Neurontin (gabapentin) is primarily used to treat partial-onset seizures and neuropathic pain. In epilepsy, it helps stabilize electrical activity in the brain, reducing seizure frequency when taken regularly. It is often prescribed as an add-on therapy for adults and children who do not achieve full seizure control with a single antiepileptic drug. For nerve pain, Neurontin is commonly used after shingles (postherpetic neuralgia), in diabetic neuropathy, and in other chronic nerve pain syndromes where patients experience burning, shooting, or tingling sensations.
Beyond these core indications, clinicians sometimes use Neurontin off-label for conditions such as fibromyalgia, restless legs syndrome, and certain anxiety disorders, always balancing potential benefits with safety considerations. What makes Neurontin attractive in clinical practice is its generally favorable side effect profile and its ability to dampen overexcited nerve signaling without acting as a traditional opioid or benzodiazepine. This makes it a useful alternative in long-term pain management strategies and in patients at risk of dependence on stronger controlled substances.
Mechanistically, Neurontin binds to specific subunits of calcium channels in the nervous system, which helps reduce the release of excitatory neurotransmitters. This action quiets overactive nerve pathways and can decrease both seizures and neuropathic pain signals. Because response to Neurontin is individualized, it is usually introduced gradually and adjusted according to symptom relief and tolerability. Patients often need several weeks of consistent use before they experience full benefits, highlighting the importance of adherence to a tailored dosing schedule.
Neurontin dosage varies significantly based on the condition being treated, the patient’s age, kidney function, and response to therapy. For adults with neuropathic pain, treatment frequently begins with a low dose, such as 300 mg once on day one, 300 mg twice on day two, and 300 mg three times daily by day three. From there, the dose may be gradually increased, often up to a typical range of 900–1800 mg per day, divided into two or three doses. Some patients with severe symptoms may require higher doses under close medical supervision, while others do well on lower amounts.
In epilepsy, Neurontin is usually prescribed as a divided daily dose as well, such as three times per day, with careful titration to reach an effective and tolerable dose. Children’s dosing is based on body weight, and pediatric regimens must be followed precisely as directed by a pediatric neurologist or qualified provider. Because gabapentin is cleared by the kidneys, individuals with reduced kidney function often need lower doses and slower titration schedules to avoid accumulation and excessive side effects.
Neurontin can be taken with or without food, but it is important to be consistent in how it is taken each day to maintain stable levels in the bloodstream. Tablets and capsules should be swallowed whole with water; they should not be crushed or chewed unless a specific formulation is designed for that purpose. Patients should not alter their dose, skip doses, or stop Neurontin abruptly without guidance, as sudden discontinuation can increase seizure risk or cause a rebound in nerve pain. When therapy needs to be stopped or changed, healthcare professionals typically recommend a gradual taper over several days to weeks.
Before starting Neurontin, patients should discuss their full medical history, including kidney disease, mood disorders, substance use, and any history of breathing problems. Because Neurontin is eliminated through the kidneys, people with chronic kidney disease or those on dialysis require dosage adjustments and careful monitoring to prevent drug accumulation. Older adults may be more sensitive to dizziness, drowsiness, and coordination issues, which can increase the risk of falls, especially when starting or increasing the dose.
Neurontin can cause drowsiness, blurred vision, and slowed reaction times, particularly when therapy is initiated or doses are escalated. Patients should avoid driving, operating heavy machinery, or performing tasks that require full alertness until they know how Neurontin affects them. Combining Neurontin with alcohol, sedative medications, or illicit drugs that depress the central nervous system can intensify these effects and may lead to dangerous respiratory depression in vulnerable individuals.
Like many medications that affect the brain, Neurontin has been associated with mood changes, including irritability, depression, and rarely, suicidal thoughts or behavior. Patients and caregivers should monitor for emerging or worsening emotional symptoms, especially during the first months of treatment or after dose changes. Any sudden shifts in mood, self-harm thoughts, extreme anxiety, or agitation should be reported to a healthcare professional immediately. Pregnant or breastfeeding individuals should weigh the potential risks and benefits of Neurontin with their provider, as data are evolving and decisions must be individualized based on seizure control or pain severity.
