Dextroamphetamine

Dosage for dextroamphetamine must be highly individualized based on the therapeutic needs and response of the patient. Healthcare providers typically follow the principle of 'start low and go slow.'

• ADHD: The standard starting dose for adults is often 5 mg once or twice daily. The daily dosage may be raised in increments of 5 mg at weekly intervals until an optimal response is obtained. While the typical range is 5 mg to 40 mg per day, some patients may require higher doses, though doses exceeding 60 mg per day are rarely recommended and require close scrutiny.
• Narcolepsy: The usual dose is 5 mg to 60 mg per day in divided doses. Your doctor may start with 10 mg daily and increase by 10 mg increments weekly.

Dextroamphetamine is approved for use in children as young as 3 years old for certain indications, though ADHD dosing usually begins at age 6.

• ADHD (Ages 6-17): Start with 5 mg once or twice daily. Increase daily dosage in 5 mg increments at weekly intervals.
• ADHD (Ages 3-5): Start with 2.5 mg daily. Increase daily dosage by 2.5 mg at weekly intervals.
• Narcolepsy (Ages 6-12): Start with 5 mg daily; increase by 5 mg weekly.
• Narcolepsy (Ages 12+): Start with 10 mg daily; increase by 10 mg weekly.

Renal Impairment

Since dextroamphetamine is primarily excreted by the kidneys, patients with severe renal impairment (low GFR) may require lower doses or less frequent administration. Your healthcare provider will monitor kidney function tests to determine the safest dose.

Hepatic Impairment

While the liver processes a portion of the drug, specific dosage adjustments for hepatic impairment are not standardized in the labeling. However, caution is advised in patients with severe liver disease.

Elderly Patients

Clinical studies of dextroamphetamine did not include sufficient numbers of subjects aged 65 and over. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function.

• Timing: Immediate-release tablets are usually taken 2 to 3 times daily. The first dose should be taken upon awakening. Subsequent doses should be spaced 4 to 6 hours apart. Avoid taking doses late in the evening to prevent insomnia (difficulty sleeping).
• Food: Dextroamphetamine can be taken with or without food. However, consistency is key. If you experience stomach upset, taking it with a small meal may help.
• Administration: Extended-release capsules should be swallowed whole. Do not crush, chew, or break them, as this destroys the controlled-release mechanism and increases the risk of immediate toxicity. For the oral solution, use a calibrated measuring device rather than a household spoon.
• Storage: Store at room temperature (20°C to 25°C / 68°F to 77°F) in a tight, light-resistant container. Keep it in a secure location to prevent unauthorized use or theft.

If you miss a dose, take it as soon as you remember, unless it is late in the afternoon or evening. If it is nearly time for your next dose, skip the missed dose and resume your regular schedule. Do not 'double up' or take extra medication to make up for a missed dose, as this increases the risk of cardiovascular side effects.

An overdose of dextroamphetamine can be life-threatening. Symptoms include restlessness, tremor, rapid breathing, confusion, aggression, hallucinations, panic states, hyperpyrexia (extremely high fever), muscle pains, and arrhythmias (irregular heartbeat).

Emergency Measures: If an overdose is suspected, call 911 or your local emergency services immediately. Treatment often involves gastric lavage (stomach pumping), administration of activated charcoal, and supportive care to manage blood pressure and body temperature. In severe cases, intravenous medications may be used to counteract the stimulant effects.

> Important: Follow your healthcare provider's dosing instructions. Do not adjust your dose without medical guidance. Misuse of this medication can lead to serious heart problems or sudden death.

Most patients taking dextroamphetamine will experience at least one mild side effect, especially during the first few weeks of treatment as the body adjusts to the medication.

• Insomnia: Difficulty falling or staying asleep is the most frequently reported issue. This is directly related to the drug's stimulant properties.
• Anorexia and Weight Loss: A significant decrease in appetite is common. Patients may find they have no interest in food during the peak hours of the medication's effect.
• Xerostomia (Dry Mouth): A parched feeling in the mouth, which can lead to dental issues if not managed with hydration.
• Upper Abdominal Pain: Often described as a 'nervous stomach' or cramping.
• Increased Heart Rate (Tachycardia): A noticeable increase in resting heart rate.

• Dizziness and Headache: Often transient but can be bothersome.
• Irritability and Mood Swings: Some patients experience a 'rebound' effect where they become irritable as the medication wears off.
• Lability (Emotional changes): Rapid shifts in mood or feeling 'flat' emotionally.
• Tics: Development of repetitive motor movements or vocalizations.
• Diarrhea or Constipation: Changes in bowel habits due to the drug's effect on the autonomic nervous system.

