Tadalafil Citrate - Cialis Profile

Tadalafil Citrate/Cialis Profile


Pharmaceutical Name: Tadalafil Citrate
Drug Classification: Long-Acting Type 5 Phosphodiesterase Isoenzyme Inhibitor
Active Life: 36-48 hours




Long-acting type 5 phosphodiesterase isoenzyme inhibitors are a class of drugs currently prescribed for the treatment of erectile dysfunction in males. Tadalafil citrate was made available after the initial drug, sildenafil citrate, had been on the market for several years. While sharing many of the pharmacokinetic properties and type 5 phosphodiesterase isoenzyme inhibitory activity profiles (1), there are several differences in the actions of the drugs although for the most part the results experienced by the user are relatively the same. The major difference between the drugs is the active life of tadalafil citrate. By extending the active life of the drug to approximately thirty-six to forty-eight hours, this allows users to be far less restricted in their dosing protocol and, for lack of a better word, spontaneity.

For the purposes of steroid users the use of tadalafil citrate is rather limited beyond that of a “recreational” purpose. One exception to this may be once a steroid user is coming off of anabolic-androgenic steroids and have suffered a significant reduction in their ability to perform sexually and/or their sex drive. The use of drugs such as tadalafil citrate can help to alleviate some of the difficulty many have during this period of time.

Type 5 phosphodiesterase isoenzyme inhibitors such as tadalafil citrate work by causing the smooth-muscles to relax in the cavernosal arteries. This in turn allows penile vasodilation and erection to occur in response to sexual stimuli (1, 2). This response allows one to achieve and maintain an erection and will help with doing so for a number of causes of the erectile dysfunction.

The effects produced by type 5 phosphodiesterase isoenzyme inhibitors can include other benefits such as a reduction in blood pressure and exhibiting other cardioprotective properties. This reduction in blood pressure includes a lowering of arterial pressure, systolic and diastolic (3, 4). Other heart protecting effects such as an improvement in atherosclerotic disease and endothelial function can also be observed with sustained use of the drug (5). These benefits, while having been proven under clinical settings, have not been put into practice in any substantive way by medical professionals on any large scale.

Nearly all of the research and scientific study of the drug tadalafil citrate has been conducted using male subjects. A small number of studies however have been done with female users. For the most part these studies have indicated that for the purpose of sexual function there appears to be a benefit that females could render from the use of tadalafil citrate (6); at this time however not enough research has been completed to be able to make recommendations about the safe and effective use of tadalafil citrate for females.


Use/Dosing

For most users, doses ranging between ten to forty milligrams should be sufficient to achieve the desired results, but as always users may use larger doses depending on their tolerance for the drug and/or their specific needs. The active life of tadalfail citrate is thirty-six to forty-eight hours (7); this long active life of course being one of the benefits of the drug and a half-life of approximately seventeen and one half hours (2), therefore one dose should be adequate for three or four days unless the user believes that the initial dosage that was administered was not enough to produce the expected results. This means that at most two or three doses per week would be the absolute maximum that a user would need to administer.

The majority of the commercially available forms of tadalafil citrate is produced and marketed as either tablets or capsules. Some underground and non-pharmaceutical company producers however also produce liquid products containing the drug. All of these products are ingested orally.

In terms of the duration with which a user can administer tadalafil citrate without experiencing any negative side effects, it appears that the drug can be used continuously for months on end without the user building a tolerance to the drug (8). Studies conducted beyond several months have not yet been conducted however. As well, these studies have not taken into account possible psychological addiction/reliance to this drug and similar ones. Despite this however there is no evidence at this time that indicates physical and/or mental reliance on these drugs are an issue with which a user would have to concern them self with, at least at this current time.


Risks/Side Effects

For the most part tadalafil citrate is well tolerated by the vast majority of users, but some risks do exist. The most commonly referred to side effect is long lasting erections requiring medical intervention. These are relatively rare and are almost never seen when a user is using the correct dosage of the drug. But if such a condition does arise the user should seek medical attention as significant physical harm can come to the user if they allow the symptom to persist for a lengthy period of time.

A more dramatic and concerning negative side effect that has more recently been publicized to a great extent is visual impairment linked to the use of type 5 phosphodiesterase isoenzyme inhibitors such as tadalafil citrate. This visual impairment is caused when blood flow to the optic nerve is disrupted; a condition known as nonarteritic ischemic optic neuropathy (9). This condition appears to be possible with all type 5 phosphodiesterase isoenzyme inhibitors used to treat erectile dysfunction. It is extremely rare in it’s occurrences in users of the drugs but has been linked in some cases of the condition. The direct causal connection between the drugs and nonarteritic ischemic optic neuropathy has not been established however. If a user is to develop eyesight difficulty while using tadalafil citrate they should consult with a physician as soon as possible.

As indicated earlier, tadalafil citrate has the ability to help lower blood pressure in some users (4). This positive effect is counteracted however by the possibility of causing problematic drops in blood pressure in users with already relatively low blood pressure readings. For this reason users who have low blood pressure should at the very least be careful when administering the drug and in the more severe cases of the condition should avoid the drug completely.



References

1. Mehrotra N, Gupta M, Kovar A, Meibohm B. The role of pharmacokinetics and pharmacodynamics in phosphodiesterase-5 inhibitor therapy. Int J Impot Res. 2006 Sep 21.

2. Wright PJ. Comparison of phosphodiesterase type 5 (PDE5) inhibitors. Int J Clin Pract. 2006 Aug;60(8):967-75.

3. Sesti C, Florio V, Johnson EG, Kloner RA. The phosphodiesterase-5 inhibitor tadalafil reduces myocardial infarct size. Int J Impot Res. 2006 Jul 20.

4. Patterson D, McInnes GT, Webster J, Mitchell MM, Macdonald TM. Influence of a single dose of 20 mg tadalafil, a phosphodiesterase 5 inhibitor, on ambulatory blood pressure in subjects with hypertension. Br J Clin Pharmacol. 2006 Sep;62(3):280-7.

5. Aversa A, Greco E, Bruzziches R, Pili M, Rosano G, Spera G. Relationship between chronic tadalafil administration and improvement of endothelial function in men with erectile dysfunction: a pilot study. Int J Impot Res. 2006 Aug 31.

6. Mayer M, Stief CG, Truss MC, Uckert S. Phosphodiesterase inhibitors in female sexual dysfunction. World J Urol. 2005 Dec;23(6):393-7.

7. Young JM, Feldman RA, Auerbach SM, Kaufman JM, Garcia CS, Shen W, Murphy AM, Beasley CM Jr, Hague JA, Ahuja S. Tadalafil improved erectile function at twenty-four and thirty-six hours after dosing in men with erectile dysfunction: US trial. J Androl. 2005 May-Jun;26(3):310-8.

8. McMahon CG, Carson CC, Fischer CJ, Wang WC, Florio VA, Bradley JD. Tolerance to the therapeutic effect of tadalafil does not occur during 6 months of treatment: A randomized, double-blind, placebo-controlled study in men with erectile dysfunction. J Sex Med. 2006 May;3(3):504-11.

9. Wooltorton E. Visual loss with erectile dysfunction medications. CMAJ. 2006 Aug 15;175(4):355.