Dose and Dosage: The dosage of amphetamine varies depending on the specific formulation (e.g., immediate-release, extended-release) and the condition being treated. For attention deficit hyperactivity disorder (ADHD) in adults, the usual starting dose is 5 mg once or twice daily, with gradual dose adjustments as needed. The maximum recommended dose is typically 60 mg per day. For narcolepsy, the usual starting dose is 5 mg to 60 mg per day, divided into multiple doses.
Frequency: Amphetamine is usually taken orally, either as a single daily dose or divided into multiple doses throughout the day, depending on the formulation and individual response. The dosing frequency may vary based on the specific condition being treated and the patient’s tolerance and response to the medication.
Route of Administration (ROA): Amphetamine is available in various formulations, including immediate-release tablets, extended-release capsules, and oral solutions. It is primarily administered orally, but it can also be administered via intranasal or intravenous routes, although these routes are less common and typically reserved for specific medical purposes.
Mechanism of Action (MOA): Amphetamine acts primarily by increasing the release of certain neurotransmitters, particularly dopamine and norepinephrine, in the brain. It also blocks the reuptake of these neurotransmitters, leading to increased levels of dopamine and norepinephrine in the synaptic cleft. These effects contribute to the stimulant properties of amphetamine and its ability to improve attention, focus, and alertness.
Pharmacokinetics (PK): After oral administration, amphetamine is rapidly absorbed from the gastrointestinal tract and reaches peak plasma concentrations within 2 to 3 hours. It is extensively metabolized in the liver by cytochrome P450 enzymes, primarily CYP2D6 and CYP3A4. The elimination half-life of amphetamine varies depending on the specific isomer (e.g., dextroamphetamine, levoamphetamine) and ranges from 9 to 14 hours.
Pharmacodynamics (PD): The pharmacodynamic effects of amphetamine include increased alertness, wakefulness, and concentration, as well as improved impulse control and decreased hyperactivity. These effects are mediated by the activation of dopamine and norepinephrine receptors in the brain’s prefrontal cortex and other regions involved in attention and executive function.
Pathophysiology: Amphetamine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) and narcolepsy. In ADHD, amphetamine helps improve attention, focus, and impulse control by increasing neurotransmitter levels in the brain. In narcolepsy, amphetamine helps reduce excessive daytime sleepiness and improve wakefulness and alertness.
Indications: Amphetamine is indicated for the treatment of attention deficit hyperactivity disorder (ADHD) in children (ages 3 and older) and adults, as well as for the management of narcolepsy. It may also be used off-label for other conditions, such as depression or obesity, under the guidance of a healthcare professional.
Contraindications: Amphetamine is contraindicated in patients with a known hypersensitivity to the drug or its components, as well as in patients with advanced arteriosclerosis, cardiovascular disease, severe hypertension, hyperthyroidism, or glaucoma. It should not be used in patients with a history of drug abuse or dependence, including alcohol abuse.
Drug Interactions: Amphetamine may interact with various medications, including monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants, antihypertensive agents, antacids containing aluminum or magnesium, and certain other stimulant medications. Concomitant use of these medications with amphetamine may increase the risk of adverse effects or reduce the effectiveness of treatment. Close monitoring and dose adjustments may be necessary when combining amphetamine with other medications.
Monitoring and Laboratory Tests: Before initiating treatment with amphetamine, healthcare providers may perform a comprehensive medical evaluation, including a review of medical history, physical examination, and laboratory tests (e.g., blood pressure, heart rate, liver function tests). During treatment, regular monitoring of vital signs, cardiovascular function, and mental status is recommended to assess treatment response and detect any potential adverse effects or complications.
Always consult with a healthcare professional for personalized medical advice and recommendations regarding the use of amphetamine or any other medications.
Why is this medication prescribed?
Amphetamine is prescribed primarily for the treatment of attention deficit hyperactivity disorder (ADHD) in children (aged 3 and older) and adults. It is also used for the management of narcolepsy, a neurological disorder characterized by excessive daytime sleepiness and sudden episodes of sleep.
How should this medicine be used?
Amphetamine is typically taken orally as directed by a healthcare provider. It is available in various formulations, including immediate-release tablets, extended-release capsules, and oral solutions. Follow the dosage instructions provided by your doctor carefully. Do not exceed the prescribed dose or take it more frequently than directed.
Other uses for this medicine
Amphetamine may be used off-label for other conditions, such as depression, obesity, or certain sleep disorders, under the supervision of a healthcare professional. However, its primary indications are for ADHD and narcolepsy.
What special precautions should I follow?
Before taking amphetamine, inform your doctor about any medical conditions you have, especially heart problems, high blood pressure, thyroid disorders, glaucoma, or a history of drug abuse. Also, disclose all medications and supplements you are currently taking to avoid potential drug interactions. Use caution when driving or operating machinery, as amphetamine may cause dizziness or impair your ability to concentrate.
What special dietary instructions should I follow?
While taking amphetamine, it’s important to maintain a balanced diet and stay hydrated. Avoid consuming large amounts of caffeine or other stimulants, as they may increase the risk of side effects such as insomnia, agitation, or palpitations. Discuss any specific dietary concerns with your healthcare provider.
What should I do if I forget a dose?
If you miss a dose of amphetamine, take it as soon as you remember, unless it’s close to your next scheduled dose. In that case, skip the missed dose and resume your regular dosing schedule. Do not double the dose to make up for a missed one.
What side effects can this medication cause?
Common side effects of amphetamine may include insomnia, headache, dry mouth, decreased appetite, weight loss, irritability, and nervousness. Less common but more serious side effects may include increased heart rate, high blood pressure, hallucinations, seizures, or mood changes. Contact your doctor if you experience any unusual or severe side effects while taking amphetamine.
What should I know about storage and disposal of this medication?
Store amphetamine at room temperature away from moisture and heat. Keep it out of reach of children and pets. Do not share your medication with others, and do not use expired or unused amphetamine. Dispose of any unused medication properly according to local regulations or guidelines.
In case of emergency/overdose
If you suspect an overdose of amphetamine or experience symptoms such as severe restlessness, confusion, hallucinations, rapid breathing, or fainting, seek immediate medical attention or contact a poison control center right away. Overdose of amphetamine can be life-threatening and requires prompt medical intervention.
Always consult with your healthcare provider or pharmacist if you have any questions or concerns about amphetamine or its use.