Dear Dr. Roach: It seems that many of the medications I see advertised on television carry a warning about “thoughts of suicide.” Can you explain why so many diverse drugs share this same side effect?

— W.S.

Answer: Unfortunately, suicide is a too-common cause of death that many people are uncomfortable talking about. However, it is clear that there are effective ways of reducing suicide risk, especially by identifying those who are at high risk through screening and treatment with effective modalities.

Because deaths by suicide are so important, any safety signal is taken seriously by the Food and Drug Administration, and manufacturers are obligated to inform users about it on the package insert and in advertising. However, a warning does not always mean there is definitive evidence of an increased suicidal risk from this medicine.

The evidence on suicide risk from medications is conflicting, as suicide is a complicated issue. The methodology used for studies is complex; for example, a person with depression is more likely to be prescribed an antidepressant, but these do not start working right away. A superficial study might conclude that antidepressants increase the risk of suicide, since people who are prescribed these medicines are more likely to attempt suicide or die by suicide than people who aren’t prescribed them.

A 2019 study took a different approach, looking at suicide attempts three months prior to being prescribed a medication compared to three months afterward. This allowed the researchers to identify 10 medications that had a significant increase in suicide risk in the three months after starting them and 44 medications that decreased suicidal events.

Some opiate combinations increased the risk. Acetaminophen/butalbital/caffeine; hydrocodone with acetaminophen; and codeine phosphate/promethazine or promethazine alone all increased suicide risk by 30% to 70%. Sedatives, including alprazolam and diazepam, also increased suicide risk. The steroid prednisone increased suicide risk, as did the antibiotic azithromycin. The muscle relaxants cyclobenzaprine and carisoprodol also increased suicide risk.

This list does not mean that these drugs should never be prescribed. There are times when some of these medicines have to be used. However, physicians should think about whether an alternative might be better or if they should at least warn patients that this is a potential side effect.

Of the 44 drugs that decreased suicide risk, most were antidepressants and antipsychotic drugs. Not surprisingly, drugs that help with addictions to alcohol and opiates reduced suicide risk. However, there were some blood pressure medicines, antiseizure medicines, and seemingly random drugs like folic acid and pantoprazole that decreased suicide risk.

Some drugs that had been suspected of suicide risk, like sleeping aids and the asthma/allergy drug montelukast, did not show any positive or negative effect in this study.

What is most important to recognize is that a diverse range of medications can have powerful effects on our minds and emotions. Recognizing that this happens should make it easier for people who have suicidal thoughts to get in touch with their medical provider or a mental-health professional quickly to identify the problem and get help if needed.

In both the U.S. and Canada, the Suicide and Crisis Lifeline is 988. This lifeline connects a person to a skilled counselor.

Contact Dr. Roach at ToYourGoodHealth@med.cornell.edu.