• Raynaud’s Phenomenon: Reduced blood flow to the fingers and toes, causing them to feel cold, numb, or change color (blue or white).
• Psychotic Episodes: Even in patients without a history of mental illness, high doses can trigger hallucinations or delusions.
• Rhabdomyolysis: A serious condition involving the breakdown of muscle tissue, often associated with extreme physical exertion or high fever while on the drug.
• Visual Disturbances: Blurred vision or difficulty with accommodation (focusing).

> Warning: Stop taking Dextroamphetamine and call your doctor immediately if you experience any of these.

• Cardiovascular Events: Chest pain, shortness of breath, or fainting. These may indicate a heart attack or stroke.
• Psychiatric Symptoms: New or worsening aggressive behavior, hearing voices, or believing things that are not true (paranoia).
• Seizures: Especially in patients with a prior history of seizure disorders.
• Serotonin Syndrome: If combined with other medications, symptoms include shivering, diarrhea, confusion, severe muscle tightness, and fever.
• Anaphylaxis: Severe allergic reactions including hives, swelling of the face or throat, and difficulty breathing.

• Growth Suppression: In pediatric patients, long-term use of stimulants has been associated with a temporary slowing in growth rate (both height and weight). Most children eventually reach their predicted adult height, but 'drug holidays' (planned breaks from the medication) are sometimes recommended by doctors to mitigate this.
• Tolerance and Dependence: Over time, the brain may become less responsive to the drug, requiring higher doses to achieve the same effect. This can lead to physical and psychological dependence.
• Cardiovascular Strain: Chronic elevation of heart rate and blood pressure may increase the long-term risk of hypertension or left ventricular hypertrophy (thickening of the heart muscle).

The FDA has issued a Boxed Warning for dextroamphetamine regarding its high potential for abuse and dependence.

1. 1Abuse and Diversion: Dextroamphetamine has a high potential for abuse. Particular attention should be paid to the possibility of subjects obtaining amphetamines for non-therapeutic use or distribution to others. It should be prescribed sparingly.
2. 2Misuse Risks: Misuse of amphetamines may cause sudden death and serious cardiovascular adverse events.
3. 3Dependence: Prolonged administration may lead to drug dependence. Abrupt cessation following prolonged high-dosage administration results in extreme fatigue and mental depression; changes are also noted on the sleep EEG.

Report any unusual symptoms to your healthcare provider. Monitoring of blood pressure and heart rate is mandatory for all patients on long-term therapy.

Dextroamphetamine is a powerful medication that affects the central nervous system and cardiovascular system. It is not suitable for everyone. Before starting treatment, a full medical history, including a family history of sudden death or ventricular arrhythmia, must be evaluated by a healthcare professional.

WARNING: ABUSE, MISUSE, AND ADDICTION

Dextroamphetamine has a high potential for abuse and misuse, which can lead to the development of a substance use disorder, including addiction. Misuse and abuse of CNS stimulants, including Dextroamphetamine, can result in overdose and death. Before prescribing, assess each patient’s risk for abuse, misuse, and addiction. Educate patients and their families about these risks and the proper storage and disposal of the drug.

• Cardiovascular Risks: Stimulant medications cause an average increase in blood pressure (about 2-4 mmHg) and heart rate (about 3-6 bpm). While these increases may be small, they can be dangerous for individuals with underlying heart conditions. Sudden death has been reported in association with CNS stimulant treatment at usual doses in children and adolescents with structural cardiac abnormalities.
• Psychiatric Risks: Stimulants may exacerbate symptoms of behavior disturbance and thought disorder in patients with a pre-existing psychotic disorder. Particular care should be taken in using stimulants to treat ADHD in patients with comorbid bipolar disorder because of concern for possible induction of a mixed/manic episode.
• Seizures: There is some clinical evidence that stimulants may lower the convulsive threshold in patients with a prior history of seizures.
• Visual Disturbance: Difficulties with accommodation and blurring of vision have been reported with stimulant treatment.
• Growth Monitoring: Growth should be monitored during treatment with stimulants. Patients who are not growing or gaining weight as expected may need to have their treatment interrupted.

Patients on dextroamphetamine require ongoing clinical surveillance:

• Cardiovascular Monitoring: Blood pressure and pulse should be recorded at every visit, typically every 3 to 6 months.
• Growth Tracking: In children, height and weight should be plotted on a growth chart at least twice a year.
• Psychiatric Assessment: Routine screening for the emergence of 'tics,' anxiety, or aggressive behavior.
• Lab Tests: While routine blood work is not always required for the drug itself, doctors may order liver function tests (LFTs) or renal function tests if underlying issues are suspected.

