Chapter 16: Histamine, Serotonin, Drugs Used in Obesity, & the Ergot Alkaloids

Question 1

Endogenous substances with complex physiologic and pathophysiologic functions that have potent nonautonomic pharmacologic effects when administered as drugs

Answer 1

Autacoids

Question 2

Disease caused by excess ingestion of ergot alkaloids; classically an epidemic caused by consumption of grain (eg, in bread) that is contaminated by the ergot fungus

Answer 2

Ergotism (“St. Anthony’s fire”)

Question 3

A drug that causes contraction of the uterus

Answer 3

Oxytocic

Question 4

Syndrome of hypersecretion of gastric acid and pepsin, often caused by gastrinoma; it is associated with severe acid-peptic ulceration and diarrhea

Answer 4

Zollinger-Ellison syndrome

Question 5

Excess production of histamine in the body can be detected by measurement of what major metabolite in the urine?

Answer 5

Imidazole acetic acid

Question 6

This Gq-coupled receptor is important in smooth muscle effects, especially those caused by IgE-mediated responses. Inositol trisphosphate (IP3) and diacylglycerol (DAG) are the second messengers.

Answer 6

H1 receptor

Question 7

This Gs-coupled receptor mediates gastric acid secretion by parietal cells in the stomach. It also has a cardiac stimulant effect.

Answer 7

H2 receptor

Question 8

This Gi-coupled receptor appears to be involved mainly in presynaptic modulation of histaminergic neurotrans- mission in the central nervous system (CNS)

Answer 8

H3 receptor

Question 9

This Gi coupled receptor is located on leukocytes (espe- cially eosinophils) and mast cells and is involved in chemotactic responses by these cells.

Answer 9

H4 receptor

Question 10

Excess production of serotonin in the body (eg, in carcinoid syndrome) can be detected by measuring what major metabolite in the urine?

Answer 10

5-hydroxyindole acetic acid (5-HIAA)

Question 11

This presents with hyperthermia, hyperreflexia, tremor, clonus, hypertension.
- Onset within hours

Precipitating drugs:

• SSRIs
• 2nd-generation antidepressants
• MAOIs

Answer 11

Serotonin syndrome

Tx:
Sedation (benzodiazepines), paralysis, intubation and ventilation; consider 5-HT2 block with cyproheptadine or chlorpromazine

Question 12

This presents with hyperthermia, acute severe par- kinsonism; hypertension, normal or reduced bowel sounds
-Onset over 1–3 days

Precipitating drugs:
D2-blocking antipsychotic drugs

Answer 12

Neuroleptic malignant syndrome

Tx:
Diphenhydramine (parenteral),
cooling if temperature is very high, sedation with benzodiazepines

Question 13

This presents with hyperthermia, muscle rigidity, hypertension, tachycardia
- Onset within minutes

Precipitating drugs:
Volatile anesthetics, succinylcholine

Answer 13

Malignant hyperthermia

Tx:
Dantrolene, cooling

Question 14

They are the first-line treatment for acute migraine and cluster headache attacks

Answer 14

5-HT1D/1B agonists

• Sumatriptan
• Naratriptan

Question 15

This serotonin receptor is most important in the brain and mediate synaptic inhibition via increased potassium conductance

Answer 15

5-HT1 receptor

Question 16

This serotonin receptor is important in both brain and peripheral tissues. It mediate synaptic excitation in the CNS and smooth muscle contraction (gut, bronchi, uterus, some vessels) or relaxation (other vessels)

Answer 16

5-HT2 receptor

Question 17

This serotonin receptor is found in the CNS, especially in the chemoreceptive area and vomiting center, and in peripheral sensory and enteric nerves.

Answer 17

5-HT3 receptor

Question 18

This serotonin receptor is found in the gastrointestinal tract and play an important role in intestinal motility.

Answer 18

5-HT4 receptor

Question 19

This drug is a GI lipase inhibitor which reduces lipid absorption

Answer 19

Orlistat

Question 20

First generation H1-receptor antagonists

Answer 20

1. DIPHENHYDRAMINE
2. BROMPHENIRAMINE
3. CHLORPHENIRAMINE
4. CYCLIZINE
5. MECLIZINE
6. BUCLIZINE
7. CARBINOXAMINE
8. DIMEHYDRINATE
9. HYDROXYZINE
10. PROMETHAZINE
11. CYPROHEPTADINE
12. CLEMASTINE
13. TRIPELENNAMINE

Question 21

Second generation H1-receptor antagonists

Answer 21

1. CETIRIZINE
2. LEVOCETIRIZINE
3. LORATADINE
4. DESLORATADINE
5. FEXOFENADINE
6. TERFENADINE
7. ASTEMIZOLE
8. EBASTINE
9. AZELASTINE
10. BILASTINE
11. RUPATADINE