TLDR Terazosin and finasteride together cause no major issues.
The study aimed to assess the pharmacokinetic-pharmacodynamic interaction between terazosin and finasteride. The results showed that there was little evidence of clinically relevant interaction between the drugs, except for some variability in the group receiving both drugs. The concurrent administration of multiple doses of terazosin and finasteride produced no significant clinical concern.
9 citations,
October 1993 in “The Journal of Clinical Pharmacology” Finasteride doesn't affect antipyrine metabolism, so interactions with cytochrome P-450 enzyme drugs are unlikely.
86 citations,
July 1993 in “Drugs” Finasteride treats enlarged prostate, shrinks it, improves urination, but may cause sexual dysfunction and isn't for women or children.
19 citations,
May 1991 in “Journal of Chromatography B: Biomedical Sciences and Applications” Reliable method detects finasteride in human plasma at low doses.
16 citations,
January 2010 in “Drug Metabolism and Pharmacokinetics” Finasteride's effect on hair loss and prostate enlargement depends on its binding to an enzyme, with maximum impact at 0.2 mg dose.
12 citations,
January 1998 in “Drug safety” Finasteride helps reduce prostate size and symptoms in BPH but is less effective than terazosin and works best for larger prostates.
6 citations,
December 1996 in “The Journal of Clinical Pharmacology” Terazosin and finasteride together cause no major issues.