Dextroamphetamine may impair the ability of the patient to engage in potentially hazardous activities such as operating machinery or vehicles. While it often improves focus, the potential for 'rebound' fatigue or dizziness means patients should be cautious until they know how the medication affects them.

Alcohol should be strictly avoided. Alcohol can increase the release of the medication in some extended-release formulations and can mask the effects of alcohol intoxication, leading to a higher risk of alcohol poisoning or unpredictable cardiovascular strain.

Do not stop taking dextroamphetamine abruptly if you have been taking it for a long period. This can lead to a 'crash' characterized by extreme fatigue, depression, and sleep disturbances. Your doctor will provide a tapering schedule to gradually reduce the dose.

> Important: Discuss all your medical conditions with your healthcare provider before starting Dextroamphetamine, especially any history of heart problems, high blood pressure, or mental health issues.

• Monoamine Oxidase Inhibitors (MAOIs): Dextroamphetamine must not be taken during or within 14 days following the administration of MAOIs (e.g., phenelzine, selegiline). This combination can cause a hypertensive crisis—a sudden, life-threatening spike in blood pressure—due to the massive accumulation of norepinephrine.

• Serotonergic Drugs: Taking dextroamphetamine with SSRIs (e.g., fluoxetine), SNRIs (e.g., venlafaxine), or triptans can increase the risk of Serotonin Syndrome. This is a potentially fatal condition caused by too much serotonin in the brain.
• Alkalinizing Agents: Substances that make the urine or stomach less acidic (e.g., sodium bicarbonate, certain antacids) increase the absorption and decrease the excretion of dextroamphetamine. This can lead to dangerously high levels of the drug in the blood.
• Acidifying Agents: Substances that make the urine or stomach more acidic (e.g., ascorbic acid/Vitamin C, fruit juices, guanethidine) decrease the absorption and increase the excretion of the drug, making it less effective.

• Antihypertensives: Dextroamphetamine can antagonize (block) the effects of blood pressure medications. Patients may need their blood pressure doses adjusted.
• Tricyclic Antidepressants (TCAs): Amphetamines may enhance the activity of TCAs, leading to increased cardiovascular effects like arrhythmias.
• Anticonvulsants: Dextroamphetamine may delay the absorption of ethosuximide or phenobarbital, potentially affecting seizure control.

• Fruit Juices and Vitamin C: As mentioned, acidic beverages can lower the effectiveness of the medication. It is best to avoid drinking orange or grapefruit juice within an hour of taking your dose.
• Caffeine: Consuming large amounts of caffeine (coffee, tea, energy drinks) while taking a stimulant can lead to excessive jitteriness, palpitations, and increased blood pressure.
• High-Fat Meals: Can delay the absorption of the drug, which might lead a patient to think the dose isn't working and take more, increasing the risk of toxicity.

• St. John’s Wort: May increase the risk of serotonin syndrome when combined with stimulants.
• Melatonin: While often used for sleep, some patients report increased morning grogginess when combined with daytime stimulants.
• Ginseng: Can have additive stimulant effects, leading to increased heart rate and anxiety.

• Urinary Steroids: Amphetamines may cause a significant elevation in plasma corticosteroid levels; this should be considered if a patient is undergoing testing for adrenal function.
• Drug Screenings: Dextroamphetamine will result in a positive test for 'amphetamines' on standard urine drug screens. Patients should provide their prescription to the testing laboratory.

For each major interaction, the management strategy usually involves dose adjustment or choosing an alternative therapy. Always consult your pharmacist for a full interaction check.

> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, including over-the-counter cold medicines which may contain other stimulants.

Dextroamphetamine is strictly prohibited in the following circumstances because the risks significantly outweigh any potential benefits:

• Advanced Arteriosclerosis: Hardening of the arteries can lead to rupture or blockage when blood pressure is elevated by the drug.
• Symptomatic Cardiovascular Disease: Any active heart disease where increased heart rate or blood pressure would be dangerous.
• Moderate to Severe Hypertension: The drug's tendency to raise blood pressure can push these patients into hypertensive crisis.
• Hyperthyroidism: The body is already in a hyper-metabolic state; adding a stimulant can cause thyroid storm or cardiac failure.
• Glaucoma: Dextroamphetamine can increase intraocular pressure (pressure inside the eye), worsening the condition and risking permanent vision loss.
• Agitated States: Patients who are currently in a state of extreme agitation or mania may see their symptoms severely worsened.
• History of Drug Abuse: Due to the high potential for addiction, the drug is generally contraindicated for those with a history of substance use disorder.
• MAOI Use: As noted, use within 14 days of a Monoamine Oxidase Inhibitor is strictly forbidden.

