
What is the half-life of pimozide?
55 hours
What’s the half-life of the long-acting intramuscular form of fluphenazine?
6-9 days
What’s the half-life for the long acting intramuscular form of Haldol?
3 weeks
What is the distribution of loxapine in the body?
Unknown
What is the distribution of Haldol in the body?
9.5-22 L per kilogram
What is the distribution of perphenazine in the body?
10-34 L per kilogram
What is the distribution of pimozide in the body?
10-46 L per kilogram
What is the distribution of thioridazine in the body?
18 L per kilogram
What is the distribution of chlorpromazine and trifluoperazine in the body?
160 L per kilogram
What is the distribution of fluphenazine in the body?
168-220 L per kilogram
Why are antipsychotics called neuroleptics?
Early researchers saw that these drugs “seized neurons”, causing motor and behavioral slowing in animals
Are there differences in efficacy among neuroleptics i.e., first and second generation antipsychotics?
Yes, there are small but significant differences in efficacy
Are there differences in side effects among the medications?
Yes, there are substantial differences
True or false: some second-generation antipsychotics can cause more adverse effects than first generation antipsychotics
True
What has research shown about the effectiveness of second-generation anti-psychotics vs. Haldol?
Some second generation antipsychotics are more effective than Haldol, which caused more EPS
What did an important multiple-treatment meta-analysis show regarding the use of clozapine vs. other neuroleptics?
The research showed that clozapine was significantly more effective than other neuroleptics
It also showed that amisulpride, olanzapine, and risperidone were the next most effective neuroleptics
Which first generation antipsychotic is associated with pigmentary retinopathy?
Thioridazine
Which first-generation antipsychotic is approved for the treatment of tics in Tourette syndrome?
Haldol
Besides haloperidol, what other first generation antipsychotic is approved for use in Tourette syndrome?
What is this other antipsychotic also used for off-label?
Pimozide
Also used off label for schizophrenia
Which first-generation antipsychotic needs to be discontinued gradually to avoid withdrawal symptoms?
Pimozide