Tadalafil (Cialis) is the third oral medicine approved by the U.S. FDA for the treatment of erectile dysfunction. Like sildenafil (Viagra) and vardenafil (Levitra), tadalafil inhibits PDE5 (as described earlier).
How effective is Tadalafil (Cialis)?
The safety and efficacy of Tadalafil in the treatment of erectile dysfunction was evaluated in 22 clinical trials involving more than 4,000 men. Seven of these trials were randomized, prospective, placebo-controlled studies of 12 weeks' duration. Two of these studies (involving 402 men) were conducted in the United States, and the other five studies (involving 1,112 men) were conducted outside the United States. Two of these trials were conducted in special populations with erectile dysfunction; one in men with diabetes mellitus, another in men who developed erectile dysfunction after nerve-sparing prostate cancer surgery.
Effectiveness of Tadalafil in these studies was assessed using a sexual function questionnaire. Study participants also were asked if they were able to achieve vaginal penetration and to maintain erections long enough for successful intercourse.
In all seven trials, Tadalafil was significantly better than placebo in improving men's ability to achieve and maintain erections. Improvements in erectile function was observed in some patients at 30 minutes after taking a dose; and improvements can last for up to 36 hours after taking Cialis when compared to placebo.
How should Tadalafil (Cialis) be administered?
The recommended starting dose of Tadalafil for most patients is 10 mg taken orally approximately one hour before sexual activity. The dose may be adjusted higher to 20 mg or lower to 5 mg depending on efficacy and tolerability. The maximum recommended dosing frequency is once per day, although for many patients Tadalafil can be taken less frequently since the improvement in erectile function may last 36 hours. Tadalafil may be taken with or without food. Tadalafil is also available in 2.5 mg. or 5 mg. dosages for daily use
What are the side effects of Tadalafil (Cialis)?
Tadalafil is generally well tolerated with only mild side effects.
The most common side effects reported include:
- headache
- indigestion
- back pain
- muscle aches
- facial flushing
- nasal congestion.
Reports of abnormal vision were rare; it occurred in less than 0.1% of patients using Tadalafil.
There have been rare reports of priapism (prolonged and painful erections lasting more than six hours) with the use of oral PDE5 inhibitors such as vardenafil, sildenafil, and tadalafil. Men with blood cell diseases such as sickle cell anemia, leukemia, and multiple myeloma have higher than normal risks of developing priapism. Untreated priapism can cause injury to the penile tissue and lead to permanent loss of potency. If there is prolonged erection (longer than four hours), immediate medical assistance should be sought.
Who should not use Tadalafil (Cialis)?
Tadalafil can cause hypotension (abnormally low blood pressure, which can lead to fainting and even shock) when given to patients who are taking nitrates. Patients taking nitrates daily should not take tadalafil. Most commonly used nitrates are medications to relieve angina (chest pain due to insufficient blood supply to heart muscle because of narrowing of the coronary arteries). These include nitroglycerine tablets, patches, ointments, sprays, pastes, and isosorbide dinitrate and isosorbide mononitrate. Other nitrates such as amyl nitrate and butyl nitrate are found in some recreational drugs called "poppers."
Tadalafil should not be used with alpha-blockers, medicines used to treat high blood pressure and benign prostate hypertrophy (BPH) because the combination of Tadalafil and an alpha-blocker may lower the blood pressure greatly and lead to dizziness and fainting.
Tadalafil is not recommended for men with the following conditions:
- unstable angina (chest pain due to coronary artery disease that occurs at rest or with minimal physical exertion),
- low blood pressure (a resting systolic blood pressure less than 90mm Hg),
- uncontrolled high blood pressure (greater than 170/110 mm Hg),
- recent stroke or heart attack (within six months),
- uncontrolled, potentially life-threatening abnormal heart rhythms,
- severe liver disease,
- severe heart failure or disease of the heart valves, for example, aortic stenosis,
- retinitis pigmentosa.
When there is angina or heart failure, the doctor may need to determine whether the heart has enough reserve to safely carry out the work necessary for sexual activity by performing cardiac treadmill stress testing.
What precautions should be taken when using Tadalafil?
In most healthy men, some of the drug will remain in the body for more than two days after a single dose of Tadalafil. Metabolism (clearing of the drug from the body) of tadalafil can be slowed by liver disease, kidney disease, and concurrent use of certain medications (such as erythromycin, ketoconazole, and protease inhibitors). Slowed breakdown allows Tadalafil to stay in the body longer and potentially increase the risk for side effects. Therefore, the dose and frequency of tadalafil has to be lowered in the following examples:
Men with severe liver disease should not take Tadalafil. Men with mild to moderate liver disease should not exceed Tadalafil dose of 10 mg once daily.
No comments:
Post a Comment