Somatic tx and psychopharm Flashcards
(104 cards)
32 y.o. male admitted to a general hospital after ingesting unknown quantity of Phenylzine. After gastric lavage and administration of charcoal slurry, he is transferred to MICU for monitoring. 24 hours later, he begins to see horses running in the hall and pulls out his IV line. Which of the following treatments would be the most important at this time?
Phenelzine is MAOI –irrev blocker of both MAO-A and MAO-B activity. These medications are extremely dangerous in overdose nd after a brief asymptomatic period of 12-24 hrs may produce hyperpyrexia and autonomic excitability –> rhabdo. Supportive care should be instituted. If delirium develops, as seen here, small doses of IV benzo should be used. Lorazepam is preferred because of its short elimination half life.
12 days after his suicide attempt with phenelzine OD, your pt receives Venlafaxine to treat his depression. One hour after ingestion he becomes tachycardia, diaphoretic and develops myoclonic jerks. Which condition did he develop?
Blocking repute of catecholamines and indolamines in patients already using an MAOI can result in potentially life threatening drug interaction known as serotonin syndrome. This includes SSRIs, TCAs, buspirone, and other antidepressants. Mild: triad of mental status changes, autonomic hyperactivity, and neuromuscular abnormalities. Symptoms include tachycardia, flushing, fever, HTN, ocular oscillations and myoclonic jerks. Severe: serious hyperthermia, coma, autonomic instability, convulsions and death. One must wait at least 14 days after D/C MAOI before starting serotonergic agent.
First line tx for major depressive disorder with atypical features
Atypical features respond best to MAOIs such as phenelzine, although these meds are rarely used due to the hypertensive crisis that can occur when eating certain tyramine containing foods. Atypical features include things like weight gain, hypersomnia, and mood receptivity. SSRIs are now first line tx, although major depression doesn’t always respond as well compared with MAOIs.
Which drugs are used in alcohol withdrawal?
Benzodiazepines are DOC for control of alcohol withdrawal sx and ppx against withdrawal seizures and DTs. Long acting, such as chlordiazepoxide and diazepam are appropriate BUT both are extensively metabolized by liver. Lorazepam, Oxazepam, Temazepam (LOT) only undergo glucuronidation prior to elimination and are therefore NOT dependent on liver functioning. These are preferred in patients with compromised liver states, such as alcoholics.
You are taking care of a patient with a history of alcohol dependence admitted for abdominal pain, nausea, and vomiting. He had been having hallucinations prior to you seeing him and now his temperature is 102.1, pulse is 130 bpm, and BP is 220/120. Which medication should you give and which route of administration?
DTs – > transfer to ICU where IV benzos (Lorazepam, oxazepam, or temazepam) can be administered with greater safety. IV route preferred to ensure adequate and rapid absorption.
Major depressive disorder with psychotic features tx
Best practice recommends a combination of antidepressant and an antipsychotic, such as fluoxetine and risperidone.
A 40 y.o. woman with bipolar disorder presents to ER 2 weeks after starting a new medication. She reports she was doing well until she got a viral gastroenteritis and was unable to eat for several days. While viral symptoms resolved, she now complains of N/V, ataxia, and tremor. What studies should you order first?
Lithium toxicity – check lithium level. Therapeutic is usually 0.8-1.2 At levels around 1.2, pts experience tremor, nausea, diarrhea, and ataxia, followed by seizures at 1.5-2.0, then acute renal failure requiring dialysis at levels >2.0 with coma and death at levels above 2.5 Because lithium has such a narrow therapeutic index, dehydration – > toxicity.
Management of a patient with akithesia as a side effect of their anti-psychotics
Akithesia is more common in first generation than second-generation. Usually begins 5-60 days after initiation. First, the neuroleptic dose should be reduced as much as possible. If sx continue in the absence of other EPS, start a beta-blocker such as propranolol. Second line would be lorazepam.
Treatment of bipolar II depression
First line: lithium, lamotrigine, or quetiapine. Valproic acid may be reasonable second line choice.
Most likely serious complication of neuroleptic malignant syndrome
Rhabdomyolysis
Long term side effect of thioridazine
Retinal pigmentation if used in high doses (>1000 mg/d) that may not remit when thioridazine is discontinued and can eventually lead to blindness.
Potency of benzos from most to least potent
Clonazepam > alprazolam > lorazepam > diazepam > oxazepam > chlordiazepoxide.
Tx of Tourette d/o
D2 receptor untag with haloperidol provides greatest sx relief. Clonidine, alpha-2 agonist, is preferable in tx of MILD touter’s as it does not have same long term side effects as antipsychotics.
Tx of tardive dyskinesia
Clozapine
One of the more serious risk of SSRI exposure during pregnancy
Persistent pulmonary HTN of newborn –newborns devo rep failure due to postnatal persistence of elevated pulmonary vascular resistance.
Common sx after stopping SSRI
Flu like – dizziness, N/V, fatigue, lethargy. Anxiety, irritability, and crying spells are not unusual.
A 20 y.o. woman is started on lamotrigine for bipolar depression. Two months later, she comes back reporting that her sx are unchanged despite being compliant. You’ double check her med list and discover she was recently started on new meds. Which med is most likely responsible for lack of efficacy?
OCPs. Valproic acid, on the other hand, decreases lamotrigine clearance, increasing its level in the blood.
MOA of trazodone
Antidepressant that affects serotonin system by weak repute inhibition and antagonist activity at 5-HT1a, 5-HT1c, and 5-HT2 receptors. It has a sedative effect, produced by alpha-adrenergic blockade and modest histamine blockade.
ECG changes possible in patients taking lithium
In about 30% of patients it can cause changes, most commonly T-wave depression or inversion.
Name medications that decrease lithium clearance
Diuretics (ethacrynic acid, spironolactone, and triamterene); NSAIDs (except ASA and sulindac) and abx metronidazole and tetracycline
First line tx for OCD
Either SSRI or Clomipramine – equally effective but SSRI side effect profile is more favorable. Other TCAs not as effective as clomipramine because they are not as serotonergic (clomipramine is mixed serotonin and NE reuptake inhibitor)
Refractory OCD treatment
If moderate response to SSRI: keep SSRI, add second gen antipsychotic such as risperidone
IF no response to SSRI : switch SSRI or to clomipramine
Explain MOA of the drug used for refractory schizophrenia
CLOZAPINE. Acts at D1, D2, D4, his-1, muscarinic, alpha-1-adrenergic, and serotonin types 5-HT2, 5-HT2c, and %-HT3 receptors. It is more potent antagonist at D4 receptor compared to D2 especially in limbic system.
Of the TCAs, which is more likely to be associated with side effects? Which is less?
More likely is imipramine, a tertiary amine which blocks multiple receptors and therefore has many side effects (esp. orthostatic hypotension due to alpha 1 blocking). Less likely is nortriptyline, a secondary amine.
