Splenomegaly Medication

The goals of pharmacotherapy in cases of splenomegaly are to reduce mortality and prevent complications. Recall that in the absence of a functional spleen, patients have a defect in bacterial clearance due to impaired opsonization. In particular, these patients are at risk for OPSI due to infection with encapsulated organisms such as H influenzae, N meningitidis, and S pneumoniae.^[17]

As previously mentioned, all patients scheduled for elective splenectomy (either diagnostic or therapeutic) should receive a pneumococcal vaccine.

Class Summary

Vaccines aid in the generation of an anamnestic response to invasion with the target organism.

Pneumococcal vaccine (Pneumovax 23)

This vaccine contains capsular polysaccharides of 23 pneumococcal types that together account for 98% of pneumococcal disease isolates.

Meningitis group A C Y and W-135 vaccine (Menomune-A/C/Y/W-135)

This vaccine contains capsular polysaccharide antigens (groups A, C, Y, and W-135) of N meningitidis. It may be used to prevent and control outbreaks of serogroup C meningococcal disease, according to guidelines from the US Centers for Disease Control and Prevention (CDC). The vaccine induces the formation of bactericidal antibodies to meningococcal antigens. It is used for active immunization against invasive meningococcal disease caused by inclusive serogroups. The vaccine induces antibody response for serogroup A in individuals as young as 3 months, but it is poorly immunogenic for serogroup C in recipients younger than 18-24 months.

Haemophilus influenza type b conjugate vaccine (ActHIB, Hiberix, PedvaxHIB)

This vaccine is used for the routine immunization of children against invasive diseases caused by H influenzae type B. It decreases nasopharyngeal colonization. The CDC Advisory Committee on Immunization Practices has recommended that all children receive a conjugate vaccine licensed for infant use at age 2 months.

Class Summary

The diagnostic workup should never delay the use of empiric therapy. Empiric antimicrobial therapy must be comprehensive and should cover all likely pathogens in the context of the clinical setting.

Possible choices of empiric antimicrobial agents include cefotaxime and ceftriaxone. Unfortunately, some penicillin-resistant pneumococcal isolates are also resistant to cephalosporins. If such resistance is suggested, consider using vancomycin.

Cefotaxime (Claforan)

Cefotaxime (adult dose of 2 g IV q8h; pediatric dose of 25-50 mg/kg IV q6h) is a third-generation cephalosporin with excellent in vitro activity against GBS and E coli and other gram-negative enteric bacilli. It attains good concentrations in serum and cerebrospinal fluid (CSF). Concern exists that emergence of drug-resistant gram-negative bacteria may occur at a more rapid rate with cefotaxime than with traditional penicillin and aminoglycoside coverage. Cefotaxime is ineffective against Listeria and enterococci; use it in combination with ampicillin.

Ceftriaxone (Rocephin)

Ceftriaxone (adult dose of 2 g IV q12-24h; pediatric dose of 50 mg/kg IV q12h) is a third-generation cephalosporin with broad-spectrum gram-negative activity; it has lower efficacy against gram-positive organisms and higher efficacy against resistant organisms. Ceftriaxone arrests bacterial growth by binding to 1 or more penicillin-binding proteins.

Vancomycin

Vancomycin is a bactericidal agent effective against most aerobic and anaerobic gram-positive cocci and bacilli. It is especially important in the treatment of methicillin-resistant Staphylococcus aureus (MRSA) and is recommended when coagulase-negative staphylococcal sepsis is suspected.