Raloxifene vs. Tamoxifene

SERMS are "designer" estrogen-related medications that activate the estrogen receptors, but have different effects on different tissues. There are two kinds of estrogen receptors, and after binding to receptors, the drug-receptor complex can have various conformations. Some of these will act like estrogen, others will inhibit the actions of estrogen.

Advantages of Raloxifene:
Many screening studies of related compounds have been done to search for those which act like estrogen in the desireable ways (stablize bone mass, improve lipid profile) but do not act like estrogen in undesireable ways (cause breast cancer, stimulate the endometrium). The effects on the cardiovascular system are still uncertain: when Ralox was first developed it was felt that estrogen had a beneficial action on the heart, now this is doubted and debated.

Effects on bone physiology
# Decreased bone formation and resorption
# No significant change in bone volume
# Slight increase in mineralization density
# No evidence of osteomalacia or bone toxicity

Another effect of Ralox is that users had fewer asthma attacks and less severe asthma symptoms, strongly suggesting that perhaps estrogen affects airway smooth muscle function by preventing the hyperresponsiveness characteristic of asthma and other chronic lung diseases.

Toxicology report that estrogen, as well as selective estrogen receptor modifiers (SERMs), completely abolished abnormal tracheal constriction in a carbachol test.Carbachol is often used to stimulate, or mimic, contractions of airway and other muscles.

Estrogen has a wide range of actions in the nervous system, including neuroprotection and potentiation of nerve regeneration (Toran-Allerand, 1999; Tanzer et al., 1999; McEwen et al., 2001; Islamov et al., 2002). In spite of the beneficial actions of estrogen on the nervous system, the opportunities for its wide therapeutic application are severely limited because of its adverse side effects in reproductive organs. Therefore, a search for pharmacological substances with selective estrogenic action on the nervous system is of great practical significance.

Other positive effects:
The HDL cholesterol level is considered a strong inverse predictor of cardiovascular disease .Therefore, the absence of an increase in serum HDL cholesterol levels raises concern that raloxifene may not be as effective as estrogen replacement in preventing cardiovascular disease. Although the findings of animal studies are difficult to generalize to humans, recent animal data have also raised concerns that raloxifene may not prevent the progression of coronary artery disease. Because no long-term trials have been conducted, it is impossible to determine whether the small lipid effects produced by raloxifene correlate with a smaller degree of cardioprotective activity.

Raloxifene vs Tamox
From the above we can infer that Ralox maybe a better choice over Tamox as it lends the following positive effects on use.
a)Increasing bone density
b)Prevention of asthma
c)Nerve regeneration and neuroprotection
d)No changes in serum concentrations of high-density lipoprotein (HDL) cholesterol and triglycerides, while reducing LDL levels.

I have requested Eli&Lilly Co makers of Evista if they have reports/studies of heptatoxicity of Raloxifene to compare the effects of Ralox vs Nolva on the Liver. While taking orals have a significant effect on the liver, the least heptatoxic SERM would be the better option during a PCT.

It would be nice if others can contribute to this thread with alternatives.

References:
http://www.medicalpost.com/mpcontent...06_194320_5208
http://www.annieappleseedproject.org/ralverris.html
bca.ns.ca/indice/1999/7index.cgi/noframes/read/23719
http://www.scienceblog.com/community...200115509.html
http://www.cpsp.edu.pk/jcpsp/ARCHIEV...5/Article4.pdf
http://www.drugs.com/cons/Raloxifene.html
http://www.ecu.edu/physio/labakm/SERMs.htm
http://www.acponline.org/chapters/va...ranscript.html