When Should You Not Take Gravol? A Guide to Safe Use

October 12, 2025 •

4 min read

Dimenhydrinate, the active ingredient in Gravol, is one of the most common over-the-counter antihistamines used for motion sickness [1.10.4]. However, there are important situations involving medical conditions, age, and other substances where you should not take Gravol [1.7.1, 1.3.1].

Quick Summary

Understand the specific circumstances and medical conditions where taking Gravol (dimenhydrinate) is not advised. Key contraindications, drug interactions, and special precautions are detailed for safe medication use.

Key Points

Medical Conditions: Do not take Gravol if you have glaucoma, chronic lung disease (like emphysema), or difficulty urinating due to an enlarged prostate [1.6.2, 1.7.1].
Alcohol Interaction: Never consume alcohol while taking Gravol, as it dramatically increases drowsiness, dizziness, and impairment [1.4.3, 1.4.5].
Drug Interactions: Avoid taking Gravol with other CNS depressants, including sedatives, tranquilizers, sleeping pills, and opioids, to prevent severe sedation [1.3.1].
Elderly Precaution: Adults over 65 are more sensitive to side effects like confusion and dizziness and should generally not take dimenhydrinate [1.8.1].
Children's Use: Gravol should not be used in children under two years old unless directed by a doctor, as it can cause paradoxical excitement [1.2.1, 1.9.1].
Pregnancy and Breastfeeding: If pregnant or breastfeeding, consult a doctor before taking any Gravol products, as the active ingredient passes into breast milk [1.5.1, 1.5.4].
Allergies: Check for allergies to dimenhydrinate or other ingredients like tartrazine, which is sometimes found in chewable tablets and can affect those with aspirin sensitivity [1.2.2].

Understanding Gravol (Dimenhydrinate)

Gravol is an over-the-counter medication primarily used to prevent and treat nausea, vomiting, and dizziness associated with motion sickness [1.2.4]. Its active ingredient, dimenhydrinate, is an antihistamine that works by depressing the sensitivity of the labyrinth apparatus in the inner ear, which communicates with the part of the brain that triggers vomiting [1.2.1]. While effective for many, its sedative and anticholinergic properties mean it's not suitable for everyone. Knowing the specific scenarios when you should not take Gravol is crucial for your safety.

Medical Conditions That Preclude Gravol Use

Due to its effects on the body, individuals with certain pre-existing health conditions should avoid Gravol or use it only with extreme caution under a doctor's supervision. The anticholinergic effects of dimenhydrinate can worsen these conditions [1.2.4].

Key contraindications include:

Respiratory Problems: People with chronic lung diseases like emphysema or chronic bronchitis should not use Gravol, as it can thicken bronchial secretions and make breathing more difficult [1.6.2, 1.9.4].
Glaucoma: The medication can increase pressure inside the eye, making it dangerous for individuals with angle-closure glaucoma [1.7.3, 1.7.1].
Enlarged Prostate: Dimenhydrinate can cause or worsen urinary retention, a common issue for those with an enlarged prostate gland (prostatic hypertrophy) [1.6.2, 1.9.4].
Allergies: Do not take this medication if you are allergic to dimenhydrinate, diphenhydramine (a component of dimenhydrinate), or any other ingredients in the product [1.2.2, 1.2.5]. Some chewable tablets contain tartrazine (FD&C Yellow No. 5), which can cause allergic reactions in individuals sensitive to aspirin [1.2.2, 1.2.4].
Phenylketonuria (PKU): Some chewable versions of dimenhydrinate contain aspartame, which forms phenylalanine and should be avoided by individuals with PKU [1.2.2].

Dangerous Drug and Substance Interactions

One of the most significant risks associated with Gravol is its interaction with other substances that depress the Central Nervous System (CNS). Combining them can lead to additive effects like intense drowsiness, dizziness, and impaired coordination [1.3.1].

Substances to avoid with Gravol:

Alcohol: Mixing Gravol and alcohol significantly increases drowsiness and dizziness, making it unsafe to drive or operate machinery. It can make side effects much worse [1.4.3, 1.4.5].
CNS Depressants: This category includes sedatives, tranquilizers, sleeping pills, muscle relaxers, opioids, and barbiturates. Combining these with Gravol can lead to profound sedation, respiratory depression, and in severe cases, coma [1.3.1, 1.3.2].
Other Antihistamines: Taking Gravol with other antihistamines, like diphenhydramine (Benadryl) or meclizine, increases the risk of side effects such as dry mouth, blurred vision, and drowsiness [1.3.1, 1.3.5].
MAO Inhibitors: You should not take Gravol if you are taking a monoamine oxidase inhibitor (MAOI), such as phenelzine or tranylcypromine, or have taken one in the past two weeks [1.9.4, 1.3.4].
Anticholinergic Drugs: Combining Gravol with other drugs that have anticholinergic effects (e.g., some antidepressants, drugs for bladder control like oxybutynin) can potentiate side effects like urinary retention, constipation, and confusion [1.2.4, 1.3.1].

