A Comprehensive Safety Guide: What Should Be Avoided When Taking Diazepam?

October 13, 2025 •

4 min read

In a 2020 study, 92.7% of overdose deaths involving benzodiazepines like diazepam also involved opioids, highlighting the critical importance of knowing what should be avoided when taking diazepam [1.10.2].

Quick Summary

This overview details the critical substances, medications, and activities to avoid while taking diazepam. It covers dangerous interactions with alcohol, opioids, and other drugs, plus necessary lifestyle precautions.

Key Points

Alcohol: Never combine diazepam with alcohol, as it dramatically increases the risk of severe sedation, respiratory depression, and death [1.4.1, 1.4.4].
Opioids: Avoid taking opioids with diazepam due to an FDA Boxed Warning about the potentially fatal combination leading to profound sedation and slowed breathing [1.5.2].
Other CNS Depressants: Steer clear of other sedating medications, including sleep aids, muscle relaxers, and other benzodiazepines, to prevent dangerous additive effects [1.6.1].
Grapefruit Juice: Do not consume grapefruit or its juice, as it can significantly increase diazepam levels in your blood, heightening the risk of side effects [1.7.1].
Driving and Machinery: Do not drive or operate heavy machinery until you understand how diazepam affects your alertness and coordination [1.8.3].
Medical Consultation: Always inform your healthcare provider of all prescription drugs, over-the-counter medications, and herbal supplements you are taking to screen for interactions [1.6.3].
Abrupt Cessation: Do not suddenly stop taking diazepam; this can cause severe withdrawal symptoms. Always consult a doctor for a gradual tapering schedule [1.3.1].

Diazepam, commonly known by the brand name Valium, is a benzodiazepine medication prescribed to treat anxiety, muscle spasms, seizures, and alcohol withdrawal [1.3.2, 1.3.3]. While effective, its use requires significant caution due to numerous potential interactions that can lead to dangerous side effects. Understanding what to avoid is paramount for patient safety.

Major Substances to Avoid

Certain substances can dangerously amplify the effects of diazepam, which acts as a central nervous system (CNS) depressant [1.4.4].

Alcohol

Combining diazepam with alcohol is extremely dangerous and should be avoided completely [1.2.1, 1.3.2]. Both are CNS depressants, and when taken together, their effects are compounded, leading to risks of [1.4.4]:

Extreme drowsiness and sedation
Impaired coordination and judgment
Slowed or difficult breathing (respiratory depression)
Memory problems
Coma or death [1.4.1]

There is no safe amount of alcohol to consume while taking diazepam [1.3.2].

Opioids

The U.S. Food and Drug Administration (FDA) has issued its strongest warning, a Boxed Warning, regarding the concurrent use of benzodiazepines and opioids [1.5.2]. This combination significantly increases the risk of profound sedation, life-threatening respiratory depression, and death [1.5.2, 1.5.3]. Opioids to avoid include prescription pain relievers like oxycodone, hydrocodone, morphine, and tramadol, as well as illicit drugs like heroin [1.3.2, 1.3.3].

Other CNS Depressants

Numerous other medications and substances that depress the central nervous system can interact negatively with diazepam. These include:

Other Benzodiazepines: Taking diazepam with other benzodiazepines like alprazolam (Xanax) or lorazepam (Ativan) should be avoided [1.6.3, 1.11.3].
Sleep Aids: Both prescription sleep aids (e.g., zolpidem/Ambien) and over-the-counter (OTC) options containing antihistamines like diphenhydramine (Benadryl, ZzzQuil) or doxylamine can cause excessive sleepiness and breathing problems when mixed with diazepam [1.6.1, 1.11.2].
Muscle Relaxers: Medications like cyclobenzaprine and baclofen can lead to increased drowsiness and risk of overdose [1.6.1].
Antipsychotics: Drugs such as quetiapine (Seroquel) can increase drowsiness and the risk of low blood pressure [1.6.1].
Certain Antidepressants: Some antidepressants, particularly SSRIs like fluoxetine, can block the breakdown of diazepam, increasing its levels and side effects [1.6.1].
Recreational Drugs: Cannabis, heroin, and stimulants like cocaine or MDMA can have dangerous and unpredictable interactions, primarily increasing drowsiness and the risk of respiratory failure [1.2.3].

Medication and Supplement Interactions

Always inform your doctor of all prescription drugs, OTC medications, and supplements you are taking [1.6.3].

Prescription and OTC Drugs

Some Antifungals: Medications like ketoconazole and fluconazole can inhibit the body's ability to break down diazepam, leading to higher concentrations in the blood and increased side effects [1.6.1].
Certain Seizure Medications: Drugs like carbamazepine may decrease diazepam levels, making it less effective, while others increase sedative effects [1.6.1].
OTC Antihistamines: Found in many allergy and cold medicines (e.g., Benadryl), these can increase drowsiness [1.11.1, 1.11.2].

Herbal Supplements

Herbal supplements are not regulated like medications, and their interactions can be unpredictable. Avoid taking the following with diazepam [1.12.2]:

St. John's Wort: May decrease the levels of diazepam in the blood [1.12.2].
Valerian and Kava: These herbs, often used for anxiety or sleep, can increase the sedative effects of diazepam [1.12.1, 1.12.2].
Gotu Kola and Passionflower: May also enhance diazepam's drowsy effects [1.12.1, 1.12.2].

