Table 3.

Effects of antibiotics on CYP3A4 mRNA and protein expression and CYP3A4 activity in primary human hepatocytes.

Antibiotic*		QT-PCR CYP3A4/GAPDH mRNA**	Protein Expression	6β-(OH) testosterone formation rate†
Rifamycins
Rifampin		10.33 ± 5.2‡	+++++	9.67 ± 1.99‡
Penicillins
Penicillin V		1.84 ± 0.12	−	1.92 ± 1.64‡
Nafcillin		6.60 ± 2.06¶	+++	5.88 ± 2.91*
Dicloxacillin		7.70 ± 4.00	++++	5.91 ± 2.05‡
Amoxicillin		1.01 ± 0.31	−	0.87 ± 0.56
Ampicillin		1.14 ± 0.21	−	1.03 ± 0.70
Cephems
Cefadroxil		1.89 ± 0.89	++	1.75 ± 1.93
Cephalexin		1.67 ± 0.15¶	−	0.91 ± 0.54
Cephradine		2.34 ± 1.13	+	1.43 ± 1.16¶
Cefaclor		1.4 ± 0.40	+	1.19 ± 0.87
Cefuroxime		1.16 ± 0.1*	−	1.04 ± 0.68
Tetracyclines
Tetracycline		3.64 ± 1.58‡	++	2.38 ± 0.91
Doxycycline		2.80 ± 0.66¶	−	1.38 ± 0.73‡
Minocycline		1.88 ± 0.16¶	−	1.09 ± 0.74
Demeclocycline		1.70 ± 0.19¶	−	0.99 ± 0.66
Sulfonamides
Sulfisoxazole		4.05 ± 1.55‡	++	2.15 ± 1.90¶
Sulfamethoxazole		2.51 ± 0.40¶	−	1.20 ± 0.73
Macrolides
Erythromycin		3.25 ± 0.44¶	++++	0.33 ± 0.20¶
Triacetyloleandomycin		8.15 ± 2.74¶	+++++	2.03 ± 1.40‡
Lincosamides
Clindamycin		4.85 ± 2.33‡	+++	1.96 ± 0.52
Others
Griseofulvin		3.20 ± 0.86	++	0.77 ± 0.38

^*Rifampin was used in a concentration of 10 µM; all others were used at a concentration of 50 µM.

^**Fold increase over vehicle control.

^†nmol/min/mg protein.

^‡p<0.05

^¶p<0.01