Set 23 Flashcards
What are the symptoms of decompression sickness?
Scuba divers come up too quickly - nitrogen gas comes out of solution and forms bubbles in blood and tissues. Symptoms based on where nitrogen goes:
- Joint and muscle pain
- Neurologic symptoms: dizziness, syncope, paralysis
- “The chokes” - nitrogen occludes capillaries in the lung : dyspnea, pulmonary edema, death
A 40-year-old man is beginning to have symptoms of a resting tremor, postural instability, and mask- like (expressionless) facies. What is the antiviral drug that can be used against this disease, and what is its mechanism of action?
Amantadine: may increase DA release, also used as an antiviral against influenza A and rubella. Toxicity = ataxia
A 28-year-old man is being treated with the combination of bleomycin, etoposide, and cisplatin for metastatic non-seminoma testicular cancer. The patient develops shortness of breath during the course of treatment. Pulmonary function testing indicates that he has a restrictive lung disease. Which of the chemotherapy agents is responsible for this restrictive lung disease? Which agent in the above regimen works by inducing free radicals to interfere with DNA structure?
Bleomycin - induces free radical formation which causes breaks in DNA strands. Used in testicular cancer, Hodgkin lymphoma. Toxicity includes pulmonary fibrosis, skin changes, mucositis. Minimal myelosuppression
Cisplatin can cause nephrotoxicity and acoustic nerve damage. Works by cross-linking DNA. Used in testicular, bladder, ovary and lung carcinomas
Etoposide inhibits topoisomerase II -> increases DNA degradation. Used in solid tumors (testicular and small cell lung cancer), leukemias and lymphomas. Toxicity: myelosuppression, GI irritation and alopecia
A 55-year-old alcoholic is admitted to the hospital because of an upper GI bleed. A ruptured esophageal varix is found to be the cause. What is the preferred medical treatment for this condition?
Ocreotide (long-acting somatostatin analog). Used for acute variceal bleeds, acromegaly, VIPoma and carcinoid tumors. Causes vasoconstriction of the splanchnic vascular bed, reduces bleeding. Toxicity: N, cramps, steatorrhea
A 3-day-old preterm infant delivered at 34 weeks gestation develops neonatal respiratory distress syndrome (RDS). Which type of pneumocyte is affected in RDS? What is the mechanism that leads to poor O2-CO2 exchange at the gas exchange barrier in preterm infants with RDS? What structures make up the gas exchange barrier? How could you increase surfactant production in preterm neonates?
Type II pneumocyte: secrete pulmonary surfactant (dipalmitoylphosphatidylcholine) - decrease alveolar surface tension and prevention of alveolar collapse (atelectasis)
Mechanism: Surfactant deficiency - increased surface tension -alveolar collapse. Hyaline membrane (made up of fibrin, cellular debris, neutrophils, macrophages and RBCs) impede gas exchange
Gas exchange barrier: Type I pneumocytes, endothelial cells of pulmonary capillaries, BM
Treatment: maternal steroids before birth (mature type II pneumocytes), artificial surfactant for infant
How does flutamide differ from finasteride in terms of clinical use and mechanism of action?
Both are antiandrogens. Used for prostate pathologies.
Finasteride is a 5alpha-reductase inhibitor (decreases conversion of testosterone to DHT). Useful in BPH. Also promotes hair growth - used to treat male-pattern baldness.
Flutamide is a nonsteroidal competitive inhibitor of androgens at the testosterone receptor. Used in prostate carcinoma.
Which bone is commonly fractured when a person hits something with the knuckles of a clenched fist, resulting in deep pain in the anatomical snuffbox?
Scaphoid bone
What might you observe in a patient who presents to the emergency room with PCP intoxication?
Belligerence*, impulsiveness, fever, psychomotor agitation, analgesia, vertical and horizontal nystagmus, tachycardia, homicidality, psychosis, delirium, seizures
Treatment: BZ, rapid-acting antipsychotic
IFN-γ stimulates macrophages and inhibits Th2 cells. What cell type releases IFN-γ?
Th1 cells
How does the mechanism of action of benzodiazepines differ from the mechanism of action of barbiturates? What toxicities of barbiturates can be fatal?
BZ - facilitate GABAa action by increasing the frequency of Cl- channel opening
Barbiturates -facilitate GABAa action by increasing duration of Cl- channel opening (barbiDURATES = incrased DURATion). Also has GABA mimetic activity
Toxicities: respiratory and cardiovascular depression
