PENTAQUINE (SN-13,276), A THERAPEUTIC AGENT EFFECTIVE IN REDUCING THE RELAPSE RATE IN VIV AX MALARIA 1

Abstract

The therapeutic effect of pentaquine (SN-13,276) has been studied in acute attacks of Chesson Southwest Pacific strain of vivax malaria, under standardized conditions. Pentaquine reduces the relapse rate. Its curative properties are enhanced by the concurrent admn. of quinine, A daily dose of 60 mg. of pentaquine base (80 mg. of the monophosphate) and 2 g. of quinine sulfate, admd. concurrently in divided doses every 4 hrs. for 14 days, reduced the relapse rate in severely infected patients from 98% to 18%. In moderate infections, the relapse rate was reduced from 67% to 4%. With massive infections, however, continued pentaquine-quinine therapy failed to prevent relapse in the 4 subjects studied. Some evidence suggests that considerably lower doses of pentaquine may effect a radical reduction of relapse rate of vivax malaria in individuals who stop suppressive therapy upon return to non-endemic areas after long residence in hyper-endemic regions. Pentaquine should only be admd. under close medical supervision, preferably during hospitalization. The daily dose of 60 mg. base should not be exceeded. This dose has approx. the same toxicity as 30 mg. of pamaquin (base) or 67 mg. of its naphthoate salt. The toxicity of pentaquine is too great to warrant its use in prophylaxis or prolonged suppression of malaria. The safe therapeutic dose for children and the toxicity of the drug in Negroes and individuals of mixed racial extraction is at present undetermined.