One of the most important decisions that your surgical team makes when you are getting ready for an operation is what medications you should and shouldn’t take. Some medications are vitally important to continue taking during the time leading up to, and after your operation. However, there are others that should be stopped well in advance of any trip to the operating room.

In this post, I’ll review some of the common medication issues that come up when planning elective surgery. I’ll also explain some general rules that doctors use to decide what medications you should stop and which ones you should keep taking.

As always, each of these decisions depends on your specific situation, and this blog shouldn’t take the place of a conversation with your surgeon and surgical team about your medications. Don’t start or stop any medications without talking to your own doctors first.

And of course, any discussion of medications with your surgeon needs to start with a complete and accurate list of the medicines (including over-the-counter vitamins or supplements) you are taking and the dose of each. Be sure to bring a list of all your medicines to your pre-operative clinic visit.

Why Some Medications are Important to Keep Taking

There are some medications that can be important to keep taking when you’re having an operation. These are usually short-acting medicines that affect the way your body works while you’re under anesthesia.

Here are some of the most common medications recommended to continue taking when having an operation:

• Beta blockers (such as metoprolol and atenolol) – missing doses can cause increased heart rate and blood pressure during surgery.
• Steroids (such as prednisone) – if you’re taking steroids for a chronic condition, it is important that you continue to take them around the time of your operation. Be sure to tell your surgeon and anesthesiologist that you’re taking steroids, because they may want you to receive an extra dose during the operation.
• Statins – these common anti-cholesterol medications have been shown to reduce inflammation around the time of surgery, particularly if you’ve already been taking them, so continuing them is generally recommended.

These medicines should usually be taken with only a sip of water. Having food or liquids in your stomach at the time of your operation increases your risk of developing pneumonia.

Medications That are Important to STOP Taking

• Anti-coagulants (“blood-thinners” such as warfarin, Plavix^®, and Pradaxa^®) can cause uncontrollable bleeding during surgery, and in most cases your surgeon will want you to stop these medications many days before your operation. Some surgeons also ask patients to stop taking aspirin and other NSAID drugs before surgery, although this is not always necessary. Depending on why you are taking the anti-coagulant medication, you may need to switch to a shorter-acting drug that you can take until the day before, or even day of surgery. Talk to your surgeon about how to manage your anti-coagulation medication around the time of surgery. If you’ll only be on these medications for a short time, your surgeon may decide to delay an elective surgery until you stop taking them, to minimize your risk of complications.
• Certain blood pressure medications, especially ACE inhibitors, can cause low blood pressure during operations, and your surgical team may recommend that you stop taking them. In certain cases, the benefits outweigh the risks, so be sure to check with your surgical team.
• Some diabetes medications, especially metformin, can cause problems with your kidneys during and after surgery, and are usually stopped the day before your operation.
• Diuretics, or water pills, can interfere with fluid management during your operation, and are usually not taken on the day of your operation.
• Herbal medicines can have unpredictable interactions with anesthesia and the medications given around the time of surgery, so you should generally stop taking them before your operation.

When to Restart Medications

Generally, most people restart their medications after surgery once they are able to eat food again. Depending on the type of operation you had, that could mean the same day, or several days later. After some operations, you may not need to restart all your medicines. Your surgery team should tell you when and whether to restart your home medications before you leave the hospital.

If you will not be able to take pills by mouth for some time, some of your medications may be delivered through an IV while you are in the hospital. Other medications may not be necessary for some time, or will need to be restarted at different doses. For example, some people need smaller doses of insulin or other diabetes medications, until they are eating normally again.

The best way to figure out which medications you should get while you’re in the hospital is to make sure your medical team has a complete list of the medicines you take at home, and talk to them about which ones they plan to give you while you’re in the hospital.

For more information, here are some good, fairly comprehensive Internet resources that support information mentioned in this blog:

• Medscape: Perioperative Medication Management
• Cleveland Clinic Journal of Medicine: Perioperative Medication Management

This story originally appeared in the  Health Dialog Care Compass Blog.