WBR0001: Difference between revisions

Jump to navigation Jump to search
No edit summary
No edit summary
Line 21: Line 21:
|MainCategory=Behavioral Science/Psychiatry, Pharmacology
|MainCategory=Behavioral Science/Psychiatry, Pharmacology
|SubCategory=Neurology
|SubCategory=Neurology
|Prompt=A 23-year-old woman presents to her primary care physician's office with symptoms of depression, insomnia, and decreased appetite. She reports that these symptoms often alternate with episodes of excited mood and euphoria. The patient is referred to a local psychiatrist for treatment of presumed bipolar disorder. After 2 months, the patient returns and reports improvement of her mood swings after she began taking a medication whose name she cannot recall. Unfortunately, she now complains of recent menstrual irregularities, constipation, and fatigue. Which of the following medications was this patient most likely prescribed?
|Prompt=A 23-year-old woman presents to her primary care physician with complaints of depression, insomnia, and decreased appetite. She reports that these symptoms often alternate with episodes of excited mood and euphoria. The patient is referred to a local psychiatrist for appropriate management. Two months later, the patient returns and reports improvement of her mood swings following daily intake of a medication whose name she cannot recall. She now complains of recent menstrual irregularities, constipation, and fatigue. Which of the following drugs was this patient most likely prescribed?
|Explanation=This patient has bipolar disorder and was most likely prescribed [[lithium]] for mood stabilization. The mechanism of action of lithium is yet to be elucidated. In bipolar disorder, lithium is indicated for the acute treatment of mania as well as for prophylaxis. It is almost totally excreted in the urine, potentially causing tubulo-interstitial nephritis and nephrogenic diabetes insipidus. Other well-established side effects of lithium include [[hypothyroidism]], manifested by fatigue, constipation, and menstrual irregularities as observed in this patient. Lithium has other side effects, which can be remembered with the mnemonic LITHIUM:
|Explanation=This patient has bipolar disorder and was most likely prescribed [[lithium]] for mood stabilization. The mechanism of action of lithium is yet to be elucidated. In bipolar disorder, lithium is indicated for the acute treatment and prophylaxis of mania. Lithium is almost totally excreted in the urine and is associated with the development of tubulo-interstitial nephritis and nephrogenic diabetes insipidus. Other well-established adverse effects of lithium therapy include [[hypothyroidism]], which manifests with fatigue, constipation, and menstrual irregularities as observed in this patient. Lithium has other adverse effects, which can be remembered with the mnemonic LITHIUM:
*'''L'''ethargy / '''L'''eucocytosis
*'''L'''ethargy / '''L'''eucocytosis
*'''I'''ntentional tremor
*'''I'''ntentional tremor
Line 33: Line 33:
It is important to perform renal and thyroid function tests before the initiation of therapy. Frequent re-assessment is also required to monitor for potential side effects.
It is important to perform renal and thyroid function tests before the initiation of therapy. Frequent re-assessment is also required to monitor for potential side effects.
|AnswerA=Carbamazepine
|AnswerA=Carbamazepine
|AnswerAExp=[[Carbamazepine]] is an anticonvulsant and mood-stabilizing drug used primarily in the treatment of epilepsy and bipolar disorder. It is also the first line treatment for trigeminal neuralgia. Carbamazepine stabilizes the inactivated state of voltage-gated sodium channels, thereby reducing the excitability of neurons. Carbamazepine is an inducer of the cytochrome P-450 system and adverse reactions to carbamazepine include SIADH, agranulocytosis, aplastic anemia, hepatotoxicity, Stevens-Johnson syndrome, and teratogenicity.
|AnswerAExp=[[Carbamazepine]] is an anticonvulsant and mood-stabilizing drug used primarily for the management of epilepsy and bipolar disorder. It is also the first line treatment for trigeminal neuralgia. Carbamazepine stabilizes the inactivated state of voltage-gated sodium channels, thereby reducing the excitability of neurons. Carbamazepine is an inducer of the cytochrome P-450 system. Adverse reactions to carbamazepine include SIADH, agranulocytosis, aplastic anemia, hepatotoxicity, Stevens-Johnson syndrome, and teratogenicity.
