ED Drugs – Viagra, Levitra, Cialis and Staxyn
The three main drugs prescribed for erectile dysfunction are sildenafil (Viagra), vardenafil (Levitra, Staxyn) and tadalafil (Cialis). All three medications belong to the same drug class –phosphodiesterase inhibitors—and they work in a similar way: by enhancing the effects of nitric oxide, a chemical that relaxes the muscles in the penis. Once the muscles relax, blood flow to the penis increases and allows for nature to take its course—an erection in response to sexual stimulation. Read more on how erectile dysfunction drugs work
It’s important to understand that taking these drugs does not guarantee you will get an erection; they simply allow an erection to happen with the added ingredient of physical and/or psychological stimulation. Many men experience an improvement in erectile function when using these medications regardless of the cause of their impotence.
What is the Difference in ED Drugs?
Although these three drugs are in the same class, they do differ in some ways. Which one is best for you? Your doctor will make that call, yet you should know that no study has directly compared these three medications, so for now no one can say for certain which drug is best for certain types of men.
- Viagra-Sildenafil: The range of dosing is 25 to 100 mg once daily, with 50 mg being the most common dose. Viagra should be taken about one hour before sexual activity, although the range can be from 30 minutes to 4 hours. The most common side effects (and the percentage of men who typically experience them) are headache (16%), flushing (10%), heartburn (7%), stuffy nose (4%), urinary tract infection (3%), abnormal vision (3%), diarrhea (3%), dizziness (2%), and rash (2%). You should seek medical advice if any of these symptoms become severe or persistent.
- Levitra -Vardenafil: The range of dosing is 5 mg to 2o mg, depending on your needs. Vardenafil can be taken once daily. The most common side effects seen in flexible dosing studies (when men can change their dose depending on side effects) are headache (15%), flushing (11%), sneezing (9%), heartburn (4%), sinusitis (3%), dizziness (2%), and nausea (2%).
- Staxyn – Vardenafil: Staxyn is a new orally disintegrating form of vardenafil, which was approved by the FDA in June 2010 and released to the market in the United States by the end of that year. Although Staxyn and Levitra both contain the generic drug vardenafil, a 10-mg film coated tablet of Levitra is not interchangeable with a 10-mg dose of Staxyn because the latter provides higher systemic exposure than Levitra. The maximum dose of Staxyn is one tablet daily. The most common side effects are headache (14%), flushing (7%), nasal congestion (3%), heartburn (3%), dizziness (2%), and back pain (2%).
- Cialis -Tadalafil: The range of dosing is 5 mg to 20 mg, depending on your needs. This drug has been shown to improve erectile function for up to 36 hours. Studies show that the most common side effects associated with dosages of 5 mg are: headache (11%), heartburn (4%), back pain (3%), muscle pain (1%), stuffy nose (2%), flushing (2%), and limb pain (1%).
How Do Erectile Dysfunction Drugs and Pills Work?
When Not to Take ED Drugs
ED Drugs are always to be taken according to the manufacturers’ instructions. Manufacturers make a number of warnings about when not to take ED drugs including the following:
· If you take nitrate drugs for angina, such as nitroglycerin, isosorbide mononitrate, isosorbide dinitrate
· If you take blood thinning medications
· If you take certain types of alpha-blockers for blood pressure or an enlarged prostate
Also, if you have any of the following health conditions, you are strongly urged to talk to your doctor before taking any ED drugs:
· Severe heart disease or heart failure
· Stroke
· Very low blood pressure
· Uncontrolled high blood pressure
· Uncontrolled diabetes
· Liver or kidney disease
· A blood cell disorder such as sickle cell anemia, leukemia, or multiple myeloma
· Hemophilia
· A stomach ulcer
· Retinitis pigmentosa (an inherited eye condition)
There are also many other side effects and warnings associated with taking PDE5i drugs. Always consult your doctor before taking any of these drugs for ED.
What’s Wrong With 4-Hour Erections?
The advertisements on TV for the major ED drugs always advise you to “seek medical attention if you have an erection lasting longer then 4-hours”. One side effect from drugs to treat ED can be a prolonged erection (known as priapism; an erection lasting longer than four hours). A prolonged erection may also be caused by other treatments such as injections and MUSE suppositories.
