Drugs For Lyme Disease Flashcards
At what point does the risk of human transmission of Lyme disease increase significantly due to tick attachment?
A) 12 hours
B) 24 hours
C) 36 hours
D) 72 hours
A) 12 hours: Incorrect. The spirochete has not yet migrated to the salivary glands, and the risk of transmission is very low.
B) 24 hours: Incorrect. The migration process has started, but transmission risk remains relatively low.
C) 36 hours: Correct. The spirochete begins migrating to the salivary glands, and transmission risk increases after this point.
D) 72 hours: Incorrect. While the risk of transmission is highest at 72 hours (20-fold increase), the migration begins by 36 hours.
Which of the following is NOT an approved method of Lyme disease prevention?
A) Use of tick repellents like DEET or icaridin
B) Wearing long sleeves and pants in tick-infested areas
C) Prophylactic vaccination
D) Regular tick checks after outdoor exposure
A) Use of tick repellents like DEET or icaridin: Incorrect. Both DEET and icaridin are effective and recommended for tick prevention.
B) Wearing long sleeves and pants in tick-infested areas: Incorrect. Physical barriers like clothing are recommended for tick prevention.
C) Prophylactic vaccination: Correct. There is no currently licensed human vaccine for Lyme disease.
D) Regular tick checks after outdoor exposure: Incorrect. Checking for ticks is an important prevention method.
What is the recommended tick repellent for children aged 6 months to 12 years?
A) DEET
B) Icaridin
C) Picaridin
D) Permethrin-treated clothing
A) DEET: Incorrect. DEET can be used, but it is not the preferred repellent for this age group.
B) Icaridin: Correct. Icaridin (aka picaridin) is the preferred insect repellent for children aged 6 months to 12 years.
C) Picaridin: Incorrect. While picaridin is an alternative name for icaridin, this option is not incorrect but redundant.
D) Permethrin-treated clothing: Incorrect. While effective for tick prevention, permethrin-treated clothing is not a topical repellent.
Which of the following conditions must be met for postexposure prophylaxis after a tick bite?
A) Tick was attached for at least 24 hours
B) Local B. burgdorferi infection rate in ticks is less than 20%
C) The tick was identified as an Ixodes species
D) Prophylaxis is administered 48 hours after tick removal
A) Tick was attached for at least 24 hours: Incorrect. The tick must be attached for at least 36 hours for postexposure prophylaxis to be considered.
B) Local B. burgdorferi infection rate in ticks is less than 20%: Incorrect. The local rate must be more than 20% for prophylaxis to be considered.
C) The tick was identified as an Ixodes species: Correct. Ixodes ticks are the primary vectors of Lyme disease.
D) Prophylaxis is administered 48 hours after tick removal: Incorrect. Prophylaxis must be administered within 72 hours after tick removal.
Which of the following antibiotics is NOT recommended for the treatment of mild localized Lyme disease in pregnant individuals?
A) Amoxicillin
B) Cefuroxime
C) Doxycycline
D) Ceftriaxone
A) Amoxicillin: Incorrect. Amoxicillin is a first-line treatment for mild localized Lyme disease in pregnant individuals.
B) Cefuroxime: Incorrect. Cefuroxime is also a first-line treatment for mild localized Lyme disease during pregnancy.
C) Doxycycline: Correct. Doxycycline is not recommended in pregnancy for treatment due to potential risks, despite being used for postexposure prophylaxis.
D) Ceftriaxone: Incorrect. Ceftriaxone is recommended for severe cases like Lyme neuroborreliosis during pregnancy.
More Information on doxycycline:
Bone and Teeth Development: Tetracyclines, including doxycycline, can bind to calcium in developing bones and teeth. This can lead to:
Permanent tooth discoloration (yellow, brown, or gray staining), especially in children and developing fetuses.
Bone growth inhibition in the fetus, which can potentially cause skeletal deformities.
Fetal Toxicity: Animal studies and some clinical data suggest that prolonged use of doxycycline during pregnancy might increase the risk of skeletal development issues, though definitive data in humans are limited. Due to this potential risk, safer alternatives are recommended during pregnancy.
Type: Doxycycline is a tetracycline antibiotic.
Mechanism: It inhibits bacterial protein synthesis by binding to the 30S ribosomal subunit.
Contraindications: In pregnancy, due to its effects on fetal bone and teeth development.
Use in Lyme Disease: While effective in non-pregnant individuals, it is not recommended in pregnancy due to these potential risks, and safer alternatives like amoxicillin and cefuroxime are preferred.
In which situation is a single dose of doxycycline recommended as postexposure prophylaxis for Lyme disease?
A) The tick was attached for 24 hours
B) The local B. burgdorferi infection rate is 15%
C) The tick was removed within 36 hours of attachment
D) The patient meets all 3 criteria for postexposure prophylaxis
A) The tick was attached for 24 hours: Incorrect. Prophylaxis is not recommended unless the tick was attached for at least 36 hours.
B) The local B. burgdorferi infection rate is 15%: Incorrect. Prophylaxis is only recommended if the local infection rate is greater than 20%.
C) The tick was removed within 36 hours of attachment: Incorrect. Prophylaxis should be administered if the tick was attached for at least 36 hours and removed within 72 hours.
D) The patient meets all 3 criteria for postexposure prophylaxis: Correct. All 3 criteria must be met for a single dose of doxycycline to be offered.
What is the preferred first-line antibiotic treatment for erythema migrans in a patient with no contraindications?
A) Amoxicillin for 10 days: Incorrect. Amoxicillin is an alternative to doxycycline but is typically given for 14 days.
B) Azithromycin for 5 days: Incorrect. Azithromycin is a second-line agent with lower efficacy (80% cure rate).
C) Cefuroxime for 14 days: Incorrect. Cefuroxime is also an alternative treatment but requires 14 days of therapy.
D) Doxycycline for 10 days: Correct. Doxycycline is the first-line agent for treating erythema migrans with 10 days of therapy.
What is the most common adverse effect associated with doxycycline treatment for Lyme disease?
A) Neurological toxicity
B) Photosensitivity
C) Renal dysfunction
D) Severe hypersensitivity
A) Neurological toxicity: Incorrect. Doxycycline is not commonly associated with neurological toxicity.
B) Photosensitivity: Correct. Photosensitivity occurs in 20-30% of patients treated with doxycycline.
C) Renal dysfunction: Incorrect. Doxycycline is not known to cause significant renal dysfunction.
D) Severe hypersensitivity: Incorrect. Severe hypersensitivity is rare with doxycycline.