These conditions require a careful risk-benefit analysis and extra monitoring:

• Mild Hypertension: Requires frequent blood pressure checks.
• Seizure Disorders: May lower the threshold for having a seizure.
• Tics or Tourette’s Syndrome: May worsen involuntary movements.
• Renal Impairment: Requires lower dosing strategies.

Patients who have had an allergic reaction or hypersensitivity to other sympathomimetic amines (such as lisdexamfetamine, mixed amphetamine salts, or ephedrine) are at a high risk of having a similar reaction to dextroamphetamine. Symptoms of cross-sensitivity include skin rashes, hives, and in severe cases, respiratory distress.

> Important: Your healthcare provider will evaluate your complete medical history before prescribing Dextroamphetamine to ensure none of these contraindications apply to you.

Dextroamphetamine is classified as FDA Pregnancy Category C. There are no adequate and well-controlled studies in pregnant women. Data from animal studies suggest that high doses may have teratogenic (birth defect) effects.

• Trimester Risks: Use during the first trimester is generally avoided unless the benefit clearly outweighs the risk to the fetus. Use in the third trimester may lead to increased risk of premature birth and low birth weight.
• Neonatal Withdrawal: Infants born to mothers dependent on amphetamines may exhibit withdrawal symptoms such as agitation, lethargy, and poor feeding.

Dextroamphetamine is excreted in human milk. Because of the potential for serious adverse reactions in nursing infants (such as tachycardia, irritability, and poor weight gain), a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.

• ADHD: Approved for children 6 years and older. In some cases, it is used for children as young as 3 for specific ADHD presentations.
• Growth: Long-term use in children requires monitoring of height and weight. If growth is slowed, the physician may recommend a temporary 'drug holiday' during school breaks.
• Safety: The safety and efficacy in children under 3 years of age have not been established.

Elderly patients (65+) should be treated with extreme caution.

• Cardiovascular Strain: Older adults are more likely to have underlying heart disease or hypertension.
• Renal Clearance: Natural decline in kidney function with age means the drug may stay in the system longer, increasing the risk of toxicity.
• Polypharmacy: Seniors are often on multiple medications, increasing the likelihood of dangerous drug-drug interactions.

In patients with severe renal disease (Stage 4 or 5 CKD), the clearance of dextroamphetamine is significantly reduced. This necessitates a lower starting dose and slower titration. Dialysis does not effectively remove dextroamphetamine from the blood, so 'extra' doses after dialysis are not required.

While the liver is not the primary route of elimination, it does play a role in metabolism. Patients with Child-Pugh Class C (severe) hepatic impairment should be monitored for signs of excessive CNS stimulation, which may indicate that the drug is not being broken down efficiently.

> Important: Special populations require individualized medical assessment and more frequent follow-up appointments with their healthcare team.

Dextroamphetamine is a non-catecholamine, sympathomimetic amine with CNS stimulant activity. Its primary mechanism involves the release of stored catecholamines (dopamine and norepinephrine) from nerve terminals in the brain. It also acts as a potent inhibitor of the reuptake of these neurotransmitters by binding to the transport proteins. Furthermore, it inhibits the enzyme Monoamine Oxidase (MAO) at high concentrations, though this is a secondary effect. The net result is a massive increase in the concentration of dopamine in the mesolimbic pathway (the reward center) and norepinephrine in the prefrontal cortex (the executive center).

The pharmacodynamic effects of dextroamphetamine include increased systolic and diastolic blood pressure, weak bronchodilation, and respiratory stimulation. In the brain, it produces a feeling of wakefulness, alertness, and a decreased sense of fatigue. At therapeutic doses for ADHD, it does not typically cause the 'euphoria' associated with abuse, but rather a 'calming' effect that allows for better focus. Tolerance to the appetite-suppressant effects usually develops within a few weeks.

| Parameter | Value |

|---|---|

| Bioavailability | >75% (Oral) |

| Protein Binding | 15% - 20% |

| Half-life | 10 - 12 hours (Adults); 7 - 9 hours (Children) |

| Tmax | 2 - 3 hours (Immediate Release) |

| Metabolism | Hepatic (CYP2D6) and Oxidative Deamination |

| Excretion | Renal (30% - 40% unchanged; pH dependent) |

• Molecular Formula: C9H13N
• Molecular Weight: 135.21 g/mol
• Solubility: Soluble in water and alcohol.
• Structure: It consists of a phenyl ring linked to an ethylamine group with a methyl substituent on the alpha carbon. The 'dextro' prefix refers to the right-handed chirality of the molecule at the alpha carbon.

Dextroamphetamine is the prototypical member of the Central Nervous System Stimulant [EPC] class. Related medications include Lisdexamfetamine (a prodrug of dextroamphetamine), Methylphenidate (Ritalin), and Mixed Amphetamine Salts (Adderall).