The resulting increased estrogen levels in men decreases facial hair, promotes breast enlargement, and can result in impotence. In addition to the estrogen-induced impotence, alcohol may result in a disease of the nerves and this may cause impotence. This drug-induced impotence may be proportionate or disproportionate to the degree of blood pressure control. Combinations of drugs that lower high blood pressure or the combination of a drug that lowers high blood pressure and diuretics may, in some men, also aggravate or cause impotence. Paradoxically some anti-hypertensive drugs, such as phentolamine, by relaxing the arteries may promote erections.
Some diuretics are more likely to aggravate or cause impotence.
If impotence occurs within a few days or a month of starting a drug, the drug, or the lowered blood pressure, must be considered as a potential cause of the impotence. If a drug aggravates or causes impotence, stopping the drug invariably reverses the impotence process. The autonomic nervous system is so arranged that sympathetic and parasympathetic nerves may activate one organ, block another, and both activate and block a third. Depending upon which part of the autonomic nervous system malfunctions, the degree of malfunction, and the relationship of the remaining parts of the autonomic nervous system to each other, symptoms of autonomic nervous system malfunctioning will differ among patients. This explains why beta blockers, that affect one part of the autonomic nervous system favorably, by lowering blood pressure, may affect another part unfavorably, causing impotence.