How your doctor decides which medication to prescribe

Odds are your doctor has several medications to choose from. Here’s what else goes into choosing the best drug for you. 

Doctors make it look easy when deciding which medication to prescribe. When you need medication, they rattle off a drug name and some general instructions about how to take it. Then they hand over a prescription slip (or send it in electronically). And off you go to the pharmacy to pick it up. 

But deciding which medication to prescribe is actually more complicated than it looks. Many factors go into making that decision. The doctor must think about: 

  • What they know about you and your medical history.
  • Possible benefits and drawbacks of the different medications for that condition.
  • Goals behind using the medication. (For example, will it cure or prevent a disease? Will it ease symptoms?)
  • Outcomes they’ve seen with other patients. 

“Not all patients are the same. And not all medications are the same. So it’s critically important that people be treated individually,” says Aaron E. Glatt, M.D.
Dr. Glatt is a professor and chair of the department of medicine at Mount Sinai South Nassau in Oceanside, New York.

Key factors when prescribing medication

If you’re among the 66% of U.S. adults who use prescription medications, it’s important to understand what goes into prescription decisions. That way, you can share key information with your doc and ask important questions. You can play an active role in finding the best treatment for you. “Be honest with your doctor about your lifestyle habits so you can get the best possible care,” Dr. Glatt says.

Here are 7 key factors your doctor will think about when deciding which medication(s) to prescribe.

  1. Weight and sex. Either may play a role in the drug or the dose you’re prescribed.
  1. Age. Prescribing drugs for older patients can be especially tricky. There are age-related changes in how we absorb, metabolize, and excrete certain drugs. Some drugs also have different physical effects when taken by older people. There can also be a higher risk of bad reactions. 
  1. Lifestyle habits. These include:
    • How much alcohol you drink.
    • Smoking habits.
    • Sun exposure.
    • Diet and exercise patterns.
    Some of these factors could impact how you respond to certain drugs. Or they may raise your chances of a bad reaction.
  1. Physical challenges. Do you have balance issues or problems with dizziness? This may inform the choice the doctor makes between two medicines for some conditions, Dr. Glatt says. Some drugs, such as certain antidepressants and blood pressure medications, can cause dizziness. 
  1. Other health conditions. Problems with kidney or liver function are especially important to pay attention to. They could affect your body’s ability to break down a drug, Dr. Glatt explains. “If you have underlying illnesses such as diabetes, high blood pressure, or cardiovascular disease, certain medicines may not work or could be dangerous,” Dr. Glatt adds.
  1. Other medications and supplements. Be sure to share the complete list of everything you’re taking with your doctor. That includes birth control, hormone therapy, over-the-counter drugs, vitamins, and street drugs. This will help them stay away from prescribing something that might cause a dangerous interaction or make a drug less effective. 
  1. Drug sensitivities and allergies. Your doctor needs to know about adverse or allergic reactions you’ve had to other drugs in the past. They may point to a risk of a similar reaction to this new drug. “It may make the medicine contraindicated for you,” Dr. Glatt explains. That means the drug should not be prescribed to you.

Your doctor should ask you about each of these factors when talking about possible treatment options. If they don’t, be sure to bring them up. Also, don’t be shy about sharing any beliefs or attitudes you have about particular drugs. It may affect a doctor’s choice of medicine for you.

What about medication costs?

Something doctors don’t always think about when writing a new prescription is how much it will cost. But that’s quite important. Research has found that some people take less medication than they’re prescribed or skip doses because of the cost of the drug. That can make the treatment less effective. 

“Cost is something doctors do need to talk about with patients,” Dr. Glatt says. “If a patient can’t afford the medicine, then even if it’s the best drug in the world, it’s no longer the right medicine for that patient.” Once your doctor knows that cost is a consideration, they might decide to prescribe one drug instead of another.

Many health plans offer 3-month refills, prescription coverage, and other benefits that help you save on your medications. Ask your plan if they offer these benefits.

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