TABLE 3.
Antimalarial activities of chloroquine, atovaquone, doxycycline, and pyrimethamine according to the different antimalarial in vitro tests
| Drug | Incubation period (h) | Geometric mean of IC50 in nM (95% CI) as determined usinga: |
||||
|---|---|---|---|---|---|---|
| MIC | [3H]HX | SYBR green | pLDH | HRP2 | ||
| Chloroquine | 48 | 14.79 | 9.56 (7.58-12.07) | 11.54 (4.74-28.12) | 14.97 (12.37-18.12) | 10.10 (8.04-12.69) |
| 72 | 4.60 | 10.04 (8.8-11.45) | 8.70 (6.17-12.28) | 9.48 (6.82-13.18) | 9.68 (7.03-13.31) | |
| Atovaquone | 48 | 0.11 | 0.06 (0.05-0.07) | 0.06 (0.02-0.18) | 6.05 (4.07-9) | 0.32 (0.12-0.82) |
| 72 | 0.13 | 0.13 (0.11-0.16) | 0.07 (0.07-0.08) | 0.30 (0.25-0.36) | 0.79 (0.39-1.58) | |
| Doxycycline | 48 | 6.58 | 2.85 (1.84-4.4) | 10.20 (8.49-12.26) | 24.39 (7.14-83.28) | 7.73 (7.56-7.9) |
| 72 | 4.20 | 0.48 (0.34-0.68) | 4.90 (3.67-6.57) | 9.68 (8.21-11.42) | 13.09 (10.27-16.7) | |
| 96 | 0.25 (0.24-0.27) | 0.35 (0.29-0.42) | 8.37 (6.48-10.81) | 21.37 (5.85-78.01) | ||
| 96 (drug removed)c | 0.23 | 0.21 (0.09-0.5) | 0.49 (0.47-0.5) | 11.38 (7.54-17.18) | 12.50 (5.74-27.18) | |
| Pyrimethamineb | 48 | 3.33 | 2.98 (2.7-3.3) | >100 | >100 | 3.29 (0.63-17.21) |
| 72 | 4.53 | 3.62 (3.2-4.14) | 3.79 (3.22-4.45) | 4.09 (3.82-4.38) | 4.63 (2.54-8.45) | |
| Pyrimethamine | 48 | 32.20 | 19.33 (17.7-21.1) | >100 | >100 | 26.57 (20.28-34.82) |
| 72 | 26.30 | 19.35 (13.96-26.81) | 23.92 (22.47-25.48) | 27.91 (24.74-31.49) | 53.85 (46.06-62.96) | |
a
MIC, microscopy; HX, hypoxanthine. Values in boldface do not match the real IC50 (see the text).
b
RPMI SP823 (with less PABA and folic acid).
c
That is, the drug was removed at 48 h and replaced by fresh complete medium.