|AnswerB=Gabapentin
|AnswerB=Gabapentin
|AnswerBExp=[[Gabapentin]] is a gamma-aminobutyric acid (GABA) analogue that inhibits voltage-gated calcium channels. It is used to treat epilepsy, peripheral neuropathy, and bipolar disorder. Adverse effects include sedation and ataxia.
|AnswerBExp=[[Gabapentin]] is a gamma-aminobutyric acid (GABA) analogue that inhibits voltage-gated calcium channels. It is used to treat epilepsy, peripheral neuropathy, and bipolar disorder. Adverse effects include sedation and ataxia.
|AnswerC=Venlafaxine
|AnswerC=Venlafaxine
|AnswerCExp=[[Venlafaxine]] is an SNRI (inhibits serotonin and norepinephrine reuptake) that may be used to treat depression and generalized anxiety disorder. It may also be used for cases of chronic pain. Classically, venlafaxine is associated with an increase in diastolic blood pressure, nausea, and sedation.
|AnswerCExp=[[Venlafaxine]] is an SNRI (inhibits serotonin and norepinephrine reuptake) that may be used to treat depression and generalized anxiety disorder. It may also be used for cases of chronic pain. Classically, venlafaxine is associated with elevations in diastolic blood pressure, nausea, and sedation.
|AnswerD=Amitriptyline
|AnswerD=Amitriptyline
|AnswerDExp=[[Amitryptyline]] is a tertiary amine tricyclic antidepressant (TCA) that blocks the reuptake of serotonin and norepinephrine. It is primarily used to treat major depression. Side effects of amitriptyline include the three C-s: Convulsions, Coma, and Cardiotoxicity. Additionally, TCAs have anticholinergic side effects, such as urinary retention, constipation, dryness of the mouth, and sedation. TCAs do not typically cause hypothyroidism as seen in this patient.
|AnswerDExp=[[Amitryptyline]] is a tertiary amine tricyclic antidepressant (TCA) that blocks the reuptake of serotonin and norepinephrine. It is primarily used to treat major depression. Adverse effects of amitriptyline include the three C-s: Convulsions, Coma, and Cardiotoxicity. Additionally, TCAs have anticholinergic adverse effects, such as urinary retention, constipation, dryness of the mouth, and sedation. Administration of TCAs is not classically associated with the development of hypothyroidism.
|AnswerE=Lithium
|AnswerE=Lithium
|AnswerEExp=Lithium is a mood stabilizer used to treat bipolar disorder. Its mechanism of action is poorly understood. One of the side effects of lithium is hypothyroidism, which is responsible for the menstrual irregularities, constipation and fatigue in this patient. Further questioning might reveal other manifestations of hypothyroidism such as cold intolerance.
|AnswerEExp=Lithium is a mood stabilizer used to treat bipolar disorder. Its mechanism of action is poorly understood. Administration of lithium is associated with the development of hypothyroidism, which is responsible for the menstrual irregularities, constipation, and fatigue in this patient. Further questioning might demonstrate other manifestations of hypothyroidism, such as cold intolerance, hair loss, and reduced concentration capacity.
|EducationalObjectives=Lithium is a mood stabilizer used to treat bipolar disorder. One common side effect of lithium therapy is hypothyroidism.
|EducationalObjectives=Lithium is a mood stabilizer used to treat bipolar disorder. Administration of lithium is associated with the development of hypothyroidism, which is responsible for the menstrual irregularities, constipation, and fatigue.
|References=Bocchetta A, and Loviselli A. Lithium treatment and thyroid abnormalities. 'Clin Pract Epidemiol Ment Health'. 2006;2:23<br>
|References=Bocchetta A, and Loviselli A. Lithium treatment and thyroid abnormalities. 'Clin Pract Epidemiol Ment Health'. 2006;2:23<br>
First Aid 2014 page 518
First Aid 2014 page 518
|RightAnswer=E
|RightAnswer=E
|WBRKeyword=Bipolar disorder, Lithium, Hypothyroidism, Side, adverse, effect, Psychiatry, Antipsychotic, Pharmacology, Drug, Mania, Constipation, Fatigue, Menstrual
|WBRKeyword=Bipolar disorder, Lithium, Hypothyroidism, Adverse effect, Psychiatry, Antipsychotic, Pharmacology, Drug, Mania, Constipation, Fatigue
|Approved=Yes
|Approved=Yes
}}
}}

