Is it safe to have an alcoholic drink when taking metoprolol tartrate?

Answer 1

No.

Metoprolol is a beta blocker, and, outside of its designed use, inhibits the ability of the alcohol dehydrogenates from changing the ethanol into formic acid (formaldehyde -> formic acid) in the liver. While this is a positive thing (you can go blind, or even die from formic acid buildup), it also means that the ethanol is sitting in your liver not being broken down.

You could feel anything from slight nausea... all the way to needing a hospital visit (or morgue visit).

Small amounts of ethanol while on the medication is alright, but this means a very small glass of wine or maybe a beer. This is different in every person however, and even if you are a heavy drinker and your body has a fair amount of tolerance, a few beers could easily put you in the hospital.

The warning of interaction:

From Drugs.com: Close monitoring for development of hypotension is recommended. Patients should be advised to avoid rising abruptly from a sitting or recumbent position and to notify their physician if they experience dizziness, lightheadedness, syncope, orthostasis, or tachycardia.

A final note.

Drinking alcohol while on metoprolol tartrate can be very lethal to your body's health, not to mention your own. Rises in blood pressure are common, especially if you have a previous blood pressure issue.