Distinguished future physicians welcome to
Stomp on Step 1 the only free video series that helps you study more efficiently by focusing
on the highest yield material. I’m Brian McDaniel and I will be your guide
on this journey through Psychiatric Medications. This is the 9th video in my playlist covering
all of Psychiatry for the USMLE Step 1 medical board exam. I already covered antidepressants in the previous
video so this video will just cover Antipsychotics, Mood Stabilizers and Anxiolytics. We will start with Antipsychotics. I am giving the overall class a High Yield
Rating of 9 on a scale from 1 to 10 based on a number of factors including how frequently
these types of questions have appeared on retired Step 1 questions. When you break down the topic further you
can see by far the most important material is the side effects related with these medications. So make sure you focus your studying on the
adverse reactions. We will start with a quick review of some
material from my previous video on psychosis. Symptoms of schizophrenia can be broken down
into 2 categories, Positive and Negative Symptoms. Positive symptoms include behaviors or sensations
that are not normally present. Examples include hallucinations, delusions,
and catatonia. These symptoms are thought to be related to
an excess of dopamine. I remember this by remembering that “doPamine
has a P in it”. So P for Positive and P for Dopamine. Negative symptoms are the absence of normal
behavior. Examples include a lack of initiative, diminished
speech, disheveled appearance & flat affect. These symptoms are thought to be related to
an excess of serotonin. As we will see antipsychotics affect dopamine
and serotonin to varying levels. The indications for this class of drugs includes
psychosis (mainly schizophrenia), Mania (mainly bipolar disorder), aggression and Tourette's
disease. Here is the list of the highest yield antipsychotics. I’ve included the trade name for some of
them just for your reference, but remember the exam will only include generic names. The Typical Antipsychotics (AKA 1st Generation
Antipsychotics or Neuroleptics) include Haloperidol, Fluphenazine, Thioridazine & Chlorpromazine. Most of them end in “Azine.” Atypical Antipsyhcotics (AKA Second Generation
Antipsychotics) include Risperidone, Aripiprazole, Quetiapine, Olanzapine, and Clozapine. Most of them end in “Apine.” Typical Antipsychotics primarily block dopamine
receptors in a non-specific manor. Therefore, these drugs work best for positive
symptoms, and have little effect on negative symptoms. The non-specific mechanism of the drug also
means there are lots of side effects. Some of these medications come in a slow release
injectable form so they can be used in non-compliant and aggressive patients. There are a lot of high yield side effects
so we will break them down one by one Neuroleptic Malignant Syndrome (or NMS) is
a rare but potentially fatal adverse reaction of typical antipsychotics. It involves fever, altered mental status,
rigidity and autonomic instability (such as tachycardia, hypertension, diaphoresis etc.). You may also see elevated myoglobin in blood
or urine and elevated Creatine Kinase (CK). One of the ways I think about it is that it
looks kinda sorta like Serotinin Syndrome that you can see with antidepressatns. If you see this you have to emergently stop
the medication, provide supportive care and consider adding Dantrolene (Think DOWN-trolene) Extrapyramidal Symptoms (or EPS) are due to
blockage of Nigrostriatal dopamine. It can present with a number of different
symptoms. Akasthisia is a general sensation of restlessness
Acute Dystonia is involuntary continuous muscle contractions often of the neck. Another common presentation of acute dystonia
is Oculogyris Crisis when your eyes get locked looking upward and you have to lean over to
see Dyskinesia (AKA Pseudoparkinsonism) presents
like Parkinson’s Disease with symptoms like a pill rolling tremor, cogwheel rigidity & bradykinesia
(or slow movement) Tardine Dyskinesia (or TD) is uncontrollable
facial tics, grimacing & tongue movements As scary as these symptoms may look, they
are generally not medical emergencies. In most cases you will continue to use the
drug with perhaps a reduction in the dose or the addition of an anticholinergic mediation
like Benzatropine or Diphenhydramine. Tardive Dyskinesia is the exception and requires
cessation of the medication as it can be permanent. Usually you would switch a patient with TD
to a 2nd gen antipsychotic. Hyperprolactinemia is a side effect due to
Blockage of Tuberoinfundibular dopamine. It presents just like any other disease that
increases prolactin. So you can have galactorrhea, gynecomastia,
decreased libido and menstrual irregularities. These are not tested as often, but typical