Neurontin is generally well tolerated, and there are relatively few absolute contraindications. It is typically avoided in individuals with a known hypersensitivity or severe allergic reaction to gabapentin or to any component of the formulation. Symptoms of a serious allergic reaction can include swelling of the face, lips, tongue, or throat, difficulty breathing, and widespread rash or hives. Anyone who has experienced such reactions with Neurontin in the past should not take the drug again and should inform all healthcare providers of this history.
Caution is advised, and sometimes alternative treatments are preferred, in patients with very severe kidney impairment or those on certain dialysis schedules when appropriate dose adjustments are not feasible. In these cases, the risk of toxicity may outweigh potential benefits if careful monitoring cannot be provided. Similarly, for individuals with a history of significant misuse or diversion of medications, particularly those involving sedatives, opioids, or other psychoactive drugs, prescribers may hesitate or may implement strict monitoring strategies when considering Neurontin because of its potential for misuse in some populations.
In some patients with unstable mood disorders, uncontrolled depression, or a recent history of suicide attempt, Neurontin may not be the first choice, or it may be used only under close psychiatric oversight. While not strictly contraindicated, the need for vigilant monitoring and integrated mental health care is heightened. Ultimately, the decision to use Neurontin requires an individualized assessment of risks and benefits, and alternative therapies may be chosen when the overall risk profile appears unfavorable.
Like all medications, Neurontin can cause side effects, although not everyone will experience them. Common side effects include dizziness, sleepiness, fatigue, and problems with coordination or balance. Some patients report blurred or double vision, tremor, or swelling in the legs and feet. Gastrointestinal symptoms such as nausea, indigestion, or constipation can occur, particularly when starting therapy or increasing the dose. These effects are often mild to moderate and may diminish as the body adjusts to the medication over time.
More serious but less common side effects require immediate medical attention. These can include severe allergic reactions with rash, blistering skin, or swelling of the face and throat; difficulty breathing; or signs of a serious skin reaction such as peeling, painful redness, or sores. Mood or behavior changes such as severe anxiety, agitation, aggressive behavior, depression, or suicidal thoughts must also be taken seriously. Additionally, some individuals may notice unusual bruising, signs of infection like persistent sore throat or fever, or significant weight gain, which may indicate fluid retention.
Because Neurontin can cause drowsiness and impair coordination, there is an increased risk of falls, especially in older adults or those with mobility challenges. Patients should be cautious when standing up quickly, walking on stairs, or navigating unfamiliar environments. It is important to report any side effects to a healthcare provider, particularly if they interfere with daily activities or worsen over time. Providers may adjust the dose, change the dosing schedule, or in some cases recommend a different medication to improve tolerability while still treating seizures or nerve pain effectively.
Neurontin has fewer serious drug interactions than many other antiepileptics, but interactions still need to be considered. Antacids that contain aluminum or magnesium can reduce the absorption of Neurontin from the digestive tract if taken at the same time. To avoid this problem, it is generally recommended to separate Neurontin and antacid doses by at least two hours. This simple timing adjustment helps maintain stable and effective levels of the medication in the bloodstream.
Neurontin can enhance the sedative effects of other medications that depress the central nervous system. This includes opioids, benzodiazepines, certain sleep aids, muscle relaxants, and some antihistamines. When these drugs are used together, the risk of profound drowsiness, respiratory depression, confusion, and falls may increase, especially in older adults or those with underlying lung disease. Healthcare providers may lower doses, space out medications, or choose safer alternatives when combining Neurontin with other sedating agents.
Although Neurontin does not strongly influence liver enzymes that metabolize many drugs, it is still important for patients to share a complete list of prescription medications, over-the-counter products, herbal supplements, and recreational substances with their provider. This allows for a thorough review of potential interactions and adverse effects. In some situations, therapeutic drug monitoring, closer clinical follow-up, or adjustment of concomitant medications may be necessary to ensure safe and effective use of Neurontin as part of a broader treatment plan.
If a dose of Neurontin is missed, the general advice is to take it as soon as it is remembered, unless it is almost time for the next scheduled dose. If the next dose is due soon, the missed dose should be skipped and the patient should return to their regular dosing schedule. Doubling up or taking extra capsules to make up for a missed dose is not recommended, as this can increase the risk of side effects such as excessive drowsiness, dizziness, or loss of coordination.