Priapism is a serious medical condition, because the penis is deprived of oxygen, which damages and destroys erectile tissue. These warnings should be taken seriously and medical attention sought immediately. Often times, your doctor may give you an information card similar to the Sloan-Kettering Wallet Card for patients using penile injections. This card details the serious nature of priapism and advises the attending medical professional of treatment options and other information.
| ERECTILE DYSFUNCTION | ||||||
|---|---|---|---|---|---|---|
| Generic | Brand (Company) | Description | Strengths | Onset | Duration of Action |
Dosing Considerations |
| PDE-5 INHIBITORS | ||||||
| sildenafil | Viagra | tabs | 25mg
50mg 100mg |
0.5–2 hrs
(1 hr) |
4 hrs |
• Usually 25mg–100mg 1 hr before anticipated sexual • >65 years old: initially 25mg. • Severe renal dysfunction (CrCl<30mL/min): initially 25mg. • Hepatic impairment: initially 25mg. • Ketoconazole, itraconazole, erythromycin, saquinavir: initially • Ritonavir: max 25mg every 48 hours. • α-blockers: initially 25 mg. |
| tadalafil | Cialis | tabs | 2.5mg
5mg 10mg 20mg |
0.5–6 hrs
(2 hrs) |
36 hrs | Use as Needed:
• Usually 5mg–20mg before anticipated sexual activity. • >65 years old: no adjustment needed. • Moderate renal dysfunction (CrCl 30–50mL/min): initially • Severe renal dysfunction (CrCl<30mL/min): max 5mg per • Mild or moderate hepatic impairment: max 10mg daily; severe: not • Ketoconazole, ritonavir: max 10mg every 72 hours. • α-blockers: lowest recommended dose |
| see literature | Once–Daily Use:
• Initially 2.5mg (taken at same time each day); may increase to • Severe renal dysfunction (CrCl<30mL/min): not recommended. • Mild or moderate hepatic impairment: use caution; severe: not • Concomitant potent CYP3A4 inhibitors: max 2.5mg • For ED + BPH: 5mg taken at same time once daily without regard |
|||||
| vardenafil | Levitra | tabs | 2.5mg
5mg 10mg 20mg |
0.5–2 hrs
(1 hr)1 |
4 hrs |
• Usually 5mg–20mg 1 hour before • >65 years old: initially 5mg. • Renal dysfunction: no adjustment needed. • Mild hepatic impairment: no adjustment; moderate: max 10mg; • Ketoconazole or itraconazole 200mg/day, or erythromycin: max 5mg • α-blockers: initially 5mg. |
| Staxyn | orally disintegrating tabs | 10mg | 0.75–2.5 hrs
(1.5 hr) |
4–6 hrs |
• Take as needed approximately 60min before sexual activity (max: 10mg/day). • Not interchangeable with Levitra 10mg. • Do not take with water. Place on tongue to disintegrate. • Moderate to severe hepatic impairment or renal dialysis: not recommended. • Concomitant moderate-to-potent CYP3A4 inhibitors, α-blockers, or other erectile |
|
| PROSTAGLANDIN E1 | ||||||
| alprostadil | Caverject | injection, intracavernous | 5mcg
10mcg 20mcg 40mcg |
5–20 minutes | 1 hr |
• Usually 1.25–60micrograms within 1 hour • Max 3 injections per week with a 24-hour period between each |
| Edex | injection, intracavernous | 10mcg
20mcg 40mcg |
7 minutes | 1 hr |
• Usually 1–40micrograms within 1 hour • Max of 3 injections per week with a 24-hour period between each |
|
| Muse | suppository, urethral | 125mcg
250mcg 500mcg 1000mcg |
5–10 minutes | 0.5–1 hr |
• Initially 125–250 micrograms. • Max 2 systems per 24 hours. |
|
| α2-BLOCKERS | ||||||
| yohimbine | Yocon | tabs | 5.4mg |
• Must be taken daily for effect. |
||
| NOTES | ||||||
|
1 A recent At all time periods ≥10 minutes, a statistically superior response was seen with (Rev. 10/2011) |
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