The Doc is In | Let’s Talk About Toking: How to Use Cannabis Safely

How to know your cannabis is not contaminated. Also, common ways cannabis may interact with the other prescription or recreational drugs you take.


Cannabis, marijuana, or weed is becoming a popular drug of choice in the U.S. Whether someone is a daily user or has only tried this product once, it is important to know a few things so the user can get their high as safely as possible.

How to tell if marijuana is laced

There has been a rapid increase in drug overdose deaths in the U.S. in the last few years. Many of these deaths are because of opioids, painkillers that slow breathing if taken in excess. Recently, there have been reports of marijuana laced with fentanyl, a very strong opioid. There are two ways to ensure safety when using cannabis products.

First, cannabis should be purchased in a store where it is legally sold. Legally produced weed is required to be tested for contaminants before it’s sold. For Iowans, this likely means going to a dispensary out of state. Illinois legalized weed in 2020, Missouri legalized weed in 2022, and Minnesota legalized edible THC in 2022. While it’s legal for Iowans over 21 to purchase out of state, it is not legal to bring cannabis from other states into Iowa.

For Iowans with conditions such as seizures, inflammatory bowel disease, cancer, or chronic pain, Iowa has a medical cannabis program. This allows the purchase of weed with the permission of a health care provider.

Second, for those who do not obtain their marijuana legally, there are tests that can detect fentanyl. These tests work rapidly, but they are considered “drug paraphernalia” by Iowa law and are technically illegal.

Medication interactions with marijuana

THC and CBD, the psychoactive chemicals in marijuana, may change medication levels or have additive effects with other drugs, which could potentially cause dangerous side effects. Here are three things every user should know:

         1. Using cannabis with alcohol, benzodiazepines (alprazolam, clonazepam), or barbiturates (phenobarbital) may cause heavy sedation.

         2. THC may lower the levels of antipsychotics (clozapine, haloperidol), blood thinners (warfarin, clopidogrel), antidepressants (duloxetine, amitriptyline), and other drugs.

         3. CBD may increase the levels of around 30 percent of all prescription medications, including antidepressants, chemotherapy drugs, blood pressure drugs, antibiotics, antifungals, blood thinners, and many more.

It’s important to speak with a physician about medication interactions before using marijuana. They may change the medication regimen or recommend against cannabis. Helping patients use marijuana safely is every health care provider’s priority.

What to do in case of overdose

If you see someone unconscious and breathing slowly or not at all, call 911 immediately. If there is naloxone (Narcan) nearby, administer it promptly, following directions on the package. If you or someone you know uses opioids, you may want to carry naloxone with you. Find an Iowa pharmacy to get it here.


Columns reflect the opinions of the authors and are not necessarily those of the Editorial Board, The Daily Iowan, or other organizations in which the author may be involved.