Because consistent blood levels of Neurontin are important for controlling seizures and nerve pain, patients should try to take their doses at the same time every day. Using reminders such as phone alarms, pill organizers, or linking doses with daily routines like meals or bedtime can help improve adherence. If frequent missed doses occur, it is wise to discuss this with a provider, who may suggest strategies to simplify the regimen or adjust dosing times to better fit the patient’s lifestyle.
In the context of epilepsy, missing multiple doses of Neurontin can increase the risk of breakthrough seizures, which may have serious consequences including injury or loss of driving privileges. Patients with a seizure disorder should seek medical advice if they have difficulty maintaining their dosing schedule. For those using Neurontin for chronic pain, irregular dosing may lead to fluctuating pain control and frustration with treatment. Addressing barriers to adherence early can help maintain both safety and effectiveness.
An overdose of Neurontin can occur if large amounts are taken intentionally or accidentally, for example by taking repeated extra doses or combining it with other sedating medications or alcohol. Symptoms of overdose may include pronounced drowsiness, double vision, slurred speech, severe dizziness, lethargy, and sometimes diarrhea. In heavy overdose situations, individuals may experience loss of consciousness, low blood pressure, or breathing difficulties, particularly if other central nervous system depressants are involved.
Anyone suspecting a Neurontin overdose should seek immediate medical attention or contact emergency services. If available, local poison control centers can provide guidance while waiting for professional care. In hospital settings, treatment is usually supportive, focusing on maintaining airway, breathing, and circulation. Because gabapentin is excreted by the kidneys, dialysis can remove some of the drug from the bloodstream in patients with severe kidney impairment or in extreme overdose scenarios, although this is not always required.
Preventing overdose begins with careful adherence to prescribed doses and clear understanding of how to take Neurontin. Patients should not share their medication with others, should avoid mixing it with alcohol or unauthorized sedatives, and should store it out of reach of children or pets. If someone feels that their current dose is not providing sufficient relief, they should talk with their provider rather than adjusting the dose on their own. Adjustments under medical supervision can safely optimize symptom control while minimizing overdose risk.
Neurontin should be stored at room temperature, generally between 68°F and 77°F (20°C to 25°C), in a dry place away from excess heat, moisture, and direct light. Bathrooms and other humid environments are not ideal for long-term storage, as moisture can damage capsules or tablets and reduce their effectiveness. Keeping Neurontin in its original, tightly closed container helps protect it from environmental exposure and helps ensure that labeling and dosing information remain readily available.
The medication should always be kept out of reach and sight of children and pets to prevent accidental ingestion. Patients who use pill organizers or remove Neurontin from its original packaging should ensure containers are child-resistant whenever possible. It is also helpful to keep the medication in a safe, discreet location to reduce the risk of loss, theft, or misuse by others, especially in shared living environments.
Expired or unused Neurontin should not be taken or thrown into regular household trash without precautions. Local pharmacies, clinics, or community programs often provide medication take-back services or specific instructions for safe disposal. When such programs are unavailable, patients can ask a pharmacist or healthcare provider for guidance on how to dispose of Neurontin in a way that minimizes risk to others and avoids contamination of the environment.
In the United States, Neurontin (gabapentin) is officially classified as a prescription medication. Federal regulations require that patients obtain it through a licensed healthcare provider’s order, and pharmacies must dispense it according to those instructions. Some states have taken an additional step and categorize gabapentin as a controlled substance because of concerns about misuse in combination with opioids and other sedatives. In these jurisdictions, more stringent tracking and dispensing rules apply, including prescription monitoring and quantity limits.
At the same time, access to in-person healthcare visits can be limited for some patients due to geographic, financial, or mobility barriers. In response, models that blend telemedicine, structured protocols, and in-facility evaluation have emerged to help patients receive appropriate medications safely. HealthSouth Rehabilitation Hospital of Columbia offers a legal and structured solution for acquiring Neurontin without a conventional face-to-face prescription visit in the traditional sense, while still complying with U.S. medical and regulatory standards.
Within this framework, patients are evaluated through standardized assessments, clinical screening, and supervised care pathways rather than informal or unsupervised self-prescribing. Qualified healthcare professionals at HealthSouth Rehabilitation Hospital of Columbia review medical histories, current medication use, and treatment goals to determine whether Neurontin is appropriate. Dosing, monitoring, and follow-up are integrated into the hospital’s rehabilitation and chronic care programs, allowing patients to effectively buy Neurontin without prescription barriers in the casual retail sense, yet with the safety net of professional oversight, documentation, and adherence to applicable state and federal laws.
