Test #31 (& 30) (PRR Week 2N Block 13: Neuro Pharm)

Question 1

Treatment for narcolepsy

Answer 1

Scheduled daytime naps & psychostimulants (e.g., modafinil) for daytime sleepiness

Question 2

Phenytoin: (1) Method of metabolism (2) Drugs that lower its serum conc. & why

Answer 2

(1) Hepatic P450 oxidase & is dose dependent (2) Drugs that induce hepatic microsomal enzymes (phenobarbital, carbamazepine, rifampin) enhance phenytoin metabolism & decrease its serum conc.

Question 3

(1) Tx/Explain: bradycardia (2) Common side effect of this tx & why

Answer 3

(1) Atropine - decreased vagal influence on SA and AV nodes (2) Increases IOP, which may precipitate acute closed angle glaucoma in susceptible individuals

Question 4

(1) Tx for alcohol withdrawal - Give general class & 2 examples (2) Mechanism (3) Specify use/tx if patient has advance liver dysfunction

Answer 4

(1) Long-acting benzodiazepines (chlordiazepoxide, diazepam) (2) Benzos substitute for action of alcohol on GABA receptors (3) Short-acting benzos (lorazepam, oxazepam) preferred in patients with advanced liver dysfunction

Question 5

Effect & mechanism by which cholinergic agonists affect vasculature

Answer 5

Bind to muscarinic receptors on endothelial cells and promote release of NO (EDRF). NO activates guanylate cyclase and diminishes endothelium calcium concentration. This produces vasodilation.

Question 6

Protocol for switching patient from MAO inhibitor to SSRI, and why

Answer 6

Co-admin. of SSRI and MAO inhibitor can produce excessive serotonin levels secondary to decreased reuptake and decreased metabolism. Excessive serotonin levels can lead to development of fatal condition known as serotonin syndrome. To avoid risk, wait at least 14 days after MAO inhibitor discont. before SSRI therapy starts, allowing time for regeneration of MAO

Question 7

Substance to avoid if patient on levodopa/carbidopa

Answer 7

Vitamin B6 supplementation, since B6 increases peripheral metabolism of Levodopa, decreasing its effectiveness

Question 8

Explain: 52 yo woman complaining of right lower-extremity swelling, warmth, and erythema. PMH Type 2 DM, htn, and depression. Meds: metformin, lisinopril, paroxetine, and multivitamin. Dx with cellulitis and started on antibiotics. 3 days later, becomes agitated and confused with severe abdominal cramps and diarrhea, temp 39.2 C (102.6 F), bp 220/130 mmHg, and HR 140/min and regular. PE tremulous and pupils dilated. Bilateral hyperreflexia and ankle clonus

Answer 8

Commonly used drugs such as analgesic tramadol, antiemetic ondansetron, and antibiotic linezolid can induce serotonin syndrome when used concomitantly with other serotonergic drugs

Question 9

Tx/Explain: for schizophrenia patient appears emotionless and with scant speech

Answer 9

Unlike first-generation neuroleptics, second-generation (atypical) agents (clozapine, risperidone, olanzapine, quetiapine) improve both positive and negative sx of shizophrenia

Question 10

Type of benzodiazepines to use in elderly patient at risk for falls & why

Answer 10

Benzodiazepines can cause daytime drowsiness (a “hangover”) can can increase risk of falls in elderly. Severity of this side effect depends on half-life of drug. Long-acting benzodiazepines (chlordiazepoxide, clorazepate, diazepam, flurazepam) cause more severe drowsiness than short-acting ones (alprazolam, triazolam, oxazepam). On the other hand, long-acting benzos far less likely to cause dependence (i.e., less addicting); Note: medium benzos include Estazolam, Lorazepam, Temazepam

Question 11

(1) Psychiatric side effect of Venlafaxine (and other antidepressants) in patients, especially those unrecognized bipolar disorder (2) Protocol addressing this

Answer 11

(1) Antidepressants can induce mania in susceptible patients, especially those with unrecognized bipolar disorder. (2) Patients treated with antidepressants should be monitored for mood elevation and sx suggestive of mania that require emergency tx

Question 12

Levodopa side effect changes with addition of carbidopa

Answer 12

Adding carbidopa can reduce most of peripheral side effects of levodopa. However, behavioral changes from levodopa can actually worsen with addition of carbidopa because more dopamine becomes available to brain

Question 13

(1) Dx/Explain: 52 yo female complains of hand tremor, most prominent when carrying out simple daily activities like drinking from glass or pouring tea kettle, drinking small amounts of alcohol improves tremor, FH mother had similar problems (2) First line tx

Answer 13

(1) Essential tremor - most common movement disorder; slowly progressive symmetric postural and/or kinetic tremor that most commonly affects upper extremities. Though to be inherited in autosomal dominant fashion, so sometimes called familial tremor. (2) nonspecific beta adrenergic antagonist propanolol