Special Populations: Age and Pregnancy

Certain age groups and life stages require special consideration before using Gravol.

Children: Gravol should not be given to children under two years of age unless directed by a doctor [1.9.1]. In young children, it can cause paradoxical hyperexcitability instead of drowsiness [1.2.1, 1.6.1].
Elderly (65+): Older adults are generally more sensitive to the side effects of antihistamines, including dizziness, sedation, confusion, dry mouth, and urinary retention. This increases the risk of falls. It is often recommended that older adults avoid dimenhydrinate as other, safer medications may be available [1.8.1, 1.2.1].
Pregnancy and Breastfeeding: If you are pregnant or breastfeeding, you should only take Gravol upon the recommendation of a doctor [1.5.1, 1.5.2]. While some studies suggest it is safe during pregnancy, it does pass into breast milk and could potentially affect a nursing infant [1.5.3, 1.5.4].

Comparison of Anti-Nausea Medications


Feature	Gravol (Dimenhydrinate)	Meclizine (Bonine)	Scopolamine (Transderm Scop)	Ginger (Natural)
Primary Use	Motion Sickness [1.2.4]	Motion Sickness, Vertigo [1.10.2]	Motion Sickness [1.10.1]	Nausea (various causes) [1.10.3]
Common Side Effects	Drowsiness, dry mouth, dizziness [1.6.4]	Drowsiness (less than Gravol), dry mouth [1.10.1]	Dry mouth, blurred vision, drowsiness [1.10.1]	Mild heartburn
Administration	Oral tablet, chewable, liquid, injection [1.2.4]	Oral tablet, chewable [1.10.1]	Transdermal patch [1.10.1]	Capsule, chew, tea, raw root [1.10.3]
Prescription Needed	No (for oral forms) [1.10.4]	No [1.10.4]	Yes [1.10.1]	No
Key Precaution	Avoid with alcohol, CNS depressants [1.3.1]	Less sedating but still caution with alcohol [1.10.1]	Must be applied hours before travel [1.10.5]	Consult doctor for high doses

Conclusion

While Gravol is a useful and accessible remedy for motion sickness, it is not universally safe. You should not take Gravol if you have certain respiratory or eye conditions, are taking other CNS depressants like alcohol or sedatives, or fall into a sensitive age group without a doctor's consultation. Always read the product label carefully, be aware of potential interactions, and consult with a healthcare professional or pharmacist if you have any doubts about whether Gravol is the right choice for you [1.2.2, 1.7.4].

For more information on dimenhydrinate, consult MedlinePlus.

Frequently Asked Questions

No, you should never consume alcohol while taking Gravol. The combination can significantly increase side effects like drowsiness and dizziness, leading to dangerous levels of impairment [1.4.3, 1.4.5].

You should not take Gravol if you have a breathing problem such as asthma, emphysema, or chronic bronchitis. The medication can thicken bronchial secretions, which may worsen your condition [1.6.2, 1.9.4].

Older adults (over 65) are more sensitive to the anticholinergic side effects of Gravol, such as dizziness, sedation, confusion, and urinary retention. This increases the risk of falls and other complications. It's recommended they seek safer alternatives [1.8.1, 1.2.1].

You should not take Gravol with many anxiety medications (like benzodiazepines) or other CNS depressants without consulting a doctor. The combination can cause additive sedative effects, leading to excessive drowsiness and respiratory depression [1.3.1, 1.3.2].

Gravol should not be given to children under 2 years old without a doctor's direction. For children aged 2 and older, use only the recommended dosage for their age group, as overdose can be dangerous and some children experience hyperactivity instead of drowsiness [1.9.3, 1.6.1].

If you have glaucoma, you should avoid Gravol. The medication can increase the pressure inside your eyes, which can be dangerous for this condition [1.7.3, 1.7.1].

If you are pregnant, you should only take Gravol on the recommendation of a healthcare practitioner. While it has been used for nausea in pregnancy, it is important to discuss the risks and benefits with your doctor [1.5.1, 1.5.3].