Revision as of 19:44, 1 April 2015

 
Author PageAuthor::Anonymous (Reviewed by Will Gibson, Alison Leibowitz, and Yazan Daaboul)
Exam Type ExamType::USMLE Step 1
Main Category MainCategory::Behavioral Science/Psychiatry, MainCategory::Pharmacology
Sub Category SubCategory::Neurology
Prompt [[Prompt::A 23-year-old woman presents to her primary care physician with complaints of depression, insomnia, and decreased appetite. She reports that these symptoms often alternate with episodes of excited mood and euphoria. The patient is referred to a local psychiatrist for appropriate management. Two months later, the patient returns and reports improvement of her mood swings following daily intake of a medication whose name she cannot recall. She now complains of recent menstrual irregularities, constipation, and fatigue. Which of the following drugs was this patient most likely prescribed?]]
Answer A AnswerA::Carbamazepine
Answer A Explanation [[AnswerAExp::Carbamazepine is an anticonvulsant and mood-stabilizing drug used primarily for the management of epilepsy and bipolar disorder. It is also the first line treatment for trigeminal neuralgia. Carbamazepine stabilizes the inactivated state of voltage-gated sodium channels, thereby reducing the excitability of neurons. Carbamazepine is an inducer of the cytochrome P-450 system. Adverse reactions to carbamazepine include SIADH, agranulocytosis, aplastic anemia, hepatotoxicity, Stevens-Johnson syndrome, and teratogenicity.]]
Answer B AnswerB::Gabapentin
Answer B Explanation [[AnswerBExp::Gabapentin is a gamma-aminobutyric acid (GABA) analogue that inhibits voltage-gated calcium channels. It is used to treat epilepsy, peripheral neuropathy, and bipolar disorder. Adverse effects include sedation and ataxia.]]
Answer C AnswerC::Venlafaxine
Answer C Explanation [[AnswerCExp::Venlafaxine is an SNRI (inhibits serotonin and norepinephrine reuptake) that may be used to treat depression and generalized anxiety disorder. It may also be used for cases of chronic pain. Classically, venlafaxine is associated with elevations in diastolic blood pressure, nausea, and sedation.]]
Answer D AnswerD::Amitriptyline
Answer D Explanation [[AnswerDExp::Amitryptyline is a tertiary amine tricyclic antidepressant (TCA) that blocks the reuptake of serotonin and norepinephrine. It is primarily used to treat major depression. Adverse effects of amitriptyline include the three C-s: Convulsions, Coma, and Cardiotoxicity. Additionally, TCAs have anticholinergic adverse effects, such as urinary retention, constipation, dryness of the mouth, and sedation. Administration of TCAs is not classically associated with the development of hypothyroidism.]]
Answer E AnswerE::Lithium
Answer E Explanation [[AnswerEExp::Lithium is a mood stabilizer used to treat bipolar disorder. Its mechanism of action is poorly understood. Administration of lithium is associated with the development of hypothyroidism, which is responsible for the menstrual irregularities, constipation, and fatigue in this patient. Further questioning might demonstrate other manifestations of hypothyroidism, such as cold intolerance, hair loss, and reduced concentration capacity.]]
Right Answer RightAnswer::E
Explanation [[Explanation::This patient has bipolar disorder and was most likely prescribed lithium for mood stabilization. The mechanism of action of lithium is yet to be elucidated. In bipolar disorder, lithium is indicated for the acute treatment and prophylaxis of mania. Lithium is almost totally excreted in the urine and is associated with the development of tubulo-interstitial nephritis and nephrogenic diabetes insipidus. Other well-established adverse effects of lithium therapy include hypothyroidism, which manifests with fatigue, constipation, and menstrual irregularities as observed in this patient. Lithium has other adverse effects, which can be remembered with the mnemonic LITHIUM:
  • Lethargy / Leucocytosis
  • Intentional tremor
  • Teratogenicity
  • Hypothyroidism
  • Diabetes Insipidus
  • Urine excess (polyuria)
  • Metallic taste

It is important to perform renal and thyroid function tests before the initiation of therapy. Frequent re-assessment is also required to monitor for potential side effects.
Educational Objective: Lithium is a mood stabilizer used to treat bipolar disorder. Administration of lithium is associated with the development of hypothyroidism, which is responsible for the menstrual irregularities, constipation, and fatigue.
References: Bocchetta A, and Loviselli A. Lithium treatment and thyroid abnormalities. 'Clin Pract Epidemiol Ment Health'. 2006;2:23
First Aid 2014 page 518]]

Approved Approved::Yes
Keyword WBRKeyword::Bipolar disorder, WBRKeyword::Lithium, WBRKeyword::Hypothyroidism, WBRKeyword::Adverse effect, WBRKeyword::Psychiatry, WBRKeyword::Antipsychotic, WBRKeyword::Pharmacology, WBRKeyword::Drug, WBRKeyword::Mania, WBRKeyword::Constipation, WBRKeyword::Fatigue
Linked Question Linked::
Order in Linked Questions LinkedOrder::