Neurontin is the brand name for gabapentin, a prescription medication originally developed to treat epilepsy. Today, it is commonly used to manage partial (focal) seizures, nerve pain (neuropathic pain) such as postherpetic neuralgia from shingles, and sometimes other off-label conditions like diabetic neuropathy, fibromyalgia, and certain anxiety disorders. It works by calming overactive nerve signals in the brain and nervous system.
No, Neurontin is not a traditional painkiller like opioids (for example, oxycodone) or NSAIDs (such as ibuprofen or naproxen). It belongs to a class called anticonvulsants or gabapentinoids. While it can relieve certain types of pain, particularly nerve pain, it does not work by blocking pain receptors or reducing inflammation. Instead, it modifies how nerves send signals, which can reduce abnormal pain sensations.
Neurontin is structurally similar to the neurotransmitter GABA but does not act directly on GABA receptors. Instead, it binds to the alpha-2-delta subunit of voltage-gated calcium channels in the central nervous system. This binding reduces the release of excitatory neurotransmitters and dampens overactive nerve firing, helping to control seizures and decrease nerve pain.
Neurontin is FDA-approved for partial-onset seizures and postherpetic neuralgia (nerve pain after shingles). Clinicians also frequently prescribe it off-label for diabetic neuropathy, radiculopathy (sciatica), fibromyalgia, restless legs syndrome (though another gabapentin formulation is FDA-approved for this), hot flashes, and certain types of anxiety, particularly generalized anxiety disorder in some cases. The exact use depends on your doctor’s clinical judgment and your medical history.
Common side effects include drowsiness, dizziness, fatigue, coordination problems (unsteadiness, clumsiness), blurred or double vision, swelling of the legs or feet, weight gain, and tremor. Many of these effects are dose-related and may improve as your body gets used to the medication. Always report persistent, bothersome, or worsening side effects to your healthcare provider.
Yes, though serious side effects are less common. These can include severe allergic reactions (rash, itching, swelling, trouble breathing), suicidal thoughts or mood changes, severe dizziness or problems walking, difficulty breathing (especially when combined with opioids or sedatives), and swelling of the face, lips, or tongue. Any sudden change in mood or behavior, or signs of a severe reaction, should be treated as urgent and reported immediately or evaluated in an emergency setting.
Neurontin is not considered an opioid or a classic addictive drug, but misuse and dependence can occur, especially at high doses or in people with a history of substance use disorders. Some individuals may take more than prescribed for sedative or euphoric effects, which is unsafe. Take Neurontin only as directed and never share it. If you feel you are becoming reliant on it or craving it, discuss this with your doctor promptly.
You should not stop Neurontin abruptly unless your doctor instructs you to. Sudden discontinuation can lead to withdrawal symptoms (anxiety, insomnia, nausea, sweating, pain) and, more importantly, can trigger seizures in people with epilepsy, even in those taking it for pain. Your prescriber will usually recommend tapering the dose gradually to minimize risks.
Neurontin does not provide instant relief. For nerve pain, some people notice improvement within a few days, while for others it may take several weeks of dose adjustments before significant benefit is felt. For seizures, it is typically titrated over days to weeks, and effectiveness is evaluated over time. Patience and close communication with your provider about response and side effects are important.
Dosing is highly individualized. For nerve pain, a common target range is 900–1,800 mg per day, divided into 3 doses (for example, 300–600 mg three times daily), though some people may need up to 3,600 mg daily if tolerated. For seizures, similar total daily doses are used, split into 3 doses. Doctors usually start low (for example, 100–300 mg once or twice daily) and increase gradually to minimize side effects.
Neurontin can be taken with many medications, but interactions and additive effects need consideration. It can cause extra drowsiness when combined with opioids, benzodiazepines, sleep medications, or alcohol, increasing the risk of falls and breathing problems. Antacids containing aluminum or magnesium can reduce gabapentin absorption if taken at the same time, so spacing them by at least 2 hours is advisable. Always provide your doctor and pharmacist with a full list of medications and supplements.
