A 42-year-old male seeks your advice regarding smoking cessation. You recommend a smoking cessation class, as well as varenicline.
You caution him that the most common side effect is:
Correct Answer E:
The most common adverse event attributed to varenicline at a dosage of 1 mg twice a day is nausea, occurring in approximately 30%-50% of patients. Taking the drug with food lessens the nausea.
At the emergency department you encounter a patient with an infectious condition that might have been contracted through the fecal-oral route.
Which of the following infectious agents is least likely to infect through this route?
Correct Answer C:
Infectious diseases can be transmitted through various routes, they may be airborne, transmitted through human animal contact, food poisoning, fecal-oral route, sexual contact, via a vector, droplet contact, or iatrogenic. Epstein-Barr virus is a herpes virus spread by kissing through the saliva of an infected person and airborne transmission in dormitories or between siblings in a family.
Clostridium difficile, Hepatitis A virus, Norwalk virus, and Polio virus can all cause infections through fecal-oral route transmission. Clostridium difficile is also commonly seen after few days to weeks of antibiotic treatment.
Other common infectious agents that can be transmitted through the fecal-oral route include Giardia lamblia, Hepatitis E virus, Rotavirus, Shigella dysenteriae, Vibrio cholera, Cryptosporidium parvum, and Ascaris lumbricoides.
→ Clostridium difficile (choice A), Hepatitis A virus (choice B), Norwalk virus (choice C), and Polio virus (choice D) can all cause infections through fecal-oral route transmission.
Common infectious agents that can be transmitted through the fecal-oral route include Polio virus, Norwalk virus, Hepatitis A virus, Clostridium difficile, Giardia lamblia, Hepatitis E virus, Rotavirus, Shigella dysenteriae, Vibrio cholera, Cryptosporidium parvum, and Ascaris lumbricoides.
A 42-year-old farmer is brought to the emergency department by his wife with symptoms of sudden difficulty breathing, muscle twitching, muscle weakness, sweating, and anxiety. He was spraying a pesticide when this occurred. They rushed to the emergency department and it has only been 30 minutes since symptoms started. The patient is given atropine, and observed for response (need of intubation).
Which of the following is the most appropriate medication to add to his treatment?
Correct Answer B:
This patient’s history and presentation are suggestive of organophosphate poisoning from pesticide exposure. Organophosphates act by inhibiting carboxyl ester hydrolases, particularly acetylcholinesterase (AChE). AChE is an enzyme that degrades the neurotransmitter acetylcholine (ACh) into choline and acetic acid. Organophosphates inactivate AChE by phosphorylating the serine hydroxyl group located at the active site of AChE. Once AChE has been inactivated, ACh accumulates throughout the nervous system, resulting in overstimulation of muscarinic and nicotinic receptors.
In patients who present within few hours of exposure, pralidoxime (choice B) can be given for treatment. It is an AChE reactivator that must be administered IV within few hours of exposure because it is ineffective after effects of “aging” (i.e., strengthening of the alkylophosphoryl-serine bond formed between AChE and organophosphate). Aging is generally considered to occur after 48 hours. This antidote is also effective in the treatment of neurotoxin agents poisoning (e.g sarin). It is most effective at the neuromuscular junction and not effective in the CNS and against carbamylated AChE. Atropine, a muscarinic receptor antagonist is also used in the treatment of organophosphate poisoning. Atropine has CNS effects and long duration of action. Because pralidoxime does not significantly relieve depression of respiratory center or decrease muscarinic effects of AChE poisoning, atropine should be administered concomitantly to block these effects of organophosphate poisoning. According to the opening stem, atropine has already been initiated in this patient so the most appropriate drug to add is pralidoxime.
→ Clonidine (choice A) is a centrally acting alpha-2 agonist in the vasomotor center of the medulla. It reduces sympathetic tone and blood pressure; it is not used in organophosphate poisoning.
→ Dantrolene (choice C) is ryanodine receptor antagonist that interferes with calcium release and is used to treat malignant hyperthermia. It is not useful in the treatment of organophosphate poisoning.
→ Succinylcholine (choice D) should be avoided because it is degraded by AChE and may result in prolonged paralysis.
→ Physostigmine (choice E) in an indirect-acting parasympathomimetic agent that inhibits AchE and increase Ach levels. It is used to treat atropine overdose.
Key point:
Exposure to pesticide results in organophosphate poisoning, which leads to inhibition of acetylcholinesterase. Pralidoxime, an AChE reactivator should be given in patients who present within few hours of exposure with nicotinic receptor symptoms. It has no CNS effects. Atropine is concomitantly given for its muscarinic receptors effects and CNS effects.
A 55-year-old man with severe chronic obstructive pulmonary disease returns to the office following a recent evaluation for possible lung transplantation in another city. He says he had been considered a suitable candidate, in all respects, but was rejected by the transplant program when a random urine test was positive for a nicotine metabolite. He had previously told you that he had stopped smoking 3 years ago. He stands by this and is at a loss to explain the positive urine test. He wants to know what he should do now.
Which of the following is the most appropriate next step?
This choice demonstrates that the physician is acting as the patient’s advocate, and is accepting his version as the truth. On the other hand, while it is possible that the patient has indeed continued to smoke, this may be insufficient reason to deny him a lung transplant. Contacting the transplant program to determine whether there are other reasons for rejecting the patient as a candidate is appropriate. Advising him to stop smoking implies that the physician does not believe that the patient has already stopped.
You plan to discharge an 78-year-old woman in a few days following a 3 week stay in the hospital for repair of a fractured hip that she sustained while gardening. Her daughter, who is in the room with the patient, says, "I want to take Mother home with me because I'm concerned that she could fall and break her hip again. Mom says she doesn't really want to leave her own home, but she will do what is best." The daughter turns to her mother and says firmly, "Isn't that right, Mom?" The mother says, "Yes, I guess so," averting eye contact with both her daughter and you by looking down toward the floor.
The most appropriate response to the mother is:
Correct Answer D:
This question describes an elderly woman who is still capable of making informed decisions. However, it is clear from the description of this scenario that the daughter is trying to coerce her mother into a decision with which she does not necessarily agree. It would therefore be appropriate to speak to the patient privately in order to better ascertain the mother’s true feelings regarding this situation. Note that even though the daughter is acting in what she assumes is the mother’s best interest, the concept of patient autonomy dictates that the mother is allowed to make her own independent decision.
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