Answer to Barry's Question

If Minoxidil causes vasodilation, would it help a diabetic by increasing perfusion in the periphery and save their extremities from amputation due to poor perfusion?

Minoxidil is a very extreme drug used for hypertensive emergencies after all of the other drugs have failed. It has extreme side effects.
It causes vasodilation in the atrerioles not the venules by acting directly on the smooth muscle. This then causes blood pressure to drop, which causes a reflex tachycardia, (can lead to heart failure) which increases the oxygen demands of the heart which causes reduced oxygenation in the periphery. You can counteract this with a beta blocker.
It also causes salt and water retension because of the vasodilation which needs to be counteracted with a diuretic like furosemide. Many DMII people already have a fluid retension problem because of renal failure for example from hyperglycemia. Glucose is a water magnet, where it goes, water follows.
It also causes hyperglycemia by supression of insulin release from the pancreas (which is already a diabetic II's problem).
It also causes postural hypotension, nausea, headache, fatigue, glucose intolerance, thrombocytopenia and a whole lot of other nasty side effects. It is contraindicated in diabetics for obvious reasons.
Another drug that can be used for emergency HTN is sodium nitroprusside. It is the fastest acting vasodilator available and causes dilation in the arterioles as well as the venules. It is safer to take than minoxidil but still has alot of the same side effects.

a note about vasodlation, it reduces the pressure through vasodilation, which causes venous pooling of blood (original problem) and reduced pushing the blood back to the heart, which causes lower cardiac output, which causes the compensatory tachycardia, viscious cycle without help for the diabetic with a perfusion problem.

Minoxidil also causes hair to grow everywhere you don't want it to, which is the leading cause of why women refuse to take it.

Any other thoughts or comments on this?