Impotence, causes

Figure 8.9 Plots of values (including the sign) of residuals (Y — Yp ) vs x, where Yp is the value of Y predicted from the sinqtle linear model (Y = A + B.x) with A and B determined by simple hnear regression, for three impotant causes of significant values of the residual variance V. Note that in the case of nonlinearity of the data (i.e., inapplicabiUty of Equation [8.19a] to this data set) the plot could just as well be concave upwards. A sufficiently high degree of itreproducibihty can mask the other two if present It is possible to observe nonlinearity of heteroscedastic data if the latter effect is not too extreme. Reproduced fi om Meier and Ziind, Statistical Methods in Analytical Chemistry, 2nd Edition (2000), with permission of John Wiley Sons Inc.

MISCELLANEOUS ANTIDEPRESSANTS. An uncommon but potentially serious adverse reaction of trazodone is priapism (a persistent erection of die penis). If not treated within a few hours, priapism can result in impotence The nurse instructs the patient to report any prolonged or inappropriate penile erection. Use of the drug is discontinued immediately and the primary care provider notified. Injection of a-adrenergic stimulants (eg, norepinephrine) may be helpful in treating priapism. In some cases, surgical intervention may be required. Venlafaxine may cause an increase in die blood pressure. A sustained increase in die blood pressure may indicate that die dosage of venlafaxine needs to be decreased. 

In some animals, consumption of a phytoestrogen-rich diet can cause temporary infertility and reproductive system disorders (Irvine, 1999). In humans, lower testosterone levels and a decline in human semen quality over the past century have been luiked to increased exposure to environmental endocrine disrupters (EDCs) (Sharpe and Skakkebaek, 1993). Furthermore, cases of sexual impotence have been reported in males exposed to synthetic estrogens in the pharmaceutical industry (Mattison et al., 1990). If this might be the case, the fetal-prepubertal period and Sertoli cell development would be of critical importance (Sharpe and Skakkebaek, 1993). However, an adverse effect of phytoestrogens on male fertility has yet to be proven. Recent work (Mitchell et al., 2001) addressing this point led to the conclusion that up to 40 mg/day of isoflavones over a two-month period had no effects on gonadotrophin and... 

Absence of regular menstrual periods (amenorrhea), impotence, and decreased libido caused by disruption of the gonadotropin secretion. 

Clinical features Priapism is defined as a painful and unwanted erection, which is classified as stuttering (less than 3 hours), often multiple prolonged (more than 3 hours). Up to 89% of males with SCD will have at least one episode by age 20. The mean age of the initial episode is 12 years of age. Repeated episodes can cause fibrosis and impotence. 

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... 

The beta blockers can cause a wide array of side effects including low blood pressure, slowed heart rate, dizziness, fatigue, and impotence. They may exacerbate asthma and depression, though this remains controversial, in vulnerable patients. Symptomatic bradycardia (slow pulse) and depression are probably less problematic when using pindolol, which in addition to blocking noradrenergic activity also increases serotonergic activity. 

Few things are more distressing to a physician than to stand beside a suffering patient who is anxiously looking to him for that relief from pain which he feels himself utterly unable to afford. His sympathy for the sufferer, and the regret he feels for the impotence of his art, engrave the picture indelibly on his mind, and serve as a constant and urgent stimulus in his search after the causes of the pain, and the means by which it may be alleviated. 

K /Na exchange in distal tubule Dose Adults. 5-10 mg PO daily Peds. 0.625 mg/kg/d X in renal impair Caution [B, ] Contra T K, SCr >1.5 mg/dL, BUN >30 mg/dL, diabetic neuropathy Disp Tabs SE T K HA, dizziness, dehydration, impotence Interactions T Risk of hyperkalemia W/ ACEI, K-sparing diuretics, NSAIDs, K salt substitutes T effects OF Li, digoxin, antihypertensives, amantadine T risk of hypokalemia W/ licorice EMS Monitor ECG for signs of hyperkalemia (peaked T waves) T effects of digoxin OD May cause bradycardia, light-headedness, and syncope symptomatic and supportive... 

At high doses, ketoconazole causes a clinically significant reduction in testosterone synthesis and blocks the adrenal response to corticotropin. Gynecomastia, impotence, reduced sperm counts, and dimiiushed libido can occur in men, and prolonged drug use can result in irregular menses in women. These hormonal effects have led to the use of ketoconazole as a potential adjunctive treatment for prostatic carcinoma. 

Human prolactin is similar in structure to human growth hormone, and both are good lactogens. In women, prolactin acts with other hormones on the mammary gland during pregnancy to develop lactation and after birth to maintain it. Hyperprolactinemia causes impotence in men and amenorrhea and infertility in women. Chronically elevated levels of circulating prolactin are associated with suppression of 17-p-estradiol and testosterone production in the ovaries and testes. 

Finasteride may cause impotence and decrease ejaculate volume... 

Guanethidine is another agent which inhibits release of noradrenaline. Causes sodium and water retention and may precipitate CHF. Endocrinal side effects are more common e.g. impotence and inhibition of ejaculation. It is also not used now clinically. 

NPT in the differentiation of functional from organic causes of impotence Evoked Potentials... 

Synthetic steroids may cause endocrine abnormalities by actions on other steroid receptors. Gynecomastia, impotence, and benign prostatic hyperplasia all have been reported with spironolactone. Such effects have not been reported with eplerenone because it is much more selective than spironolactone for the mineralocorticoid receptor, being virtually inactive on androgen or progesterone receptors. 

Hyperprolactinemia in women results in the amenorrhea-galactorrhea syndrome and infertility in men, loss of libido, impotence, and infertility may result. Hyperprolactinemia may cause osteoporosis, particularly in women. If dose reduction is not indicated, or ineffective in controlling this pattern, switching to one of the atypicals that do not raise prolactin levels, eg, aripiprazole, may be indicated. 

Cimetidine inhibits binding of dihydrotestosterone to androgen receptors, inhibits metabolism of estradiol, and increases serum prolactin levels. When used long-term or in high doses, it may cause gynecomastia or impotence in men and galactorrhea in women. These effects are specific to cimetidine and do not occur with the other H2 antagonists. 

DDT was probably harmful to wildlife when used in massive doses on cotton farms in the 1950s in America (although not so harmful as Carson and her followers made out), but it has never been proved to harm humans except those who tried to commit suicide with it. In any event, any harm to wildlife in America and Europe has been reversed. In contrast to its agricultural use, malaria control requires only that the insides of houses be sprayed used properly, little DDT is released into the environment. Yet myths persist about the harms it causes. Many Zambians think it causes male impotence. Most Westerners think it causes cancer. Nearly everyone forgets that only in massive doses can DDT cause problems. 

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