Testing Apple's Drug Interaction Checker - How Accurate is it?

Note: These features were tried on iOS 16.5, and on iOS 17 Developer Beta 1. 

I tried to put Apple’s drug interaction checker to the test, and let me start off by saying that overall it does a good job of catching interactions. It’s not perfect though, and can even be dangerous. That is why you should always consult your care team to determine if any medications need to be stopped or changed based on your health situation.

With that being said, let me set the scenario here.

I used a bunch of drugs to test out Apple’s system, and to see how well it can track drug interactions and interaction factors. First, let’s check out the list of drugs:

1. Crestor (generic name is rosuvastatin) - cholesterol medicine.

2. Zocor (generic name is simvastatin) - this is the same drug category as above, used for cholesterol medicine.

3. Simvastatin - literally the same drug as Zocor.

4. Rifampin - used for treating tuberculosis.

5. Lisinopril - blood pressure medication. 

6. Accutane - for severe acne.

7. Chantix - for smoking cessation.

8. Promethazine VC with Codeine - used to treat cold, stuffiness, and allergy symptoms.

After putting in your medications, you get a list of drug interactions that pop up. When you enter the interactions page, you will see “Current Factors” at the top. These life factors can look for interactions between your medications and said life factors. Apple currently provides three life factors:

1. Alcohol consumption

2. Marijuana

3. Tobacco

With all life factors turned OFF, there was 1 Serious and 4 Moderate interactions.

After turning ON all 3 Interaction Factors, the number of interactions increased to 8 Serious and 4 Moderate, which is no surprise.

Although technically all of the drug interactions are present, there are fine details that many people might not be aware of. A thorough pharmacy based system would find a few more discrepancies. 

Let’s look at my list of drugs from above once again:

1. Crestor (generic name is rosuvastatin) - cholesterol medicine.

2. Zocor (generic name is simvastatin) - this is the same drug category as above, used for cholesterol medicine.

3. Simvastatin - literally the same drug as Zocor.

4. Rifampin - used for treating tuberculosis.

5. Lisinopril - blood pressure medication. 

6. Accutane - for severe acne.

7. Chantix - for smoking cessation.

8. Promethazine VC with Codeine - used to treat cold, stuffiness, and allergy symptoms.

Drugs 2 and 3 are duplicates, and drug 1 is in the same category as 2 and 3. In a pharmacy drug utilization review system, these 3 drugs would pop-up as 2 or even 3 separate drug interactions, and would require consultation with the patient. Odds are the patient is stopping one medication and starting another, or they have switched from a brand name to a generic. Apple’s interaction checker however doesn’t give you these warnings. 

Does Apple’s drug interaction checker screen for pregnant patients?

In its current version of iOS 17 Developer Beta 1, Apple’s drug interaction checker is not designed to screen for pregnant patients. Here’s the process that I used to find out.

I changed my gender in the Health app to female and added an active pregnancy that is currently nearing 3 months. I wanted to trigger more life factor interactions, since some of these drugs on my list are a big no no during pregnancy. 

After adding my pregnancy status, I still had the same 8 severe and 4 moderate interactions. I even gave the phone a few days to perhaps “sync” the pregnancy information and maybe it would trigger some sort of alert. After a few days, I checked the drug interaction checker again and it still had the same 8 severe and 4 moderate interactions. There was nothing in the medications section indicating that Apple was aware that I was pregnant, and there was nothing in the pregnancy section that triggered any alerts based on my drug profile and substance use. There was no warning to stop drinking alcohol, or to stop using tobacco or cannabis due to direct fetal harm, even though I was “using” all those substances.

Now let’s disregard the life factors and just think about the medications and the active pregnancy. If these drugs were in a patient’s profile at a pharmacy and the patient had a pregnancy status of positive, the computers would sound red alarms: 

Let’s look at the list of drugs again (for the 3rd time now!):

1. Crestor (generic name is rosuvastatin) - cholesterol medicine.

2. Zocor (generic name is simvastatin) - this is the same drug category as above, used for cholesterol medicine.

3. Simvastatin - literally the same drug as Zocor.

4. Rifampin - used for treating tuberculosis.

5. Lisinopril - blood pressure medication. 

6. Accutane - for severe acne.

7. Chantix - for smoking cessation.

8. Promethazine VC with Codeine - used to treat cold, stuffiness, and allergy symptoms.

Drugs 1, 2, and 3 would be considered very high risk to the fetus.

Drug 5 is considered Pregnancy Category D, which means positive evidence of human fetal risk.

Drug 6 is considered Pregnancy Category X (not allowed at all during pregnancy), and with this drug in particular there is up to a 35% chance of severe birth defects. 

As you can see from such a patient drug profile, a successful pregnancy would most likely not happen. 

Now in fairness to Apple, they do state the following to let people know that not all interactions might be caught by the Health app:

“Health is not able to check for all potential interactions. More information is available on the labels of your medications. Discuss any questions about your medications with your care team.”

Is Apple’s drug interaction checker flawed?

Right now, Apple’s drug interaction checker works in a bubble. It can take hundreds of drugs, along with the life factors of alcohol, tobacco, and cannabis use, and spit out every interaction between these factors. 

While I believe that Apple has made great progress by adding a medication log and even providing drug interactions, it still requires more work. The pregnancy section of the Health app needs to talk to the medications section in order to make it a more robust and reliable system that holistically looks at the person’s health. I believe this is a work in progress for Apple, and in due time they will get there since they have a strong focus on health and fitness.

Even when Apple does get there, remember to always seek professional advice from your healthcare team in regards to your medications and health concerns.