This study was conducted to investigate the effects of matrix metalloproteinase (MMP) inhibitors dexamethasone and minocycline administrations —both single and in combination with N-acetylcysteine (NAC) and vitamin E—on the tissue distribution and lethal dose (LD)50 of aflatoxin (AF)B1 in rats. We performed this study on male Wistar rats (8–10 weeks) in two phases. In the first phase, rats were administered dexamethasone (5 and 20 mg/kg) and minocycline (45 and 90 mg/kg), both as single treatments and in combination with NAC (200 mg/kg) and vitamin E (600 mg/kg); these treatments followed AFB1 administration (2 mg/kg). In the second phase, the therapeutic effect value (TEV) was calculated to determine the treatment effect on the LD50 level of AFB1. The tissue affinity of AFB1 from high to low was liver, kidney, intestine, brain, heart, spleen, lung, testis, and vitreous humor, respectively. Dexamethasone at the 20 mg/kg dose significantly reduced AFB1 concentrations in the plasma and the other tissues, except for the vitreous humor. The effects of minocycline on the plasma and tissue concentrations of AFB1 varied by dose and tissue. The combinations of dexamethasone or minocycline with NAC and vitamin E increased the AFB1 concentrations in the plasma and all tissues, except for vitreous humor and liver. In male rats, the LD50 value of AFB1 was 11.86 mg/kg. The TEV of dexamethasone (20 mg/kg) was calculated to be 1.5. Dexamethasone can be administered in repeated doses at ≥20 mg/kg to increase survival in AFB1 poisoning.