purchase & taking medicine out of the country

A friend of mine, her mother has PAH and need to use a certain medicine for 6 months, but the cost is like HKD 7000 approximate JPY 102200 for 1 month supply, the medicine is call Revatio by pfizer or sometimes called Sildenafil Citrate from other brand, it's a prescription medicine in Hong Kong but can be purchased in the US with/without prescription.

Does anyone know if they can be purchase off the counter in pharmacies in Japan without prescriptions, and can it be taken out of the country, will it be cheaper and can you purchase generic type of the same medicine.

First, check the Customs laws in your country. It may be illegal to import what is a prescription medication in your country without a prescription.

It should be alright over at my end, I have a copy of a doctors letter for the purchase of this medicine.

It's prescription medicine also here in Japan.

Thanks, I guess the doctors letter from Hong Kong is not accepted in Japan.