<prompt> Drug which can used in management of streptococcal endocarditis susceptible to penicillin, but patient developing immediate allergy following penicillin administrationCeftriaxoneVancomycinMeropenemCarbenicillin  <response>: Ans. is b i.e., Vancomycin Following table depicts the medical treatment of choice in patients with streptococcal endocarditis:Antibiotic Treatment for infective Endocarditis Caused by Common OrganismsOrganismDrug Dose, DurationCommentsStreptococciPe nicill i n - susceptible streptococci, S. gallolyticus Penicillin G 2-3 mU IV q4h for 4 weeks-- Ceftriaxone 2 gd IV as a single dose for 4 weeks Vancomycin 15 mgkg IV q I2h for 4 weeks Penicillin G 2-3 mU IV q4h or ceftriaxone 2 g IV qd for 2 weeks plus Gentamicin or divided into equal doses q8h for 2 weeksCan use ceftriaxone in patients with nonimmediate penicillin allergy Use vancomvcin in patients with severe or immediate b-lactam allergyAvoid 2-weeks regimen when risk of aminoglycoside toxicity is increased and in prosthetic valve or complicated endocarditisRelatively penicillin - resistant streptococci Penicillin G 4 mU IV q4h or ceftriaxone 2 g IV qd for 4 weeks plus Gentamicindd 3mgkg qd IV or IM, as a single dosee or divided into equal doses q8h for 2 weeks Vancomycin0 as noted above for 4 weeksPenicillin alone at this dose for 6 weeks or with gentamicin during initial 2 weeks preferred for prosthetic valve endocarditis caused by streptococci with penicillin MICs of 0.1 mg mLModerately penicillin -resistant streptococci, nutritionally variant organisms, or Gemella morbillorum Penicillin G 4-5 mU IV q4h or ceftriaxone 2g IV qd for 6 weeks plus Gentamicin 3 mgkg qd IV or IM as a single dosee or divided into equal doses q8h for 6 weeksPreferred for prosthetic valve endocarditis caused by streptococci with penicillin MICs fo 0.1 mgmL Vancomycinc as noted above for 4 weeks-- 