A drug interaction happens when a drug’s activity or action is altered when taken with something else. Your pharmacist is an expert at determining whether the drugs you're taking will interact with each other.
READ MORE: Manage medications with your pharmacist
We talked to Stacey Fowler, Pharmacy Manager at Yellowknife Co-op in Yellowknife, N.W.T., about what happens when drugs interact and how your pharmacist can help ensure your medications are performing safely.
What are the consequences of drug interactions, and how can I reduce my risk?
"Because everyone’s body is different, what may have a drastic effect on one person may not be noticeable in another," said Fowler.
In extreme situations, drug interactions can be responsible for medication failure and dangerous side effects, including death.
"This is why it is crucial we have a comprehensive medication history," said Fowler. "If we don't know you're taking a particular medication, we can’t screen for potential interactions."
What are the different types of drug interactions?
Some of the more common types of interactions are these:
- Medications that alter the activity of liver enzymes, which may cause your body to be either more or less efficient at breaking down medications, resulting in higher or lower levels of the drug than expected.
- Medications that interfere with the absorption of other medications, resulting in a medication’s not being as effective.
- Medications that increase risks of side effects, such as abnormal heart rhythm, risk of bleeding, changes in blood pressure or blood sugar, or excessive confusion or drowsiness.
"Each drug interaction carries a risk rating," explained Fowler. "Some drug interactions are more likely to occur than others, and some come with a higher potential safety risk than others."
If they deem the interaction to be too risky, pharmacists and physicians look at alternative medications to avoid the risk.
What else can cause medication interactions?
In addition to prescriptions, over-the-counter medications, vitamins, minerals and natural or herbal products, alcohol, marijuana and even some foods can cause problems.
"People will quite often assume medications available without a prescription are safe, but this is not necessarily the case," said Fowler.
It's important to check with your pharmacist or physician when you're selecting a new non-prescription medication or natural product.
Who is at higher risk of negative drug interactions?
Older patients or those with decreased kidney or liver function are at higher risk of negative drug interactions. Also at higher risk are patients on multiple or high doses of medications or those taking warfarin, digoxin, amiodarone, lithium, some anticonvulsants and certain antibiotics, since these medications are more likely to interact with others.
How can my pharmacist help?
Your pharmacist checks for potential issues any time you bring in a new prescription to fill, working with you to identify and manage potential interactions, and if necessary, contacting your physician to check for alternatives or to arrange extra monitoring. The pharmacist will also explain if you need to separate the taking of your medications or watch for potential side effects.
By determining any problems and weighing the risks versus the benefits, your pharmacist can decide the best medication-management strategy to avoid complications.
Talk to your pharmacist today if you have any questions about drug interactions.