Side Effects of Promethazine: Signs of Abuse

Medical Providers:
Dr. Michael Vines, MD
Alex Spritzer, FNP, CARN-AP, PMHNP
Clinical Providers:
Natalie Foster, LPC-S, MS
Last Updated: January 12, 2026

Promethazine is often prescribed for nausea, allergies, or motion sickness. For many people, it feels routine. Just another medication. Problems tend to show up when it is taken more often than prescribed or used to calm nerves or help with sleep. According to the FDA, promethazine has required updated safety labeling due to risks from improper administration and potential tissue damage.​

At The Hope House, we regularly talk with people who did not expect promethazine to cause problems. Over the past decade, reported promethazine exposures have increased, especially among teens and young adults. Understanding how this medication affects the body, and how misuse can develop, helps people recognize risk earlier instead of later.

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Promethazine abuse usually does not start suddenly. It builds over time. Doses increase. Use becomes more frequent. The reasons for taking it slowly change.

People misusing promethazine may show:

  • Heavy drowsiness that does not improve with rest
  • Slurred or slowed speech
  • Noticeable decline in appearance or hygiene

Behavior changes are often clearer than physical ones:

  • Mood changes or poor concentration
  • Pulling away from family or friends
  • Financial stress linked to obtaining medication
  • Declining work or school performance
  • Visiting multiple providers for prescriptions
  • Legal trouble tied to risky decisions

Does Promethazine Make You High?

Promethazine is not intended to create a high. It is an antihistamine with sedating effects. Some people misuse it because it makes them feel slowed down or emotionally numb. At higher doses, or when mixed with other substances, it can feel calming. For some, that feeling becomes something they rely on. Over time, misuse can turn into dependence. Understanding the risks of medication-assisted treatment can be important when addressing dependence.​

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Promethazine can be helpful short term. Side effects become more likely when use continues or increases.​
At higher doses, or when mixed with other substances, it can feel calming. For some, that feeling becomes something they rely on. Over time, misuse can turn into dependence.

Our dual diagnosis program addresses both the physical and emotional aspects of medication misuse.

Short-Term Effects of Promethazine

icon depicting sleepy the side effects of addiction

Drowsiness

icon depicting dizziness which is one of the side effects of addiction

Dizziness

Icon Dry Mouth

Dry Mouth

Icon Showing Blurred Vision

Blurred Vision

Icon Showing Constipation

Constipation

urination problem

Difficulty Urinating

icon showing the effects of addiction on the body include Increased heart rate

Increased Heart Rate

Long-Term Effects of Promethazine

icon depicting drug tolerance can result to overdose

Drug Tolerance and Dependence

The body adjusts, and more medication is needed to feel the same effects.

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Addiction

Use continues even when problems appear. Professional help can make a difference.

icon of impaired memory caused by Addiction

Cognitive Impairment

Memory and focus can decline.

icon showing slowed breathing which is a symptom of drug use

Respiratory Depression

Breathing may slow, especially when combined with other depressants.​

icon showing the effects of addiction on the body can increased High blood pressure

Cardiovascular Effects

Changes in heart rhythm or blood pressure may occur.

Icon Representing that addiction can cause Depression Disorder

Psychological Effects

Anxiety, depression, or severe mood changes may worsen.

Does Promethazine Make You Sleepy?

Yes. Sleepiness is common. While this may help with nausea, it can interfere with daily life. Driving or working while overly sedated increases accident risk. According to MedlinePlus, drowsiness and impaired coordination are significant concerns with promethazine use.​

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Promethazine has been combined with codeine in cough medications in the past. Codeine is an opioid. Misuse of this combination has led to addiction and overdose. Even without opioids, promethazine misuse is dangerous. Sedation affects coordination and judgment. Falls and car accidents become more likely.​

High doses or mixing with alcohol, opioids, or benzodiazepines increases overdose risk. Symptoms may include confusion, hallucinations, seizures, slowed breathing, coma, or death.

Risk Factors and Precautions

People with substance use histories face higher risk. Asthma, heart conditions, and blood pressure problems can complicate use. Allergic reactions are rare but serious.

Drug Interactions

Promethazine interacts with other sedating medications. Alcohol increases danger. Long-term use has also been linked to liver injury, especially with alcohol.

Special Populations at Risk

Children under 2, older adults, and people with breathing problems are more vulnerable. Pregnancy and breastfeeding require medical guidance.

Is Promethazine Safe in Pregnancy?

Promethazine is sometimes used for severe nausea, but it is not usually the first option. It is classified as FDA Category C. Providers often explore alternatives first.

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Treatment focuses on safety and stability. Many people using promethazine also struggle with anxiety, sleep issues, or emotional distress. At The Hope House in Scottsdale, care is individualized.

Our comprehensive addiction recovery program provides treatment that may include medical monitoring, therapy, and long-term recovery planning. Early help often prevents more serious harm. We also offer specialized treatment for co-occurring mental health conditions to address both addiction and underlying issues.

Your path to recovery starts here. Embrace a healthier future today.