Which drug is not used for erectile dysfunction?
a. Physiological erection occurs in response to release of nitric oxide from nonadrereigic - norcholinergic nerves associated with parasympathetic discharge.
Nitric oxide acts by activating guanylyl cyclase →↑ CGMP → cavemosal relaxation resulting in erection.
Thus the drugs which can be used for erectile dysfunction are:
- PGE-1 analogues eg Alprostadil
- Sildenafil (PDE - inhibitor) and its congeners tadalafil and vardenafil
- Apomorphine (releases DA in CNS).