Question 14

(1) Zolpidem mechanism (2) How it relates to benzos in terms of structuer & side effects (3) Clinical use

Answer 14

(1) Short-acting hypnotic agent (mechanism similar to benzos: both bind to same portion of GABAa receptor and enhance inhibitory action of GABA on CNS) (2) structurally unrelated to benzodiazepine. All benzodiazepines have higher risk of addiction and tolerance than zolpidem (3) Short-term tx of insomnia

Question 15

(1) Dx/Explain: 32 yo male agitation and chest pain, combative and uncooperative, bp 170/110 mmHg, HR 130/min and regular, pupils dilated and reactive to light. Atrophy of nasal mucosa and partial destruction of nasal septum. ECG reveals MI. (2) Underlying Mechanism

Answer 15

(1) Cocaine intoxication - causes agitation, dramatic symmetric pupillary dilation that remains responsive to light, tachycardia, and bp elevation (2) Both cocaine and tricyclic antidepressants inhibit neurotransmitter reuptake in adrenergic synapses

Question 16

(1) Dx: 26 yo woman tx for mood swings and sleep problems for past 2 years, sx generally improved. New onset constipation, dry skin, hair loss, and weight gain, bp 110/70 mmHg and pulse 55 (2) Explain (3) Precautions/Protocols for preventing this

Answer 16

(1) Hypothyroidism secondary to Lithium use (2) Lithium can cause hypothyroidism and nephrogenic DI and can accumulate in patients with renal insufficiency. (3) Serum TSH levels, Lithium levels, and renal function (BUN and Cr) should be meas. routinely

Question 17

(1) Tx for organophosphate poisoning (2) Explain mechanism(s)

Answer 17

(1) Atropine & pralidoxime (2) Organophosphate stimulate both M & N cholinergic receptors. Atropine reverses M effects but does not prevent development of N effects (e.g., muscle paralysis). Pralidoxime = only med that reverses BOTH M and N effects by “restoring” cholinesterase from its bond with these substrates

Question 18

Listeria monocytogenes: (1) patient populations at risk (2) treatment of choice

Answer 18

(1) causes diseases in neonates and immunocompromised (2) Ampicillin (not sensitive to cephalosporins, unlike other causes of meningitis - N. mengitidis, S. pneumoniae, GBS, H. influenzae)

Question 19

Explain “on off” versus “wearing off” phenomenons & which disease they pertain to

Answer 19

“On off” phenomenon is unpredictable and dose-independent characteristic of Parkinson disease - no clear etiology. “Wearing off” phenomenon of PD is due to progressive destruction of striatonigral dopaminergic neurons over a period of time.

Question 20

(1) Effect of epinephrine on insulin release (2) Explain what can be done to change this effect

Answer 20

(1) Decrease insulin (2) Alpha receptors inhibit insulin secretion & Beta receptors stimulate insulin secretion. Pretreat with alpha blocker (e.g., phenoxybenzamine) would result in predominance of beta-effects (since epinephrine binds both alpha and beta receptors)

Question 21

(1) Dx/Explain: infant born to 28 yo female expresses shrill cyring, tremor, rhinorrhea, sneezing, and diarrhea, accompanied by myoclonic jerks and rapidly progresses to seizures, mother lives on street & had little prenatal care (2) Tx protocol

Answer 21

(1) Acute neonatal narcotic withdrawal: pupillary dilatation, rhinorrhea, sneezing, nasal stuffiness, diarrhea, nausea, & vomiting. Chills, tremors, and jittery movements occur commonly as well and can rarely lead to seizures. (2) Opium solution given as dilated ticture of opium tx of choice & can be given orally. Dose initially titrated to pt. sx. & tapered off

Question 22

(1) Dx: 23 yo restlessness in legs and inability to lie or sit still, dx w/ schizophrenia a month ago & improved sx, bp 140/90 mmHg, HR 90/min, alert, oriented, fidgety, and anxious (2) Explain (3) Clinical caution

Answer 22

(1) Akathisia (2) Extrapyramidal side effect of antipsychotic meds characterized by inner restlessness and inability to sit or stand in one position. (3) Akathisia frequently misdiagnosed because restlessness misinterpreted as worsening psychotic agitation. Patient’s antipsychotic dose often increased rather than decreased, exacerbating akathisia.

Question 23

(1) Drugs not to be used in context with lithium & why (2) Best tx for lithium toxicity

Answer 23

Lithium almost exclusively excreted by kidneys with filtration and resorption in proximal tubules following sodium reabsorption. Renal injury, toxins, and drugs that lead to increased proximal tubular absorption of sodium (e.g., NSAIS, thiazide diuretics, & ACE inhibitors) also increase Lithium levels and risk of lithium toxicity. (2) Hemodialysis most effective way to decrease blood lithium level