If you’ve recently stopped taking your allergy medication and are feeling worse—restless, itchy, or unusually anxious—you might be wondering: is this withdrawal, or are your allergies just back? The symptoms can be confusing, but there are key differences worth noting.
Sneezing, itching, and watery eyes usually signal a return of allergy symptoms. On the other hand, issues like insomnia, irritability, dizziness, or heightened anxiety may suggest your body is reacting to the absence of the medication itself. Recognizing the distinction can help you decide whether it’s time to reassess your allergy management plan—or take a closer look at your medication use.
What Is an Antihistamine?
Antihistamines are a class of medications used to treat allergy symptoms by blocking the effects of histamine, a chemical released by the immune system in response to allergens like pollen, dust, pet dander, or certain foods. When histamine binds to its receptors, it triggers symptoms such as sneezing, itching, nasal congestion, a runny nose, watery eyes, and skin rashes like hives.
By preventing histamine from attaching to these receptors, antihistamines help calm the body’s allergic response. They come in different forms—tablets, liquids, nasal sprays, and eye drops—and are available in both over-the-counter and prescription strengths. Some antihistamines also cause drowsiness, while others are formulated to be non-sedating for daytime use.
Types of Antihistamines
Antihistamines are broadly categorized into two groups: over-the-counter (OTC) and prescription medications. They also vary in how long they last, how sedating they are, and how likely they are to cause side effects or withdrawal-like symptoms when stopped.
They are further divided into first-generation and second-generation types. First-generation antihistamines easily cross into the brain and often cause drowsiness. Second-generation antihistamines are newer, designed to stay mostly outside the brain, and are less likely to cause sedation—making them more suitable for daytime use.
Over-the-Counter (OTC) Antihistamines
These are readily available over-the-counter and commonly used to treat seasonal allergies, mild allergic reactions, and hives.
A first-generation antihistamine known for its strong sedative effects. It’s often used for short-term relief of severe allergies or as a sleep aid. It’s more likely to cause drowsiness and may be associated with withdrawal-like symptoms if used regularly.
A second-generation, non-sedating antihistamine. It’s long-acting and typically used for daily allergy management with minimal drowsiness.
Another second-generation antihistamine. It may cause more drowsiness than loratadine, but it is often more effective for certain individuals.
A non-drowsy, second-generation option with minimal central nervous system effects. Often preferred for daytime use.
Prescription Antihistamines
These are typically used when OTC medications are ineffective or when a more substantial, more sedating effect is needed.
A first-generation antihistamine with strong sedative and anti-anxiety properties. Commonly used to treat itching, hives, and sometimes anxiety or insomnia. Due to its potency, abrupt discontinuation may lead to more noticeable rebound symptoms.
A long-acting, non-sedating antihistamine related to loratadine. It’s used for chronic allergy symptoms and is less likely to cause sedation or withdrawal effects.
A purified form of cetirizine with similar effectiveness but potentially fewer side effects. Mild sedation is possible in some individuals.
Each medication affects individuals differently, and factors like duration of use, dosage, and underlying conditions can influence the likelihood of experiencing withdrawal-like symptoms. Choosing the right antihistamine often depends on the severity of your symptoms, the timing, and your daily activities.
Common Side Effects of Antihistamines
While antihistamines are generally safe and effective for managing allergies, they can cause side effects—especially with long-term or high-dose use. The type and severity of side effects often depend on whether the antihistamine is a first- or second-generation antihistamine.
- Drowsiness or sedation: This is especially common with first-generation types and may cause fatigue and reduced alertness.
- Dry mouth: Due to decreased saliva production, it may cause discomfort over time.
- Dizziness: Often linked to sedation or drops in blood pressure when standing.
- Nausea: May cause mild stomach upset, especially on an empty stomach.
- Constipation: Slows digestion, particularly with sedating antihistamines.
- Blurred vision: Caused by dryness and effects on eye focus.
- Confusion (especially in older adults): Older adults may experience memory issues or disorientation, which can be particularly pronounced.
What Are the Symptoms of Antihistamine Withdrawal?
Stopping antihistamines abruptly—especially after long-term or high-dose use—can lead to withdrawal-like symptoms in some individuals. These symptoms can show up even when no allergens are present, such as:
- Anxiety: Feelings of unease, nervousness, or panic without a clear cause
- Insomnia: Difficulty falling or staying asleep, even when tired.
- Nausea: A sensation of queasiness or upset stomach.
- Restlessness: An urge to move constantly or an inability to relax.
- Irritability: Increased sensitivity or frustration over minor triggers.
- Sweating: Excessive perspiration, even without physical exertion.
