II. Indications
- Erectile Dysfunction (PDE5 Inhibitor)
- Other indications
- Pulmonary Arterial Hypertension Management (PDE5 Inhibitor)
- COPD (PDE3 and PDE4 Inhibitors)
III. Contraindications
- Absolute Contraindications
- Men using nitrates (causes profound Hypotension)
- Men using alpha blockers (e.g. Hytrin for BPH)
- Relative Contraindications
- Active coronary ischemia in men not on nitrates
- Congestive Heart Failure
- Borderline low Blood Pressure
- Bordrline low volume status
- Multidrug Antihypertensive regimen
- Taking Cytochrome P450-3A4 (CYP3A4) inhibitor
- Areas where PDE5 agents may be used safely
- Safe in stable coronary disease (no nitrates)
IV. Mechanism
- Phosphodiesterase Type 5 Inhibitor
- Phosphodiesterase Type 5 causes Erection to subside
- Blocks Phosphodiesterase Type 5
- Enhances vasodilating effect of Nitrous Oxide
- Normally released during sexual stimulation
V. Medications
- Phosphodiesterase 5 Inhibitors (Erectile Dysfunction, and also used in Pulmonary Hypertension)
- Sildenafil (Viagra)
- Vardenafil (Levitra, Staxyn)
- Tadalafil (Cialis)
- Avanafil (Stendra)
- Released in 2014 with similar activity as Viagra (onset in 30 minutes and duration for 5 hours)
- Similar Drug Interactions as for Vardenafil (Levitra, Staxyn)
- Phosphodiesterase 4 Inhibitors (COPD)
- Roflumilast (Daliresp, only PDE4 activity)
- Ensifentrine (Ohtuvayre, combined PDE3 and PDE4 activity)
VI. Adverse Effects: Viagra (but most apply to the PDE5 Class as a whole)
- Hypotensive effect for men on Nitrates (Avoid)
-
Vision effects
- Light Sensitivity (Photophobia)
- Temporary color Vision disturbance (6%)
- Blue colors may appear to be green
- Blurred Vision or Vision Loss (Retinal Detachment, Optic Neuropathy)
- Higher risk if atherosclerosis
- Vision Loss can be permanent
- Appears to occur with all PDE5 Inhibitors
- Rare occurence (although some recent data as of 2022 suggests Incidence as high as 16 in 10,000)
- Etminan (2022) JAMA Ophthalmol 140(5):480-4 +PMID: 35389459 [PubMed]
- Mild Headache (21%)
- Facial Flushing (27%)
- Indigestion or Dyspepsia (11%)
- Myalgias
- Does not cause Priapism
-
Sensorineural Hearing Loss
- Sudden onset and permanent Hearing Loss
- McGwin (2010) Arch Otolaryngol Head Neck Surg 136(5):488-49 [PubMed]
VII. Drug Interactions
- Decreased effect (or delayed affect) after a fatty meal (esp. Sildenafil, Verdenafil)
- Inhibit breakdown of Viagra via Cytochrome P3A4
- Cimetidine (Tagamet)
- Ketoconazole (Nizoral)
- Itraconazole (Sporonox)
- Mibefradil (Posicor)
- Protease Inhibitors (Ritonavir, Indinavir, Saquinavir, Atazanavir)
- Macrolides (Clarithromycin, Erythromycin)
- Profound Vasodilitation and Hypotension (Avoid)
- Nitroglycerin and other Nitrates (e.g. Nitroglycerin, Isosorbide Dinitrate)
- Avoid Avanafil (Stenda) within 12 hours of nitrates
- Avoid Sildenafil (Viagra) and Verdenadil (Levitra) within 24 hours of nitrates
- Avoid Tadalafil (Cialis) within 48 hours of nitrates
- Alpha-blockers (Flomax or Tamsulosin may be used instead with caution)
- Nitroglycerin and other Nitrates (e.g. Nitroglycerin, Isosorbide Dinitrate)
VIII. Efficacy
IX. References
- (2022) Presc Lett 29(6): 33-4
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Definition (NCI) | Any substance that inhibits phosphodiesterase, an enzyme that catalyzes the breaking of a phosphodiester bond. Usually, this refers to cyclic nucleotide phosphodiesterase, an enzyme that breaks the phosphodiester bond in the second messenger molecules cAMP and cGMP. Inhibition of cyclic nucleotide phosphodiesterase can be used to affect vasodilation. |
