Erectile Effect

Apomorphine hydrochloride (44 Apokyn Bertek, 2004), is a semisynthetic derivative of opium alkaloid morphine (43) isolated from poppy (Papaver somniferum), and it has long been known for its erectile activity at the effective dose of 2-6 mg physicians discovered the effect over 100 years ago, but found the drug, at a much higher dose (ca. 200 mg), to be more suitable for poison victims as an emetic because it also causes serious nausea and vomiting. Apomorphine exerts its erectile effect at the central nervous system the drug has been found to be a non-selective dopamine agonist which activates both Di-like and D2-like... 

Various factors have been hypothesized by different investigators and these include changes in the external pressures (in particular pericardial pressures), incomplete relaxation and the erectile effect due to increased coronary perfusion (Alderman et al., 1976 Brodie et al., 1977 Mirsky and Rankin, 1979). 

Figure 7 displays the diastolic P-V relations in the control state and following methoxamine infusion. Note the dramatic parallel shift in these relations following the infusion. Also shown are the computed pressure-volume curves resulting from variations in the various factors namely (a) an increase in elasticity constants by 30%, (b) assuming a spherical geometry for the LV and (c) an increase of 30% in the LV wall mass to simulate the erectile effect due to increased coronary perfusion. In these computations, external pressure was assumed to be zero. It is... 

Therapeutic opportunities for NO synthons include angina, for which nitroglycerin is effectively used, as well as penile erectile dysfunction. NOS inhibitors have demonstrated some protection in cerebral ischemia models and may be potentially beneficial in alleviating cell death associated with cerebral ischemia. l-NMA is under clinical study for treatment of sepsis. 

Nitric oxide (NO) is a minor but villainous component of the atmosphere. It is involved in the formation of both smog (Chapter 11) and acid rain (Chapter 14). You may be surprised to learn that small amounts of NO are also produced in the human body, where it has a generally beneficial effect. In particular, it has the ability to dilate blood vessels, lowering blood pressure and reducing the likelihood of strokes or heart attacks. Beyond that, NO is effective in treating what television commercials refer to as erectile dysfunction it increases blood flow to the penis. 

Erectile dysfunction is treated by local or systemic application of vasodilator drugs. The most effective is sildenafil, a phosphodiesterase-type 5 inhibitor. 

Phosphodiesterase 5 inhibitors such as sildenafil are effective for MS-induced erectile dysfunction.14 In women, vaginal dryness or dyspareunia may respond to lubricating jellies. 

Gresser U, Gleiter CH. Erectile dysfunction comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil review of the literature. Eur J Med Res 2002 7 435-446. 

The most common adverse effects reported with LHRH agonist therapy include a disease flare-up during the first week of therapy, hot flashes, erectile impotence, decreased libido, and injection-site reactions.19 The disease flare-up is thought to be caused by initial induction of LH and FSH by the LHRH agonist and manifests clinically as either increased bone pain or increased urinary symptoms.19 This flare reaction usually resolves after 2 weeks and has a similar onset and duration pattern for the depot LHRH products.33,34... 

Orthostatic hypotension is common due to blockade of reflex-mediated vasoconstriction. Other side effects include erectile dysfunction, diarrhea, and weight gain. Because of these complications, postganglionic sympathetic inhibitors have little or no role in the management of hypertension. 

The most common adverse effects of LHRH agonists are disease flare-up during the first week of therapy (e.g., increased bone pain, urinary symptoms), hot flashes, erectile impotence, decreased libido, and injection-site reactions. 

Phenothiazines with fewer anticholinergic effects can be substituted in some patients it erectile dysfunction is a problem. 

It is interesting to note that the nitrosyl moieties of S N P and Roussin s salts exhibit significant N0+ character and they are also excellent NO donors. In particular, S N P is used widely to induce hypotension during surgery [14,15]. It significantly reduces the cerebral infarct size [16,17] and also inhibits platelet aggregation [18]. Transurethral administration of SNP can also induce an erectile response in cats without much side effects [19]. 

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