- Headaches: Persistent or throbbing head pain, often associated with tension.
- Itching or skin discomfort: Tingling, prickling, or itching without allergen exposure.
These symptoms can last from a few days to a few weeks, depending on the individual’s usage history and the type of antihistamine used.
Can You Take Allergy Medicine With Alcohol?
Combining alcohol with antihistamines—particularly first-generation, sedating types like diphenhydramine (Benadryl) or hydroxyzine—can be risky and is generally not recommended. Both substances act as central nervous system (CNS) depressants, which means they can slow down brain activity and impair key functions.
When taken together, the sedative effects may be amplified, leading to:
- Excessive drowsiness: Making it unsafe to drive, work, or perform tasks requiring focus.
- Poor coordination and slower reflexes: Increasing the risk of accidents and falls.
- Impaired judgment: Leading to risky behavior or poor decision-making.
- Respiratory depression (in severe cases): Slowed or difficult breathing, which can be dangerous, especially in high doses or with underlying health conditions.
Even with second-generation, non-drowsy antihistamines like loratadine or fexofenadine, caution is still advised. While the sedative risk is lower, alcohol may still interact unpredictably, particularly in sensitive individuals.
If you’re taking allergy medication regularly, it’s best to limit alcohol or consult your healthcare provider about safe use.
Can You Overdose on Alcohol and Allergy Medicine?
Overdosing on a combination of alcohol and antihistamines is not only possible but potentially life-threatening. While moderate use of either substance alone can carry risks, combining them—especially in high amounts—can overwhelm the body’s ability to process them safely.
Unlike the typical side effects from casual use, an overdose involves toxic levels that affect vital functions, particularly in the brain and heart. This risk is heightened when multiple sedating agents are taken together, intentionally or unintentionally.
Warning signs of an overdose may include symptoms such as
- Severe confusion or disorientation
- Hallucinations or agitation
- Seizures
- Unresponsiveness or loss of consciousness
- Abnormally fast heart rate
- Dilated pupils
- Skin flushing or dryness
- Coma
- In extreme cases, death
The specific symptoms can vary depending on the type and dose of antihistamine used, how much alcohol was consumed, and the individual’s overall health.
Who Is More Likely to Abuse Antihistamines?
Specific populations are more at risk of abusing antihistamines:
- Teenagers and young adults experimenting with over-the-counter drugs
- Individuals with a history of substance abuse
- Those using antihistamines to sleep or self-medicate anxiety
- People are unaware of the potential dangers of long-term or excessive use
Misuse can lead to dependency and serious health consequences, including withdrawal when stopping the medication.
Antihistamine Withdrawal Timeline
Antihistamine withdrawal varies by drug type, dosage, duration, and individual sensitivity, but most people experience a general pattern of symptom progression.
This is when initial symptoms typically begin to appear. These early signs may be mistaken for regular allergy flare-ups, but the addition of restlessness or difficulty sleeping can point to withdrawal.
Symptoms usually reach their highest intensity during this period. This phase can be uncomfortable but is temporary. Supportive care, hydration, and sleep hygiene are critical in this context.
Many symptoms begin to subside during this time. Some individuals may notice improvements sooner, while others may continue to experience lingering symptoms.
By the end of the first month, most withdrawal symptoms have resolved or significantly improved. At this stage, the body has typically readjusted to functioning without the antihistamine.
If symptoms persist for more than four weeks or significantly impact quality of life, it’s essential to consult a healthcare provider. Persistent symptoms may indicate another underlying issue or require a more tailored tapering approach.
Treating Antihistamine Withdrawal
Managing antihistamine withdrawal requires medical guidance, symptom relief, and addressing the root causes of long-term use, tailored to each individual’s needs.
Gradually reducing the dose under medical supervision is safer than stopping suddenly and helps ease withdrawal symptoms like insomnia and anxiety.
Staying hydrated and getting quality sleep supports recovery and reduces fatigue, headaches, and irritability.
Comprehensive therapy can help address underlying anxiety or sleep issues that led to antihistamine overuse, offering healthier coping tools.
Switching to second-generation antihistamines or non-drug options like nasal sprays or allergy shots can reduce dependence.
Severe cases may require professional help, including detox programs or inpatient care for safe withdrawal and stabilization.
Recover From Drug Addiction at Laguna Shores
If you’re struggling with antihistamine misuse or other forms of substance dependency, you’re not alone. At Laguna Shores Recovery, we offer a compassionate, medically supervised environment to help you detox safely and begin your journey toward lasting wellness. Our personalized treatment plans address both physical withdrawal and underlying emotional triggers. Reach out to us today!
Matthew Beck B.A, M.A, LMFT 