antipsychotics can also cause QT Interval Prolongation & Anticholinergic effects such
as sedation, orthostatic hypotension, dry mouth, constipation etc. Atypical Antipsychotics (AKA 2nd Generation
Antipsychotics) block dopamine and serotonin receptors meaning they treat positive and
negative symptoms. They also may have improved specificity which
limits side effects when compared to typical antipsychotics. They are largely used as first line medications
instead of the 1st generation antipsychotics. You can still get all of the same side effects
as you do with the typical antipsychtoics, but at least in theory they should be much
less common. In particular Risperidone has a side effect
profile closer to the typical antipsychotics as it has EPS and hyperprolactinemia more
commonly than the other 2nd gens. Clozapine and Quetiapine are the least like
the typicals as they essentially never have EPS or high prolactin. So if you are using a typical antipsychotic
and have to switch meds based on the side effects, Quetiapine is probably your best
option. Like some of the 1st Gens, most of the 2nd
Gen Antipsychotics also commonly have sedation as a side effect. QT prolongation is another side effect seen
in both classes. It is especially common in Ziprasidone. There are also side effects that are unique
to Atypical Antipsychotics. One of them is Metabolic Syndrome (diabetes,
weight gain, hyperlipidemia etc.). So patients on atypical antipsychotics should
have their weight, blood pressure, blood glucose and lipids monitored regularly. Olanzapine & clozapine are the worst for causing
metabolic syndrome so they should be avoided in patients who have diabetes or obesity. Ziprasadone and Aripiprazole cause metabolic
syndrome less than the other 2nd gens. Clozapine is the “prototype” for the atypical
antipsychotics as it was the first one developed and has higher efficacy. However, it isn’t used nearly as much as
the others because it causes agranulocytosis and seizures. This drug is usually reserved as a last resort
if the other options don’t work. Patients on Clozapine needs to have a CBC
very frequently to monitor for agranulocytosis. If a low WBC count is found the medication
needs to be discontinued to prevent life threatening infections. Mood Stabilizers are a group of medications
that help to steady and/or prevent intense mood swings. These medications are used primarily for Bipolar
Disorder and Schizoaffective Disorder. Many antipsychotic medications can have a
mood stabilizing effect. They are a first line treatment for mania
when there are psychotic features and/or you need a fast onset of action. However, when we use the term Mood Stabilizer
we are generally talking about Lithium and anticonvulsants rather than antipsychotics. Mood Stabilizers require gradual titration
and take about 1 week to kick in so they are not as useful in the acute setting. However, for long term treatment they are
often the treatment of choice for Bipolar Disease. A combination of an antipsychotic and a mood
stabilizer is often used for Bipolar Disorder as it usually works better than monotherapy
for acute management and relapse prevention. Lithium is the first line mood stabilizer
according to most guidelines and textbooks, but in practice many psychiatrists use other
medications first due to better side effect profiles and other considerations that make
it easier to prescribe. Lithium has a narrow therapeutic window which
means dosing can be difficult and requires close monitoring with Lithium Blood Levels
(which correlate with efficacy). The mechanism of Lithium is not very well
understood. Lithium Toxicity (AKA Lithium Overdose) may
occur acutely from intentional or unintentional large doses of lithium or chronically from
a prescribed lithium dose that was not properly titrated. It can present with nausea/vomiting, diarrhea,
tremors, altered mental status, incoordination, and seizures. If these symptoms arise the Lithium treatment
should be discontinued immediately to prevent fatal consequences. Lithium is a teratogen that causes cardiac
deformation in the fetus so it should not be used in anyone who is or may become pregnant. Lithium commonly causes Hypothyroidism. They love to write questions about that. Lithium is nephrotoxic and can cause Nephrogenic
Diabetes Insipidus (thirst, polyuria etc.). This is another super high yield point
Before you start the medication and regularly after initiation you should get a pregnancy
test, thyroid level and creatinine test to monitor for the onset of side effects. That brings us to Anticonvulsants. Some, but not all, epilepsy drugs can be used
as mood stabilizers. This includes Valproate or Valproic Acid,
Carbamazepine and Lamotrigine. These drugs are known to be hepatotoxic so
