This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Post exposure prophylaxis for HIV should be given for a minimum period of: March 2005 
Select and explain. 
A. 4 weeks, B. 6 weeks, C. 8 weeks, D. 10 weeks
A: 4 weeks
Answer: A: 4 weeks 
Explanation: Ans. A: 4 weeks PEP should normally be continued for 4 weeks. This time course, or the drugs used may need to be modified if problems of tolerance and/or toxicity are encountered .Since nausea is a common problem, the prescription of prophylactic anti-emetics should be considered. Anti-motility drugs may be helpful if diarrhoea develops - a common side effect of nelfinavir. A combination of two nucleoside analogue reverse transcriptase inhibitors for less severe exposures and combination of two nucleoside analogue reverse transcriptase inhibitors and a 3rd drug for severe exposures.