Definition (MSH) | Compounds which inhibit or antagonize the biosynthesis or actions of phosphodiesterases. |
Definition (CSP) | any substance or agent which suppresses, prevents or opposes the actions or biosynthesis of phosphodiesterases. |
Concepts | Pharmacologic Substance (T121) |
MSH | D010726 |
SnomedCT | 346625000, 373692009 |
English | Antiphosphodiesterases, Phosphodiesterase Antagonists, Phosphoric Diester Hydrolase Inhibitors, PHOSPHODIESTERASE INHIB, PHOSPHORIC DIESTER HYDROLASE INHIB, PHOSPHODIESTERASE ANTAG, PDE Inhibitor, phosphodiesterase inhibitor, phosphodiesterase inhibitors, Phosphodiesterase inhibitor, Phosphodiesterase inhibitor (product), Phosphodiesterase inhibitor (substance), Phosphodiesterase Inhibitor, Phosphodiesterase Inhibitors |
French | Inhibiteurs de la phosphodiestérase, Antiphosphodiestérases, Anti-phosphodiestérases |
Swedish | Fosfodiesterashämmare |
Czech | sildenafil, fosfodiesteráza - inhibitory, inhibitory fosfodiesterázy, antagonisté fosfodiesterázy, fosfodiesterasa - inhibitory |
Finnish | Fosfodiesteraasinestäjät |
Russian | FOSFODIESTERAZY INGIBITORY, FOSFODIESTERAZY ANTAGONISTY, ФОСФОДИЭСТЕРАЗЫ АНТАГОНИСТЫ, ФОСФОДИЭСТЕРАЗЫ ИНГИБИТОРЫ |
Japanese | ホスホジエステラーゼ拮抗物質, ホスホジエステラーゼ阻害物質, ホスホジエステルヒドロラーゼ阻害剤, ホスホジエステラーゼ阻害剤 |
Polish | Inhibitory fosfodiesterazy |
Spanish | inhibidor de la fosfodiesterasa (producto), inhibidor de la fosfodiesterasa (sustancia), inhibidor de la fosfodiesterasa, Antagonistas de Fosfodiesterasa, Inhibidores de Fosfodiesterasa, Inhibidores de Hidrolasa Diéster Fosforica |
German | Phosphodiesterase-Antagonisten, Phosphodiesteraseinhibitoren, Phosphorsäure-Diester Hydrolase Inhibitoren |
Italian | Inibitori della fosfodiesterasi |
Portuguese | Antagonistas da Fosfodiesterase, Inibidores de Fosfodiesterase, Inibidores de Fosfodiester Hidrolase |
Ontology: Phosphodiesterase 5 inhibitor (C1318700)
Definition (MSH) | Compounds that specifically inhibit PHOSPHODIESTERASE 5. |
Concepts | Pharmacologic Substance (T121) |
MSH | D058986 |
SnomedCT | 407313002, 407316005 |
English | Phosphodiesterase 5 inhibitor, PDE-V Inhibitor, Phosphodiesterase V Inhibitor, PDE5 Inhibitor, Inhibitors, PDE5, Phosphodiesterase Type 5 Inhibitors, Phosphodiesterase 5 Inhibitors, Inhibitors, PDE-5, PDE 5 Inhibitors, PDE-5 Inhibitors, Inhibitors, Phosphodiesterase 5, PDE5 Inhibitors, pde 5 inhibitor, 5 inhibitors phosphodiesterase, phosphodiesterase 5 inhibitor, PDE 5 inhibitor, Phosphodiesterase 5 inhibitor (product), Phosphodiesterase 5 inhibitor (substance) |
French | Inhibiteurs de la PDE-5, Inhibiteurs de la phosphodiestérase de type 5, Inhibiteurs de la phosphodiestérase-5, Inhibiteurs de la PDE5 |
German | PDE5-Hemmer, Phosphodiesterase-5-Inhibitoren, PDE5-Inhibitoren, PDE-5-Inhibitoren, Phosphodiesterase-5-Hemmer, PDE-5-Hemmer |
Czech | PDE5 inhibitory, fosfodiesterasa 5 - inhibitory, fosfodiesteráza 5 - inhibitory, inhibitory fosfodiesterázy 5 |
Italian | Inibitori della fosfodiesterasi 5 |
Spanish | Inhibidores de Fosfodiesterasa 5, inhibidor de fosfodiesterasa 5 (producto), inhibidor de fosfodiesterasa 5 (sustancia), inhibidor de fosfodiesterasa 5 |
Russian | ФОСФОДИЭСТЕРАЗЫ 5 ИНГИБИТОРЫ, FOSFODIESTERAZY 5 INGIBITORY |
Portuguese | Inibidores da Fosfodiesterase 5 |
Polish | Inhibitory 5 fosfodiesterazy |