Asthma may be moderately treated as well as some skin disorders; notably plaque psoriasis for which Apremilast is formally approved for. Drotaverine, though not directly indicated for skin disorders has shown efficacy in smaller pilot studies.
Apremilast is also known by it's trade-name/brand-name OTEZLA; frequently shown on TV ads as a primary treatment for plaque psoriasis.
Rolipram is used in scientific study as an anti-depressant and shows high affinity for brain PDE4.
BUYING PDE-4 INHIBITORS ONLINE
Drotaverine can be purchased online without a script --> http://www.internationaldrugmart.com/drotaverine.shtml
Rolipram can be purchased on apex bio with ease. --> http://www.apexbt.com/rolipram.html
The only natural PDE 4 inhibitor with any appreciable affinity for the PDE4 isoform would be butea superba; however, it is less potent than it's pharmaceutical superiors...none the less, it does have beneficial effects on blood vessels, testosterone levels and on the brain/CNS.
All other PDE Inhibitors such as Tadalafil (Cialis) and Sildenafil (Viagra) can be bought --> HERE http://www.secure-sales.org.uk/clinic/page.cgi?id=inversi0n