WBR1094

Author	PageAuthor::Chetan Lokhande
Exam Type	ExamType::USMLE Step 2 CK
Main Category	MainCategory::Pharmacology
Sub Category	SubCategory::Infectious Disease
Prompt	[[Prompt::A 18-year-old female presents to you with chief complaints of fever, headache, running nose, nasal congestion. After careful examination you make a diagnosis of bacterial sinusitis. You decide to start her on oral Amoxicillin as that is the recommended treatment. The patient comes to you after a week and says that her symptoms have not improved. You suspect drug resistance micro-organism. Which of these antibiotics should be prescribed considering the fact that the organism has amoxicillin resistance?]]
Answer A	AnswerA::Macrolide
Answer A Explanation	[[AnswerAExp::Incorrect: Macrolide are not recommended following failure of amoxicillin in a patient of sinusitis. They are not recommended in the treatment of sinusitis or upper respiratory tract infection buy may prove effective in lower respiratory tract infection.]]
Answer B	AnswerB::Cephalosporin
Answer B Explanation	AnswerBExp::'''Incorrect''': Cephalosporins are indicated in sinusitis only if the patient has a type 2 hypersensitivity reaction to penicillin. They are not indicated following failure of amoxicillin.
Answer C	AnswerC::Fluoroquinolone
Answer C Explanation	AnswerCExp::'''Correct''': Following no response to amoxicillin in a patient of sinusitis newer respiratory fluoroquinolones are prescribed. They include moxifloxacin and levofloxacin.
Answer D	AnswerD::Tetracyclines
Answer D Explanation	AnswerDExp::'''Incorrect''': Tetracycline specially doxycycline are indicated if the patient has a type 1 hypersensitivity to penicillins.
Answer E	AnswerE::Aminoglycosides
Answer E Explanation	AnswerEExp::'''Incorrect''': Aminoglycoside have proved to be ineffective in patients of sinusitis.
Right Answer	RightAnswer::C
Explanation	[[Explanation::The vast majority of cases of sinusitis are caused by viruses and will therefore resolve without antibiotics. However, if symptoms do not resolve within 10 days, amoxicillin is a reasonable antibiotic to use first for treatment with amoxicillin/clavulanate being indicated when the person's symptoms do not improve after 7 days on amoxicillin alone. Antibiotics are specifically not recommended in those with mild / moderate disease during the first week of infection due to risk of adverse effects, antibiotic resistance, and cost. Due to increasing resistance to amoxicillin the Infectious Diseases Society of America recommends amoxicillin-clavulanate as the treatment of choice for acute sinusitis. They also recommend against other commonly used antibiotics, including azithromycin, clarithromycin and trimethoprim/sulfamethoxazole, because of growing drug resistance. Fluoroquinolones, and a newer macrolide antibiotic such as clarithromycin or a tetracycline like doxycycline, are used in those who have severe allergies to penicillins. Because of increasing resistance to amoxicillin the 2012 guideline of the Infectious Diseases Society of America recommends amoxicillin-clavulanate as the initial treatment of choice for bacterial sinusitis. The guidelines also recommend against other commonly used antibiotics, including azithromycin, clarithromycin and trimethoprim/sulfamethoxazole, because of growing drug resistance. A short-course (3–7 days) of antibiotics seems to be just as effective as the typical longer-course (10–14 days) of antibiotics for those with clinically diagnosed acute-bacterial sinusitis without any other severe disease or complicating factors. The IDSA guideline suggest five to seven days of antibiotics is long enough to treat a bacterial infection without encouraging resistance. The guidelines still recommend children receive antibiotic treatment for ten days to two weeks. Educational Objective: If failure of treatment even after 7 days of diagnosis the the patient should be started on 1. Amoxicillin-clavulanate 4g per day of amoxicillin equivalent,2. Levofloxacin 500 mg orally once daily, 3. Moxifloxacin400 mg orally once daily. References: ]]
Approved	Approved::Yes
Keyword	WBRKeyword::Amoxocillin resistance, WBRKeyword::Sinusitis
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::