This allows the list of drugs included to be very selective so that, with difficult cases, GPs are allowed to go outside the list. Also where a drug is included, it would be available in all strengths and forms. The most common side-effect of diuretics is postural hypotension, which is dependent on the drug, the dose and the patient. For example, a loop diuretic at a high dose in an elderly patient is likely to produce falls due to postural hypotension. As with all drugs, mild gastro-intestinal effects are also common, but should be less problematic as the patient becomes accustomed to the drug.
Impotence is a reversible side-effect that disappears on withdrawing the drug.
It is particularly problematic for many men who find difficulty seeking help for a problem they do not readily identify as an adverse drug reaction. Communicating the possibility of this side-effect by way of a readable product insert or leaflet will avoid embarrassment and might help more men to seek advice and, where necessary, have the medicine altered. The metabolic side-effects that frequently occur with thiazides result in hyperglycaemia which must be avoided in diabetic patients. They also cause a rise in serum cholesterol levels but the clinical significance of this is controversial. It has been argued that the rise in serum cholesterol caused by these drugs outweighs the benefits of treating hypertension resulting in no net gains in patient survival.