Many antibiotic drugs exhibit high levels of protein binding which can contribute to antibiotic efficacy both positively and negatively. In humans, approximately 60% of penicillin in the bloodstream is bound to plasma proteins when the drug is within the normal therapeutic concentration range. Broad-spectrum antibiotics such as penicillin are often used to treat sepsis. However, in some cases of sepsis, severe inflammatory responses lead to hypoalbuminemia.
Using this information, please answer the following questions:
a. What change (if any) would be expected in the protein-bound and free fractions of penicillinafter a single dose in a patient with hypoalbuminemia compared to a control patient? Please assume both patients are 160 lb males that got the same dose via the same route of administration, and that drug levels were measured at the same time exactly 1 hour after penicillin administration.
b. Besides the stated facts that both of the 160 lb male patients got the same penicillin dose via the same route of administration, give list three additional characteristics of these two patients that must not differ in order to support your answers for Part (a) above and explain it in detail.
c. Clearly explain how would you expect hypoalbuminemia to affect:
i) penicillin distribution into tissues,
ii) penicillin metabolism and
iii) penicillin excretion?
d. Explain one advantage and one disadvantage caused by the relatively high level of protein binding of penicillin (in the control patient) in terms of antibiotic efficacy.