Ed. Daniels et al., RHEUMATIC-FEVER PROPHYLAXIS IN SOUTH-AFRICA - IS BICILLIN 1,2-MILLIONUNITS EVERY 4 WEEKS APPROPUIATE, South African medical journal, 84(8), 1994, pp. 477-481
Rheumatic fever is a major health problem in South Africa. Although in
tramuscular benzathine penicillin (bicillin) 1,2 million units (MU) ev
ery 4 weeks is widely used for secondary prophylaxis, studies in other
countries have shown a recurrence rate of 3 - 8% over 5 - 6 years in
patients on this regimen. It has been recommended that serum penicilli
n concentrations should be maintained above 0,02 mg/ml to prevent such
recurrences. The World Health Organisation (WHO) and the American Hea
rt Association have recommended since 1988 that patients in high-risk
areas for the development of rheumatic fever should receive benzathine
penicillin 1,2 MU every 3 weeks rather than every 4. The aims of this
study were, firstly, to determine the prevalence of serum penicillin
concentrations below 0,02 mu g/ml in rheumatic fever patients on benza
thine penicillin 1,2 MU 1-weekly and, secondly, to study the effect of
increasing the dose to 1,8 MU 4-weekly in patients with subtherapeuti
c concentrations. Forty-five of 51 rheumatic fever patients (88%) in t
his study on benzathine penicillin 1,2 MU 4-weekly had low serum penic
illin concentrations (< 0,02 mu g/ml) at the end of the 4th week after
the injection. Penicillin was detected in the urine of 30 of the 45 p
atients (67%) with low concentrations, suggesting that such patients h
ave tissue-bound penicillin which might be important in preventing rhe
umatic fever. The 15 patients (33%) with subtherapeutic serum penicill
in concentrations and no detectable penicillin in the urine could be a
t very high risk for recurrent attacks of rheumatic fever. Fourteen of
29 patients (48%) given the higher dose of benzathine penicillin (1,8
MU 4-weekly) had subtherapeutic serum penicillin concentrations at th
e end of the 4th week after the injection, but in all 29 penicillin wa
s detected in the urine. Review of our present policy of secondary pro
phylaxis for rheumatic fever is necessary. Concentrated preparations o
f benzathine penicillin (600 000 U/ml) are not available in South Afri
ca; administration of a higher dose (1,8 MU) 4-weekly would therefore
require a double injection, which could affect compliance adversely. W
e recommend that rheumatic fever patients in our area should receive b
enzathine penicillin 1,2 MU 3-weekly as recommended by the WHO until s
trategies for secondary prophylaxis have been evaluated further.