What Drugs Cause Dilated Pupils?

what drugs cause dilated pupils

They say that the eyes are windows to the soul; just one look can tell you a lot about a person. If you spend enough time with someone, then you can tell something’s off with a quick glimpse.

For instance, they may have dilated pupils, which can be caused by a wide variety of things. However, a likely culprit is drugs, whether they’re prescribed or illicit.

Are you now wondering, “what drugs cause dilated pupils?” Then read on to find out more.

What Drugs Cause Dilated Pupils?

It’s important that you don’t immediately panic if you see dilated pupils in your loved one. As we’ve mentioned above, prescribed medications can cause pupil dilation, so as long as they’re taking the medications as directed, you don’t have to worry.

In this category, there are several drugs that can explain why your loved one is experiencing dilated pupil symptoms.

Anticholinergic Medications

To understand these drugs, we need to first explore the nervous system. The neurotransmitter acetylcholine aids in muscle contractions, gastrointestinal processes, and communication within the central and peripheral nervous systems.

As the name implies, anticholinergic drugs inhibit the action of acetylcholine. This means the medicines can help with allergies, motion sickness, GI disorders, and some psychiatric disorders. Some prescriptions here include antihistamines, antidepressants, and antipsychotics.

When you take anticholinergic medications, they can help alleviate symptoms such as nausea, muscle spasms, and excessive salivation. However, you can experience side effects like dry mouth, constipation, blurred vision, and cognitive impairment, as well as pupil dilation.

Atropine and Scopolamine

These two substances are found in nature, such as in the plant belladonna. So it’s possible to pick plants in the wild, ingest them, and have dilated pupils as a result.

However, these substances are used in medications too. In fact, they’re both anticholinergic drugs. The former can be used to treat certain heart rhythm abnormalities and toxic poisoning, while the latter can be used to prevent motion sickness and treat nausea and vomiting.

Sympathomimetic Agents

Sympathomimetic agents are also known as adrenergic agonists. They’re medicines that stimulate the sympathetic nervous system. by mimicking the neurotransmitters norepinephrine and epinephrine.

When you stimulate the body’s adrenergic receptors, responses include increased heart rate, elevated blood pressure, bronchodilation, and heightened alertness. Dilated pupils occur too.

Medications commonly used here are decongestants and bronchodilators. For example, there’s albuterol for asthma and epinephrine for allergic reactions. Sympathomimetic agents are also used as appetite suppressants.

What Illicit Drugs Cause Dilated Pupils?

Your loved one may have completely legitimate reasons for having dilated pupils. But if they don’t seem like themselves, then it’s likely that they’re abusing illicit drugs.

Below are some examples, including psychotropic substances.


Stimulant abuse can definitely cause your loved one’s pupils to dilate. These drugs are psychoactive and act on the central nervous system by enhancing the activity of dopamine and norepinephrine. This results in an increase in alertness, energy, and cognitive function.

Stimulants that people often use recreationally are amphetamines (i.e., methamphetamine) and cocaine, as well as MDMA (ecstasy). Side effects include increased heart rate, elevated blood pressure, decreased appetite, insomnia, and increased anxiety. With prolonged or excessive use, you may develop cardiovascular problems and psychiatric disorders.

Do note that some stimulants are legal and used for medical purposes. For example, Adderall (an amphetamine) and Ritalin (methylphenidate) are used to treat ADHD and narcolepsy. Used responsibly, they can significantly improve someone’s quality of life.


Hallucinogens are also known as psychedelics or hallucinogenic drugs. These psychoactive substances can alter your perception, mood, and consciousness. And as you might’ve already guessed, you’ll have vivid visual and auditory hallucinations.

Some examples of hallucinogens are:

  • LSD (lysergic acid diethylamide)
  • Psilocybin (magic mushrooms)
  • PCP (phencyclidine)
  • DMT (dimethyltryptamine)
  • Mescaline
  • Ketamine

Many people use these hallucinogens recreationally for deep introspection. Plus, some of these drugs have potential therapeutic uses. For instance, they may treat depression, anxiety, and post-traumatic stress disorder (PTSD).

Considering that users can see and hear things that don’t really exist, you must be extremely responsible and use hallucinogens in a controlled setting. It’s not recommended to use them outside of a professional one.

Bath Salts

Bath salts are technically a type of stimulant, but they deserve their own category. They’re also known as synthetic cathinones; natural cathinones are usually found in a shrub.

Bath salts contain various amphetamine-like chemicals. The user can experience increased energy, alertness, agitation, paranoia, and even hallucinations. The effects are unpredictable, which means results can be vastly different with each use.

Not only are bath salts highly addictive, but they can cause a variety of health issues. In addition to increased heart rate and blood pressure, you can get chest pain and experience violent behavior. You can never be sure of the purity too, which further increases the risks you’re taking.

What to Do if You Think You Loved One’s Abusing Drugs

Maybe you’ve witnessed your loved one acting out of character, in addition to having dilated pupils. If you want to help them, then it’s important that you don’t aggressively confront them or judge them for their actions.

Instead, treat them with love and compassion. Have an honest yet gentle talk and express your concerns. By treading lightly, you’ll have a better chance at them opening up.

You can then encourage them to get into addiction treatment at a reputable facility. There, they can safely detox and speak to professionals to get on the road to sobriety.

Get Your Loved One the Help They Need

Now you know the answer to the question, “what drugs cause dilated pupils?”

It’s possible for prescription medications to make your loved one’s eye dilate, so don’t automatically assume that they’re abusing drugs. Carefully consider what other signs are present, such as mood swings, social isolation, and any other sudden changes. Don’t be confrontational, but instead, express your concern and care.

If you suspect that your loved one is abusing drugs, then be the support that they need. Contact us now to learn more about admission to Purpose Healing Center. We offer individualized programs that are effective for recovery.