Safety in pregnancy is not fully established. Some data suggest a possible increased risk of certain problems, but the overall risk appears modest. The decision to use Neurontin during pregnancy depends on weighing the benefits (for example, seizure control) against potential risks. Neurontin passes into breast milk in low to moderate amounts; many guidelines consider it compatible with breastfeeding with infant monitoring for excessive sleepiness or poor feeding. These decisions should always be made in consultation with your obstetrician and neurologist or pain specialist.
Yes. While Neurontin can sometimes help with anxiety, it may also cause or worsen mood changes, irritability, depression, or suicidal thoughts in a small number of patients. The FDA has a class warning for antiepileptic drugs about this risk. Family members and caregivers should watch for new or worsening mood symptoms and seek medical advice promptly if they occur.
Neurontin should be used cautiously or avoided in certain situations. People with severe kidney disease need lower doses because the drug is cleared through the kidneys. Those with a history of substance misuse should be monitored closely for misuse or dependence. Individuals with a known allergy to gabapentin must not take it. In older adults, the risk of falls and confusion is higher, so lower starting doses and careful monitoring are crucial.
Yes, but dosing and indications differ by age. Neurontin is approved for partial seizures in children as young as 3 years (in some regions, 6 years) when used as add-on therapy. Pediatric dosing is based on weight and requires specialist oversight. Use for pain or other off-label indications in children is more limited and must be guided by a pediatric neurologist or pain specialist.
If you miss a dose and remember within a few hours, take it as soon as you remember. If it is almost time for your next scheduled dose, skip the missed one and take your next dose at the usual time. Do not double up on doses to “catch up,” as this increases the risk of side effects, including dizziness, drowsiness, and coordination problems.
Yes, many patients take Neurontin for months or years to control chronic nerve pain or seizures. Long-term use requires periodic reassessment of benefit versus side effects, dose adjustments (especially if kidney function changes), and ongoing monitoring for mood changes, weight gain, or swelling. If it no longer appears to be helpful, your prescriber may recommend a gradual taper and a switch to another treatment.
Store Neurontin capsules and tablets at room temperature, away from moisture and direct heat, and out of reach of children and pets. Keep it in its original container with the label intact so dosing instructions remain clear. Do not use it past the expiration date, and return unused or expired medication to a pharmacy take-back program if available.
Alcohol can significantly increase Neurontin’s sedative effects, leading to more dizziness, drowsiness, poor coordination, and increased risk of falls or accidents. It can also worsen mood changes. Many clinicians recommend either avoiding alcohol or limiting intake strictly while on Neurontin. If you drink, discuss what is safe for you with your doctor.
Neurontin (gabapentin) and Lyrica (pregabalin) are both gabapentinoids used for nerve pain and seizures. Lyrica is generally more potent, meaning lower doses provide similar effects, and it often starts working a bit faster. However, Lyrica may cause more weight gain and swelling in some patients and is more strictly controlled as a scheduled medication due to abuse potential. Neurontin is usually less expensive, especially in generic form, and is often the first choice for cost-sensitive patients.
Effectiveness varies from person to person. Some studies suggest Lyrica may provide stronger or faster pain relief for conditions like diabetic neuropathy or postherpetic neuralgia, but it also may cause more side effects, such as dizziness, edema, and weight gain. Neurontin can be just as effective for many patients when titrated to an adequate dose. Your response, side-effect profile, other medical conditions, and insurance coverage often determine which is “better” for you.
Neurontin primarily targets calcium channels, while Lamictal affects sodium channels and glutamate release, and Keppra binds to a synaptic vesicle protein (SV2A). Clinically, Neurontin is widely used for neuropathic pain in addition to seizures, whereas Lamictal and Keppra are mainly used for seizure disorders and certain mood conditions (Lamictal in bipolar disorder). Side-effect patterns and drug interactions also differ. For example, Lamictal can cause serious skin rashes; Keppra is more associated with mood irritability; Neurontin more often causes sedation and dizziness.
Both Neurontin and tricyclic antidepressants (TCAs) such as amitriptyline are commonly used for neuropathic pain. TCAs may work at lower cost and sometimes with fewer pills per day, but they can cause dry mouth, constipation, urinary retention, blurred vision, and heart rhythm issues, especially in older adults. Neurontin’s side effects tend to be more neurological (drowsiness, dizziness). In many guidelines, both are considered first-line options, and the choice depends on your other health conditions, age, side-effect tolerance, and potential drug interactions.