Food and Beverage Interactions

Grapefruit and Grapefruit Juice: This is a significant interaction. Grapefruit can inhibit an enzyme (CYP3A4) responsible for metabolizing diazepam, leading to a 3.2-fold increase in its concentration in the blood. This elevates the risk of side effects like dizziness and excessive drowsiness [1.7.1].
Caffeine: As a stimulant, caffeine can counteract the calming effects of diazepam. It's best to avoid coffee, tea, and other caffeinated beverages, especially if taking diazepam for anxiety or insomnia [1.2.3, 1.7.1].

Activities to Avoid

Diazepam can significantly impair mental and physical abilities.

Driving and Operating Machinery: Do not drive, operate heavy machinery, or perform any hazardous tasks until you know how diazepam affects you [1.8.2, 1.8.3]. The medication can cause drowsiness, dizziness, and impaired coordination, making these activities unsafe [1.8.3].

Comparison Table: Key Diazepam Interactions


Substance/Medication Category	Type of Interaction	Risk Level	Action Required
Alcohol	Additive CNS Depression	Major/Severe	Avoid completely [1.2.1].
Opioids (e.g., Oxycodone)	Profound Sedation, Respiratory Depression	Major/Severe	Avoid combination unless no alternative exists and under strict medical supervision [1.5.2, 1.5.3].
Other Benzodiazepines	Additive CNS Depression	Major/Severe	Avoid combination [1.11.3].
Sleep Aids (e.g., Ambien, Benadryl)	Increased Sedation, Respiratory Depression	Major	Avoid combination; discuss sleep issues with your doctor [1.6.1].
Grapefruit Juice	Increased Diazepam Blood Levels	Major	Avoid consuming grapefruit products [1.7.1].
Herbal Supplements (e.g., St. John's Wort, Valerian)	Altered Drug Efficacy/Increased Sedation	Moderate	Avoid; consult doctor before use [1.12.1, 1.12.2].
Caffeine	Antagonizes Sedative Effect	Mild	Limit or avoid, especially near bedtime [1.2.3].

Special Populations

Elderly Patients: Older adults are more sensitive to diazepam's side effects, including drowsiness, confusion, and unsteadiness, which increases the risk of falls and fractures. Lower doses are typically required [1.9.1, 1.13.1]. The American Geriatrics Society generally recommends avoiding benzodiazepines in older adults [1.13.3].
Pregnancy and Breastfeeding: Taking diazepam late in pregnancy can cause sedation or withdrawal symptoms in the newborn [1.9.3, 1.14.2]. The medication passes into breast milk and can cause sedation and poor feeding in infants, so it should be used with caution and under medical advice [1.14.1, 1.14.3].
Medical Conditions: Patients with severe lung disease, sleep apnea, myasthenia gravis, or severe liver disease should generally not take diazepam [1.9.1].

Conclusion

To use diazepam safely and effectively, it is essential to be aware of what should be avoided when taking diazepam. The most critical rule is to abstain from alcohol and opioids due to the life-threatening risk of respiratory depression. Always maintain open communication with your healthcare provider, disclosing all medications, supplements, and lifestyle habits to prevent dangerous interactions. Never stop taking diazepam abruptly, as this can cause withdrawal; your doctor can create a safe tapering plan [1.3.1].

For more information from an authoritative source, visit the National Library of Medicine's page on Diazepam: https://medlineplus.gov/druginfo/meds/a682047.html

Frequently Asked Questions

Drinking alcohol while taking diazepam is extremely dangerous. Both are central nervous system depressants, and combining them can lead to severe drowsiness, impaired coordination, dangerously slowed breathing, memory loss, coma, and even death [1.4.1, 1.4.4].

You should be very cautious. Many OTC cold and allergy medicines, like Benadryl, contain antihistamines (e.g., diphenhydramine) that cause drowsiness. Combining them with diazepam can lead to excessive sedation. Always consult your doctor or pharmacist first [1.11.1, 1.11.2].

Yes, over-the-counter pain relievers like acetaminophen (Tylenol) and ibuprofen (Advil) are generally considered safe to take with diazepam as there is no direct interaction. However, it's always best to check with your healthcare provider before taking any new medication [1.15.1].

Yes, you must avoid grapefruit and grapefruit juice. They interfere with the body's ability to process diazepam, which can lead to dangerously high levels of the medication in your bloodstream and increase side effects [1.7.1].

You should not drive a car or operate machinery until you know how diazepam affects you personally, as it can cause significant drowsiness, dizziness, and impaired coordination. This effect can be more pronounced when you first start the medication [1.8.2, 1.8.3].

It is best to avoid or limit caffeine. As a stimulant, caffeine can work against the calming or sedative effects of diazepam, potentially making the medication less effective for treating anxiety or insomnia [1.2.3, 1.7.1].

Yes, elderly patients are more sensitive to diazepam's side effects, including confusion, drowsiness, and unsteadiness, which increases the risk of falls and fractures. Healthcare providers often recommend avoiding benzodiazepines or using lower doses in older adults [1.13.1, 1.13.3].