Avodart or Proscar side effect, Decreased Libido. How do you treat it? Can you take extra testosterone?

My husband is on Avodart or Proscar so his sex drive has been really diminished. now according to the Avodart instructions it says

"How Does Avodart Work?
Avodart works by blocking the conversion of testosterone into DHT (dihydrotestosterone), thereby decreasing the amount of DHT in the body. Since DHT is responsible for enlarging the prostate, using Avodart to decrease DHT levels can treat an enlarged prostate.

So wanted to know if he could take Testosterone supplements to pump up his sex drive again. But if the conversion of testosterone into DHT, is the cause for prostate inflamation, I’m not sure if he took extra Testosterone supplements/shots, if that would make his prostate bigger too?

According to what I checked, it is not testosterone that causes the prostate to swell, but the DHT that testosterone is converted to.

Anybody have any experiece with this and is this possible ?
Viagra only gives men erections, it does not increase the libido, so that is not an option.

He has a swollen prostate so his doctor put him on Avodart and Proscar, which appear to be working for his prostate, but it killed his sex drive. He has to keep taking the medication, but he was wondering if he could take Testosterone therapy to increase his sex drive, but we are not sure if that will negate the beneficial effects of the Avodart/ proscar he is taking?
If avodart blocks the conversion of testosterone to DHT, then it shouldn’t matter if you increase the overall testosterone in a man’s body would it? I thought the Avodart is not to stop the production of testosterone, it’s just to stop it from converting to DHT isnt it?