Tadalafil- An Overview
Tadalafil has a half-life of 17.5 hours; therefore, it can work as long as 36 hours in comparison to Sildenafil and Vardenafil those work for 8 and 10 hours respectively. The advantage of its longer duration of action is, it can be taken as a once a day prescription and even longer than that. For the same reason, it is often called a “weekend pill”.
Mechanism of Action: Tadalafil works by inhibiting the enzyme phosphodiesterase-5E (PD5E), which is normally found in our blood vessels. This enzyme acts to break down cyclic Gaunosine Monophosphate (cGMP) that acts to dilate the blood vessels, hence increasing the blood flow to any organ. Inhibition of the enzyme PDE5 results in increased levels of cGMP because of its decreased breakdown by the same enzyme, which in turn results in increased blood flow to a particular organ. Tadalafil is specially used for erectile dysfunction regarding the same fundamentals of increased blood flow through the penile blood vessels, which results in erection.
However, it has no response in the absence of sexual stimulation because the primary mediator for release of cGMP is nitric oxide (NO) that is released from the blood vessels only in the presence of sexual stimulation. Therefore, it can be used to attain erection in patients with erectile dysfunction while having sexual intercourse.
Indications: As of now, Tadalafil is being used for the treatment of erectile dysfunction only. Its other clinical usages are still under study particularly its use in patients with pulmonary arterial hypertension. It is commonly prescribed in such patients who do not respond to one of the other agents like, Sildenafil (Viagra) or Vardenafil (Levitra) as it has a longer half-life or duration of action (approx. 36 hours) than the traditional ones.
Tadalafil Usage/Dose: Ideally it should be taken as prescribed and indicated by your attending physician. It can be taken before or after meals and with water. However, it should not be taken with alcohol and grapefruit juice because of some drug interactions that can take place if it is taken with any of these substances. The recommended dose for Tadalafil is 10 mg. The dose may be increased to 20 mg or decreased to 5 mg based on its effects and side effects.
Side Effects: The most common side effects are those related to the increased blood flow to other parts of the body. For example, it can cause headache due to increased blood flow in vessels of brain. It can cause indigestion, flushing, backaches, muscle pains, runny nose due to increased blood flow to the respective organs blood vessels. Certain patients can also experience altered color vision. These effects are not long lasting and usually subside after 36-48 hours when the drug is metabolized in our body and excreted to vain off its effects. Priapism or painful erection can occur in some patients. If the side effects last longer than 4 hours or become troublesome, you should immediately contact your physician and seek medical attention.
Contraindications: It is generally contraindicated in patients who already suffer from other blood vessel disorders.
Caution is advised for men who have
- suffered a heart attack, stroke or a life-threatening arrhythmia within the previous 6 months
- Men who have resting hypotension (decreased blood pressure) or hypertension (increased blood pressure)
- And men who have a history of heart failure or have unstable angina.
Drugs to be avoided while taking Tadalafil: Patients are advised not to take the following drugs while on Tadalafil treatment.
1. Other drugs with similar modes of action, for example, Sildenafil (Viagra),Vardenafil (Levitra), Alprostadil (Muse, Edex, Caverject) and Yohimbine (Yodoxin, Yocon) etc. so as to prevent increased manifestation of their effects and side- effects.
2. Drugs that interfere with its metabolism in our body to potentiate its effects, such as Erythromycin (E-mycin), Itraconazole (Sporanox), Ketoconazol (Nizoral) etc.
3. The concurrent use of anti-HIV drugs especially protease inhibitors like, Indinavir, Ritonavir, Saquinavir and others should also be avoided.
4. Use of Nitrates such as Nitrolingual, Nitrostat, Minitran, Nitro-Dur, Nitro-Bid, Deponit, Isordil, Sorbitrate, Dilatrate-SR, ISMO, Monoket, Imdur is contraindicated in patients on Tadalafil due to their similar effects on smooth muscle relaxation in blood vessels, which can eventually result in very low blood pressure, and even sudden death.
5. Alpha-blockers such as Doxazocin (Cardura), Prazosin (Minipress), Terazosin (Hytrin), Guanadrel (Hylorel), and Alfuzosin (Uroxatral) should also be avoided due to their vasodilating effects on blood vessels.
6. Any subsequent administration of other herbal, natural, or homemade prescriptions should also be avoided or at least it should be done only after consulting your doctor.
Jamie is the author of Generic Cialis, Tadalafil information located at Generic Cialis, Tadalafil site