Over-the-counter drugs of abuse

• ALSO KNOWN AS: Pharming

DEFINITION: Over-the-counter (OTC) drugs are medications that do not require a prescription and are sold at supermarkets, drug stores, convenience stores, pharmacies, and over the internet. OTC abuse is the use of nonprescribed medications for reasons other than those instructed by a health care provider or listed on the medication’s label. OTC drugs are considered to be abused when taken more frequently, at a greater dose, or for a longer time than directed, to produce changes in mental or physical status.

Causes

OTC medications are readily obtainable, making them easy to abuse. Also, these substances are difficult to detect in urine drug tests, which allows for abuse without consequences at school or work. The most commonly abused OTC drugs include cough syrup, cold medications, and antihistamines. Other OTC medications of abuse include sleep aids, herbal supplements, steroids, laxatives, and aspirin and other pain relievers.

The main ingredient of abuse in cough and cold medications is dextromethorphan hydrobromide (DXM), which causes hallucinations at high doses, but the other ingredients in cough medicines, such as acetaminophen and pseudoephedrine, can lead to fatal overdoses when taken at high levels. Additionally, 5 percent of persons of European ancestry are unable to metabolize DXM properly, which causes a buildup of toxic levels of the substance and causes more severe drug effects.

Diphenhydramine is a common antihistamine that is often abused for its sedative effects. Diphenhydramine can compound the sedative properties of anti-anxiety medications, particularly benzodiazepines, and abusers often take these drugs in combination to increase their high.

Other OTC drug abuse, such as with steroids or laxatives, is done as a means of changing one's body composition. People who overuse steroids are typically looking to gain a lot of muscle mass quickly, while, on the other hand, people who overuse laxatives are likely looking to lose body mass through stool excretion. However, neither steroids nor laxatives have the long-term effects users are seeking and can instead lead to harmful complications.

Risk Factors

Adolescents are at particularly high risk because the substances are easy to obtain. Individuals with substance use disorders are also at a higher risk, as they often seek OTC drugs when they are unable to acquire other illegal drugs or alcohol. Persons with a psychiatric diagnosis are also at greater risk, and those who are suicidal are more likely to use OTC medications with alcohol to attempt suicide. Medical personnel have an increased risk of antihistamine abuse because these medications are easily accessible at their place of employment.

Symptoms

OTC medications cause different symptoms when they are used according to the drug’s label than when they are abused, or used off-label. Also, each OTC medication has a different set of effects. For example, cold and cough medications are intended to act as decongestants and cough suppressants. When taken in high doses, the DXM in these medications acts like the illegal drugs phencyclidine (PCP) and ketamine. DXM, PCP, and ketamine cause euphoria, hallucinations, dissociation, and psychosis. The stimulants in many of these medications can lead to prolonged sexual performance and erection, but also to agitation, priapism, and dangerous elevations in heart rate.

Antihistamines are used to treat the symptoms of allergic reactions. The symptoms of antihistamine abuse include dizziness, loss of coordination, drowsiness, dry mouth, headaches, and stomach pain. Using high doses of antihistamines in combination with alcohol can cause nausea, heart palpitations, and liver damage.

Dietary supplements and herbal medications can cause psychosis when taken in large quantities. The misuse of sedatives may induce coma, and steroid abuse may cause aggressive behavior, agitation, and rage.

In severe cases, symptoms of OTC drug overuse can be fever, liver or kidney damage, jaundice, and fatigue, particularly if the use is over a long period of time.

Screening and Diagnosis

Emergency physicians often do not ask patients about the OTC medications they are taking or the reasons they are using them. Therefore, OTC abuse is often identified only during a regular medical appointment or during a mental health screening. Many of the OTC medications will not appear on a routine urine drug test, but abuse of DXM at high doses may cause a drug screen to be abnormal for PCP.

OTC overuse may, however, show up in certain clinical and blood tests, such as the drug-induced lymphocyte stimulation test (DLST).

Treatment and Therapy

Symptoms of withdrawal have been reported with OTC abuse and differ based on the specific medication used. As with many substances of abuse, a gradual tapering of the OTC medication may help with the process of detoxification and may minimize withdrawal symptoms. Persons who have an addiction may be referred to Pills Anonymous to complete a twelve-step, group therapy program, which is similar to the programs of Alcoholics Anonymous or Narcotics Anonymous. Outpatient or inpatient therapy for substance abuse is also available, although often underutilized for OTC abuse.

Prevention

Supermarkets and pharmacies began enforcing stricter policies on the purchase of many OTC medications in the twenty-first century. While cold, cough, and allergy medications were traditionally found in store aisles, many are now behind the counter at a store’s pharmacy and require proof of legal age (18) to purchase. Also, there are limits on the number of medication packages a customer can purchase per day. While these are not foolproof methods to reduce OTC medication abuse, they make it more difficult for minors to abuse OTCs and for any person to obtain large quantities of the substances at one time. For adolescents, parental education and awareness about OTC medication abuse have been demonstrated to successfully reduce the problem of OTC abuse.

Bibliography

Al Meslamani, Ahmad Z., and Derar H Abdel-Qader. “The Abuse and Misuse of Over-the-Counter Medicines during COVID-19.” Hospital Pharmacy, vol. 58, no. 5, 2023, pp. 437-40, doi:10.1177/00185787231158777. Accessed 24 Oct. 2025.

"Drinking Alcohol While Using Other Drugs Can Be Deadly." Centers for Disease Control and Prevention, 31 Jan. 2025, www.cdc.gov/alcohol/about-alcohol-use/other-drug-use.html. Accessed 24 Oct. 2025.

"The Effects of Mixing Alcohol and Over-the-Counter Drugs?" Alcohol, 25 Oct. 2022, alcohol.org/mixing-with/over-the-counter. Accessed 24 Oct. 2025.

Gracious, Barbara, et al. “The Importance of Taking a History of Over-the-Counter Medication Use: A Brief Review and Case Illustration of ‘PRN’ Antihistamine Dependence in a Hospitalized Adolescent.” Journal of Child and Adolescent Psychopharmacology, vol. 20, no. 6, 2010, pp. 521–24, doi:10.1089/cap.2010.0031. Accessed 24 Oct. 2025.

Hitti, Miranda. "11 Commonly Abused OTC and Prescription Drugs." WebMD, 17 June 2025, www.webmd.com/mental-health/addiction/ss/slideshow-commonly-abused-drugs. Accessed 28 Oct. 2025.

“Over-the-Counter Medicines DrugFacts.” National Institute on Drug Abuse, 17 Dec. 2017, nida.nih.gov/publications/drugfacts/over-counter-medicines. Accessed 24 Oct. 2025.

Satoh, Kasumi, et al. “Severe Drug-Induced Liver Injury from Over-the-Counter Medication.” Cureus, vol. 15, no. 1, 2023, p. e33558, doi:10.7759/cureus.33558. Accessed 24 Oct. 2025.