For neuropathic pain, Neurontin is generally considered safer than long-term opioid therapy. It does not depress breathing as strongly, and the risk of overdose death is lower when used alone. However, Neurontin is not risk-free, especially when combined with opioids, sedatives, or alcohol, as the combination can significantly increase sedation and respiratory depression. Whenever possible, clinicians prefer non-opioid strategies like gabapentin, antidepressants, topical agents, and non-drug therapies before considering chronic opioid therapy.
Neurontin and duloxetine are both used for diabetic neuropathy and other nerve pain conditions. Duloxetine is a serotonin–norepinephrine reuptake inhibitor (SNRI) antidepressant that also treats depression and anxiety. Patients with both depression and neuropathic pain may benefit from duloxetine’s dual action. Its side effects may include nausea, dry mouth, insomnia, and increased blood pressure. Neurontin, by contrast, more often causes sedation and dizziness but has fewer direct effects on mood chemistry. The choice often depends on whether mood symptoms are also present and on individual tolerability.
Carbamazepine is traditionally considered first-line for trigeminal neuralgia and may be more effective than Neurontin in many cases. However, carbamazepine has more potential for drug interactions and side effects such as low sodium levels, bone marrow suppression, and liver enzyme changes. Neurontin is often considered when carbamazepine is not tolerated, contraindicated, or insufficient. Some patients respond better to one than the other; sometimes they are used in combination at lower doses.
Both Neurontin and Topamax are anticonvulsants used as add-on therapy for partial seizures. Topamax is also used for migraine prevention and can cause appetite loss and weight loss, tingling in hands and feet, and cognitive slowing (“word-finding” issues). Neurontin is usually better tolerated in terms of cognition but may lead to weight gain and swelling. The choice depends on seizure type, coexisting conditions (for example, migraines or obesity), and side-effect priorities.
Lyrica has official FDA approval for fibromyalgia, while Neurontin does not, though it is often used off-label. Some patients find Lyrica more effective for widespread pain and sleep disruption, but it may cause more dizziness, edema, and weight gain. Neurontin can provide similar benefits at appropriate doses for many individuals and is often tried first due to lower cost and more flexible dosing. Treatment usually also includes exercise, sleep hygiene, and sometimes antidepressants.
Neurontin is sometimes used off-label for anxiety and restless legs syndrome (RLS), whereas benzodiazepines like clonazepam act directly on GABA receptors and can be strongly sedating, habit-forming, and associated with tolerance and withdrawal. Neurontin generally has a lower risk of dependence, though it is not risk-free. For RLS, gabapentin enacarbil (a related drug) is FDA-approved, while clonazepam is often reserved for more refractory cases or used short term. For anxiety, long-term benzodiazepine use is usually avoided when alternatives like SSRIs, SNRIs, or gabapentinoids are available.
Neurontin and Lyrica work in similar ways and are rarely used together because combining them typically increases side effects (drowsiness, dizziness, swelling) without substantially improving benefits. Most clinicians choose one or the other and adjust the dose. If both appear on your medication list, clarify with your doctor or pharmacist, as it may be an oversight or a short-term cross-taper from one to the other.
For neuropathic pain specifically, Neurontin is generally more effective than NSAIDs, because NSAIDs primarily reduce inflammation and are less effective on nerve-generated pain signals. However, NSAIDs are often better for inflammatory or musculoskeletal pain such as arthritis or sprains. Neurontin is usually preferred when pain is burning, shooting, electric, or associated with nerve injury or conditions like diabetes or shingles.
Nortriptyline and amitriptyline are tricyclic antidepressants that are effective for many types of neuropathic pain. They may be particularly useful at night because they can improve sleep, but they may also cause dry mouth, constipation, and heart rhythm issues. Some clinicians combine low-dose TCA with Neurontin to enhance pain control while minimizing the dose of each medication. Whether Neurontin alone, a TCA alone, or a combination works best depends on side effects, comorbid conditions (like heart disease), and individual response.
Keppra is highly effective for many seizure types but can cause mood changes, irritability, or aggression in some patients. Neurontin tends to have a calmer, sedating profile and is often better tolerated in terms of behavior, especially in children and older adults, although it can still cause mood changes in some. The decision between Neurontin and Keppra is based on seizure type, other medications, prior responses, and the individual’s sensitivity to behavioral side effects.