regular liver function tests (LFTs) should be performed. A CBC should also be checked as these drugs
can have hematologic effects such as Thrombocytopenia. Valproate or Valproic Acid is the most commonly
used anticonvulsant for Bipolar Disorder. It is associated with spina bifida, so you
have to give folate to patients if they are trying to get pregnant. It is also associated with pancreatitis. Carbamazepine& Lamotrigine are alternatives. They are associated with rashes and severe
hypersensitivity reactions like Stevens Johnson Syndrome. They can also lead to an increased metabolism
of the hormones is oral contraceptives and unintentional pregnancies. This is obviously a bad thing considering
the drug is also a teratogen. Next up is Anxiolytics. This is a group of medications that relieve
or abort anxiety. SSRIs and SNRIs are considered first line
pharmacologic treatment for Generalized Anxiety and Panic Disorder. We discussed these types of medication in
depth in our previous video on antidepressants, and most of them do have anxiolytic properties. The only real difference is that higher doses
are usually needed to treat anxiety than depression. Cognitive Behavioral Therapy has similar efficacy
to SSRIs/SNRIs and is also considered a first line treatment. The best treatment option may be a combination
of an antidepressant with CBT. The downside to both of these 1st line options
is that they take about a month to start working. Buspirone is another good anxiolytic while
Benzos and TCAs are considered second line medications. Beta Blockers (like propranolol) are not true
anxiolytics, but they can help mask some of the symptoms of anxiety such as palpitations. Buspirone (or Buspar) is another treatment
option to consider for GAD, but it does not work for Panic Disorder. It is a non-benzo anxiolytic that functions
by acting as a partial serotonin agonist. It does not have the risk of dependence, abuse,
or withdrawal like Benzos and does not have nearly as much sedation. However, Buspirone does take a couple weeks
to kick in. Benzos usually end in “Zepam” or “Azolam.” They are broken down into short acting, intermediate
acting and long acting groups. However, short acting Benzos aren’t used
as much and are lower yield for the exam so I haven’t listed them. The highest yield intermediate acting benzos
are Lorazepam, Alprazolam & Temazepam. The most important long acting benzodiazepines
are Clonazepam & diazepam. Benzodiazepines increase the effects of Gamma-Aminobutyric
Acid (AKA GABA, an inhibitory neurotransmitter) by increasing GABAs affinity for the receptor
and increasing the frequency of the Cl channel opening. Benzodiazepines are great at aborting acute
anxiety and panic attacks quickly. They have a much faster onset of action than
other anxiolytics. However, Benzos don’t work very well to
prevent anxiety and panic attack prophylactically. Perhaps the best use for Benzos is in addition
to an SSRI or SNRI. You can start both together and then after
about a month when the antidepressant has started working you can taper off the Benzo. Benzos are largely considered safe for short
term use, but long term use is very controversial due to the risk of abuse, dependence, sedation
and withdrawal. These medications are generally contraindicated
in those with a history of substance abuse, and use in elderly populations should be limited
due to the increased level of risk of adverse events. Scheduled long acting doses are preferred,
because as needed use of short acting benzos has a higher risk for psychologic dependence. My last video in the Psych section was on
substance abuse and discussed things like Benzo overdose and withdrawal, so go watch
that one if you haven’t already. I have also already covered the use of benzo
for alcohol withdrawal so I won’t cover that here. Later when I make the neuro videos I will
cover things like the use of Benzos for seizures or status epilepticus. Benzos also have action as Hypnotic medications
and can be used for the short-term treatment of insomnia. However, their use should be limited to a
few weeks duration due to the risk of dependence. It is preferred that Benzos be used intermittently
and at the lowest effective dose. Higher doses of Benzos are needed for a Hypnotic
effect when compared to anxiolytic action. There are also non-benzo hypnotics that are
at least in theory safer options for long term use. This would include drugs like Lunesta and
Ambien, but this topic is very low yield for the Step 1 exam so I will skip it. That brings us to the end of the video. If you found it useful please click on this
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be taken to the table of contents page which will list the different sections I have covered. Thanks so much and good luck studying.
