Rules to follow when enjoying a drink:

Rule #1: you should not drink when your blood glucose is low or on an empty stomach. This is true because insulin and some diabetic medications like sufonylureaus and meglitinides or Prandin, will cause lower blood glucose by a making more insulin.

Rule #2: (similar to rule one) be sure to eat before you drink or while you drink.

Rule #3: Limit your intake to one drink per day for adult women, two drinks per day for adult men.

Rule #4: check your blood glucose before you got to bed. Drinking alcohol may cause hypoglycemia soon after drinking and even up to eight to twelve hours afterward. Check the level to make sure it is safe – it should be between 100 and 140 mg/dl. If you find your blood glucose is low you should eat something and monitor to be sure you are safe.
 
The American Diabetes foundation will give you thumbs up to enjoy an occasional alcoholic beverage if your diabetes is under control and you are not new to the habit. [1] They also recommend if you are going to drink choose a mixer that is sugar free.

Safety first -- Always remember to wear a bracelet or other identifier that will alert others to your diabetes.  

When not to drink at all:

Do not drink if you have difficulty telling the difference between low blood sugar and catching a buzz. Feeling light headed and drowsy are symptoms of both. Know the difference.

Do not drink before or after exercise. Exorcizing lowers your blood sugar.

Do not drink if you have nerve damage. Drinking can exasperate it and increase pain, numbness or other unpleasant side effects.

Do not drink if you are pregnant.

You should not drink at all if your heath professional has not approved a plan or if you have difficulty recognizing the symptoms of low blood sugar.

Do not drink if you have an issue with alcohol abuse.

Do not drink on an empty stomach.

Do not drink alcohol if you are taking any perscription or over the counter medication that does not mix with alcohol. Check with your pharmacist or heath care provider for possible reactions. 

Do not drink if your blood glucose is not under control -- either too high or too low.